Science Alert

Philpott, S. M.; Perfecto, I.; Vandermeer, J.

1. Ants are important predators in agricultural systems, and have complex and often strong effects on lower trophic levels. Agricultural intensification reduces habitat complexity, food web diversity and structure, and affects predator communities. Theory predicts that strong top-down cascades are less likely to occur as habitat and food web complexity decrease. 2. To examine relationships between habitat complexity and predator effects, we excluded ants from coffee plants in coffee agroecosystems varying in vegetation complexity. Specifically, we studied the effects of eliminating ants on arthropod assemblages, herbivory, damage by the coffee berry borer and coffee yields in four sites differing in management intensification. We also sampled ant assemblages in each management type to see whether changes in ant assemblages relate to any observed changes in top-down effects. 3. Removing ants did not change total arthropod densities, herbivory, coffee berry borer damage or coffee yields. Ants did affect densities
of some arthropod orders, but did not affect densities of different feeding groups. The effects of ants on lower trophic levels did not change with coffee management intensity. 4. Diversity and activity of ants on experimental plants did not change with coffee intensification, but the ant species composition differed. 5. Although variation in habitat complexity may affect trophic cascades, manipulating predatory ants across a range of coffee agroecosystems varying in management intensity did not result in differing effects on arthropod assemblages, herbivory, coffee berry borer attack or coffee yields. Thus, there is no clear pattern that top-down effects of ants in coffee agroecosystems intensify or dampen with decreased habitat complexity.

Source :  J Anim Ecol 2008 vol.77 (3), pp 505 - 511

Fenilli, T. A.; Reichart, K.; Bacchi, O. O.; Trivelin, P. C.; Dourado-Neto, D.

The use of the 15N label for agronomic research involving nitrogen (N) cycling and the fate of fertilizer-N is well established, however, in the case of long term experimentation with perennial crops like citrus,
coffee and rubber tree, there are still shortcomings mainly due to large plant size, sampling procedures, detection levels and interferences on the system. This report tries to contribute methodologically to the design and development of 15N labeled fertilizer experiments, using as an example a coffee crop fertilized with 15N labeled ammonium sulfate, which was followed for two years. The N of the plant derived from the fertilizer was studied in the different parts of the coffee plant in order to evaluate its distribution within the plant and the agronomic efficiency of the fertilizer application practice. An enrichment of the fertilizer-N of the order of 2% 15N abundance was sufficient to study N absorption rates and to establish fertilizer-N balances after one and two years of coffee cropping. The main source of errors in the estimated values lies in the inherent variability among field replicates and not in the measurements of N contents and 15N enrichments of plant material by mass-spectrometry.

Source :  An Acad Bras Cienc 2007 vol.79 (4), pp 767 - 776  (full text)

Winter, G.; Hazan, R.; Bakalinsky, A. T.; Abeliovich, H.

Weak organic acids are an important class of food preservatives that are particularly efficacious towards yeast and fungal spoilage. While acids with small aliphatic chains appear to function by acidification of the cytosol and are required at high concentrations to inhibit growth, more hydrophobic organic acids such as sorbic and benzoic acid have been suggested to function by perturbing membrane dynamics and are growth-inhibitory at much lower concentrations. We previously demonstrated that benzoic acid has selective effects on membrane trafficking in Saccharomyces cerevisiae. Benzoic acid selectively blocks macroautophagy in S. cerevisiae while acetic acid does not, and sorbic acid does so to a lesser extent. Indeed, while both benzoic acid and nitrogen starvation are cytostatic when assayed separately, the combination of these treatments is cytocidal, because macroautophagy is essential for survival during nitrogen starvation. In this report, we demonstrate that Zygosaccharomyces bailii, a food spoilage yeast with relatively high resistance to weak acid stress, also exhibits a cytocidal response to the combination of benzoic acid and nitrogen starvation. In addition, we show that nitrogen starvation can be replaced by caffeine supplementation. Caffeine induces a starvation response that includes the induction of macroautophagy, and the combination of caffeine and benzoic acid is cytocidal, as predicted from the nitrogen starvation data.

Source : Autophagy 2008 vol.4 (1), pp 28 - 36

Fujii, K.; Takeshi, K.

Coffee residue is an agricultural waste which inhibits the growth of several crops. Therefore coffee residue-degrading microbes in soil were screened, isolated and characterized. METHODS AND RESULTS: Forty isolates were obtained after enrichment culture of soil samples. Seven strains (fast degraders) showed strong degrading activity, while 18 strains (slow degraders) showed weak degrading activity. DNA analysis suggested that the fast degraders are Penicillium, and the slow degraders are Penicillium, Trichoderma/Hypocrea, Fusarium/Gibberella, Phaeoacremonium/Togninia or Acidocella. The all fast degraders are cellulolytic, mannolytic and pectinolytic. CONCLUSIONS: Although it is generally thought that fungi such as Trichoderma contribute largely to aerobic degradation of cellulosic biomass, our data suggested that Penicillium overwhelms them in coffee residue degradation. It was implied that polysaccharides in coffee residue are not degraded independently by different microbes, but degraded simultaneously by strains with cellulolytic, mannolytic and pectinolytic activity. Since there is no report of an ascomycete possessing all the three enzyme activities, the fast degraders are ecologically important and have the potential to be used as producers of the costly enzymes from agricultural wastes.

SIGNIFICANCE AND IMPACT OF STUDY: The present results advance our understanding of microbial degradation of a phytotoxic agricultural waste, and offer a new tool for recycling it.

Source : J Appl Microbiol 2007 vol.103 (6), pp 2713 - 2720

Lopez-Garcia, R.; Mallmann, C. A.; Pineiro, M.

