Bioavailability of epicatechin and effects on nitric oxide metabolites of an apple flavanol-rich extract supplemented beverage compared to a whole apple puree: a randomized, placebo-controlled, crossover trial

SCOPE

Flavanol-rich foods are known to exert beneficial effects on cardiovascular health. The biological effects depend on bioavailability of flavanols which may be influenced by food matrix and dose ingested. We compared the bioavailability and dose-response of epicatechin from whole apple and an epicatechin-rich extract, and the effects on plasma and urinary nitric oxide (NO) metabolites.

METHODS AND RESULTS

In a randomized, placebo-controlled, crossover trial, subjects consumed drinks containing 70 and 140 mg epicatechin from an apple extract and an apple puree containing 70 mg epicatechin. Blood and urine samples were collected for 24 h post ingestion. Maximum plasma concentration, AUC(0-24 h) , absorption and urinary excretion were all significantly higher after ingestion of both epicatechin drinks compared with apple puree (p < 0.05). Time to maximum plasma concentration was significantly later for the puree compared with the drinks (p < 0.01). Epicatechin bioavailability was >2-fold higher after ingestion of the 140 mg epicatechin drink compared to the 70 mg epicatechin drink (p < 0.05). Excretion of NO metabolites was higher for all test products compared with placebo, which was significant for the high dose drink (p = 0.016).

CONCLUSIONS

Oral bioavailability of apple epicatechin increases at higher doses, is reduced by whole apple matrix and has the potential to increase NO bioavailability.

High quality RNA isolation from ployphenol-, polysaccharide- and protein-rich tissues of lentil (Lens culinaris)

Current RNA isolation methods have limitations in their ability to yield good quality and quantity of RNA from plants that have high content of phenols, polysaccharides and storage proteins. Existing methods also do not eliminate accompanying chromosomal DNA in RNA preparation that causes false positives in gene expression studies. Standard isolation technique was modified for rapid and quick extraction of RNA, and lentil tissue most appropriate to extract good quality RNA was determined. The concentration of the phenol blocker polyvinylpyrrolidone in the extraction buffer was determined, DNase I was added to eliminate chromosomal DNA and the timing of this step was optimized. RNA up to 568 μg of RNA from 1 g of tissue was isolated from four different tissues of lentil in less than half the time typically required by reported methods. The method avoids the use of toxic phenol–chloroform, hazardous guanidinium thiocyanate (GTC) and laborious CsCl ultracentrifugation. Absorbance A260/A280 ratio of 1.9 and A260/A230 ratio of 2.7 reveal RNA to be of high purity. Modified method yielded RNA that was free from contaminants and suitable for RT-PCR and cDNA library construction.

Resveratrol metabolites inhibit human metastatic colon cancer cells progression and synergize with chemotherapeutic drugs to induce cell death

SCOPE

Resveratrol (RSV) has been proposed to prevent tumor growth; nevertheless, these preventive effects are controversial since RSV pharmacokinetics studies show a low bioavailability. Recent clinical trials show that patients with colorectal cancer and receiving oral RSV have high levels of RSV conjugates in the colorectum, mainly RSV-3-O-sulfate (R3S), RSV-3-O-glucuronide, and RSV-4'-O-glucuronide. However, their potential biological activity has not yet been established. This study thus investigated in human colorectal cancer cell lines whether RSV main metabolites retain anticarcinogenic properties as their parental molecule.

METHODS AND RESULTS

Proliferation, apoptosis assays and cell cycle analysis were performed to study the effect of RSV, R3S, RSV-3-O-glucuronide, or RSV-4'-O-glucuronide alone or of a mixture of the three metabolites. R3S inhibits colon cancer cells proliferation and an accumulation of cells in S phase. Interestingly, the mixture induced a synergistic effect. This process was associated with an induction of DNA damages and apoptotic process, which allowed sensitization of colon cancer cells to the anticancer drugs.

CONCLUSION

Altogether, our data provide significant new insight into the molecular mechanism of RSV and support the notion that despite low bioavailability in vivo, RSV biological effects could be mediated by its metabolites.

Membranar effects exerted in vitro by polyphenols - quercetin, epigallocatechin gallate and curcumin - on HUVEC and Jurkat cells, relevant for diabetes mellitus

Polyphenols are largely studied for their beneficial action in various pathologies, but the correlation with their effects on cell membranes is still elusive. In the present study we assessed the effects exerted in vitro by quercetin, epigallocatechin gallate and curcumin on membrane fluidity and transmembrane potential of human umbilical vein endothelial cells and Jurkat T lymphoblasts, in experimental conditions mimicking diabetes mellitus, i.e. high glucose conditions or increased concentration of advanced glycation end products. Results showed that the investigated polyphenols had beneficial effects on cell membranes altered in diabetic conditions, by restoring transmembrane potential and by membrane "stiffening". Moreover, they limited the release of pro-inflammatory factors, like monocyte chemotactic protein-1. These effects were more obvious for cells exposed to advanced glycation end products specific for the late stages of diabetes. Apparently, the inhibitory action of polyphenols on lipid peroxidation was associated with a decrease of membrane fluidity. Concluding, our in vitro study highlighted the potential beneficial action of polyphenols mainly in the late stages of diabetes, exerted at the level of membrane fluidity and transmembrane potential, accompanied by an anti-inflammatory effect on endothelial and immune cells.

Antioxidant and antiproliferative activities of phenolics isolated from fruits of Himalayan yellow raspberry (Rubus ellipticus)

Yellow Himalayan raspberry, a wild edible fruit, was analyzed for phenolic contents, and antioxidant, antibacterial and antiproliferative activities. Phenolics were extracted using 80 % aqueous solvents containing methanol, acidic methanol, acetone and acidic acetone. Our analysis revealed that the acidic acetone extracts recovered the highest level of total phenolics (899 mg GAE/100 g FW) and flavonoids (433.5 mg CE/100 g FW). Free radical scavenging activities (DPPH, ABTS, superoxide and linoleate hydroperoxide radicals) and ferric reducing activity were highest in the acetone and acidic acetone extracts. No metal chelating or antibacterial activity was detected in any of the extracts. Acetone and methanol extracts showed potent antiproliferative activity against human cervical cancer cells (C33A) with an EC50 of inhibition at 5.04 and 4. 9 mg/ml fruit concentration respectively, while showing no cytotoxicity to normal PBMCs cells. Therefore, the present study concluded that the yellow Himalayan raspberry is a potent source of phytochemicals having super antioxidant and potent antiproliferative activities.

