Wanke, V.; Cameroni, E.; Uotila, A.; Piccolis, M.; Urban, J.; Loewith, R.; De Virgilio, C.
Dietary nutrient limitation (dietary restriction) is known to increase lifespan in a variety of organisms. Although the molecular events that couple dietary restriction to increased lifespan are not clear, studies of the model eukaryote Saccharomyces cerevisiae have implicated several nutrient-sensitive kinases, including the target of rapamycin complex 1 (TORC1), Sch9, protein kinase A (PKA) and Rim15. We have recently demonstrated that TORC1 activates Sch9 by direct phosphorylation. We now show that Sch9 inhibits Rim15 also by direct phosphorylation. Treatment of yeast cells with the specific TORC1 inhibitor rapamycin or caffeine releases Rim15 from TORC1-Sch9-mediated inhibition and consequently increases lifespan. This kinase cascade appears to have been evolutionarily conserved, suggesting that caffeine may extend lifespan in other eukaryotes, including man.
Dash, S. S.; Sailaja, N. S.; Gummadi, S. N.
Pseudomonas sp. isolated from soil of coffee plantation area has been shown to degrade higher concentrations of caffeine ( approximately 15 g l(-1)) by N-demethylation at a rate higher than what has been reported for any strain so far. This strain exhibits positive chemotaxis towards caffeine (1,3,7-trimethylxanthine) in swarm plate assay and modified capillary assay in a dose dependant manner. Related methylxanthines and xanthine also act as chemoattractants for the strain with the highest relative chemotactic response (RCR) seen for xanthine. Chemotaxis in Pseudomonas sp. is possibly plasmid mediated as indicated by positive chemotaxis of plasmid transformed E. coli DH5alpha. The chemotactic abilities of Pseudomonas sp. combined with higher rates of degradation of caffeine can be used in the development of strategies for biodecaffeination of caffeine containing wastes.
Almeida, R. P.; Nascimento, F. E.; Chau, J.; Prado, S. S.; Tsai, C. W.; Lopes, S. A.; Lopes, J. R.
Xylella fastidiosa is a vector-borne, plant-pathogenic bacterium that causes disease in citrus (citrus variegated chlorosis [CVC]) and coffee (coffee leaf scorch [CLS]) plants in Brazil. CVC and CLS occur sympatrically and share leafhopper vectors; thus, determining whether X. fastidiosa isolates can be dispersed from one crop to another and cause disease is of epidemiological importance. We sought to clarify the genetic and biological relationships between CVC- and CLS-causing X. fastidiosa isolates. We used cross-inoculation bioassays and microsatellite and multilocus sequence typing (MLST) approaches to determine the host range and genetic structure of 26 CVC and 20 CLS isolates collected from different regions in Brazil. Our results show that citrus and coffee X. fastidiosa isolates are biologically distinct. Cross-inoculation tests showed that isolates causing CVC and CLS in the field were able to colonize citrus and coffee plants, respectively, but not the other host, indicating biological isolation between the strains. The microsatellite analysis separated most X. fastidiosa populations tested on the basis of the host plant from which they were isolated. However, recombination among isolates was detected and a lack of congruency among phylogenetic trees was observed for the loci used in the MLST scheme. Altogether, our study indicates that CVC and CLS are caused by two biologically distinct strains of X. fastidiosa that have diverged but are genetically homogenized by frequent recombination.
Source : Appl Environ Microbiol 2008 vol.74 (12), pp 3690 - 3701
Noonim, P.; Mahakarnchanakul, W.; Varga, J.; Frisvad, J. C.; Samson, R. A.
Two novel species of Aspergillus section Nigri from Thai coffee beans are described as Aspergillus aculeatinus sp. nov. and Aspergillus sclerotiicarbonarius sp. nov. Their taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles) and molecular (beta-tubulin, internal transcribed spacer and calmodulin gene sequences) characteristics. A. aculeatinus sp. nov. is a uniseriate species with a similar morphology to Aspergillus aculeatus and Aspergillus japonicus, but producing smaller conidia (2-5 mum). A. aculeatinus sp. nov. produced neoxaline, secalonic acid D and F, and aculeacins. A. sclerotiicarbonarius sp. nov. is a biseriate species similar to Aspergillus carbonarius and Aspergillus ibericus, but produces abundant sclerotia and some unique indol-alkaloids. The type strain of Aspergillus sclerotiicarbonarius sp. nov. is CBS 121057(T) (=IBT 28362(T)) and the type strain of Aspergillus aculeatinus sp. nov. is CBS 121060(T) (=IBT 29077(T)).
Source : Int J Syst Evol Microbiol 2008 vol.58 (Pt 7), pp 1727 - 1734
Moore, M. T.; Greenway, S. L.; Farris, J. L.; Guerra, B
Organic wastewater contaminants, including pharmaceuticals, caffeine, and nicotine, have received increased scrutiny because of their detection in water bodies receiving wastewater discharge. Despite recent measurement in United States streams, caffeine\'s effect on freshwater organisms is not well documented. The present study measured caffeine\'s lethal and sublethal effects on the freshwater species, Ceriodaphnia dubia, Pimephales promelas, and Chironomus dilutus. These organisms, which are used in standard testing or effluent monitoring, were exposed to aqueous caffeine solutions under static exposure for 48 hours and daily renewed static exposure for 7 days. Averaged responses of 48-hour acute end points indicated that C. dubia was more sensitive to caffeine exposures (LC50 = 60 mg/L) than either P. promelas (LC50 = 100 mg/L) or C. dilutus (LC50 = 1,230 mg/L). Exposure-response slopes confirmed these findings (3% mortality/mg/L for C. dubia; 0.5% mortality/mg/L for P. promelas; and 0.07% mortality/mg/L for C. dilutus). Comparative 7-day responses between C. dubia and P. promelas (LC50 = 46 and 55 mg/L, respectively) were more similar than the broad range of acute values. Sublethal effects measured for caffeine exposure included impaired C. dubia reproduction (IC50 = 44 mg/L) and inhibited P. promelas growth (IC50 = 71 mg/L). According to the results of this study, combined with earlier studies reporting environmental concentrations and product half-lives, caffeine should pose negligible risk for most aquatic vertebrate and invertebrate organisms.
Source : Arch Environ Contam Toxicol 2008 vol.54 (1), pp 31 - 35
Gniechwitz, D.; Reichardt, N.; Meiss, E.; Ralph, J.; Steinhart, H.; Blaut, M.; Bunzel, M.
Brews from differently roasted Arabica coffees were shown to contain 8-12% ethanol soluble substances with molecular masses greater than 2 kDa, possibly contributing to their dietary fiber contents. About 13% of these substances were nondigestible carbohydrates, mainly arabinogalactans. The nondigestible high molecular weight ethanol soluble fraction (HESF) of the medium roasted coffee brew was further characterized and subjected to in vitro fermentation with human fecal bacteria. In addition to carbohydrates, HESF contained proteins/peptides (approximately 20%), but the main fraction was composed of structurally unknown Maillard reaction products. From NMR spectroscopy, we conclude that intact caffeic and ferulic acid derivatives were not incorporated into the melanoidins to a significant extent. Stepwise ultrafiltration and gel filtration indicated a large variation in the molecular weights of HESF constituents. Coffee HESF was shown to be less fermentable by fecal bacteria than soluble coffee fiber isolated by the enzymatic-gravimetric methodology, and because of its lower carbohydrate content, less short-chain fatty acids were produced during the fermentation. Total cell counts, destructive chemical analysis, and NMR spectroscopy indicated that coffee carbohydrates are the preferred substrates for colonic microbiota. However, NMR spectra, absorbances at 405 nm, and nonprotein nitrogen contents showed that noncarbohydrate and nonprotein compounds were also utilized to some extent but the bacterial species involved in this degradation remain to be identified.
Escudero, C.; Gabaldon, C.; Marzal, P.; Villaescusa, I.
Effect of EDTA on divalent metal adsorption onto grape stalk and exhausted coffee wastes Source : J.Hazard.Mater. vol.152 Issue 2 pp 476 - 485 Pub date: 1-4-2008 Abstract:
In the present work, two industrial vegetable wastes, grape stalk, coming from a wine producer, and exhausted coffee, coming from a soluble coffee manufacturer, have been investigated for the removal of Cu(II) and Ni(II) from aqueous solutions in presence and in absence of the strongly complexing agent EDTA. Effects of pH and metal-EDTA molar ratio, kinetics as a function of sorbent concentration, and sorption equilibrium for both metals onto both sorbents were evaluated in batch experiments. Metal uptake was dependent of pH, reaching a maximum from pH around 5.5. EDTA was found to dramatically reduce metal adsorption, reaching total uptake inhibition for both metals onto both sorbents at equimolar metal:ligand concentrations. Kinetic results were successfully modelled by means of the pseudo second order model. Langmuir and Freundlich models were used to describe the sorption equilibrium data. Grape stalk showed the best performance for Cu(II) and Ni(II) removal in presence and in absence of EDTA, despite exhausted coffee appears as less sensitive to the presence of complexing agent. The performance of Cu(II) and Ni(II) sorption onto grape stalk in a continuous flow process was evaluated. In solutions containing EDTA, an initial metal concentration in the outlet flow corresponding to the complexed metal fraction was observed from the beginning of the process. A high metal recovery yield (>97%) was achieved by feeding the metal-loaded column with 0.05 M HCl.
Gopinandhan, T. N.; Pannerselvam, P.; Velmourougane, K.; Raghuramulu, Y.; Jayarama
Moisture determination in green coffee is important, as it contributes to the visual and intrinsic quality of the coffee beans. In this study, a low-cost multichannel moisture meter was evaluated for its suitability in testing the moisture level in a green coffee sample. Moisture meters used for instantaneous measurement of moisture content are discussed. Advantages of the moisture meter tested in this study are listed, and its use in the production of quality coffee in India is suggested.
Source : Indian Food Industry 2008 vol.27 (1), pp 60-63 (not available on line)
Hernandez-Diaz, W. N.; Ruiz, Lopez, II; Salgado-Cervantes, M. A.; Rodriguez-Jimenes, G. C.; Garcia-Alvarado, M. A.