Coffee is an important export product of Ecuador. Producers are challenged by the implementation of regulatory limits for ochratoxin A. Ecuador has 4 coffee production areas and the potential for mycotoxin contamination varies due to different environmental conditions and cultural differences in harvesting, storage, processing and commercialization. The major contributors to contamination are the lack of selection during harvesting, delays in drying or rewetting, lack of proper drying and storage conditions, mixing of products with different levels of moisture and cross-contamination. The long commercialization chain involves different intermediaries that use foreign materials to increase the wt. of the product without consideration of quality. In this study, an integrated mycotoxin management system using HACCP principles was developed to prevent mycotoxin contamination at each stage of production. Critical control points were developed based on the resources available at the different stages of the production chain. Training programmes helped increase awareness about the impact of contamination, but failed to transform knowledge into improved practices. Thus, different demonstrative models specific for each productive region at all production levels were developed to show the application of prevention mechanisms using limited resources and to demonstrate the increased commercial value of coffee produced using good practices throughout the chain so producers have a better disposition to adopt improved practices. Preliminary results showed that coffee managed using the models had better quality, lower contamination, higher yield and better commercial value. It is concluded that the use of local resources and low-cost technology is important in demonstrating a practical approach.

Source : Food Addit Contam 2008 vol.25 (2), pp 231 - 240

Lopez-Galilea, I.; Andriot, I.; de Pena, M. P.; Cid, C.; Guichard, E.

The aims of this study were (1) to study the effect of lyophilized coffee extract on the retention of aroma compounds and (2) to study if aroma compounds selected are differently affected by the lyophilized coffee extracts obtained from conventional and Torrefacto coffee brews prepared by filter coffeemaker and by espresso coffee machine. Variable amounts of lyophilized coffee extracts, relative to coffee powder, containing different percentages of high molecular weight compounds, mainly melanoidins (value given in parentheses), were obtained: 20.9% (14.8) and 24.9% (23.3), respectively, for conventional and Torrefacto coffee brew prepared by filter coffeemaker and 18.1% (18.8) and 20.7% (57.5), respectively, for conventional and Torrefacto coffee brew prepared by espresso coffee machine. The retention of aroma compounds increased by increasing the lyophilized coffee extract concentration and was found to be dependent on the aroma compounds. The retention of aroma compounds was found to be slightly different depending on the brewing procedure employed, showing lyophilized coffee extracts obtained with espresso coffee machine had higher retention values that those extracted by filter coffeemaker. Retention capacity of lyophilized coffee extracts obtained from the conventional and the Torrefacto roasted coffee did not show differences except in the case of ethyl nonanoate.

Source : J Food Sci  2008 vol.73 (3), pp S165 - S171

Giacomin, E.; Palmerini, E.; Ballo, P.; Zaca, V.; Bova, G.; Mondillo, S.

Few data exist regarding the direct effects of caffeine and smoking on cardiac function. We sought to explore the acute effects of caffeine assumption, cigarette smoking, or both on left ventricular (LV) and right ventricular (RV) function in a population of young normal subjects. METHODS: Forty-five healthy subjects aged 25 +/- 2 years underwent echocardiography. Fifteen of them were non-smokers and habitual coffee consumers (group 1), 15 were smokers and not habitual coffee consumers (group 2), and 15 were smokers and habitual coffee consumers (group 3). Peak systolic (Sa), early diastolic Ea, and late diastolic (Aa) velocity of mitral annulus were measured by pulsed Tissue Doppler, and left atrioventricular plane displacement was determined by M-mode. Tricuspid annular velocities and systolic excursion (TAPSE) were also determined. Measurements were performed at baseline and after oral assumption of caffeine 100 mg in group 1, one cigarette smoking in group 2, and both in group 3. RESULTS: No changes in ventricular function were observed in group 1 after caffeine administration. In group 2, cigarette smoking yielded an acute increase in mitral Aa (+12.1 %, p = 0.0026), tricuspid Sa (+9.8%, p = 0.012) and TAPSE (+7.9%, p = 0.017), and a decrease in the mitral Ea/Aa ratio (-8.5%, p = 0.0084). Sequential caffeine assumption and cigarette smoking in group 3 was associated with an acute increase in mitral Aa (+13.0%, p = 0.015) and tricuspid Aa (+11.6%, p < 0.0001) and a reduction in mitral Ea/Aa ratio (-8.5%, p = 0.0084) tricuspid Ea (-6.6%, p = 0.048) and tricuspid Ea/Aa ratio (-9.6%, p = 0.0003). In a two-way ANOVA model controlling for hemodynamic confounding factors, changes in the overall population remained significant for mitral Aa and Ea/Aa ratio, and for tricuspid Aa and Ea/Aa ratio.

CONCLUSION: In young healthy subjects, one cigarette smoking is associated to an acute impairment in LV diastolic function and a hyperdynamic RV systolic response. Caffeine assumption alone does not exert any acute effect on ventricular long-axis function, but potentiates the negative effect of cigarette smoking by abolishing RV supernormal response and leading to a simultaneous impairment in both LV and RV diastolic function.

Source : Cardiovasc Ultrasound 2008 vol.6, pp 9

Savegnago, L.; Jesse, C. R.; Nogueira, C. W.