Antiglycation, antioxidant and toxicological potential of polyphenol extracts of alligator pepper, ginger and nutmeg from Nigeria

OBJECTIVE

To evaluate the antioxidant and antiglycation potential of polyphenols from three spices; alligator pepper, ginger and nutmeg.

METHODS

Polyphenol extracts of these spices were subjected to brine-shrimp lethality assay, phytotoxicity test, DPPH and superoxide anion radical scavenging as well as BSA-glucose antiglycation assay.

RESULTS

Results obtained showed that polyphenol extract of ginger has the highest antioxidant potential with IC50 0.075 and 0.070 mg/mL for DPPH and superoxide anion radical scavenging assay while alligator pepper displayed highest antiglycation activity with IC50 0.125 mg/mL. However, nutmeg extract exhibited weakest cytotoxic and phytotoxic potential with LD50 4359.70 and 1490 µg/mL respectively.

CONCLUSIONS

It can be concluded that the polyphenol extracts of alligator pepper, ginger and nutmeg displayed good antioxidant as well as antiglycation potential and are safe for consumption.

SIRT1 as a therapeutic target in inflammaging of the pulmonary disease

OBJECTIVE

Chronic inflammation and cellular senescence are intertwined in the pathogenesis of premature aging, which is considered as an important contributing factor in driving chronic obstructive pulmonary disease (COPD). Sirtuin1 (SIRT1), a nicotinamide adenine dinucleotide (NAD(+))-dependent protein/histone deacetylase, regulates inflammation, senescence/aging, stress resistance, and deoxyribonucleic acid (DNA) damage repair via deacetylating intracellular signaling molecules and chromatin histones. The present review describes the mechanism and regulation of SIRT1 by environmental agents/oxidants/reactive aldehydes and pro-inflammatory stimuli in lung inflammation and aging. The role of dietary polyphenols in regulation of SIRT1 in inflammaging is also discussed.

METHODS

Analysis of current research findings on the mechanism of inflammation and senescence/aging (i.e., inflammaging) and their regulation by SIRT1 in premature aging of the lung.

RESULTS

COPD is a disease of the lung inflammaging, which is associated with the DNA damage response, transcription activation and chromatin modifications. SIRT1 regulates inflammaging via regulating forkhead box class O 3, p53, nuclear factor kappa B, histones and various proteins involved in DNA damage and repair. Polyphenols and its analogs have been shown to activate SIRT1 although they have anti-inflammatory and antioxidant properties.

CONCLUSIONS

Targeting lung inflammation and cellular senescence as well as premature lung aging using pharmacological SIRT1 activators or polyphenols would be a promising therapeutic intervention for COPD/emphysema.

Antimicrobial activity of Carpolobia lutea extracts and fractions

Carpolobia lutea (G. Don) (Polygalaceae) is a tropical medicinal plant putative in traditional medicines against gonorrhea, gingivitis, infertility, antiulcer and malaria. The present study evaluated the antimicrobial, antifungal and antihelicobacter effects of extracts C. lutea leaf, stem and root. The extracts were examined using the disc-diffusion and Microplates of 96 wells containing Muller-Hinton methods against some bacterial strains: Eschericia coli (ATCC 25922), E. coli (ATCC10418), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Staphyllococus aureus (ATCC 6571), Enterococcus faecalis (ATCC 29212) and Bacillus subtilis (NCTC 8853) and four clinical isolates: one fungi (Candida albican) and three bacteria (Salmonella, Sheigella and staphylococcus aureus). The Gram-positive bacteria: Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Bacillus subtilis (ATCC 19659) and the Gram-negative bacteria: Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Cândida albicans (ATCC 18804) and Helicobacter pylori (ATCC 43504). Some of these extracts were found to be active against some tested strains but activity against H. pylori was >1000mg/ml and good fungistatic activity against C. albican. The MIC against C. albican is in the order n-HF > CHF > ETF= EAF.The order of potency of fraction was the ethanol root > n-HF leaf > ethanol fraction stem > chloroform fraction leaf = ethyl acetate fraction leaf. Polyphenols were demonstrated in ethanol fraction, ethyl acetate fraction, crude ethyl acetate extract and ethanol extract, respectively. These polyphenols isolated may partly explain and support the use of C. lutea for the treatment of infectious diseases in traditional Ibibio medicine of Nigeria.

Role of nutraceuticals in human health

Nutraceutical is the hybrid of 'nutrition' and 'pharmaceutical'. Nutraceuticals, in broad, are food or part of food playing a significant role in modifying and maintaining normal physiological function that maintains healthy human beings. The principal reasons for the growth of the nutraceutical market worldwide are the current population and the health trends. The food products used as nutraceuticals can be categorized as dietary fibre, prebiotics, probiotics, polyunsaturated fatty acids, antioxidants and other different types of herbal/ natural foods. These nutraceuticals help in combating some of the major health problems of the century such as obesity, cardiovascular diseases, cancer, osteoporosis, arthritis, diabetes, cholesterol etc. In whole, 'nutraceutical' has lead to the new era of medicine and health, in which the food industry has become a research oriented sector.

Antioxidant, total phenol and flavonoid contents of two pedicularis L. Species from eastern azerbaijan, iran

INTRODUCTION

Pedicularis sibthorpii and P. wilhelmsiana are endemic species mainly found in North-West of Iran. Plants of genus Pedicularis produce some important poly-phenols and flavonoids. In the present work, total phenol and flavonoid contents of the mentioned species as well as their antioxidant capacity have been evaluated.

METHODS

Methanol extract of samples was fractionated by SPE method using an ODS cartridge and their (1)H-NMR spectra were recorded. Total phenols and flavonoids of methanol extracts were determined using Folin- Ciocalteu and aluminum chloride methods. For determining antioxidant activity of the extracts and fractions, bleaching of purple color methanol solu-tion of 1, 1-diphenylpycryl hydrazyl (DPPH) was measured by spectrophotometric assay.

RESULTS

Total phenols of Pedicularis sibthorpii and P. wilhelmsiana were in the range of 8-30 mg g(-1) and 9-20 mg g(-1), respectively. The 40% and 60% fractions of P. sibthorpii and the 20%, 40% and 60% fractions of P. wilhelmsiana showed higher amounts of phenolic compounds. The total flavonoid contents of P. sibthorpii and P. wilhelmsiana were in the range of 0-215 mg g(-1) and 0-177 mg g(-1), respectively, whereas the 40% and 60% fractions showed higher flavonoid amounts. Antioxidant activity of P. sibthorpii and P. wil-helmsiana were in the range of 0.01-0.7 mg mL(-1) and 0.01-1.02 mg mL(-1). In the same manner, the 20% and 40% fractions of P. sibthorpii and the 40% and 60% fractions of P. wilhelmsiana had lower RC50 than that of other fractions.