Problems of mycotoxin contamination of coffee beans can be eliminated with artificial drying. An adequate heat and mass transfer representation of coffee drying is required to determine optimal operating conditions guaranteeing minimal energy consumption and maximising bean quality. In this study, the heat and mass transfers during green coffee bean drying at constant air conditions were modelled with mathematical representation that approximated the coffee bean shape - a half prolate spheroidal geometry. A drying kinetic equation valid for this geometry was obtained, and the water diffusivity was calculated. The finite difference equation for mass transfer 3D models provided information about the moisture distribution profiles inside the grain during drying, allowing zones more susceptible to contamination or mechanical stress and cracking to be predicted. The use of the model developed in the design of coffee dryers is suggested.
Source : J Food Engin 2008 vol.86 (1), pp 1-9
Wetmore, C. M.; Ichikawa, L.; LaCroix, A. Z.; Ott, S. M.; Scholes, D.
This study assessed associations between habitual caffeine intake and bone mass among young women. Analyses of the entire study population revealed no significant associations, while analyses restricted to women using depot medroxyprogesterone acetate (DMPA) showed modest inverse associations between caffeine intake and bone mineral content (BMC). INTRODUCTION: Some previous investigations among postmenopausal women suggest an inverse relationship between caffeine intake and bone mass, yet studies of this association among young women are few. METHODS: The association between habitual caffeine intake and bone mass was evaluated prospectively in a population-based cohort of 625 females, aged 14 to 40 years, adjusting for relevant biological and lifestyle factors. Caffeinated beverage intake was self-reported, and bone mineral content (BMC) and bone mineral density (BMD) were measured at baseline and every 6 months throughout a 24-month follow-up period using dual-energy x-ray absorptiometry. RESULTS: Cross-sectional analyses revealed no significant differences in mean BMC or BMD at baseline. Mean percentage and absolute changes in BMC and BMD were not associated with caffeine use. Repeated measures analyses similarly showed no significant association between caffeine intake at baseline and mean BMC or BMD measured during follow-up. However, among women using depot medroxyprogesterone acetate (DMPA), modest inverse associations between caffeine and BMC (but not BMD) were detected. CONCLUSIONS: Our data suggest that heavy habitual consumption of caffeinated beverages does not adversely impact bone mass among young women in general. Greater caffeine intake may be associated with lower BMC among DMPA users.
Ye, Y.; Abu-Said, G. H.; Lin, Y.; Manickavasagam, S.; Hughes, M. G.; McAdoo, D. J.; Perez-Polo, R. J.; Birnbaum, Y.
We asked whether caffeinated coffee (CC) blunts the infarct size (IS)-limiting effects of atorvastatin (ATV). BACKGROUND: Adenosine receptor activation is essential for mediating the IS-limiting effects of statins. Caffeine is a nonspecific adenosine receptor blocker, and thus drinking CC may block the myocardial protective effects of statins. METHODS: Rat received 3-day ATV (10 mg/kg/day) or water by oral gavage once daily. Drinking water was replaced by water + sugar (7.5 g/100 ml), CC with sugar, or decaffeinated coffee (DC) with sugar. On the 4th day, rats were anesthetized and underwent 30 min of coronary artery occlusion and 4 h reperfusion. Area at risk was assessed by blue dye and infarct size by TTC. RESULTS: Body weight and area at risk was comparable among groups. IS was 25.1 +/-3.9% of the area at risk in the control group. In rats not receiving ATV, CC (25.5 +/- 3.1%) and DC (34.0 +/- 2.8%) did not affect IS. IS was significantly reduced by ATV in the water + sugar (11.7 +/- 0.7%, p = 0.015) and DC (11.5 +/- 1.0%; p < 0.001) groups, but not in the CC group (32.3 +/- 3.0%; p = 0.719). ATV increased myocardial levels of Ser-473 phosphorylated Akt in the water + sugar and DC groups, but not in the CC group.
CONCLUSIONS: CC, but not DC, abrogated the IS-limiting effects of ATV by blocking the adenosine receptors and preventing the phosphorylation of Akt. CC did not affect IS in rats not receiving ATV.
Moisey, L. L.; Kacker, S.; Bickerton, A. C.; Robinson, L. E.; Graham, T. E.
The ingestion of caffeine before an oral glucose tolerance test has been shown to result in an acute insulin-sensitive environment in healthy and obese men and in those with type-2 diabetes. This study examined whether a similar impairment in blood glucose management occurred when coffee and foods
typical of a Western diet were used. Ingestion of caffeinated coffee with either a high- or low-glycaemic-index meal impaired acute blood glucose management and insulin sensitivity compared with ingestion of decaffeinated coffee. Further studies are suggested.
Shapiro, R. E.
Caffeine is the most widely consumed psychostimulant drug in the world. With intermittent exposures, caffeine may act as a mild analgesic for headache or as an adjuvant for the actions of other analgesics. Chronic repetitive exposures to caffeine increase the risks for development of analgesic-overuse headache, chronic daily headache, and physical dependency. Cessation of caffeine use after chronic exposures leads to a withdrawal syndrome with headache as a dominant symptom. At dosages achieved by common dietary intake, caffeine acts as a potent antagonist of central and peripheral nervous system adenosine receptors. The complex effects of caffeine on headache disorders suggest important roles for adenosine in these disorders and in the induction of caffeine dependency.
Source : Curr Pain Headache Rep 2008 vol.12 (4), pp 311 - 315
Jones, G.
Stimulants, illegal and legal, continue to be used in competitive sport. The evidence for the ergogenic properties of the most potent stimulants, amphetamines, cocaine and ephedrine, is mostly insubstantial. Low doses of amphetamines may aid performance where effects of fatigue adversely affect higher psychomotor activity. Pseudoephedrine, at high doses, has been suggested to improve high intensity and endurance exercise but phenylpropanolamine has not been proven to be ergogenic. Only caffeine has substantial experimental backing for being ergogenic in exercise. The mode of action of these stimulants centres on their ability to cause persistence of catecholamine neurotransmitters, with the exception of caffeine which is an adenosine receptor antagonist. By these actions, the stimulants are able to influence the activity of neuronal control pathways in the central (and peripheral) nervous system. Rodent models suggest that amphetamines and cocaine interact with different pathways to that affected by caffeine. Caffeine has a variety of pharmacological effects but its affinity for adenosine receptors is comparable with the levels expected to exist in the body after moderate caffeine intake, thus making adenosine receptor blockade the favoured mode of ergogenic action. However, alternative modes of action to account for the ergogenic properties of caffeine have been supported in the literature. Biochemical mechanisms that are consistent with more recent research findings, involving proteins such as DARPP-32 (dopamine and cAMP-regulated phosphoprotein), are helping to rationalize the molecular details of stimulant action in the central nervous system.
Source : Essays Biochem 2008 Vol.44, pp 109 - 123 (not available on line)
Whalen, D. J.; Silk, J. S.; Semel, M.; Forbes, E. E.; Ryan, N. D.; Axelson, D. A.; Birmaher, B.; Dahl, R. E.
Sleep problems are a cardinal symptom of depression in children and adolescents and caffeine use is a prevalent and problematic issue in youth; yet little is known about caffeine use and its effects on sleep in youth with depression. We examined caffeine use and its relation to sleep and affect in youth\'s natural environments. METHODS: Thirty youth with major depressive disorder (MDD) and 23 control youth reported on caffeine use, sleep, and affect in their natural environment using ecological momentary assessment at baseline and over 8 weeks, while MDD youth received treatment. RESULTS: Youth with MDD reported more caffeine use and sleep problems relative to healthy youth. Youth with MDD reported more anxiety on days they consumed caffeine. Caffeine
CONCLUSIONS: Findings suggest that both sleep quality and caffeine use are altered in pediatric depression; that caffeine use, but not sleep problems, improves with treatment; and that caffeine may exacerbate daily anxiety among youth with depression.
Kawahara, M.; Takahashi, Y.; Takazawa, K.; Tsuchiya, H.; Tomita, K.; Yokogawa, K.; Miyamoto, K.
Caffeine-assisted chemotherapy has been used in the treatment of osteosarcomas. However, there is little in vivo evidence for this treatment, and thus we sought to verify the dose and effect of caffeine in combination with cisplatin in osteosarcoma-bearing rats. MATERIALS AND METHODS: Seven-week-old male Fischer rats were transplanted with chemical carcinogen-induced osteosarcoma, selected lung metastatic lesions tumor block. The osteosarcoma-bearing rats were treated with saline,
caffeine, cisplatin or cisplatin and caffeine. RESULTS: The most growth inhibition was observed in the co-administration group. When three different dosing schedules of caffeine were given, the extent of tumor inhibition was closely correlated with the average plasma concentration of caffeine. The cisplatin concentration in the tumor was significantly increased when caffeine was co-administered.
CONCLUSION: This study confirms that a high concentration of caffeine (about 0.4 mM) is effective in enhancing the antitumor effects of cisplatin.
Source : Anticancer Res 2008 vol.28 (3A), pp 1681 - 1685 (not available on line)
Khalil, S. N.; Maposa, D.; Ghelber, O.; Rabb, M. F.; Matuszczak, M.; Ganesan, B. A.; Tabrizi, H. K.; Chuang, A. Z.
Children with obstructive sleep apnea (OSA) have a higher rate of adverse post-extubation respiratory events, such as laryngospasm, upper airway obstruction, apnea, desaturation and/or need for re-intubation. They are overly sensitive to sedatives and narcotics. Although the etiology of OSA is primarily obstruction (mechanical or neuromuscular), a central element may contribute to OSA. Caffeine citrate has been shown to be effective in treating apnea of prematurity. This study evaluated whether the administration of caffeine benzoate to children with OSA decreases the number of children who experience adverse post-extubation respiratory events. METHODS: In a randomized, double-blind and placebo-controlled study, children with OSA scheduled for adenotonsillectomy (T&A) received either caffeine benzoate, 20 mg/kg IV, (caffeine group, n = 36) or saline (placebo group, n = 36). The primary outcome evaluated the number of children who developed adverse post-extubation respiratory events, and the secondary outcome was the incidence of those events. RESULTS: The results demonstrated the two groups differed in the number of children who developed adverse post-extubation respiratory events (p = 0.032). The overall incidence of adverse postoperative respiratory events was less in the caffeine group than the placebo group (p = 0.0196).
CONCLUSION: In children with OSA scheduled for T&A, administration of caffeine benzoate, 20 mg/kg IV, decreased the number of children who developed adverse post-extubation respiratory events and decreased the overall incidence of adverse post-extubation respiratory events. PACU duration, hospital discharge time and postoperative delirium did not differ between groups.