The present study examined the antinociceptive effect of diphenyl diselenide (PhSe)(2), given orally
(p.o.), in the hot-plate test in mice. The administration of diphenyl diselenide (10-100mg/kg, p.o.) caused a significant inhibition of thermal nociception induced by hot-plate test in mice. Pretreatment of animals by intraperitoneal route (i.p.) with caffeine (10mg/kg; a non-specific adenosine receptor antagonist) and PSB1115 (1 mg/kg; an adenosine A(2B) receptor antagonist), but not DPCPX (2mg/kg; an adenosine A(1) receptor antagonist) and SCH5826 (3mg/kg; an adenosine A(2A) receptor antagonist) significantly blockaded the antinociceptive effect caused by diphenyl diselenide (10mg/kg, p.o.) in the hot-plate test. Moreover, the pretreatment of animals with efaroxan (1 mg/kg, i.p.; a mixed I(1) imidazoline/alpha(2)- adrenoceptor antagonist) and idazoxan (3mg/kg, i.p.; a mixed I(2) imidazoline/alpha(2)-adrenoceptor antagonist) did not significantly reverse the antinociception caused by oral administration of diphenyl diselenide (10mg/kg, p.o.) in the hot-plate test. These results indicate that diphenyl diselenide produced antinociception in a thermal model of pain in mice and its effect was prevented by caffeine and by a selective adenosine A(2B) receptor, but not by imidazoline receptor antagonists in mice.

Source : Neurosci Lett 2008 vol.436 (2), pp 120 - 123

Chen, X.; Gawryluk, J. W.; Wagener, J. F.; Ghribi, O.; Geiger, J. D.

High levels of serum cholesterol and disruptions of the blood brain barrier (BBB) have all been implicated as underlying mechanisms in the pathogenesis of Alzheimer\'s disease. Results from studies conducted in animals and humans suggest that caffeine might be protective against Alzheimer\'s disease but by poorly understood mechanisms. Using rabbits fed a cholesterol-enriched diet, we tested our hypothesis that chronic ingestion of caffeine protects against high cholesterol diet-induced disruptions of the BBB. New Zealand rabbits were fed a 2% cholesterol-enriched diet, and 3 mg caffeine was administered daily in drinking water for 12 weeks. Total cholesterol and caffeine concentrations from blood were measured. Olfactory bulbs (and for some studies hippocampus and cerebral cortex as well) were evaluated for BBB leakage, BBB tight junction protein expression levels, activation of astrocytes, and microglia density using histological, immunostaining and immunoblotting techniques. We found that caffeine blocked high cholesterol diet-induced increases in extravasation of IgG and fibrinogen, increases in leakage of Evan\'s blue dye, decreases in levels of the tight junction proteins occludin and ZO-1, increases in astrocytes activation and microglia density where IgG extravasation was present. Chronic ingestion of caffeine protects against high cholesterol diet-induced increases in disruptions of the BBB, and caffeine and drugs similar to caffeine might be useful in the treatment of Alzheimer\'s disease.

Source : J Neuroinflammation 2008 vol.5, pp 12

Mukwevho, E.; Kohn, T. A.; Lang, D.; Nyatia, E.; Smith, J.; Ojuka, E. O.

This study was conducted to explore the mechanism by which caffeine increases GLUT4 expression in C(2)C(12) myotubes. Myoblasts were differentiated in DMEM containing 2% horse serum for 13 days and the resultant myotubes exposed to 10 mM caffeine in the presence or absence of 25 microM KN93 or 10 mM dantrolene for 2 h. After the treatment, cells were kept in serum-free medium and harvested between 0 and 6 h later, depending on the assay. Chromatin immunoprecipitation (ChIP) assays revealed that caffeine treatment caused hyperacetylation of histone H3 at the myocyte enhancer factor 2 (MEF2) site on the Glut4 promoter (P < 0.05) and increased the amount of MEF2A that was bound to this site approximately 2.2-fold (P < 0.05) 4 h posttreatment compared with controls. These increases were accompanied by an approximately 1.8-fold rise (P < 0.05 vs. control) in GLUT4 mRNA content at 6 h post¬caffeine treatment. Both immunoblot and immunocytochemical analyses showed reduced nuclear content of histone deacetylase-5 in caffeine-treated myotubes compared with controls at 0-2 h posttreatment. Inclusion of 10 mM dantrolene in the medium to prevent the increase in cytosolic Ca(2+), or 25 microM KN93 to inhibit Ca(2+)/calmodulin-dependent protein kinase (CaMK II), attenuated all the above caffeine¬induced changes. These data indicate that caffeine increases GLUT4 expression by acetylating the MEF2 site to increase MEF2A binding via a mechanism that involves CaMK II.

Source :  Am J Physiol Endocrinol Metab 2008 vol.294 (3), pp E582 - E588

James, J. E.; Keane, M. A.

The broad aim of this review is to critically examine the implications of new understanding concerning caffeine withdrawal and withdrawal reversal in the context of research concerned with the effects of caffeine on sleep and wakefulness. A comprehensive search was conducted for relevant experimental studies in the PubMED and PsycINFO databases. Studies were assessed with particular reference to methodological adequacy for controlling against confounding due to caffeine withdrawal and withdrawal
reversal. This assessment was used to clarify evidence of effects, highlight areas of ambiguity and derive recommendations for future research. It was found that researchers have generally failed to take account of the fact that habitual use of caffeine, even at moderate levels, leads to physical dependence evidenced by physiological, behavioural and subjective withdrawal effects during periods of abstinence.
Consequently, there has been near-complete absence of adequate methodological controls against confounding due to reversal of withdrawal effects when caffeine is experimentally administered. The findings of what has been a substantial research effort to elucidate the effects of caffeine on sleep and wakefulness, undertaken over a period spanning decades, are ambiguous. Current shortcomings can be redressed by incorporating suitable controls in new experimental designs.

Source : Hum Psychopharmacol 2007 vol.22 (8), pp 549 - 558

van Woudenbergh, G. J.; Vliegenthart, R.; van Rooij, F. J.; Hofman, A.; Oudkerk, M.; Witteman, J. C.; Geleijnse, J. M.