CONCLUSION

Fractions with lower RC50 had higher contents of phenolic and flavonoid compounds. The results of NMR spectra were parallel with these findings and show that it is worth to do phytochemi-cal studies on P. sibthorpii and P. wilhelmsiana.

Phytochemical study of polyphenols in Perilla Frutescens as an antioxidant

Perilla frutescens is an annual herb of the mint family native to East Asia. Polyphenols present in perilla have various structural varieties with large diversity of biological activities. It is direct influence the quality of perilla plant and their potential functions. Some of these products have been studied and proven to be effective source of phenolic antioxidants. The aqueous extract contains phenolic compounds such as phenolic acids, cinnamic acid derivatives, flavonoids, and lignans. Gallic acid, hydroxytyrosol (3,4-DHPEA), cinnamic acid derivatives (coumaroyl tartaric acid, caffeic acid and rosmarinic acid), flavonoids, scutellarein 7-O-diglucuronide, luteolin 7-O-diglucuronide, apigenin 7-O-diglucuronide, luteolin 7-O-glucuronide, and scutellarein 7-O-glucuronide), and anthocyanins (mainly cis-shisonin, shisonin, malonylshisonin and cyanidin 3-O-(E)-caffeoylglucoside-5-O-malonylglucoside) are present.

Plum pomaces as a potential source of dietary fibre: composition and antioxidant properties

Plums because of their composition, especially of dietary fibre, sorbitol and polyphenols content, have positive influence on human health. Generally growing interest in cloudy juices production due to their prevalence compared to clear ones resulted in the appearance of plum cloudy juices on the market. Cloudy plum juice may be the attractive plum product, however during juice production some pomace appears, which is discarded or used for feeding animals most of all. This by product might be a source of valuable health-promoting compounds. The aim of this work was to characterize the composition and properties of pomaces of three cultivars obtained in pilot plant scale. The influence of drying parameters and cultivar on bioactive components and antioxidant activity were measured. Plum pomaces were characterized by 38-49% of total dietary fibre in d. m., with the share of soluble fraction from 7 to 13%. Energy value was from 202 to 240 kcal 100 g(-1) d.m. Antioxidant activity was from 10 to 17.4 mikroM TEAC g(-1) d.m. Cultivar and technology of drying had significant influence on polyphenols content of investigated plum pomaces. Considering their health-beneficial components: dietary fiber and polyphenols, plum pomaces can be used for production of dietary fiber preparations.

Differential partitioning of antioxidants, including hydroxytyrosol, in human plasma and LDL: implications for their antioxidant activity in vivo

In vivo studies of LDL oxidation following consumption of natural phenolic compounds have yielded mixed results. It is reported that the amphiphilic hydroxytyrosol, after addition to human plasma, does not accumulate in LDL but protects plasma lipids, which are extracted together with hydroxytyrosol, from chemically-induced oxidation. Thus, a novel methodology was proposed, which does not rely on LDL separation and subsequent oxidation but is based on the oxidation of total lipids - simultaneously extracted from plasma with antioxidants - to evaluate the effects of micronutrients that do not partition into LDL, after in vivo supplementation.

Evaluation of nutritional composition and antioxidant activity of Borage (Echium amoenum) and Valerian (Valerian officinalis)

The nutritional composition and antioxidant activity (in aqueose and solvent extracts) of two medicinal plants of Iranian origin Borage (Echium amoenum) and Valerian (Valerian officinalis) used as tea were determined. Samples were analyzed for antioxidant components viz. polyphenols, vitamin C, β carotene, flavonoids, anthocyanins and tannins. Antioxidant assays such as free radical scavenging activity, reducing power and total antioxidant activity were carried out for ethanol, methanol, acetone, 80% methanol and 80% ethanolic extracts. In borage highest and least activity was observed in water and acetone extract respectively in all assays. In Valerian, 80% methanolic extract showed highest activity in reducing power and free radical scavenging activity assay. Total polyphenols in borage and valerian were 1,220 and 500 mg in ethanolic extracts and 25 and 130 mg in acetonic extracts respectively. Total carotenoids and vitamin C contents were 31.6 and 133.69 mg and 51.2 and 44.87 mg for borage and valerian respectively. Highest amount of tannins were extracted in 80% methanolic extract. It can be concluded that borage and valerian exhibited antioxidant activity in all extracts. The antioxidant activity could be attributed to their polyphenol and tannin and flavonoids contents. In all assays borage showed higher activity than valerian.

Nutritional and functional properties of Vicia faba protein isolates and related fractions

The goal of this research was the characterisation of Vicia faba (broadbean) protein isolates and related fractions in order to determine whether this grain legume could be used for production of high quality protein products and other fractions rich in functional components. Alkaline extraction of the defatted seed flour, followed by precipitation at the isoelectric pH, yielded a 92% protein isolate with a high oil absorption capacity. The contents of the favism-inducing glycosides, vicine and convicine, in the isolate were reduced by more than 99% as compared to the original flour, although the amino acid composition was similar to that of the flour. Some of the by-products of protein isolate production may also be of interest from a nutritional and functional point of view. Thus, the oil resulting from hexane extraction of the flour is rich in unsaturated fatty acids, and polyphenols (resulting from extraction of the defatted flour with acetone) showed a high ABTS radical-scavenging activity. In addition, the solid residue (resulting from protein solubilisation) was high in fibre and showed good water absorption. These results show good nutritional and functional properties in V. faba protein isolates and related fractions, which may favour the revalorisation of this traditional bean crop.

Hill coefficients of dietary polyphenolic enzyme inhibitiors: can beneficial health effects of dietary polyphenols be explained by allosteric enzyme denaturing?

Inspired by a recent article by Prinz, suggesting that Hill coefficients, obtained from four parameter logistic fits to dose-response curves, represent a parameter allowing distinction between a general allosteric denaturing process and real single site enzyme inhibition, Hill coefficients of a number of selected dietary polyphenol enzyme inhibitions were compiled from the available literature. From available literature data, it is apparent that the majority of polyphenol enzyme interactions reported lead to enzyme inhibition via allosteric denaturing rather than single site inhibition as judged by their reported Hill coefficients. The results of these searches are presented and their implications discussed leading to the suggestion of a novel hypothesis for polyphenol biological activity termed the insect swarm hypothesis.