Source : Middle East J Anesthesiol 2008 vol.19 (4), pp 885 - 899 (not available on line)
Norman, D.; Bardwell, W. A.; Loredo, J. S.; Ancoli-Israel, S.; Heaton, R. K.; Dimsdale, J. E.
In healthy individuals, caffeine intake may improve performance on cognitive tests. Obstructive sleep
apnea (OSA) is a disorder that has been associated with impaired cognitive function. In this study, we investigated whether increased caffeine intake in untreated patients with OSA is linked to better cognitive performance. Forty-five untreated OSA patients underwent baseline polysomnography after completing a survey of 24-h caffeine intake. Participants completed a battery of neuropsychological tests, then demographically corrected T scores and a global deficit score (GDS) were calculated on these tests. Partial correlation analysis was performed to compare daily caffeine intake with GDS, after controlling for body mass index (BMI) and sleep apnea severity. Analysis of covariance was done to examine differences in daily caffeine intake between cognitively impaired (GDS >/= 0.5) and non-impaired (GDS < 0.5) individuals. Seven out of the 45 subjects met the criteria (GDS >/= 0.5) for cognitive impairment. There was a significant inverse association between caffeine intake and the GDS, both when controlling for BMI (r = -0.331, p = 0.04) and when controlling for BMI and apnea severity (r = -0.500, p = 0.002); those with less impairment consumed more caffeine. Analysis of covariance demonstrated that cognitively impaired individuals consumed one-sixth as much caffeine as non-impaired individuals (p < 0.05). In patients with moderately severe OSA, higher average daily caffeine intake was associated with less cognitive impairment .
Liau, J.; Perthen, J. E.; Liu, T. T.
Measures of the spatial extent of functional activation are important for a number of functional magnetic resonance imaging (fMRI) applications, such as pre-surgical planning and longitudinal tracking of changes in brain activation with disease progression and drug treatment. The interpretation of the data from these applications can be complicated by inter-subject or inter-session variability in the measured fMRI signals. Prior studies have shown that modulation of baseline cerebral blood flow (CBF) can directly alter the functional CBF and blood oxygenation level dependent (BOLD) responses, suggesting that the spatial extents of functional activation maps based on these signals may also depend on baseline CBF. In this study, we used a caffeine dose (200 mg) to decrease baseline CBF and found significant (p<0.05) reductions in both the CBF activation extent and contrast-to-noise ratio (CNR) but no significant changes in the BOLD activation extent and CNR. In contrast, caffeine significantly changed the temporal dynamics of the BOLD response but not the CBF response. The decreases in the CBF activation extent and CNR were consistent with a significant caffeine-induced decrease in the absolute CBF change accompanied by no significant change in the residual noise. Measures of baseline CBF also accounted for a significant portion of the inter-subject variability in the CBF activation map area and CNR. Factors that can modulate baseline CBF, such as age, medication, and disease, should therefore be carefully considered in the interpretation of studies that use functional CBF activation maps.
Sawynok, J.; Reid, A. R.; Fredholm, B. B.
Amitriptyline is used to treat neuropathic pain in humans. It produces antinociception in several animal models of pain, and this effect is blocked by methylxanthine adenosine receptor antagonists which implicates adenosine it its actions. Here, the antinociceptive effect of amitriptyline, and the ability of caffeine to reverse it, were examined using the formalin test (a model of persistent pain) in wild type mice and mice lacking the adenosine A(1) receptor (A1R). Amitriptyline produced dose-related suppression of flinching in wild type mice following both systemic and intraplantar drug administration; both of these effects were unaltered in A1R -/- mice. Following systemic administration, caffeine reversed the systemic effect of amitriptyline in wild type, but not A1R -/- mice; -/+ mice exhibited an intermediate effect. Intraplantar administration of caffeine also reversed the effect of intraplantar amitriptyline in A1R +/+, but not in -/- or +/- mice. These results indicate that adenosine A(1) receptors are not required in order for amitriptyline to cause antinociception in mice, but they are required to see caffeine reversal of this antinociceptive effect. When A1Rs are present, actions of amitriptyline may, however, partly depend on A1Rs.
Liu, P. S.; Watanabe, S.; Kirino, Y.
Calcium release from intracellular stores has various actions in neurons, but its effects on network oscillation have not been well understood. The olfactory center (procerebrum, PC) of the terrestrial slug Limax valentianus shows a regular oscillation in the local field potential (LFP). Here we report that caffeine, which is an agonist for ryanodine receptors and triggers calcium release from intra-cellular stores, has strong modulatory effects on the PC. In isolated PC neurons, caffeine enhanced the cytoplasmic calcium concentration, and this was blocked by ryanodine. Caffeine elevated the frequency and amplitude of the LFP oscillation, which was also blocked by ryanodine. The time lag between the frequency and amplitude effects suggests distinct mechanisms for the modulation of these two parameters. These results suggest that calcium release from intracellular stores through ryanodine receptors activates network activity in the PC.
Koizumi, T.; Nakaya, N.; Okamura, C.; Sato, Y.; Shimazu, T.; Nagase, S.; Niikura, H.; Kuriyama, S.; Tase, T.; Ito, K.; Tsubono, Y.; Okamura, K.; Yaegashi, N.; Tsuji, I.
This study examined the association between coffee consumption and the risk of endometrial endometrioid adenocarcinoma (EEA) in Japan by a case-control design. The cases consisted of 107 women <80 yr of age from 2 medical centres who had been histopathologically diagnosed to have EEA. The controls, selected from the participants of a cancer-screening programme, were 214 women, with 2 controls selected for each case (matched for age and for area of residence). A self-administered questionnaire containing questions to determine dietary and beverage consumption, as well as reproductive history, was distributed to the cases and controls. Conditional logistic regression analysis was used to estimate the odds ratio (OR) of EEA for 3 levels of coffee consumption with adjustment for potential confounding factors. The multivariate-adjusted OR of EEA for individuals in the highest tertile of coffee consumption (<greater than or equal to>2-3 cups/day) was 0.4 (95% confidence interval (CI), 0.2¬0.9), and that of cases in the intermediate tertile (5-6x/wk-1 cup/day) was 0.6 (95% CI, 0.3-1.2), relative to the individuals in the lowest tertile of coffee consumption (<less than or equal to>3-4x/wk; P for trend = 0.014). The above association was observed in postmenopausal women (P for trend = 0.016), but not in premenopausal women (P for trend = 0.90). This study thus revealed an inverse dose-response relationship between coffee consumption and the risk of EEA, and its strong association in postmenopausal women but not in premenopausal women.
Source : Eur J Cancer Prevention 2008 vol.17 (4), pp 358 - 363 (not available on line)
Happonen, P.; Laara, E.; Hiltunen, L.; Luukinen, H.
The present study assessed the relationship between coffee consumption and mortality in a home-dwelling elderly population. A population-based cohort of 817 men and women born in 1920 or earlier and living in northern Finland provided complete data on daily coffee consumption and other variables at the baseline examination in 1991-1992. Deaths were monitored through to the end of 2005 by national death certificates, resulting in 6960 person-years of follow-up. Hazard rate ratios for mortality by daily coffee intake were estimated by Poisson regression models adjusted for some known predictors of mortality. During 14.5 years of follow-up, 623 deaths occurred. The total mortality rate was inversely related to the number of cups (average volume, 125 ml) of coffee consumed daily. After adjustment for age, sub-period of follow-up, sex, marital status, basic educational level, previous occupational group, current smoking, BMI, history of myocardial infarction, self-rated health and presence of diabetes, cognitive impairment or physical disability, the estimated relative risk reduction of total mortality per an increment of one more cup of coffee per d reported at baseline was 4 (95% CI 0, 8) %. The observed associations between coffee consumption and mortality from CVD, cancer, and other or unknown causes, respectively, were qualitatively similar to that of total mortality but the estimates were less precise. The effect of coffee consumption at baseline appeared to attenuate after 10 years since the start of follow-up. The present study provides evidence for daily (caffeine-containing) coffee intake being inversely associated with mortality in the elderly.
Hong, B. N.; Yi, T. H.; Park, R.; Kim, S. Y.; Kang, T. H.
Coffee is a widely consumed beverage and has recently received considerable attention for its possible beneficial effects. Auditory neuropathy is a hearing disorder characterized by an abnormal auditory brainstem response. This study examined the auditory neuropathy induced by diabetes and investigated the action of coffee, trigonelline, and caffeine to determine whether they improved diabetic auditory neuropathy in mice. Auditory brainstem responses, auditory middle latency responses, and otoacoustic emissions were evaluated to assess auditory neuropathy. Coffee or trigonelline ameliorated the hearing threshold shift and delayed latency of the auditory evoked potential in diabetic neuropathy. These findings demonstrate that diabetes can produce a mouse model of auditory neuropathy and that coffee consumption potentially facilitates recovery from diabetes-induced auditory neuropathy. Furthermore, the active constituent in coffee may be trigonelline.
Black, A. M.; Pandya, S.; Clark, D.; Armstrong, E. A.; Yager, J. Y.
Apnea of pre-maturity is common, occurring in 85% of infants born less than 34 week gestation. Oral caffeine is the most frequent form of therapy, often in conjunction with the use of intubation and intermittent ventilation. Morphine is used to reduce the pain believed to be associated with the latter. Little information is available on the effects of caffeine, morphine or their combination, on the developing brain. We determined the effect of caffeine and morphine alone and in combination of cell death on the developing brain of the rat. Cell death, measured by Fluoro-jade B and activated caspase-3, was significantly increased at 12 and 24 hour post-caffeine injection (P < 0.05) in the cortex, caudate, nucleus accumbens, hypothalamus, hippocampus and superior colliculus. No alterations were seen following morphine injection alone. However, in the thalamus, the combination of caffeine and morphine did increase cell death to a significantly greater extent than caffeine alone. Further research is required to determine the long-term pathologic and functional effects of caffeine and the combination of caffeine and morphine on the developing immature brain.
Source : Brain Res 2008 vol.219, pp 136 - 142
Mattioli, A. V.; Bonatti, S.; Zennaro, M.; Melotti, R.; Mattioli, G.