The role of coffee in the cardiovascular system is not yet clear. We examined the relation of coffee intake with coronary calcification in a population-based cohort. METHODS AND RESULTS: The study involved 1570 older men and women without coronary heart disease who participated in the Rotterdam Study. Coffee intake was assessed with a semiquantitative food frequency questionnaire. Coronary calcification was detected with electron beam computed tomography. Severe calcification was defined as an Agatson calcium score >400. Sex-specific odds ratios (ORs) with 95% confidence intervals (95% CI) were obtained by logistic regression with adjustment for age, smoking, body mass index, education, and intake of energy and alcohol. In multivariable analysis, coronary calcification in women was significantly reduced for moderate (>3 to 4 cups) and high (>4 cups) coffee intake, compared with a daily intake of 3 cups or less (OR of 0.41 [95% CI: 0.25 to 0.65] and 0.54 [0.33 to 0.87], respectively). The association persisted after additional adjustment for tea and other dietary confounders, and was not modified by smoking. A nonsignificant inverse relationship was also found in men who smoked, whereas in nonsmoking men a direct association was observed. CONCLUSIONS: The present study suggests a beneficial effect of coffee drinking against coronary calcification, particularly in women. More research is needed to confirm these findings and to clarify possible effect modification by gender and smoking.

Source : Arterioscler Thromb Vasc Biol 2008 vol.28 (5), pp 1018 - 1023

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.

Source :  Br J Nutr 2008 vol.99 (6), pp 1354 - 1361

Lu, Y. P.; Lou, Y. R.; Peng, Q. Y.; Xie, J. G.; Nghiem, P.; Conney, A. H.

Administration of caffeine was shown in earlier studies to enhance UVB-induced apoptosis and inhibit UVB-induced carcinogenesis in hairless SKH-1 mice. Here, we describe a potential mechanism for these in vivo effects. A single irradiation of mouse skin with UVB activated the ataxia-telangiectasia mutated- and Rad3-related (ATR) pathway, causing a severalfold increase in keratinocytes with phospho-Chk1 (Ser(345)) and a marked decrease in mitotic keratinocytes with cyclin B1 compared with baseline. When given in the drinking water for 1 to 2 weeks before UVB, caffeine (0.4 mg/m L) markedly inhibited the UVB¬induced phosphorylation of Chk1 on Ser(345) and caused premature expression of cyclin B1 in the epidermis. Normal keratinocytes had delayed mitotic entry for >10 h following UVB. Caffeine administration reduced this mitotic delay to only 4 h and caused markedly increased apoptosis by 6 to 10 h after UVB. p53 knockout mice were used to determine the role of p53 in these processes. Irradiation with UVB markedly decreased the number of mitotic keratinocytes with cyclin B1 in p53 knockout mice, and topical caffeine immediately after UVB abrogated this response and increased UVB-induced apoptosis severalfold. These effects of caffeine in knockout mice were substantially greater than in wild-type mice. The ability of caffeine to promote the deletion of p53(-/-) keratinocytes may be relevant to its inhibitory effect on UVB-induced skin cancer. Our studies indicate that administration of caffeine enhances the removal of DNA-damaged cells by inhibiting the ATR-mediated phosphorylation of Chk1 and prematurely increasing the number of cyclin B1-containing cells that undergo lethal mitosis.

Source : Cancer Res 2008 vol.68 (7), pp 2523 - 2529

Abara, A. E.; Obochi, G. O.; Obi-Abang, M.; Malu, S. P.; Ekam, V. S.; Uboh, F. E.; Edu, F. E.

Effect of caffeine-coconut products interactions on induction of drug-metabolizing enzyme in wistar albino rats was studied. Twenty rats were randomly divided into four groups: The control group (1) received via oral route a placebo (4.0ml of distilled water). Groups 2 to 4 were treated for a 14-day period with 50 mg/kg body weight of caffeine, 50 mg/kg body weight of caffeine and 50 mg/kg body weight of coconut water, and 50 mg/kg body weight of caffeine and 50 mg/kg body weight of coconut milk in 4.0ml of the vehicle via gastric intubation respectively. One day after the final exposure, the animals were anaestheticized by inhalation of an overdose of chloroform. The blood of each rat was collected by cardiac puncture while the liver of each rat was harvested and processed to examine several biochemical parameters, i.e., total protein and RNA levels, protein/RNA ratios, and activities of alanine and aspartate amino transferase (ALT and AST, respectively). The results showed that while ingestion of coconut milk and coconut water increased the values of protein and protein/RNA ratios, it decreased alanine and aspartate amino transferase (ALT and AST) activities. These effects, in turn, enhanced the induction of the metabolizing enzymes and a resultant faster clearance and elimination of the caffeine from the body, there by reducing the toxic effect on the liver.

Source :  Niger J Physiol Sci 2007 vol.22 (1-2), pp 75 - 81 (not available on line)

Nikitin, A. G.; Navitskas, S.; Gordon, L. A

No abstract available

Source : J Gerontol A Biol Sci Med Sci 2008 vol.63 (2), pp 149 - 150

Corsetti, G.; Pasini, E.; Assanelli, D.; Bianchi, R.