Antiproliferation and redifferentiation in thyroid cancer cell lines by polyphenol phytochemicals

Thyroid carcinogenesis is accompanied by loss of thyroid-specific functions and refractory to radioiodine and thyroid stimulating hormone (TSH) suppression therapy. Redifferentiating agents have been shown to inhibit tumor growth and improve the response to conventional therapy. Polyphenol phytochemicals (PPs) in fruits and vegetables have been reported to inhibit cancer initiation, promotion, progression and induce redifferentiation in selected types. In this study we examined PPs induce redifferentiation in thyroid cancer cell lines. We investigated the effects of genistein, resveratrol, quercetin, kaempferol, and resorcinol on the F9 embryonal carcinoma cell differentiation model. The thyroid cancer cell lines, TPC-1, FTC-133, NPA, FRO, and ARO, displayed growth inhibition in response to genistein, resveratrol, quercetin. We further demonstrated that genistein decreased the dedifferention marker CD97 in NPA cells and resveratrol decreased CD97 in FTC-133, NPA, FRO cells and quercetin decreased CD97 in all cell lines. We observed increased expression of differentiation marker NIS in FTC-133 cells in response to genistein, and resveratrol but no change in NPA, FRO, ARO cells. Quercetin increased or induced NIS in FTC-133, NPA, FRO cells. These findings suggest that PPs may provide a useful therapeutic intervention in thyroid cancer redifferentiation therapy.

Separation of polyphenols using porous polyamide resin and assessment of mechanism of retention

A porous polyamide resin is shown to possess hydrogen bond acceptor properties suitable for the separation of polyphenolic solutes such as phenolic acids, flavonols and flavonoids. The separation is achieved in the presence of solvent mixtures of acetic acid and ethanol. The extent of hydrogen bond adsorption is reviewed based on data obtained from the elution behaviour of a variety of simple polyphenolic solutes. Polyamide adsorption chromatography was applied for the purification of resveratrol and polydatin from Polygonum cuspidatum Sieb. & Zucc.

Influence of sonication treatments and extraction solvents on the phenolics and antioxidants in star fruits

The present study was conducted to examine the effects of sonication treatments (time intervals of 0, 15, 30, 45 and 60 min.) on phenolics and other antioxidant compounds in starfruits extracted in methanol and water. Overall, methanolic extracts exhibited significantly higher extractability, percentage inhibition of DPPH radicals, ferric reducing antioxidant property (FRAP) value, antioxidant capacity, flavonoids, total phenolics and tannins (p < 0.05) compared to control (0 min) and aqueous extracts. Methanolic extract obtained after 30 min of sonication proved to be the best treatment with regard to various parameters evaluated. Results of the present study clearly indicated sonication treatments to be effective in enhancing the antioxidant compounds in starfruit extracts and could be further explored for commercial purposes to benefit the consumers.

Effect of spray drying and storage on the stability of bayberry polyphenols

Bayberry juice was spray dried with maltodextrin (DE 10) as a carrier and then stored under different temperature and water activities (aw). The retention of the total phenolic content (TPC) and total anthocaynins (ACN) during the drying process were about 96% and 94%, respectively, suggesting spray drying was a satisfactory technique for drying heat sensitive polyphenols. Under an aw of 0.11-0.44, the TPC and ACN in bayberry powders decreased by about 6-8% and 7-27%, respectively, after 6months storage at 4°C; at 25°C for the same storage period the decreases were between 6-9% and 9-37%, respectively, while at 40°C the decreases were in the range 7-37% and 9-94%. The anthocyanin component was more readily degraded relative to other phenolic compounds. The results suggest that bayberry powder should be stored at less than 25°C and aw of 0.33, on account of greater polyphenol stability under such conditions.

Comparative study of polyphenols and caffeine in different coffee varieties affected by the degree of roasting

The bioactive composition of coffee, as one of the most popular beverages in the world, has attracted interest as a potential source of beneficial bioactive compounds, especially polyphenols and caffeine. Since the content of these compounds is affected by the processing conditions, the objective of this study was to determine the content of polyphenolic compounds and caffeine in four different coffee varieties: Minas and Cioccolatato (Coffea arabica), and Cherry and Vietnam (Coffea canephora syn. Coffea robusta), roasted by three varying degrees (light, medium and dark). The content of the polyphenolic compounds and the antioxidant capacity of coffees were determined using UV/Vis spectrophotometric methods, while the content of chlorogenic acid derivatives was determined using HPLC analysis. The caffeine content was determined by means of two spectrophotometric methods, as well as HPLC analysis. Additionally, raw caffeine was also obtained by an isolation procedure with chloroform. Cherry coffee, a variety of C. canephora exhibited the highest overall content of total phenols (42.37mg GAE/g), followed by Minas coffee, while Cioccolatato contained the lowest TPC (33.12mg GAE/g). Cherry coffee also exhibited the highest content of individual classes of polyphenols (flavan-3-ols, procyanidins and tannins), while the highest content of chlorogenic acid (CQA) derivatives was determined in Minas and Cioccolatato coffees (C. arabica). The highest content of total and individual polyphenolic compounds was determined in coffees roasted in both light and medium roasting conditions, which was also observed for the content of CQA derivatives and antioxidant capacity of roasted coffees. The highest caffeine content in the coffee samples was determined by employing the HPLC analysis (0.06-2.55%). Light roasted Cherry coffee contained the highest overall content of caffeine among all coffees, which exhibited a decrease with intensified roasting.

Polyphenolic profiles detected in the ripe berries of Vitis vinifera germplasm

Polyphenolic profiles in the berry samples of 344 European grape (Vitis vinifera) cultivars were evaluated for two consecutive years. These cultivars represent a diverse collection of V. vinifera germplasm maintained at the USDA-Agricultural Research Service Vitis Clonal Repository in Davis of California, USA. A total of 36 polyphenolic compounds, including 16 anthocyanins, 6 flavonols, 6 flavanols, 6 hydroxycinnamic acids and 2 hydroxybenzoic acids, were identified via HPLC-MS and quantified by HPLC-DAD. The mean contents for anthocyanins, flavanols, flavonols, hydroxycinnamic acids and hydroxybenzoic acids were 0.946 (coloured cultivars), 0.147, 0.043, 0.195 and 0.016mgg(-1) FW, respectively. On average, wine grapes had higher concentrations than had table grapes for all of these compounds except hydroxycinnamic acids. Berry colours affected the total contents of anthocyanins, but not others. Positive correlations (0.151-0.535) were found among these groups of compounds. As expected, these groups of compounds were all negatively correlated with berry weight.