The study evaluated the relationships between acute stress, lifestyle and coffee consumption, and acute lone atrial fibrillation (AF). METHODS: The study group included 400 patients with mean age of 54 +/- 11 years, 205 of whom were men. They all presented with a first episode of AF. Patients underwent a series of cognitive tests to evaluate acute psychological stress (mean life acute stress score). Lifestyle and nutritional parameters (diet, alcohol and espresso coffee consumption, smoking and obesity) were investigated. An age-matched and sex-matched control group was selected and compared. RESULTS: Recent stress, high intake of coffee, and obesity were associated with greater risk of AF. Acute stress induces an increase in coffee consumption and changes in lifestyle. The increase in coffee consumption was more marked in nonhabitual drinkers, leading to a higher risk of developing AF [odds ratio (OR) 4.1; 95% confidence interval (CI): 1.98-4.56; P < 0.001]. Spontaneous conversion of AF to sinus rhythm was observed in 191 patients (47%). Patients who experienced AF after an acute stress showed the highest probability of spontaneous conversion. High espresso coffee consumption (OR 0.86; 95% CI: 0.49-1.21; P < 0.01) and obesity (OR 0.88; 95% CI: 0.84-1.20; P < 0.01) were associated with a significantly greater risk of persistent AF.
CONCLUSION: Acute stress induced changes in lifestyle, including an increase in coffee consumption, leading to a higher risk of AF. Patients who developed AF after an acute stress showed the highest probability of spontaneous conversion. High espresso coffee consumption and obesity were associated with an increased risk of persistent AF.
Source : J Cardiovasc Med (Hagerstown.) 2008 vol.9 (8), pp 794 - 798 (not available on line)
Haddis, A.; Devi, R.
The objective of this study was to assess the effect of wastewater produced from coffee processing plant on nearby water bodies and human health. A study was conducted around the coffee processing plant in Zimma zone (Ethiopia) to assess the physico-chemical characteristics of effluent generated from this plant. Analysis of the water samples taken from the surrounding water bodies had also been done. It was found, from the present investigation, that the wastewater from coffee processing plant was heavily polluted with organic matter as it showed high concentration of COD (upstream 25,600mg/l and downstream 15,780mg/l), BOD (upstream 14,200mg/l and downstream 10,800mg/l), phosphate (upstream 7.3mg/l and downstream 4.6mg/l), nitrate (upstream 23mg/l and downstream 10.5mg/l) and suspended solids (upstream 5870mg/l and downstream 2080mg/l) and these concentrations were much higher than the permissible limits prescribed by WHO. It was also found, from this study, that the people residing in the vicinity of this plant were consuming this polluted water and as a result suffered from many diseases like skin irritation, stomach problem, nausea and breathing problem.
Lohsiriwat, S.; Kongmuang, P.; Leelakusolvong, S.
This study was designed to evaluate the effects of caffeine on anorectal function by anorectal manometry. METHODS: Ten healthy subjects were studied. They drank 200 ml of water and later 200 ml of a solution that contained caffeine 3.5 mg/kg body weight. The anorectal manometric study was divided into three periods: basal, water, and caffeine; each period lasted 45 minutes. RESULTS: After the ingestion of water, the basal anal sphincter pressure showed no change during the 45-minute recording, whereas after caffeine consumption the basal anal sphincter pressure increased at 10 minutes (P = 0.047) and 15 minutes (P = 0.037). The average basal anal sphincter pressure throughout the 45 minutes was significantly higher after caffeine ingestion than after water (P = 0.013). After caffeine intake, the maximum squeeze pressure increased significantly (P = 0.017) compared with the basal period. Both water and caffeine consumption caused a decrease in the rectal sensory threshold for the desire to defecate.
CONCLUSIONS: Caffeine 3.5 mg/kg body weight in 200 ml of water resulted in stronger anal sphincter contractions both at basal period and during voluntary squeeze. The sensory threshold was also decreased, leading to an earlier desire to defecate. Caffeine consumption may result in an earlier desire to defecate, leading to defecation if the anal sphincter can relax voluntarily.
El Yacoubi, M.; Ledent, C.; Parmentier, M.; Costentin, J.; Vaugeois, J. M.
Long-term caffeine intake has been reported to decrease the susceptibility to convulsants in mice. Occurrence of seizures following long-term oral administration of caffeine (0.3g/l) was investigated using adenosine A(2A) receptor knockout (A(2A)R KO) and control (A(2A)R WT) mice. Clonic seizures induced by acute pentylenetetrazol (PTZ, 50mg/kg i.p.) were significantly attenuated in adenosine A(2A)R KO mice drinking only water and reduced by a 14-day caffeine treatment in adenosine A(2A)R WT mice. In addition we showed a protecting effect of a 21-day caffeine treatment in A(2A)R WT mice against kindled seizures induced by PTZ in an increasing dose schedule. Summing up, these protective effects against PTZ-induced seizures occurring when adenosine A(2A)R is absent or chronically blocked by a relevant dose of caffeine may be related to a decreased neuronal excitability.
Derbyshire, E.; Abdula, S.
High caffeine intakes are associated with many adverse health effects, particularly in women. This study used 3-day food diaries and lifestyle questionnaires to investigate habitual caffeine intakes and knowledge about caffeine in women from business offices in the Manchester area. Their mean caffeine intake was 174 mg/day, but 18% of women exceeded the UK recommended upper limit of 300 mg/day. These subjects tended to be older and smokers. Many women were unaware of the health problems associated with excess caffeine consumption (delayed conception, infertility and increased risk of osteoporosis, cardiovascular diseases and cancer). Individuals given previous advice had lower caffeine intakes.
Pedersen, D. J.; Lessard, S. J.; Coffey, V. G.; Churchley, E. G.; Wootton, A. M.; Ng, T.; Watt, M. J.; Hawley, J. A.
We determined the effect of coingestion of caffeine (Caff) with carbohydrate (CHO) on rates of muscle glycogen resynthesis during recovery from exhaustive exercise in seven trained subjects who completed two experimental trials in a randomized, double-blind crossover design. The evening before an experiment subjects performed intermittent exhaustive cycling and then consumed a low-CHO meal. The next morning subjects rode until volitional fatigue. On completion of this ride subjects consumed either CHO [4 g/kg body mass (BM)] or the same amount of CHO + Caff (8 mg/kg BM) during 4 h of passive recovery. Muscle biopsies and blood samples were taken at regular intervals throughout recovery. Muscle glycogen levels were similar at exhaustion [ approximately 75 mmol/kg dry wt (dw)] and increased by a similar amount ( approximately 80%) after 1 h of recovery (133 +/- 37.8 vs. 149 +/- 48 mmol/kg dw for CHO and Caff, respectively). After 4 h of recovery Caff resulted in higher glycogen accumulation (313 +/-69 vs. 234 +/- 50 mmol/kg dw, P < 0.001). Accordingly, the overall rate of resynthesis for the 4-h recovery period was 66% higher in Caff compared with CHO (57.7 +/- 18.5 vs. 38.0 +/- 7.7 mmol.kg dw(-1).h(-1), P < 0.05). After 1 h of recovery plasma Caff levels had increased to 31 +/- 11 muM (P < 0.001) and at the end of the recovery reached 77 +/- 11 muM (P < 0.001) with Caff. Phosphorylation of CaMK(Thr286) was similar after exercise and after 1 h of recovery, but after 4 h CaMK(Thr286) phosphorylation was higher in Caff than CHO (P < 0.05). Phosphorylation of AMP-activated protein kinase (AMPK)(Thr172) and Akt(Ser473) was similar for both treatments at all time points. We provide the first evidence that in trained subjects coingestion of large amounts of Caff (8 mg/kg BM) with CHO has an additive effect on rates of postexercise muscle glycogen accumulation compared with consumption of CHO alone.
Yamaguchi, T.; Chikama, A.; Mori, K.; Watanabe, T.; Shioya, Y.; Katsuragi, Y.; Tokimitsu, I.
Coffee is rich in chlorogenic acids (CGA), whose metabolites may have beneficial effects such as anti-hypertensive effects. However, trial results concerning the effects of coffee on blood pressure (BP) are not consistent. A recent study suggested that hydroxyhydroquinone (HHQ), produced by the roasting of green coffee beans, inhibits the effect of CGA. In the present study, the dose-response for CGA in HHQ-free coffee on BP were investigated in mildly hypertensive men and women. METHODS AND RESULTS: The trial design was a double-blind, randomized controlled trial, with five study groups including, control, zero-dose, low-dose, middle-dose and high-dose. The control beverage was identical to ordinary coffee. The others contained reduced HHQ levels, compared to ordinary coffee, and the CGA were adjusted in target concentration. A total of 203 subjects were randomly allocated. Each subject drank one cup of coffee per day. The study involved a screening and a baseline observation period of 6 weeks and an intervention period of 4 weeks. BP response showed CGA has an anti-hypertensive effect in a dose-dependent manner in HHQ-free coffee, and ordinary coffee showed almost no effect. As a result, a significant correlation between BP change and the three dose-response patterns was observed (p<0.001).
CONCLUSIONS: This study demonstrates a dose-dependent decrease in BP for CGA in HHQ-free coffee.
Source : Nutr Metab Cardiovasc Dis 2008 vol.18 (6), pp 408 - 414
Cramer, B.; Konigs, M.; Humpf, H. U.
The mycotoxin ochratoxin A is degraded by up to 90% during coffee roasting. In order to investigate this degradation, model heating experiments with ochratoxin A were carried out, and the reaction products were analyzed by HPLC-DAD and HPLC-MS/MS. Two ochratoxin A degradation products were identified, and their structure and absolute configuration were determined. As degradation reactions, the isomerization to 14-(R)-ochratoxin A and the decarboxylation to 14-decarboxy-ochratoxin A were identified. Subsequently, an analytical method for the determination of these compounds in roasted coffee was developed. Quantification was carried out by HPLC-MS/MS and the use of stable isotope dilution analysis. By using this method for the analysis of 15 coffee samples from the German market, it could be shown that, during coffee roasting, the ochratoxin A diastereomer 14-(R)-ochratoxin A was formed in amounts of up to 25.6% relative to ochratoxin A. The decarboxylation product was formed only in traces. For toxicity evaluations, first preliminary cell culture assays were performed with the two new substances. Both degradation products exhibited higher IC50 values and caused apoptotic effects with higher concentrations than ochratoxin A in cultured human kidney epithelial cells. Thus, these cell culture data suggest that the degradation products are less cytotoxic than ochratoxin A.