Caffeine is the most frequently ingested neuroactive drug in the world and it is largely used to delay fatigue and improve physical activity. Caffeine can modulate NO synthesis in cells and may influence muscular function by modifying the cellular cycle life-death. There is little data concerning the relationship between caffeine in the heart, NOS expression and apoptosis and no data regarding the acute effect of high doses of caffeine in the in vivo myocardium. We therefore studied hemodynamic NOS and Bax/Bcl2 expression in the rat myocardium after a single cafffeine administration. Thirty-two male rats were divided into six groups: the first was iv-injected with caffeine (16 mg/kg), the second with caffeine + L-NAME (30 mg/kg), the third with caffeine + L-arg (0.5 g/kg), the fourth with caffeine + L-NAME + L-arg and finally the fifth with saline. Mean arterial blood pressure (MAP) was monitored for 30 min, then the animals were killed. The sixth group was injected with caffeine and killed after 2 h. The hearts were isolated and processed by imm unohistochemistry. We found that caffeine increased MAP temporarily while caffeine + L-NAME increased it for a longer period. In the control myocardium, all NOS isoforms were expressed. The Bcl2 were strongly expressed inside the perinuclear cytoplasm whereas Bax was very faintly detectable in the peripheral cytoplasm. In caffeine and caffeine + L-NAME treated animals, NOS expression disappeared. Bax and Bcl2 expression did not vary. The l-arg administration reversed these caffeine and L-NAME effects on NOS expression. Two hours after caffeine, NOS expression increased and Bax and Bcl2 expression did not vary, although Bcl2 was mainly expressed in the peripheral cytoplasm. We conclude that improved caffeine-induced physical performance could also be related to caffeine\'s ability to interfere with endogenous myocardial NO synthesis. Furthermore, we suggest that myocardial cell plays an effective anti-apoptotic role against acute caffeine administration.

Source :  Pharmacol Res 2008 vol.57 (1), pp 19 - 25

Velasco, M. V.; Tano, C. T.; Machado-Santelli, G. M.; Consiglieri, V. O.; Kaneko, T. M.; Baby, A. R.

Cellulite is a physiological condition that presents etiologic plurality. Caffeine and its derivatives are used in anticellulite cosmetics due to their lipolytic activity on fatty cells. Siloxanetriol alginate caffeine (SAC) is a silanol derived from organic silicon. Radicals primarily from SAC are caffeine and the mannuronic acid. AIMS: This study aims to analyze the effects of caffeine and siloxanetriol alginate caffeine on fatty tissue by histological evaluation. METHODS: Formulations were developed with caffeine, caffeine + sodium benzoate or SAC and were applied topically for 21 days on Wistar female mice. The study regarded the histological aspects by determination of diameter and number of fatty cells with a light microscope. RESULTS: Emulsion with caffeine caused a reduction of 17% on the diameter of the fatty cells compared with the control. The emulsion with caffeine + sodium benzoate did not cause alterations on cell diameter. Emulsion with SAC provoked reduction on fatty cell diameters of 16%. No significant alterations were observed on the diameter of the fatty cells treated with gels, although it was noticed that gel with SAC promoted a reduction of 26% on the number of fatty cells.

CONCLUSIONS: Emulsion with SAC was considered more indicated to promote the lipolytic action on fatty tissue, acting as a complement to treat cellulite. When sodium benzoate was added to the preparations, it inhibited the caffeine efficiency. Gel was not an adequate vehicle to be incorporated with caffeine and SAC.

Source : J Cosmet Dermatol 2008 vol.7 (1), pp 23 - 29

Keane, M. A.; James, J. E.; Hogan, M. J.

Despite several decades of research into the effects of caffeine on EEG, few consistent findings have emerged. Notwithstanding the likelihood that differences in methodology may explain some of the inconsistency, confidence in the published findings is undermined by the failure in previous studies to control for the effects of caffeine withdrawal and withdrawal reversal. METHODS: Participants (n = 22) alternated weekly between ingesting placebo and caffeine (1.75 mg/kg) 3 times daily for 4 consecutive weeks. EEG activity was measured at 32 sites during eyes closed, eyes open, and performance of a vigilance task. RESULTS: Caffeine was found to have few and modest effects on EEG in the theta and alpha bandwidths, and no effects in the delta and beta bandwidths. Evidence was found of withdrawal, withdrawal reversal, and tolerance in relation to observed increases in theta power during task performance; withdrawal and withdrawal reversal in relation to increases in alpha power during all three behavioural conditions (eyes closed, eyes open, and task performance), and withdrawal-induced adverse effects in relation to aspects of subjective mood.

CONCLUSION: The finding of similar increases in theta power following caffeine challenge and acute caffeine withdrawal casts doubt on whether caffeine may be viewed as having direct stimulant effects. Results could suggest that change in drug state, whether in the form of acute caffeine withdrawal or challenge, may be disruptive to electrophysiological activity in the brain.

Source : Neuropsychobiology 2007 vol.56 (4), pp 197 - 207

Derbyshire, E.; Abdula, S.

For women, delayed conception and recurrent pregnant loss are just a few of the health implications associated with a caffeine-rich diet. At present there is a deficit of prospective research measuring current habitual intakes of caffeine in UK women. The aim of this study was to collect up-to-date baseline data to assess caffeine intake and knowledge in a group of UK women (aged 16-45 yr). 70 Caucasian subjects (mean age 30.4 ± 8.7 yr) were recruited from business offices within the Manchester area. Each participant completed a 3-day food diary and lifestyle questionnaire. Mean intake of caffeine was 173.95 mg/day (±128.39 mg/day). 18% of subjects exceeded caffeine guidelines and consumed 300 mg caffeine or more each day. Subjects consuming over 300 mg/day were more likely to be older (P = 0.016) and smokers (P = 0.000). Individuals given previous advice about caffeine and health, had lower intakes (P = 0.002). Many women are unaware of health perturbations associated with caffeine consumption. A diet abundant in caffeine may result in delayed conception, infertility and increased risk of osteoporosis, cardiovascular disease and cancer later in life. Such information needs to be conveyed to the public sector. Future research is also required to devise specific caffeine guidelines, particularly safe upper limits.

Source : J Human Nutr Diet 2008 vol.21 (2),  pp 159 - 164

Cavin, C.; Marin-Kuan, M.; Langouet, S.; Bezencon, C.; Guignard, G.; Verguet, C.; Piguet, D.; Holzhauser, D.; Cornaz, R.; Schilter, B.