Lack of toxicological effect through mutagenicity test of polyphenol extracts from peanut shells

The toxicological effect of polyphenols extracted from peanut shells was investigated in animal models. The safety data were needed to proceed with further clinical trials. The oral LD50 of peanut shells polyphenols was determined to be higher than 15,000mg/kg body weight. We also carried out a sperm abnormality test, a chromosomal aberration test and a micronucleus test in rats. The peanut shell polyphenols did not cause any abnormalities in the system. Furthermore, the administration of peanut shell polyphenols did not significantly alter changes in body weight or clinical signs. These results strongly indicated that peanut shell polyphenols did not induce mutagenicity. The results of this study suggested a lack of toxicological effect and supported the further use of polyphenol-rich extracts from peanut shells as a potential natural antioxidant.

The free radical scavenging and antioxidant activities of pod and seed extract of Clitoria fairchildiana (Howard)- an underutilized legume

We evaluated the phenolic content and antioxidant capacities of pod and seed extracts (in methanol, ethanol, and water) of an underutilized legume, Clitoria fairchildiana (Howard). The antioxidant capacity of the extracts was determined using the ferric reducing antioxidant potential assay, and the free radical-scavenging capacity was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical-scavenging and ABTS assays. In addition, the total flavonoids, flavonols, and tannin contents were also determined. Overall, the methanol extracts of the pod contained high concentration of phenolics and showed high antioxidant capacities compared to seed extracts. In addition, a positive correlation was found between total phenol and tannin versus antioxidant capacity. Results of the present study indicate pods and seeds of C. fairchildiana to possess rich amount of natural antioxidants, and can be further explored for their possible use as a natural additive in food or in pharmaceutical industries.

Valorisation of grape pomace by the extraction of phenolic antioxidants: Application of high voltage electrical discharges

The aim of this study was to optimise the electrically assisted extraction in order to obtain grape pomace extracts with high polyphenols content, which would be potentially interesting for applications as natural antioxidants. High voltage electrical discharges (HVED) were applied for intensification of the extraction. The effects of the energy input, the electrodes distance gap and the liquid-to-solid ratio were studied. Diffusion was then carried out in different mixtures of water and ethanol for one hour at 20, 30, 40 and 60°C. The most efficient extraction was (i) an HVED pre-treatment at 80kJ/kg with an electrodes distance of 5mm in a liquid-to-solid ratio of 5 followed by (ii) a diffusion with 30% ethanol in water at 60°C for 30min. The highest total polyphenols content reached 2.8±0.4gGAE/100gDM with a corresponding antioxidant activity of 66.8±3.1gTEAC/kgDM. The polyphenols extraction rate increased with temperature in accordance to an Arrhenius type of relationship: activation energy of 21.5±1.1kJ/mol for HVED treated systems against 0.5±0.2kJ/mol for untreated ones.

Effect of winemaking treatment and wine aging on phenolic content in Vranec wines

Phenolic compounds and colour stability of red wines produced from Vranec Vitis vinifera L. grape variety were investigated by means of different maceration times (3, 6 and 10 days), two doses of SO2 (30 and 70 mg/L SO2), two yeasts for fermentation (Vinalco and Levuline), temperature of storage and time of aging (3, 6 and 16 months). In general, maceration time influenced the phenolics extraction from the grapes into the wine. Highest concentrations of phenolic components were observed in the wines produced with 6 days of maceration, except for the flavan-3-ols which were present in highest amounts in the wines macerated for 10 days. Higher doses of SO2 increased the extraction of polyphenols, preventing the wines from oxidation, while the effect of yeast on phenolics extraction was not significant. Wine aging affected the phenolic content of wines produced with 3 days of maceration and caused intensive decrease of anthocyanins during the storage period. Wines aged at higher temperature showed lower anthocyanin levels and less intense coloration. Principal component analysis revealed that separation of the wines was performed according to the hue value in correlation with the maceration time and time of wine aging.

Neuroprotective properties of Spanish red wine and its isolated polyphenols on astrocytes

The neuroprotective effect of Merlot red wine and its isolated polyphenols was evaluated in an oxidative stress model induced by Fenton reaction and hydrogen peroxide in the human astrocytoma U373 MG cell line. Compared with cells treated only with oxidative stress inductors, the pre-incubation with Merlot red wine for 24h caused a significant increase in cell viability for all concentrations assayed. The most abundant polyphenols found in Merlot red wine were the flavonoids catechin (37.8mg/l), epicatechin (52.3mg/l), quercetin (5.89mg/l) and procyanidins (15.2mg/l), the hydroxybenzoic acid gallic acid (16.7mg/l), and the phenolic alcohol tyrosol (31.4mg/l). The potential protective role of these polyphenols when isolated was then assessed in treated Fenton reaction U373 MG cells. Polyphenols decreased reactive oxygen species generation and increased the activity and the protein expression of the antioxidant enzymes catalase, superoxide dismutase, glutathione reductase and glutathione peroxidase. Of the polyphenols, quercetin and procyanidins showed the highest neuroprotective effect.

Comparative assessment of tea quality by various analytical and sensory methods with emphasis on tea polyphenols

Attempts were made to evolve an efficient technique for quality assessment of tea (Camellia sinensis) using a tyrosinase based biosensor to detect polyphenols (PP). Tyrosinase catalyzes the polymerization of PP to form theaflavins (Tf) and thearubigins (Tr) contributing to the colour and astringency of tea, which determine tea quality. Variation in biosensor response of tea infusions gave an indication of differential amount of Tf and Tr. A comparative study of quality attributes of 8 varieties of commercially available brands of tea (A-H) was done using biosensor and results were compared with conventional techniques such as spectrophotometry, high performance liquid chromatography (HPLC), Commission Internationale de I'Eclairage (CIE) system and sensory evaluation. Considerable correlation was observed among the biosensor, sensory and spectrophotometric evaluation of tea samples. Sample A showed high Tf content and also showed a relative high biosensor response whereas sample G showed relatively poor response. Application of biosensors would serve as a basis for the evaluation of market value of tea in the near future.

Total phenolics, flavonoids, anthocyanins and antioxidant activity following simulated gastro-intestinal digestion and dialysis of apple varieties: Bioaccessibility and potential uptake

In the present study, an in vitro model simulating gastrointestinal (GI) digestion, including dialysability, was adapted to assess free soluble polyphenols from apples (four varieties). Results indicated that polyphenol release was mainly achieved during the gastric phase (ca. 65% of phenolics and flavonoids), with a slight further release (<10%) during intestinal digestion. Anthocyanins present after the gastric phase (1.04-1.14mg/100g) were not detectable following intestinal digestion. Dialysis experiments employing a semipermeable cellulose membrane, presenting a simplified model of the epithelial barrier, showed that free soluble dialysable polyphenols and flavonoids were 55% and 44% of native concentrations, respectively, being approximately 20% and 30% lower than that of the GI digesta. Similar results were found for the antioxidant capacity of dialysable antioxidants, being 57% and 46% lower compared to total antioxidants in fresh apples (FRAP and ABTS test, respectively). It is suggested that some polyphenols are bound to macromolecular compounds that are non-dialysable, that the presented method allowed the study of free soluble polyphenols available for further uptake, and that both chemical extraction and concentrations in final digesta would overestimate polyphenol availability.