C. Cavin, M. Marin-Kuan, S. Langouët, C. Bezençon, G. Guignard, C. Verguet, D. Piguet, D. Holzhäuser, R. Cornaz, B. Schilter
Coffee consumption has been associated with a significant decrease in the risk of developing chronic diseases such as Parkinson disease, diabetes type-2 and several types of cancers (e.g. colon, liver). In the present study, a coffee-dependent induction of enzymes involved in xenobiotic detoxification processes was observed in rat liver and primary hepatocytes. In addition, coffee was found to induce the mRNA and protein expression of enzymes involved in cellular antioxidant defenses. These inductions were correlated with the activation of the Nrf2 transcription factor as shown using an ARE-reporter luciferase assay. The induction of detoxifying enzymes GSTs and AKR is compatible with a protection against both genotoxicity and cytotoxicity of aflatoxin B1 (AFB1). This hypothesis was confirmed in in vitro and ex vivo test systems, where coffee reduced both AFB1-DNA and protein adducts. Interestingly, coffee was also found to inhibit cytochrome CYP1A1/2, indicating that other mechanisms different from a stimulation of detoxification may also play a significant role in the chemoprotective effects of coffee. Further investigations in either human liver cell line and primary hepatocytes indicated that the chemoprotective effects of coffee against AFB1 genotoxicity are likely to be of relevance for humans. These data strongly suggest that coffee may protect against the adverse effects of AFB1. In addition, the coffee-mediated stimulation of the Nrf2-ARE pathway resulting in increased endogenous defense mechanisms against electrophilic but also oxidative insults further support that coffee may be associated with a protection against various types of chemical stresses.
Rogozin, E. A.; Lee, K. W.; Kang, N. J.; Yu, H.; Nomura, M.; Miyamoto, K.; Conney, A. H.; Bode, A. M.; Dong, Z.
Some xanthine analogues, including 1,3,7-trimethylxanthine (caffeine) and 1,3-dimethylxanthine (theophylline), have been shown to exert anticancer activities in both cell culture and animal models. The present study focused on the relationship of structure and activity of 50 different caffeine analogues in preventing epidermal growth factor (EGF)-induced malignant transformation of mouse epidermal JB6 promotion-sensitive (P+) Cl41 (JB6 P+) cells. Results indicated that the inhibition of cell transformation by the 1,3,7-trialkylxanthines depends on the number of carbons at the alkyl groups R1 and R3, but not R7. Notably, 1-ethyl-3-hexylxanthine (xanthine 70) was the most effective compound for inhibiting EGF-induced neoplastic transformation among the 50 xanthine analogues tested. The 50% inhibition of cell transformation (ICT(50)) value for xanthine 70 was 48- or 75-fold less than the ICT(50) value of caffeine or theophylline, respectively. Further study revealed that xanthine 70 (5-40 muM) dose dependently inhibited EGF-induced transactivation of activator protein 1 (AP-1), whereas theophylline or caffeine (up to 500 muM) had no effect on AP-1 activity. In addition, xanthine 70 (10 muM) inhibited 12-O-tetradecanoylphorbol-13-acetate- or H-Ras-induced neoplastic transformation in JB6 P+ cells by 78.2 or 62.0%, respectively. Collectively, these results indicated that the number of carbons at R1 and R3 is important for the antitumor-promoting activity of the trialkylxanthines and xanthine 70 might be a promising anticancer agent.
Hu, G.; Tuomilehto, J.; Pukkala, E.; Hakulinen, T.; Antikainen, R.; Vartiainen, E.; Jousilahti, P.
Only three Japanese prospective studies have suggested an inverse association between coffee drinking and liver cancer risk. No prospective studies on the association between serum gamma-glutamyltransferase (GGT) and liver cancer risk have been reported. We aimed to determine the single and joint associations of coffee consumption and serum GGT with the risk of primary liver cancer. Study cohorts included 60,323 Finnish participants who were 25-74 years of age and free of any cancer at baseline. During a median follow-up period of 19.3 years (interquartile range: 9.3-29.2 years), 128 participants were diagnosed with an incident liver cancer. The multivariable-adjusted (age, sex, alcohol consumption, education, smoking, diabetes and chronic liver disease at baseline and during follow-up, and body mass index) hazards ratios of liver cancer in participants who drank 0-1, 2-3, 4-5, 6-7, and > or =8 cups of coffee daily were 1.00, 0.66, 0.44, 0.38, and 0.32 (P for trend = 0.003), respectively. Further adjustment for serum GGT in subgroup analysis affected the results only slightly. The multivariable-adjusted and coffee-adjusted hazard ratio of liver cancer for the highest versus the lowest quartile of serum GGT was 3.13 (95% confidence interval = 1.22-8.07). The multivariable-adjusted inverse association between coffee consumption and liver cancer risk persisted when stratified by baseline factors: age more/less than 50 years, current smoker/never smoked/ever smoked, alcohol drinker/never drinker, obese/nonobese, and the highest/lowest three quartiles of serum GGT. A combination of very low coffee consumption and high level of serum GGT was associated with nearly nine-fold increased risk. CONCLUSION: Coffee drinking has an inverse and graded association with the risk of liver cancer. High serum GGT is associated with an increased risk of liver cancer.
Kelly, S. P.; Gomez-Ramirez, M.; Montesi, J. L.; Foxe, J. J.
Recent neuropharmacological research has suggested that certain constituents of tea may have modulatory effects on brain state. The bulk of this research has focused on either L-theanine or caffeine ingested alone (mostly the latter) and has been limited to behavioral testing, subjective rating, or neurophysiological assessments during resting. Here, we investigated the effects of both L-theanine and caffeine, ingested separately or together, on behavioral and electrophysiological indices of tonic (background) and phasic (event-related) visuospatial attentional deployment. Subjects underwent 4 d of testing, ingesting either placebo, 100 mg of L-theanine, 50 mg of caffeine, or these treatments combined. The task involved cued shifts of attention to the left or right visual hemifield in anticipation of an imperative stimulus requiring discrimination. In addition to behavioral measures, we examined overall, tonic attentional focus as well as phasic, cue-dependent anticipatory attentional biasing, as indexed by scalp-recorded alpha-band (8-14 Hz) activity. We found an increase in hit rate and target discriminability (d\') for the combined treatment relative to placebo, and an increase in d\' but not hit rate for caffeine alone, whereas no effects were detected for L-theanine alone. Electrophysiological results did not show increased differential biasing in phasic alpha across hemifields but showed lower overall tonic alpha power in the combined treatment, similar to previous findings at a larger dosage of L-theanine alone. This may signify a more generalized tonic deployment of attentional resources to the visual modality and may underlie the facilitated behavioral performance on the combined ingestion of these 2 major constituents of tea.
da Silva, R. S.; Richetti, S. K.; da Silveira, V. G.; Battastini, A. M.; Bogo, M. R.; Lara, D. R.; Bonan, C. D.
Transcriptional factors and signalling molecules from intracellular metabolism modulate a complex set of events during brain development. Neurotransmitter and neuromodulator synthesis and their receptor expressions vary according to different stages of brain development. The dynamics of signalling systems is often accompanied by alterations in enzyme expression and activity. Adenosine is a neuromodulator that controls the release of several neurotransmitters, including acetylcholine, which is an important neurotransmitter during brain development. Caffeine is a non-specific antagonist of adenosine receptors and can reach the immature brain. We evaluated the effects of rat maternal caffeine intake (1g/L) on acetylcholine degradation and acetylcholinesterase expression from hippocampus of 7-, 14- and 21-day-old neonates in caffeine-treated and control groups. Caffeine was not able to change the age-dependent increase of acetylcholinesterase activity or the age-dependent decrease of acetylcholinesterase expression. However, caffeine promoted an increase of acetylcholinesterase activity (42%) without modifications on the level of acetylcholinesterase mRNA transcripts in 21-day-old rats. Considering the high score of phosphorylatable residues on acetylcholinesterase, this profile can be associated with a possible regulation by specific phosphorylation sites. These results highlight the ability of maternal caffeine intake to interfere on cholinergic neurotransmission during brain development.
Mose, T.; Kjaerstad, M. B.; Mathiesen, L.; Nielsen, J. B.; Edelfors, S.; Knudsen, L. E.
Ex vivo perfusion of the human term placenta is a method to study placental transfer without extrapolation from animal to human and with no ethical concerns for mother and child. However, ex vivo placenta perfusion has a limited potential within chemical screening and testing as the method is time-consuming. This study was an attempt to construct data needed to develop quantitative structure-activity relationship (QSAR) models that are able to predict placental transfer of new compounds. Placental transfer is a biological activity that statistically may be related to the physiochemical properties of a given group of compounds. Benzoic acid, caffeine, and glyphosate were chosen as model compounds because they are small molecules with large differences in physiochemical properties. Caffeine crossed the placenta by passive diffusion. The initial transfer rate of benzoic acid was more limited in the first part of the perfusion compared to caffeine, but reached the same steady-state level by the end of perfusion. The transfer of glyphosate was restricted throughout perfusion, with a lower permeation rate, and only around 15% glyphosate in maternal circulation crossed to the fetal circulation during the study period.
Source : J Toxicol Environ Health A 2008 vol.71 (15), pp 984 - 991
Saaksjarvi, K.; Knekt, P.; Rissanen, H.; Laaksonen, M. A.; Reunanen, A.; Mannisto, S.
Objective To examine the prediction of coffee consumption on the incidence of Parkinson\'s
disease.Subjects and methods:The study population comprised 6710 men and women, aged 50-79 years and free from Parkinson\'s disease at the baseline. At baseline, enquiries were made about coffee consumption in a self-administered questionnaire as the average number of cups per day. During a 22-year follow-up, 101 incident cases of Parkinson\'s disease occurred. Parkinson\'s disease cases were identified through a nationwide registry of patients receiving medication reimbursement, which is based on certificates from neurologist.Results:After adjustments for age, sex, marital status, education, community density, alcohol consumption, leisure-time physical activity, smoking, body mass index, hypertension and serum cholesterol, the relative risk for subjects drinking 10 or more cups of coffee per day compared with non-drinkers was 0.26 (95% confidence interval 0.07-0.99, P-value for trend=0.18). The association was stronger among overweight persons and among persons with lower serum cholesterol level (P-value for interaction=0.04 and 0.03, respectively).Conclusions:The results support the hypothesis that coffee consumption reduces the risk of Parkinson\'s disease, but protective effect of coffee may vary by exposure to other factors.