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.

Source :  Food Chem Toxicol 2008 vol.46 (4), pp 1239 - 1248

Hamada, T.; Kotani, K.; Higashi, A.; Ikeda, J.; Tagaki, E.; Igarashi, A.; Matsubara, C.; Yoshida, T.; Sakane,
N.

A close relationship between coffee intake and certain metabolic disorders is known. Caffeine, one of coffee components, can increase energy expenditure (EE), but there are considerable individual differences in the caffeine effects on EE, and the causes have not been fully established in humans. The Arg allele in the beta(3)-adrenergic receptor gene (beta(3)-AR), a marker for obesity-related traits, may be a contributor to individual variations in EE. This study investigated the effect of the Arg allele of beta(3)- AR on caffeine-induced increases in EE. In 44 healthy young women (21 +/- 1 years), physical characteristics, blood pressure, biochemical profiles and dietary nutritional intake were measured. A caffeine-loading test was conducted at a dosage of 4 mg per body weight (kg). EE was measured using an indirect open-circuit calorimeter for a 10-min period before, and at 30 min and 60 min after the caffeine-loading test. The beta(3)-AR Trp64Arg polymorphism was detected with a PCR-restriction fragment length polymorphism method. The frequency of the Arg allele was 24%. The distribution of the Trp/Trp, Trp/Arg, and Arg/Arg genotypes was 58%, 36%, and 6%, respectively. At the baseline, subjects with the Arg/Arg genotype had a significantly lower EE level than those with the Trp/Trp or Trp/Arg genotype. After the caffeine-loading test, there were caffeine-induced increases in EE in all genotypes, but there were no differences in the levels of increase among the genotypes. These findings suggest that the genotypes of beta(3)-AR Trp64Arg polymorphism might be not associated with caffeine-induced increases in EE levels.

Source : Tohoku J Exp Med 2008 vol.214 (4), pp 365 - 370

Singh, S.; Singh, K.; Patel, S.; Patel, D. K.; Singh, C.; Nath, C.; Singh, M. P.

Epidemiological evidence revealed that cigarette smokers and coffee drinkers have lower risk of Parkinson\'s disease (PD). Nicotine inhibits monoamine oxidase activity, and induces expression of neurotrophic factors and nicotinic acetylcholinergic receptors. However, caffeine is capable of antagonizing adenosine A(2A) receptor. Toxicant responsive enzymes and vesicular monoamine transporter-2 (VMAT-2) play critical roles in chemically induced PD. Despite some known functions, the effects of nicotine and caffeine on the expression and activity of toxicant responsive genes and on VMAT¬2 are still not known. The study was therefore undertaken to investigate the effect of nicotine and caffeine on the expression and activity of toxicant responsive genes, i.e., CYP1A1, CYP2E1, GST-ya, GST-yc, GSTA4-4 and VMAT-2 in the striatum of control and MPTP-induced PD phenotype in mouse. The animals were treated intraperitoneally daily with nicotine (1 mg/kg) or caffeine (20 mg/kg) for 8 weeks, followed by 1-methyl 4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 20 mg/kg)+nicotine or caffeine for 4 weeks. MPTP significantly attenuated CYP1A1 and VMAT-2, and augmented CYP2E1, GST-ya, GST-yc and GSTA4-4 expression/activity. Nicotine or caffeine-treated animals showed significant restoration against most of the MPTP-induced alterations. The results obtained thus suggest that nicotine and caffeine modulate MPTP-induced alterations in CYP1A1, CYP2E1, GST-ya, GST-yc, GSTA4-4 and VMAT-2 expression/activity.

Source :  Brain Res 2008 vol. 1207, pp 193 - 206

Barbelivien, A.; Billy, E.; Lazarus, C.; Kelche, C.; Majchrzak, M.

This study investigated if sub-populations of rats characterized by their basal level of impulsivity (BLI) in a delayed-reinforcement task, displayed differences in the functioning of neurotransmitter systems modulating impulsive choice behavior. For this, the effects of various doses of caffeine and d¬amphetamine were investigated in three sub-populations of rats displaying pronounced differences in their impulsive choice behavior and their post-mortem serotonergic and dopaminergic functions were assessed. Caffeine and d-amphetamine reduce impulsive choice behavior only in the Medium BLI sub¬population. Dopamine utilization was similar in the three sub-populations, but serotonin utilization was lower in the prefrontal cortex of the Medium and Very high BLI sub-populations as compared to the low BLI one. These results suggest that anti-impulsive effects of caffeine and d-amphetamine are dependent on the BLI of rats and that a low serotonergic function in the prefrontal cortex may be a trait marker of impulsivity evaluated by impulsive choice behavior.

Source : Behav Brain Res 2008 vol.187 (2), pp 273 - 283

Wierzchowski, J.; Pietrzak, M.; Szelag, M.; Wroczynski, P.

We have applied fluorimetric method to monitor aldehyde dehydrogenase (ALDH*) activity in human saliva samples to study inactivation, reactivation and inhibition of the enzyme. DESIGN: Saliva samples were collected to buffer stock solution, containing various thiols, and assayed in the presence of the fluorogenic substrate 6-dimethylamino-2-naphthaldehyde and NAD(+). Fluorescence of the produced 6-dimethylamino-2-naphthalene carboxylate was used to measure the reaction rate. RESULTS: Kinetic
parameters for the highly fluorogenic substrate, 6-dimethylamino-2-naphthaldehyde were measured, with apparent K(m) of 7.9muM at pH 7.3. The apparent K(m) for NAD(+) was 1.2muM. The observed ALDH activity is unstable in the absence of thiols, but can be stabilized by 1 mM glutathione, and inactivated enzyme can be re-activated within 10min by treatment of 0.5mM DTT. Two-assay procedure was applied to measure degree of inactivation of ALDH in saliva samples. It was found that degree of ALDH inactivation in fresh samples, stabilized by glutathione, is between 0% and 90%, with average value ca. 40%. Caffeine and theophylline were shown to be moderate inhibitors of salivary ALDH.