Enzymatic treatment to improve the quality of black tea extracts

Enzymatic extraction was investigated to improve the quality of black tea extracts with pretreatment of pectinase and tannase independently, successively and simultaneously. Pectinase improved the extractable-solids-yield (ESY) up to 11.5%, without much of an improvement in polyphenols recovery, while tannase pre-treatment showed a significant improvement in polyphenols recovery (14.3%) along with an 11.1% improvement in ESY. Among the four treatments, tannase-alone treatment showed the maximum improvement in tea quality, with higher polyphenols-in-extracted solids. Treatments involving tannase resulted in the significant release of gallic acid, due to its hydrolytic activity, leading to greater solubility besides favourably improving TF/TR ratio. The results suggested that employing a single enzyme, tannase, for the pre-treatment of black tea is desirable. Enzymatic extraction may be preferred over enzymatic clarification as it not only displayed reduction in tea cream and turbidity but also improved the recovery of polyphenols and ESY in the extract, as well as maintaining a good balance of tea quality.

Effect of pasteurization temperature on quality of aonla juice during storage

A study was carried out to detect the changes in colour and quality attributes of aonla juice during storage after pasteurization at different temperatures. After extracting juice from aonla cv. Chakaiya, it was pasteurized at five different temperatures and preserved with 500 ppm SO2 in PET bottles under ambient conditions. Juice was periodically analysed for colour and chemical characters up to 9 months of storage. Though the contents of ascorbic acid and polyphenols in juice decreased with increase in storage period, the effect of pasteurization temperature was not significant. High degree of browning was observed in juice heated at higher temperatures (90 and 95 °C) as compared to lower temperatures (75 and 80 °C) throughout the storage period as indicated by increase in NEB values. The degree of browning was further confirmed by higher negative numerical values of whiteness index in Hunter's scale for intensity of colour. HPLC data indicated that content of gallic acid in juice decreased initially but increased sharply as the storage period prolonged. Higher amount of gallic acid was detected after 9 months of storage in juice pasteurized at 95 °C than in juice heated at 75 °C. The contents of kaempferol and caffeic acid decreased throughout the storage period irrespective of pasteurization temperature. Though least browning was observed in juice pasteurized at 75 °C, but microbial growth was observed after 9 months of storage. Hence, pasteurization temperature of 80 °C was found optimum for preservation of aonla juice under ambient conditions.

Antinociceptive study of extracts of Platanus orientalis leaves in mice

Platanus orientalis L. (Platanaceae) is a medicinal tree used in Iranian folklore and traditional medicine as a pain and inflammation reliever. In this study, the polyphenolic and total extract of P. orientalis leaves were prepared and their antinociceptive effects were studied in mice using the acetic acid-induced writhing, formalin and light tail flick tests. Both hydroalcoholic and polyphenolic extracts of P. orientalis at a dose of 2 g/kg significantly (P<0.05) reduced acetic acid-induced abdominal writhes. These extracts were also effective in suppression of formalin-induced pain behavior but they did not show any significant analgesia in light tail flick test. It is concluded that P. orientalis extracts have moderate analgesic effect and further studies are needed to elucidate the mechanism and active constituents.

Effects of apple consumption on lipid profile of hyperlipidemic and overweight men

OBJECTIVES

Fruits and vegetables may be beneficial on lipid profile of hyperlipidemic subjects. The present study was aimed to verify the effect of golden delicious apple on Lipid Profile in hyperlipidemic and overweight men.

METHODS

Forty six hyperlipidemic and overweight men were randomly divided into two groups. Intervention group received 300g golden delicious apple per day for 8 weeks. Control group had the regular dietary regimen for the same period of time. Blood samples were analyzed for serum triglycerides (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), very low density lipoprotein-cholesterol (VLDL), apolipoprotein B (Apo B), lipoprotein a (Lp a) and LDL/HDL ratio at baseline and after intervention.

RESULTS

Total polyphenols and fibers were 485 mg/kg and 4.03 g/100g in fresh apple respectively. After 8 weeks, significant statistical differences were observed considering the TG and VLDL levels between two groups, but no significant differences were observed regarding TC, LDL-C, HDL-C, Apo (B), Lp (a) and LDL/HDL ratio.

CONCLUSIONS

Consumption of Golden delicious apple may be increased serum TG and VLDL in hyperlipidemic and overweight men. We need more studies to assay the effect of apple consumption on serum TC, LDL-C, HDL-C, Apo (B), Lp (a) and LDL/HDL ratio.

A critical review of methods for characterisation of polyphenolic compounds in fruits and vegetables

Phenolic compounds, ubiquitous in plants, are of considerable interest and have received more and more attention in recent years due to their bioactive functions. Polyphenols are amongst the most desirable phytochemicals due to their antioxidant activity. These components are known as secondary plant metabolites and possess also antimicrobial, antiviral and anti-inflammatory properties along with their high antioxidant capacity. Many efforts have been made to provide a highly sensitive and selective analytical method for the determination and characterisation of polyphenols. The aim of this paper is to provide information on the most recent developments in the chemical investigation of polyphenols emphasising the extraction, separation and analysis of these compounds by chromatographic and spectral techniques.

The influence of roasting, pasteurisation, and storage on the polyphenol content and antioxidant capacity of California almond skins

Polyphenols and antioxidant activity of skins from California almonds subjected to roasting, pasteurisation, and storage were determined by LC-MS quantification, total phenols (TP), and ferric reducing antioxidant power (FRAP). Pasteurisation did not significantly change TP, FRAP, or flavonoids and phenolic acids (FP). Roasted almonds had 26% less TP and 34% less FRAP than raw, but equivalent FP (n = 12). Storing almonds at 4 and 23 °C for 15 mo resulted in gradual increases in FP, up to 177% and 200%, respectively (n = 13). At 4 °C and 15 mo, polyphenols increased 18-fold for p-hydroxybenzoic acid, whilst others were 45-200% higher compared to baseline values. Isorhamnetin-3-O-rutinoside accounted for 48% of the increase in FP. After 15 mo, FRAP and TP increased to 200% and 190% of initial values. Accelerated ageing of whole almonds increased FP content by 10% after 3 days, but TP and FRAP values were not significantly different from baseline to day 10. Thus, in almond skins, roasting decreases TP and FRAP but not FP, whilst storage for up to 15 mo doubles FP.