Karita, M.; Tsuchiya, H.; Kawahara, M.; Kasaoka, S.; Tomita, K.
Drug delivery systems are for the purpose of targeting a drug to a specific tissue selectively and at the same time preventing a drug from accumulating in healthy organs. Liposomes have been proposed as useful drug carriers in targeted drug delivery system and are under investigation in several therapeutic fields. Caffeine has been identified as belonging to the group of xanthines that enhances the action of cisplatin. MATERIALS AND METHODS: In this study, liposomes containing polyethylene glycol encapsulated cisplatin (CDDP-L) were prepared. The action of CDDP-L on rat osteosarcoma and the enhancing action of caffeine on the antitumor effect of CDDP-L were evaluated. Using osteosarcoma-bearing rats, the retention of CDDP-L in the blood, its intratumor concentration, cytoreductive effect and the enhancing action of caffeine on its antitumor effect were examined. RESULTS: The liposomes were able to remain in the systemic circulation for a long time and to be concentrated in the osteosarcoma, but that action did not produce an effect corresponding to the quantity of cisplatin which was encapsulated reaching the tumor. In rats administered CDDP-L, it was discovered that the antitumor effect was not only enhanced by the coadministration of caffeine but also further enhanced when the dosing period of caffeine was increased.
CONCLUSION: CDDP-L combined with caffeine treatment can produce better results for osteosarcoma.
Source : Anticancer Res 2008 vol.28 (3A), pp 1449 - 1457 (not available on line)
Lopez-Garcia, E.; van Dam, R. M.; Li, T. Y.; Rodriguez-Artalejo, F.; Hu, F. B.
Coffee consumption has been linked to various beneficial and detrimental health effects, but data on its relation with mortality are sparse. OBJECTIVE: To assess the association between coffee consumption and mortality from cardiovascular disease (CVD), cancer, and all causes during 18 years of follow-up in men and 24 years of follow-up in women. DESIGN: Sex-specific Cox proportional hazard models were used to investigate the association between coffee consumption and incidence of all-cause and disease-specific mortality in a prospective cohort study. SETTING: Health Professionals Follow-up Study and Nurses\' Health Study. PARTICIPANTS: 41,736 men and 86,214 women with no history of CVD or cancer at baseline. MEASUREMENTS: Coffee consumption was assessed first in 1986 for men and in 1980 for women and then every 2 to 4 years through 2004. Investigators documented 6888 deaths (2049 due to CVD and 2491 due to cancer) among men and 11,095 deaths (2368 due to CVD and 5011 due to cancer) among women. RESULTS: After adjustment for age, smoking, and other CVD and cancer risk factors, the relative risks for all-cause mortality in men across categories of coffee consumption (<1 cup per month, 1 cup per month to 4 cups per week, 5 to 7 cups per week, 2 to 3 cups per day, 4 to 5 cups per day, and >or=6 cups per day) were 1.0, 1.07 (95% CI, 0.99 to 1.16), 1.02 (CI, 0.95 to 1.11), 0.97 (CI, 0.89 to 1.05), 0.93 (CI, 0.81 to 1.07), and 0.80 (CI, 0.62 to 1.04), respectively (P for trend = 0.008). For women, the relative risks were 1.0, 0.98 (CI, 0.91 to 1.05), 0.93 (CI, 0.87 to 0.98), 0.82 (CI, 0.77 to 0.87), 0.74 (CI, 0.68 to 0.81), and 0.83 (CI, 0.73 to 0.95), respectively (P for trend < 0.001). This inverse association was mainly due to a moderately reduced risk for CVD mortality and was independent of caffeine intake. By contrast, coffee consumption was not statistically significantly associated with risk for cancer death after adjustment for potential confounders. Decaffeinated coffee consumption was associated with a small reduction in all-cause and CVD mortality. LIMITATION: Coffee consumption was estimated from self-report; thus, some measurement error is inevitable.
CONCLUSION: Regular coffee consumption was not associated with an increased mortality rate in either men or women. The possibility of a modest benefit of coffee consumption on all-cause and CVD mortality needs to be further investigated.
Reiter-Reisacher, R. B.; Wald, M.; Weninger, M.; Herkner, K. R.
This is the first study comparing the caffeine testing by HPLC to the MicroTip Technology patented by Ortho-Clinical Diagnostics. For the determination of the precision for intra-run and day to day variances, control materials with concentration ranges between 2.3 microg/mL and 23.3 microg/mL were used. Test evaluation was done using plasma samples. The coefficient of variation for intra-run precision was calculated to range from 4.3% to 2.1%. The coefficients of variation for the day-to-day precision were between 4.9% and 2.3%. A coefficient of correlation of 0.99% was calculated for the comparison of the two methods. In the statistical analysis of the comparison of the methods. Differences between + 4.5% and - 0.92% could be found. The HPLC system must be ready for use at any time necessitating maintenance and increased costs. This, in addition to the low sample throughput for caffeine analysis and the findings of this study favour the use of an automated clinical chemistry system.
Source : Clin Lab 2008 vol.54 (3-4), pp 89 - 94 (not available on line)
Perez-Martinez, M.; Sopelana, P.; Paz-de-Pena, M.; Cid, C.
In this work, the chemical changes occurring in the volatile fraction of Arabica coffee brews during storage at 4 and 25°C for 30 days have been characterized for the 1 st time by means of HS-GC-MS. A total of 47 compounds were identified and quantified: 2 S compounds, 7 aldehydes, 3 esters, 15 furans, 5 ketones, 1 alcohol, 2 thiophenes, 4 pyrroles, 1 pyridine, 5 pyrazines, 1 alkene, and 1 acid. No new volatile compounds were detected at the end of the storage time. The changes observed are, in general, slower and less pronounced at refrigeration temp. Storage also affects the sensory characteristics of the stored coffee brews, which lose part of their aroma intensity and freshness, acquiring some nondesirable notes such as rancid aroma, mainly during storage at 25°C. Furthermore, 7 aroma indices have been proposed as indicators of coffee brew staling, which show a good correlation with some sensory attributes, not only for aroma but also overall sensory quality. Consequently, they could be considered useful to monitor both the \'age\' and the sensory quality of stored coffee brews.
Akiyama, M.; Murakami, K.; Hirano, Y.; Ikeda, M.; Iwatsuki, K.; Wada, A.; Tokuno, K.; Onishi, M.; Iwabuchi, H.
A sampling method to isolate headspace volatiles of freshly brewed drip coffee using a solid-phase microextraction fiber (fiber type: divinylbenzene/carboxen/polydimethylsiloxane) in a short time (2 min) immediately after extraction has been developed. Volatile compounds and potent odorants obtained from each headspace aroma of various arabica coffee extracts (3 production countries: Ethiopia, Tanzania, and Guatemala; 3 roasting degrees for each country: L26, L23, and L18) using the sampling method were examined by gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O, CharmAnalysis). The results of principal component analysis (PCA) using the data of GC/O analysis showed that the aroma profile of Ethiopian coffee was discriminately different from those of Tanzanian coffee and Guatemalan coffee. In addition, it was suggested from the factor loading of the PCA that 4-(4\'-hydroxyphenyl)-2-butanone (raspberry ketone; sweet-fruity odor) characterized the aroma profile of freshly brewed Ethiopian coffee. Therefore, the 4-(4\'-hydroxyphenyl)-2-butanone was quantified in the 9 kinds of coffee extracts. Ethiopian coffee extract of the lightly roasted degree (roasting degree: L26) contained the highest amount of this component, while it was only a little over the reported threshold. In the sensory test, the headspace aromas of Tanzanian and Guatemalan coffees in which 4-(4\'-hydroxyphenyl)-2-butanone was added were, respectively, discriminated from not added samples, and "sweet" odor was selected as an odor description that assessors found similarity between the added Tanzanian or Guatemalan coffee aroma and the Ethiopian coffee aroma. It was suggested that 4-(4\'-hydroxyphenyl)-2-butanone made some detectable change on total aroma profile even though the added amount was only near threshold level.
Source : J Food Sci 2008 vol.73 (5), pp C335 - C346
Baggenstoss, J.; Poisson, L.; Kaegi, R.; Perren, R.; Escher, F.
The impact of time-temperature combinations of roasting processes on the kinetics of aroma formation in coffee was investigated. The development of 16 aroma compounds and the physical properties of coffee beans was followed in a commercial horizontal drum roasting process and in laboratory scale fluidizing-bed roasting processes at high temperature-short time and low temperature-long time conditions. All trials were run to an equal roast end point as defined by the lightness of coffee beans. In addition, the effect of excessive roasting on aroma composition was studied. Compared to low temperature-long time roasting, high temperature-short time roasting resulted in considerable differences in the physical properties and kinetics of aroma formation. Excessive roasting generally led to decreasing or stable amounts of volatile substances, except for hexanal, pyridine, and dimethyl trisulfide, whose concentrations continued to increase during over-roasting. When the drum roaster and the fluidizing bed roaster were operated in the so-called temperature profile mode, that is, along the identical development of coffee bean temperature over roasting time, the kinetics of aroma generation were similar in both processes.
Franska, M.
A number of copper salts, Cu(OOCCH(3))(2), Cu(ClO(4))(2), Cu(NO(3))(2), CuCl(2) and CuSO(4) have been tested for their ability to form binuclear copper-caffeine complexes. The electrospray ionization (ESI) mass spectra of methanol solution containing caffeine and CuCl(2) or CuSO(4) show signals of two copper atom containing ions, so the signals correspond to binuclear complexes: [2Caf + Cu(2)SO(4)](+), [2Caf + Cu(2)](+), [2Caf + Cu(2)Cl](+), [2Caf + Cu(2)Cl(2)](+) and [2Caf + Cu(2)Cl(3)](+). Sulfate and chloride anion are characterized by charge densities higher than those of the carboxylate, nitrate and perchlorate anion. Thus, due to the electrostatic forces, the binuclear complexes containing SO(4)(2-) or Cl(-) can survive the transfer from solution to the gas phase and then can successfully be observed on ESI mass spectra. The ion [2Caf + Cu(2)Cl(3)](+) is present in solution and could be detected when using methanol/chloroform as solvent. The ions [2Caf + Cu(2)](+), [2Caf + Cu(2)Cl](+) and [2Caf + Cu(2)Cl(2)](+) are formed from the [2Caf + Cu(2)Cl(3)](+) ion (by subsequent loss of Cl atoms) on transfer from the solution to the gas phase or in the gas phase. The ion [2Caf + Cu(2)](+) does not contain a bridging agent, thus it is reasonable to assume that it contains a Cu-Cu bond.