CONCLUSIONS: Oxidation of the salivary ALDH in fresh saliva may be reliably measured using fluorimetric two-assay procedure. Preliminary statistics indicate that in most individuals this enzyme is partially inactive. Inhibition of the salivary ALDH by caffeine may have consequences for nutrition safety.

Souce :  Arch Oral Biol 2008 vol.53 (5) pp 423 - 428

Klatsky, A. L.; Koplik, S.; Kipp, H.; Friedman, G. D.

After decades of conflicting studies, the relation of coffee drinking to coronary artery disease (CAD) risk remains unresolved. Using Cox proportional-hazards models with 5 covariates, 127,212 subjects who supplied baseline data at voluntary health examinations from 1978 to 1985 were studied. Subsequently, 8,357 subjects were hospitalized for CAD. Coffee drinking was unrelated to CAD risk in 58,888 never smokers, but in ex-smokers and current baseline smokers, daily coffee intake was associated with higher CAD risk. This disparity was generally consistent in stratified subgroups. In conclusion, this relation of coffee consumption to increased CAD risk only in smokers could be explained by incomplete control for smoking, by other traits of smokers, or by an adverse biologic interaction of a coffee ingredient with smoking effect on CAD.

Source : Am J Cardiol 2008 vol. 101 (6), pp 825 - 827

Ruxton, C.-H. S.

The reputed benefits of moderate caffeine consumption include improvements in physical endurance, cognitive function, particularly alertness and vigilance, mood and perception of fatigue. In contrast, there are concerns that excessive intakes increase the risks of dehydration, anxiety, headache and sleep disturbances. In this paper, double-blind, placebo-controlled trials published over the past 15 yr are reviewed to establish what range of caffeine consumption would maximize benefits and minimize risks for cognitive function, mood, physical performance and hydration. Of the 41 human studies meeting the inclusion criteria, the majority reported benefits associated with low to moderate caffeine intakes (37.5- 450 mg per day). The available studies on hydration found that caffeine intakes up to 400 mg per day did not produce dehydration, even in subjects undergoing exercise testing. It was concluded that the range of
caffeine intake that appeared to maximize benefit and minimize risk is 38-400 mg per day, equating to 1-8 cups of tea per day, or 0.3-4 cups of brewed coffee per day. The limitations of the current evidence base are discussed.

Source :  Nutrition Bulletin 2008 vol.33 (1), pp 15 - 25

Rubach, M.; Lang, R.; Hofmann, T.; Somoza, V.

Consumption of coffee beverages has been reported to cause gastric irritation in some consumers as a result of increased gastric acid secretion. In the complex mechanisms of gastric acid secretion, the activity and expression of the H(+),K(+)-ATPase is regulated by transmitters, such as histamine, acetylcholine, gastrin, somatostatin, and their corresponding receptors. Here, we report the effect of three coffee constituents, chlorogenic acid, caffeine, and N-methyl pyridinium ions, on the expression of the histamine receptor H2, the acetylcholine receptor M3, the gastrin receptor, the somatostatin receptor, and the H(+),K(+)-ATPase. Human gastric cancer cells were exposed to chlorogenic acid, caffeine, or N-methyl pyridinium in their coffee brew-representative concentrations as well as to physiological stimulators of gastric acid secretion. Gene expression levels of receptor proteins and those of the H(+),K(+)-ATPase were measured at different time points by real-time PCR. Expression of prosecretory receptors significantly increased between one and one-half to twofold after treatment with chlorogenic acid or caffeine compared to control cells at the same time point. Chlorogenic acid and caffeine also increased the H(+),K(+)-ATPase gene expression twofold higher compared to control cells. In contrast, N-methyl pyridinium downregulated the expression of the prosecretory gastrin receptor significantly, by -27%. In conclusion, chlorogenic acid, caffeine, and N-methyl pyridinium impair the expression of gastric acid secretion-related proteins in a time-dependent manner. Future work will be aimed at the elucidation of the cooperative interplay of individual components using recombinates of single coffee constituents.

Source :  Ann N.Y. Acad Sci 2008  vol.1126, pp 310 - 314

Manduva, R.; Kett, V. L.; Banks, S. R.; Wood, J.; Reading, M.; Craig, D. Q.

We describe a novel integrated approach to the study of polymorphic transformation that includes quasi-isothermal modulated temperature differential scanning calorimetry (QI-MTDSC) and microthermal analysis (MTA), with a view to studying the thermal, kinetic and spatial characteristics of the process. Form II and I caffeine was prepared and conventional DSC and hot stage microscopy performed. The Form II to I transition at circa 413 K was associated with a change in crystal habit to needle shaped crystals. QI-MTDSC was used to measure the heat capacity of the system as a function of temperature, while MTA was able to spatially differentiate between the two polymorphs in compressed systems. We present a novel extension of the reduced temperature method whereby we apply it for the first time to linear rising temperature data corresponding to the transition; the analysis suggests a close approximation to Arrhenius behavior. We also describe a heat transfer model that allows calculation of the thermal gradients within a hermetically sealed pan for the first time. The combined approach has therefore allowed the characterization of the thermodynamics and kinetics of the transformation process as well as spatial identification of the distribution of the transformation in compressed systems.

Source : J Pharm Sci 2008 vol.97 (3), pp 1285 - 1300

Urakova, I. N.; Pozharitskaya, O. N.; Shikov, A. N.; Kosman, V. M.; Makarov, V. G.