Anti-inflammatory effects of Mangifera indica L. extract in a model of colitis

AIM: To investigate the effect of aqueous extract from Mangifera indica L. (MIE) on dextran sulfate sodium (DSS)-induced colitis in rats.

METHODS: MIE (150 mg/kg) was administered in two different protocols: (1) rectally, over 7 d at the same time as DSS administration; and (2) once daily over 14 d (by oral gavage, 7 d before starting DSS, and rectally for 7 d during DSS administration). General observations of clinical signs were performed. Anti-inflammatory activity of MIE was assessed by myeloperoxidase (MPO) activity. Colonic lipid peroxidation was determined by measuring the levels of thiobarbituric acid reactive substances (TBARS). Reduced glutathione (GSH) levels, expression of inflammatory related mediators [inducible isoforms of nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, respectively] and cytokines [tumor necrosis factor (TNF)-α and TNF receptors 1 and 2] in colonic tissue were also assessed. Interleukin (IL)-6 and TNF-α serum levels were also measured.

RESULTS: The results demonstrated that MIE has anti-inflammatory properties by improvement of clinical signs, reduction of ulceration and reduced MPO activity when administered before DSS. In addition, administration of MIE for 14 d resulted in an increase in GSH and reduction of TBARS levels and iNOS, COX-2, TNF-α and TNF R-2 expression in colonic tissue, and a decrease in IL-6 and TNF-α serum levels.

CONCLUSION: MIE has anti-inflammatory activity in a DSS-induced rat colitis model and preventive administration (prior to DSS) seems to be a more effective protocol.

Polyphenol content and antioxidant activity of California almonds depend on cultivar and harvest year

The polyphenol content and antioxidant activity of Nonpareil, Carmel, Butte, Sonora, Fritz, Mission, and Monterey almond cultivars harvested over three seasons in California were examined. LC-MS was employed to quantify 16 flavonoids and two phenolic acids in acidified methanol extracts of almond skins. The 3-year mean polyphenol content of cultivars ranged from 4.0 to 10.7 mg/100 g almonds. Isorhamnetin-3-O-rutinoside was the most abundant flavonoid, present at 28-49% of total polyphenols among cultivars. Almonds from 2006 and 2007 had 13% fewer polyphenols than 2005, but FRAP and total phenols were comparable. Cultivar, but not season, had a differential impact on individual polyphenol synthesis. Using the results of polyphenol, total phenol, and FRAP, multivariate analysis distinguished harvest years and most cultivars with 80% confidence. Flavonoid content and antioxidant activity of almonds may be more dependent on cultivar than on seasonal differences.

Chocolate: (un)healthy source of polyphenols?

There is recent epidemiological evidence that chocolate consumption may improve vascular health. Furthermore, several small-scale human intervention studies indicate that habitual chocolate intake enhances the production of vasodilative nitric oxide and may lower blood pressure. It is hypothesized that potential beneficial effects of chocolate on vascular health are at least partly mediated by cocoa polyphenols including procyanidins. Based on cell culture studies, molecular targets of chocolate polyphenols are endothelial nitric oxide synthetase as well as arginase. However, human bioavailability studies suggest that the plasma concentrations of cocoa polyphenols are manifold lower than those concentrations used in cultured cells in vitro. The experimental evidence for beneficial vascular effects of chocolate in human interventions studies is yet not fully convincing. Some human intervention studies on chocolate and its polyphenols lack a stringent study design. They are sometimes underpowered and not always placebo controlled. Dietary chocolate intake in many of these human studies was up to 100 g per day. Since chocolate is a rich source of sugar and saturated fat, it is questionable whether chocolate could be recommended as part of a nutrition strategy to promote vascular health.

The potential role of honey and its polyphenols in preventing heart diseases: a review

Honey is rich in phenolic compounds, which act as natural antioxidants and are becoming increasingly popular because of their potential role in contributing to human health. A wide range of phenolic constituents is present in honey like quercetin, caffeic acid phenethyl ester (CAPE), acacetin, kaempferol, galangin which have promising effect in the treatment of cardiovascular diseases. Many epidemiological studies have shown that regular intake of phenolic compounds is associated with reduced risk of heart diseases. In coronary heart disease, the protective effects of phenolic compounds include mainly antithrombotic, anti-ischemic, anti-oxidant, and vasorelaxant. It is suggested that flavonoids decrease the risk of coronary heart disease by three major actions: improving coronary vasodilatation, decreasing the ability of platelets in the blood to clot, and preventing low-density lipoproteins (LDLs) from oxidizing. In this review paper, we discussed the preventive role of polyphenols of honey against cardiovascular diseases.

The protective effects of green tea extract against L-arginine toxicity to cultured human mesangial cells

The aim of this study was to investigate whether green tea extract (GTE) has the protective effects on excess L-arginine induced toxicity in human mesangial cell. Human mesangial cells treated with L-arginine were cultured on Dulbecco's modified eagle medium in the presence and absence of inducible nitric oxide synthase (iNOS) inhibitor and GTE. The cell proliferation was determined by 3 (4,5-dimethylthiazol-2-yl)-2, 5-diphengltetrqzolium bromide, a tetrazole assay. The iNOS mRNA and its protein expression were detected by reverse transcription polymerase chain reaction and Western blot, respectively. The concentration of nitric oxide (NO) was measured by NO enzyme-linced immuno sorbent assay kit. L-arginine significantly inhibited the proliferation of human mesangial cells, and induced the secretion of NO to the media. NO production by L-arginine was significantly suppressed by GTE and iNOS inhibitor (p<0.01). The expression level of iNOS mRNA and its protein that was significantly increased by L-arginine was decreased by iNOS inhibitor but not by GTE. GTE protected the mesangial cells from the NO-mediated cytotoxicity by scavenging the NO rather than by iNOS gene expression. Therefore, we conclude that GTE has some protective effect for renal cells against oxidative injury possibly by polyphenols contained in GTE.