Injac, R.; Srdjenovic, B.; Prijatelj, M.; Boskovic, M.; Karljikovic-Rajic, K.; Strukelj, B.
A method is described for the quantification of caffeine, theobromine, theophylline, paracetamol, propyphenazone, acetylsalicylic acid, salicylic acid and codeine phosphate in real samples of foods, beverages, natural products, pharmaceuticals, and cosmetics via micellar electrokinetic capillary chromatography. Separation is carried out at 25°C and 25 kV, using a 20mM phosphate buffer (pH 9.0), 80mM SDS, and 7.5% (v/v) acetonitrile. UV detection is at 210 nm. The method was shown to be specific, accurate (recoveries of 98.9-101.2%), linear over the tested range (correlation coeff. = 0.9993), and precise (relative s.d. <2.1%). The method was applied for the quantitative analysis of these compounds in different foods, beverages, natural products, pharmaceuticals and cosmetic products.
Vatinno, R.; Aresta, A.; Zambonin, C. G.; Palmisano, F.
Determination of ochratoxin A in green coffee beans by solid-phase microextraction and liquid chromatography with fluorescence detection Source : J.Chromatogr.A vol.1187 Issue 1-2 pp 145 - 150 Pub date: 11-4-2008 Abstract:
A new method for the determination of Ochratoxin A (OTA) in green coffee beans by solid-phase microextraction (SPME) coupled to liquid chromatography with fluorescence detection (LC-FD) is described for the first time. Coffee samples were extracted by a 5% NaHCO(3) solution, followed by a clean-up step of the extract by chloroform partition. The aqueous extract was then acidified and finally subjected to SPME-LC-FD analysis. The investigated linear range in coffee was 2-32 ng/g. Within-day RSD% in coffee spiked at 2 and 32 ng/g levels were 3.3 and 2.7, respectively, whereas the between-days RSD% were 4.1 and 3.8, respectively. The limits of detection (LOD) and quantitation (LOQ), calculated at a signal-to-noise ratio of 3 and 10 (noise calculated peak to peak on a blank chromatogram at the OTA retention time), were 0.3 and 2 ng/g, respectively.
Risticevic, S.; Carasek, E.; Pawliszyn, J.
Feasibility of using GC-TOF-MS with multivariate data analysis for characterizing coffee samples according to their geographical origin, of importance for authenticity testing, was investigated. Sample pre-treatment involving rapid, automated headspace solid-phase microextraction using divinylbenzene/carboxen/polydimethylsiloxane fibre was optimized and combined with the GC-MS analysis which could be performed in 7.9 min. Data obtained were subjected to principal component analysis, which allowed discrimination of samples according to geographical origin. The method was tested for distinguishing a reference authentic Brazilian coffee sample from samples of coffee from other countries.
Source : Analytica Chimica Acta 2008 vol.617 (1-2), pp 72-84
Belay, A.; Ture, K.; Redi, M.; Asfaw, A.
Caffeine causes physiological effects, and its concentration in vivo is a key marker for disorders. The chemical analysis of caffeine in coffee beans is used for evaluating coffee quality, and there is interest in the development of a rapid analytical method for the determination of caffeine in coffee beans. In this study, the caffeine content in Arabic coffee beans of Ethiopia was determined using UV/visible spectrophotometry. Pure caffeine was characterised in water and dichloromethane. Fast and simple methods were developed to quantify the caffeine content in coffee beans. Advantages of the proposed methods are discussed.
Houessou, J. K.; Goujot, D.; Heyd, B.; Camel, V.
Roasting is a critical process in coffee production, as it enables the development of flavour and aroma. At the same time, roasting may lead to the formation of nondesirable compounds, such as PAH. In this study, Arabica green coffee beans from Cuba were roasted under controlled conditions to monitor PAH formation during the roasting process. Roasting was performed in a pilot-spouted bed roaster, with the inlet air temp. varying from 180 to 260°C, for roasting conditions ranging from 5 to 20 min. Several PAHs were determined in both roasted coffee samples and green coffee samples. Different models were tested, with more or less assumptions on the chemical phenomena, with a view to predict the system\'s global behaviour. 2 kinds of models were used and compared: kinetic models (based on Arrhenius law) and statistical models (neural networks). The numbers of parameters to adjust differed for the tested models, varying from 3 to 9 for the kinetic models and from 5 to 13 for the neural networks. Interesting results are presented, with satisfactory correlations between experimental and predicted concentrations for some PAHs, such as pyrene, benz[a]anthracene, chrysene and anthracene.
Keast, R. S. J.
Caffeine is a xanthine derivative found in coffee and cocoa, which acts as a stimulant to enhance mood and attention. However, it is also bitter tasting, which limits food applications. This work assessed the abilities of peripheral (sodium gluconate, zinc lactate, sucrose and milk) and cognitive (coffee, chocolate and mocha aromas) manipulation on the perception of caffeine bitterness among 33 individuals. Peripheral (i.e. food supplements to mask caffeine) strategies were more effective than cognitive (i.e. flavour addition to mask caffeine) strategies to reduce the perceived bitterness. Zinc lactate was the best inhibitor of bitterness, although it is also claimed to inhibit sweetness so this might limit its application in new product development.
Nunes, F. M.; Reis, A.; Silva, A. M.; Domingues, M. R.; Coimbra, M. A.
The hot water soluble green coffee arabinogalactans, representing nearly 7% of total coffee bean arabinogalactans, were characterized by (1)H and (13)C NMR and, after partial acid hydrolysis, by ESI-MS/MS. Data obtained showed that these are highly branched type II arabinogalactans covalently linked to proteins (AGP), with a protein moiety containing 10% of 4-hydroxyproline residues. They possess a beta-(1-->3)-Galp/beta-(1-->3,6)-Galp ratio of 0.80, with a sugars composition of Rha:Ara:Gal of 0.25:1.0:1.5, and containing 2mol% of glucuronic acid residues. Beyond the occurrence of single alpha-L-Araf residues and [alpha-L-Araf-(1-->5)-alpha-L-Araf-(1-->] disaccharide residues as side chains, these AGPs contain unusual side chains at O-3 position of the beta-(1-->6)-linked galactopyranosyl residues composed by [alpha-L-Rhap-(1-->5)-alpha-L-Araf-(1-->] and [alpha-L-Rhap-(1-->5)-alpha-L-Araf-(1-->5)-alpha-L-Araf-(1-->] oligosaccharides. Rhamnoarabinosyl and rhamnoarabinoarabinosyl side chains are reported for the first time as structural features of plant arabinogalactan-proteins.
Srdjenovic, B.; Djordjevic-Milic, V.; Grujic, N.; Injac, R.; Lepojevic, Z.
A rapid and selective HPLC method was developed for separation and determination of caffeine, theobromine and theophylline. The chromatography is performed on a Zorbax Eclipse XDB-C8 column (4.6 x 150 mm i.d., 5 mum particle size) at 25°C, with a mobile phase of water-THF (0.1% THF in water, pH 8)-acetonitrile (90:10, v/v). The flow rate is 0.8 ml/min, and absorption of UV radiation at 273 nm is detected. This method permits simultaneous determination of caffeine, theobromine and theophylline in foods, beverages and herbal products with detection limits of 0.07-0.2 mg/l and recoveries of 100.20¬100.42%. Correlation coeff., for calibration curves in the linear range of 0.2-100 mg/l, were >0.9999 for all compounds. Values of within- and between-day precision were determined for both retention times and peak area. The data suggests that the proposed HPLC method can be used for routine quality control of foods, beverages and herbal products.
Chu, Q.; Lin, M.; Yu, X.; Ye, J.
This work describes the development and performance of a capillary electrophoresis-amperometric detection method for the determination of natural antioxidants (including catechin, rutin, ferulic acid, ortho-dihydroxybenzene, chlorogenic acid, caffeic acid, gallic acid and protocatechuic acid) in coffee. Detection limits were in the range 0.06-0.36 mcg/ml for all of the analytes. Pure water (rather than water-ethanol mixtures) gave the best extraction efficiency.
Source : Eur Food Res Technol 2008 vol.226 (6), pp 1373-1378
Toci, A. T.; Farah, A.
A proportion of Brazil\'s coffee production contains defective beans, and is considered inappropriate for export. This study investigated the volatile composition of common Brazilian defective coffee beans in comparison with good quality beans from respective lots, to identify potential marker compounds characteristic of specific defects. Using solid-phase microextraction-GC-MS, defective coffee bean markers were identified for raw and roasted coffees. In the raw samples, 2-methylpyrazine and 2-furylmethanol acetate were identified in black-immature beans, and butyrolactone was found only in sour beans. Benzaldehyde and 2,3,5,6-tetramethylpyrazine were found to be potential markers of defective beans in general. Potential defective markers in roasted beans are listed.
Efrain-Ramirez-Benitez, J.; Chee-Gonzalez, L.; Teresa-Hernandez-Sotomayor, S. M.
The primary Al-tolerance mechanism in plants involves exudation and/or accumulation of specific organic acid species, which form non-phytotoxic complexes with Al(3+) under physiological conditions. An evaluation was done of the role of organic acids in the tolerance mechanism of a cell suspension line of coffee Coffea arabica that exhibits Al-tolerance (LAMt) but for which the metabolic tolerance mechanism remains unknown. Significant differences existed in malate dehydrogenase and citrate synthase activities (key enzymes in organic acids metabolism) between protein extracts (day 7 of culture cycle) of the L2 (Al-sensitive) and LAMt (Al-tolerant) cells when cell suspensions were treated with 100muM AlCl(3). HPLC analysis showed that the suspension cells of both lines exudate malate when incubated in a minimal solution but that exudation was not enhanced by treatment with AlCl(3) (100muM). This is the first study demonstrating that plant Al-tolerance may be associated with down-regulation of malate dehydrogenase and citrate synthase activities.
Bhaskara, S.; Chandrasekharan, M. B.; Ganguly, R.