Two chromatographic methods, high performance TLC (HPTLC) and HPLC, were developed and used for separation and quantitative determination of chlorogenic acid in green coffee bean extracts. For HPTLC, silica gel Kieselgel 60 F 254 plates with ethyl acetate/dichlormethane/formic acid/acetic acid/water (100:25:10:10:11, v/v/v/v/v) was used as a mobile phase. Densitometric determination of chlorogenic acid using HPTLC was performed at 330 nm. A gradient reverse phase HPLC method was carried out at 330 nm. All necessary validation tests for both methods were developed for their comparison. There were no statistically significant differences between HPLC and HPTLC for quantitative determination of chlorogenic acid according to a test of equality of the means.

Source : J Sep Sci 2008 vol.31 (2), pp 237 - 241

Theis, C.; Patzold, R.; Bruckner, H.

This item reports on research into the amino acid content of Kopi Luwak, which is a very expensive Indonesian coffee speciality. The research identified types and quantities of amino acids.

Source : Lebensmittelchemie 2008 vol.62  (1), pp16 (not available on line)

Kim, D.; Kim, H. M.; Yang, K. Y.; Kim, S. K.; Kim, N. J.

We investigated electronically excited states of caffeine and its 1:1 complex with water by using resonant two-photon ionization (R2PI) and UV-UV hole-burning techniques. Strong vibronic coupling between a pair of close-lying pi-pi(*) and n-pi(*) transitions is proposed to be responsible for the broad spectral feature observed. By comparing the experimental results with those of theoretical calculations, both the O-bonded and N-bonded forms were suggested to be initially produced for the 1:1 complex. The electronic transitions of the O-bonded complex were blueshifted in the R2PI spectrum. For the N-bonded complex, the excited state undergoes an ultrafast decay process, followed by dissociation on a repulsive potential energy surface, which gives rise to a characteristically anomalous cluster distribution in nanosecond experiments.

Source : J Chem Phys 2008 vol.128 (13), pp 134310

Bita, M. G.; Preda, M.

Vitis vinifera seeds are a source of natural antioxidants that might be used to prevent lipid oxidation in roasted coffee. The effects of grapeseed polyphenols on characteristic indices of coffee lipids were investigated. Peroxide value, refraction index and acidity index were determined for oils extracted from coffee and from a mixture of Vitis vinifera seeds and coffee. Coffee samples were packaged in vacuum pouches and stored for 12 months at an average room temperature of 22.5 C. Experimental values of characteristic indices of lipids extracted from both sets of samples are tabulated. The natural antioxidant decreased the number of double bonds in fatty acids, leading to reduced accumulation of oxidation products. Pyrogallol formed during roasting of grapeseeds reduced oxidation of lipids by decreasing the amount of oxygen in the coffee package. Results suggested grapeseeds might have potential use as a natural antioxidant in coffee owing to their low redox potential and health benefits.

Source : Italian Food Bever Technol 2007 (March), 47, pp 21-23

Salmona, J.; Dussert, S.; Descroix, F.; de Kochko, A.; Bertrand, B.; Joet, T.

Due to its economic importance, Coffea arabica is becoming the subject of increasing genomic research and, in particular, the genes involved in the final chemical composition of the bean and the sensorial quality of the coffee beverage. The aim of the present study was to decipher the transcriptional networks that govern the development of the C. arabica seed, a model for non-orthodox albuminous seeds of tropical origin. For this purpose, we developed a transcriptomic approach combining two techniques: targeted cDNA arrays, containing 266 selected candidate gene sequences, and real-time RT-PCR on a large subset of 111 genes. The combination of the two techniques allowed us to limit detection of false positives and to reveal the advantages of using large real-time RT-PCR screening. Multivariate analysis was conducted on both datasets and results were broadly convergent. First, principle component analysis (PCA) revealed a dramatic re-programming of the transcriptional machinery between early cell division and elongation, storage and maturation phases. Second, hierarchical clustering analysis (HCA) led to the identification of 11 distinct patterns of gene expression during seed development as well as to the detection of genes expressed at specific developmental stages that can be used as functional markers of phenological changes. In addition, this study led to the description of gene expression profiles for quality-related genes, most of them formerly uncharacterised in Coffea. Their involvement in storage compound synthesis and accumulation during endosperm development and final metabolic re-adjustments during maturation is discussed.

Source : Plant Mol Biol 2008 vol.66 (1-2), pp 105 - 124

DaMatta, F. M.; Cunha, R. L.; Antunes, W. C.; Martins, S. C.; Araujo, W. L.; Fernie, A. R.; Moraes, G. A.

Perturbations of the source-sink balances were performed in field-grown coffee (Coffea arabica) trees to investigate the possible role of carbohydrates in feedback regulation of photosynthesis. Four treatments were applied at the whole-plant level: (i) complete defruiting and maintenance of the full leaf area, (ii) the half crop load and full leaf area, (iii) the full crop load and full leaf area and (iv) the full crop load and half leaf area. Sampling and measurements were performed twice during the phase of dry matter
accumulation of fruits. Gas exchange, chlorophyll a fluorescence, carbon isotope labelling and steady¬state metabolite measurements were assessed in source leaves. The average rate of net photosynthetic rate (A) and stomatal conductance (g(s)) were larger (> 50%), and carbon isotope composition ratio was lower, in trees with a full crop load and half leaf area than in defruited trees, with individuals of the other two treatments showing intermediate values. However, differences in A seem unlikely to have been caused either by photochemical impairments or a direct end-product-mediated feedback down-regulation of photosynthesis. It is proposed that the decreased A in defruited coffee trees was independent of carbon metabolism and was rather directly related to a lower CO(2) availability coupled to lower g(s).

Source : New Phytol 2008 vol.178 (2), pp 348 - 357