A comparison of three amperometric phenoloxidase-Sonogel-Carbon based biosensors for determination of polyphenols in beers

Three phenoloxidases based biosensors were successfully developed using as electrochemical transducer a new type of electrode recently developed by our group: the "Sonogel-Carbon electrode". The employed enzymes were Trametes versicolor laccase (Lac), Mushroom tyrosinase (Tyr), and Horseradish peroxidase (HRP). Immobilization step was accomplished by doping the electrode surface with a mixture of the individual enzyme and Nafion ion exchanger as additive-protective. The biosensor responses, optimized in beer real samples, were evaluated for five individual polyphenols. It was found that the developed biosensors were sensitive to nanomolar concentrations of the tested polyphenols. As example, the limit of detection, sensitivity, and response linear range for caffeic acid for Nafion-Lac/Sonogel-Carbon biosensor were 0.06μmolL(-1), 99.6nAμmol(-1)L, and 0.04-2μmolL(-1), respectively. The stability and reproducibility of the biosensors were evaluated by applying them directly to beer real samples. It has been demonstrated that the Nafion-Lac/Sonogel-Carbon system is the more stable with a relative standard deviation of 3.3% (n=10), maintaining 84% of its stable response for at least three weeks. Estimation of polyphenol index in eight lager beers and a comparison of the results with those obtained by a classical method was carried out.

Bioaccessibility of Ca, Mg, Mn and Cu from whole grain tea-biscuits: Impact of proteins, phytic acid and polyphenols

Levels of some essential minerals (Ca, Mg, Cu and Mn) were determined in ten different types of experimentally prepared hard biscuits. In relation to the wheat flour-based reference sample, other investigated samples were enriched with different ratios of integral raw materials of different origin or various dietary fibers in view of improving their functionality and nutritive quality. The goal of the research was to evaluate enriched biscuits as additional sources of calcium, magnesium, copper and manganese in nutrition and to investigate if the modifications of wheat flour based biscuit composition significantly change the amounts of total and bioaccessible minerals in the final product. Since our results indicated significant changes of mineral bioaccessibility among the samples, obtained results were correlated to the content of proteins, phytic acid and polyphenols for the sake of assessing their impact as limiting factors of mineral bioaccessibility in these types of foods.

Processing blackcurrants dramatically reduces the content and does not enhance the urinary yield of anthocyanins in human subjects

Blackcurrant (BC) fruits are a rich source of biologically active anthocyanins but little is known of the anthocyanin content of commonly consumed BC products or how processing affects the absorption. We report that whereas fresh and frozen whole BC were a rich source of anthocyanins, containing 897 and 642mg (100gFW)(-1) of total anthocyanins the levels in all other products were substantially lower (0.05-10.3% of the levels in fresh fruit). Further, when the absorption and excretion of BC was assessed in volunteers consuming a portion (100g) of frozen whole BC (642mg total anthocyanins) and, 300g of a BC drink made by diluting concentrated syrup (33.6mg total anthocyanins), only small quantities of BC anthocyanins were excreted in urine (fruit, 0.053±0.022%; drink, 0.036±0.043%; mean percent urinary yield±SD) and they were not detected in plasma. These data indicate that fresh and frozen BC, but not processed products, are rich sources of anthocyanins but, regardless of the food source, these anthocyanins are poorly bioavailable.

Antiulcerative properties of crude polyphenols and juice of apple, and Chinese quince extracts

Effects of Chinese quince extract, apple juice, semi-purified phenolics and soluble pectin from these fruits on ethanol-induced gastric ulcers in rats were investigated. In rats given Chinese quince extract or apple juice, ulcer induction was strongly suppressed, and the effect was stronger for Chinese quince extract than for apple juice. Myeloperoxidase activity in gastric mucosa showed a similar tendency. The DPPH radical scavenging activity and total phenolic content were 4 times higher in Chinese quince extract than in apple juice. Semi-purified phenolics from both fruits strongly suppressed ulcer induction at doses of 5-10mg; however, a 20mg dose of apple phenolics showed a pro-ulcerative effect. The soluble pectin fraction also showed moderate activity. These results suggest that phenolic compounds are responsible for antiulcerative activity of Chinese quince extract and apple juice, and that concentration may be an important factor in the case of apple phenolics.

Red wine and green tea reduce H pylori- or VacA-induced gastritis in a mouse model

AIM: To investigate whether red wine and green tea could exert anti-H pylori or anti-VacA activity in vivo in a mouse model of experimental infection.

METHODS: Ethanol-free red wine and green tea concentrates were administered orally as a mixture of the two beverages to H pylori infected mice, or separately to VacA-treated mice. Gastric colonization and gastric inflammation were quantified by microbiological, histopathological, and immunohistochemical analyses.

RESULTS: In H pylori-infected mice, the red wine and green tea mixture significantly prevented gastritis and limited the localization of bacteria and VacA to the surface of the gastric epithelium. Similarly, both beverages significantly prevented gastric epithelium damage in VacA-treated mice; green tea, but not red wine, also altered the VacA localization in the gastric epithelium.

CONCLUSION: Red wine and green tea are able to prevent H pylori-induced gastric epithelium damage, possibly involving VacA inhibition. This observation supports the possible relevance of diet on the pathological outcome of H pylori infection.

Experimental evidence for the cardioprotective effects of red wine

Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary vasodilation in addition to attenuating oxidative stress by its action on the central nervous system. The antioxidant components of red wine may provide cardioprotection by their ability to reduce oxidative stress in the heart under different pathological conditions. Mild-to-moderate red wine consumption improves cardiac function in the ischemic myocardium through the protection of endothelial function, the expression of several cardioprotective oxidative stress-inducible proteins, as well as the activation of adenosine receptors and nitrous oxide synthase mechanisms.

Protective effects of red wine polyphenolic compounds on the cardiovascular system

Phenolic phytochemicals are widely distributed in the plant kingdom. In terms of protective effects on organisms, the group of polyphenols is the most important. In various experiments, it has been shown that selected polyphenols, mainly flavonoids, confer protective effects on the cardiovascular system and have anti-cancer, antiviral and antiallergic properties. In coronary artery disease, the protective effects are due mainly to antithrombic, antioxidant, anti-ischemic and vasorelaxant properties of flavonoids. Flavonoids are low molecular weight compounds composed of a three-ring structure with various substitutions, which appear to be responsible for the antioxidant and antiproliferative properties. It has been hypothesized that the low incidence of coronary artery disease in the French population may be partially related to the pharmacological properties of polyphenolic compounds present in red wine. Many epidemiological studies have shown that regular flavonoid intake is associated with reduced risk of cardiovascular diseases.

Species height and root symbiosis, two factors influencing antiherbivore defense of woody plants in East African savanna

In East African savanna we found that leaves of mature tree species with symbiotic N₂ fixation contained lower concentrations of polyphenols than leaves of species without this symbiosis. We suggest that the root symbiosis is costly to the plant in terms of photosynthate that otherwise could be used in chemical defense. Further, a negative relationship between concentration of polyphenols and the height of the species was found, independent of their ability to fix N₂. These findings suggest that root symbioses and apparency to herbivory are important factors mediating the production of chemical defenses in plants.