Cytochrome P450 monooxygenases or CYPs, a family of endobiotics and xenobiotics metabolizing enzymes, are found in all organisms. We reported earlier that the promoters of Drosophila Cyp6a2 and Cyp6a8 genes are induced by caffeine. Since caffeine antagonizes adenosine receptor (AdoR) and inhibits cAMP phosphodiesterase (PDE), we used luciferase reporter gene to examine whether in SL-2 cells and adult Drosophila, induction of the two Cyp6 genes is mediated via AdoR and/or PDE pathway. Results showed that AdoR is not involved because AdoR agonists or antagonists do not affect the Cyp6 promoter activities. However, inhibition of PDE by specific inhibitors including caffeine causes induction of both Cyp6 gene promoters. We also found that flies mutant for dunce gene coding for cAMP-PDE, have higher Cyp6a8 promoter activity than the wild-type flies. We demonstrate that caffeine treatment increases intracellular cAMP levels, and cAMP treatment induces the Cyp6 gene promoters. Since both Cyp6 genes have multiple sites for JUN transcription factors, which generally play a positive role in cAMP pathway, effect of Drosophila jun (D-jun) on the Cyp6a8 promoter activity was examined. Results showed that the expression of D-jun sense plasmid causes downregulation rather than activation of the Cyp6a8 promoter. Conversely, expression of antisense plasmid increased the promoter activity. Interestingly, caffeine treatment decreased the D-JUN protein level in SL-2 cells as well as in adult flies. These results suggest that D-jun acts as a negative regulator, and caffeine induction of Cyp6a8 and Cyp6a2 genes is mediated by the upregulation of cAMP pathway and downregulation of the D-JUN protein level.
Source : Gene 2008 vol.415 (1 -2), pp 49 - 59
Pre, M.; Caillet, V.; Sobilo, J.; McCarthy, J.
Galactomannans act as storage reserves for the seeds in some plants, such as guar (Cyamopsis tetragonoloba) and coffee (Coffea arabica and Coffea canephora). In coffee, the galactomannans can represent up to 25 % of the mass of the mature green coffee grain, and they exert a significant influence on the production of different types of coffee products. The objective of the current work was to isolate and characterize cDNA encoding proteins responsible for galactomannan synthesis in coffee and to study the expression of the corresponding transcripts in the developing coffee grain from C. arabica and C. canephora, which potentially exhibit slight galactomannan variations. Comparative gene expression analysis was also carried out for several other tissues of C. arabica and C. canephora. METHODS: cDNA banks, RACE-PCR and genome walking were used to generate full-length cDNA for two putative coffee mannan synthases (ManS) and two galactomannan galactosyl transferases (GMGT). Gene-specific probe-primer sets were then generated and used to carry out comparative expression analysis of the corresponding genes in different coffee tissues using quantitative RT-PCR. KEY RESULTS: Two of the putative galactomannan biosynthetic genes, ManS1 and GMGT1, were demonstrated to have very high expression in the developing coffee grain of both Coffea species during endosperm development, consistent with our proposal that these two genes are responsible for the production of the majority of the galactomannans found in the grain. In contrast, the expression data presented indicates that the ManS2 gene product is probably involved in the synthesis of the galactomannans found in green tissue. CONCLUSIONS: The identification of genes implicated in galactomannan synthesis in coffee are presented. The data obtained will enable more detailed studies on the biosynthesis of this important component of coffee grain and contribute to a better understanding of some functional differences between grain from C. arabica and C. canephora.
Source : Ann Bot (Lond) 2008 vol.102 (2), pp 207 - 220
Hendre, P. S.; Phanindranath, R.; Annapurna, V.; Lalremruata, A.; Aggarwal, R. K.
Species-specific microsatellite markers are desirable for genetic studies and to harness the potential of MAS-based breeding for genetic improvement. Limited availability of such markers for coffee, one of the most important beverage tree crops, warrants newer efforts to develop additional microsatellite markers that can be effectively deployed in genetic analysis and coffee improvement programs. The present study aimed to develop new coffee-specific SSR markers and validate their utility in analysis of genetic diversity, individualization, linkage mapping, and transferability for use in other related taxa. RESULTS: A small-insert partial genomic library of Coffea canephora, was probed for various SSR motifs following conventional approach of Southern hybridisation. Characterization of repeat positive clones revealed a very high abundance of DNRs (1/15 Kb) over TNRs (1/406 kb). The relative frequencies of different DNRs were found as AT >> AG > AC, whereas among TNRs, AGC was the most abundant repeat. The SSR positive sequences were used to design 58 primer pairs of which 44 pairs could be validated as single locus markers using a panel of arabica and robusta genotypes. The analysis revealed an average of 3.3 and 3.78 alleles and 0.49 and 0.62 PIC per marker for the tested arabicas and robustas, respectively. It also revealed a high cumulative PI over all the markers using both sib-based (10-6 and 10-12 for arabicas and robustas respectively) and unbiased corrected estimates (10-20 and 10¬43 for arabicas and robustas respectively). The markers were tested for Hardy-Weinberg equilibrium, linkage dis-equilibrium, and were successfully used to ascertain generic diversity/affinities in the tested germplasm (cultivated as well as species). Nine markers could be mapped on robusta linkage map. Importantly, the markers showed ~92% transferability across related species/genera of coffee.
CONCLUSION: The conventional approach of genomic library was successfully employed although with low efficiency to develop a set of 44 new genomic microsatellite markers of coffee. The characterization/validation of new markers demonstrated them to be highly informative, and useful for genetic studies namely, genetic diversity in coffee germplasm, individualization/bar-coding for germplasm protection, linkage mapping, taxonomic studies, and use as conserved orthologous sets across secondary genepool of coffee. Further, the relative frequency and distribution of different SSR motifs in coffee genome indicated coffee genome to be relatively poor in microsatellites compared to other plant species.
Source : BMC Plant Biol 2008 vol.8 pp 51
Privat, I.; Foucrier, S.; Prins, A.; Epalle, T.; Eychenne, M.; Kandalaft, L.; Caillet, V.; Lin, C.; Tanksley, S.; Foyer, C.; McCarthy, J.
* Coffea arabica (Arabica) and Coffea canephora (Robusta) are the two main cultivated species used for coffee bean production. Arabica genotypes generally produce a higher coffee quality than Robusta genotypes. Understanding the genetic basis for sucrose accumulation during coffee grain maturation is an important goal because sucrose is an important coffee flavor precursor. * Nine new Coffea genes encoding sucrose metabolism enzymes have been identified: sucrose phosphate synthase (CcSPS1, CcSPS2), sucrose phosphate phosphatase (CcSP1), cytoplasmic (CaInv3) and cell wall (CcInv4) invertases and four invertase inhibitors (CcInvI1, 2, 3, 4). * Activities and mRNA abundance of the sucrose metabolism enzymes were compared at different developmental stages in Arabica and Robusta grains, characterized by different sucrose contents in mature grain. * It is concluded that Robusta accumulates less sucrose than Arabica for two reasons: Robusta has higher sucrose synthase and acid invertase activities early in grain development - the expression of CcSS1 and CcInv2 appears to be crucial at this stage and Robusta has a lower SPS activity and low CcSPS1 expression at the final stages of grain development and hence has less capacity for sucrose re-synthesis. Regulation of vacuolar invertase CcInv2 activity by invertase inhibitors CcInvI2 and/or CcInvI3 during Arabica grain development is considered.
Cardona, Y. P.; Oliveros, C. E.; Arias, D. F.; Alvarez, F.; Devia, A.
Healthy mature fruits are required for a coffee of high quality in the cup, and selection methods are required for coffee fruits. In this study, the epicarp of coffee fruit was characterised, and changes in the roughness, in the mature and green states, were characterised, and the dimensions and density of the cells of the epicarp were examined using atomic force microscopy. The densities and dimensions of the coffee cells were also determined. The roughness of the epicarp of the coffee fruit was found to be appropriate for differentiating fruits of coffee in green and mature states.
Moretti, S.; Wilm, A.; Higgins, D. G.; Xenarios, I.; Notredame, C.
The R-Coffee web server produces highly accurate multiple alignments of noncoding RNA (ncRNA) sequences, taking into account predicted secondary structures. R-Coffee uses a novel algorithm recently incorporated in the T-Coffee package. R-Coffee works along the same lines as T-Coffee: it uses pairwise or multiple sequence alignment (MSA) methods to compute a primary library of input alignments. The program then computes an MSA highly consistent with both the alignments contained in the library and the secondary structures associated with the sequences. The secondary structures are predicted using RNAplfold. The server provides two modes. The slow/accurate mode is restricted to small datasets (less than 5 sequences less than 150 nucleotides) and combines R-Coffee with Consan, a very accurate pairwise RNA alignment method. For larger datasets a fast method can be used (RM-Coffee mode), that uses R-Coffee to combine the output of the three packages which combines the outputs from programs found to perform best on RNA (MUSCLE, MAFFT and ProbConsRNA). Our BRAliBase benchmarks indicate that the R-Coffee/Consan combination is one of the best ncRNA alignment methods for short sequences, while the RM-Coffee gives comparable results on longer sequences. The R-Coffee web server is available at http://www.tcoffee.org.
Source : Nucleic Acids Res 2008 vol.36 Issue Web Server issue pp W10 - W13 (full text)
Lopes, F. R.; Carazzolle, M. F.; Pereira, G. A.; Colombo, C. A.; Carareto, C. M.
Transposable elements are major components of plant genomes and they influence their evolution, acting as recombination hot spots, acquiring specific cell functions or becoming part of protein-coding regions. The latter is the subject of the present analysis. This study is a report on the annotation of transposable elements (TEs) in expressed sequences of Coffea arabica, Coffea canephora and Coffea racemosa, showing the occurrence of 383 ESTs and 142 unigenes with TE fragments in these three Coffea species. Based on selected unigenes, it was possible to suggest 26 putative proteins with TE-cassette insertions, demonstrating a likely contribution to protein variability. The genes for two of those proteins, the fertility restorer (FR) and the pyrophosphate-dependent phosphofructokinase (PPi-PFKs) genes, were selected for evaluating the impact of TE-cassettes on host gene evolution of other plant genomes (Arabidopsis thaliana, Oryza sativa and Populus trichocarpa). This survey allowed identifying a FR gene in O. sativa harboring multiple insertions of LTR retrotransposons that originated new exons, which however does not necessarily mean a case of molecular domestication. A possible transduction event of a fragment of the PPi-PFK beta-subunit gene mediated by Helitron ATREPX1 in Arabidopsis thaliana was also highlighted.