Antioxidant-rich Beverages Research Articles

A REVIEW OF KOMBUCHA ANTIOXIDANT EFFECTS ON ATHEROSCLEROSIS IN PRECLINICAL STUDIES

Background Atherosclerosis is the leading cause of death among cardiovascular diseases in Indonesia, in which death is possible if uncontrolled. The prevalence of the disease may be prevented by consuming foods or drinks containing high levels of antioxidant such as kombucha. Exploration of kombucha properties as an antioxidant that will improve atherosclerosis could be obtained from preclinical studies. Objective To discuss the antioxidant effect of kombucha on atherosclerosis in preclinical studies. Method This study is a narrative review with literatures from 2013 to 2022. Result Kombucha is an antioxidant-rich beverage made from enzymes generated by the SCOBY bacteria, which are fermented in sweet tea for 7-14 days to achieve optimal quantities of polyphenols. In addition to the antioxidants in the blood, the effect will lower the levels of LDL, VLDL, triglycerides, and total cholesterol in the blood. Moreover, it can increase HDL in blood and inhibit lesion forming in the aorta. Conclusion Polyphenol in kombucha tea has an antiatherogenic effect that may prevent atherosclerosis in preclinical studies. Keywords: antioxidant, atherosclerosis, kombucha, polyphenol

Hot water infusion technique to prepare antioxidant-rich beverage with pomegranate peel: Formulation, nutritional study and cost analysis

This study aimed to utilize the pomegranate by-product for the formulation of antioxidant-rich beverage by the hot water infusion technique. The beverage was prepared with twelve variations of pomegranate peel powder at three different levels i.e. 2, 3 and 4 g along with combinations of three different spices (cardamom, ginger and cinnamon). Organoleptic properties of all the infusion formulations were examined, and it was noticed that the acceptable rate with no significant difference were there amongst the three levels of the pomegranate peel powder. Whereas, significant (p ≤ 0.05) difference in the acceptability of infusions with different spice powders was observed. However, cardamom spiced infusion was most liked by the panellist followed by ginger and cinnamon. Additionally, the antioxidant activity of the beverage was compared with four commercial brands of green teas. Peel infusion's DPPH● and FRAP values were found to be greater than those of the green tea brands by 18 % and 11 %, respectively. Cost estimation for the most accepted flavour, was also done.

Dijetarni antioksidansi i zdravstveni efekti - koliki je optimalan unos?

A well-balanced diet provides many compounds with antioxidant properties, such as vitamins, minerals, provitamins (e.g., b-carotene), and phytochemicals (e.g., carotenoids, polyphenols, organosulfur compounds). In addition to direct antioxidants, foods indirectly support the endogenous defense system, by providing substrates for the synthesis of glutathione, antioxidant defense enzymes, metal-binding proteins, or modulators of redox-dependent signaling pathways. Epidemiological studies indicate that higher intakes and circulating concentrations of vitamins C, E, carotenoids, and flavonoids reflect a lower risk of chronic diseases and all-cause mortality, suggesting the importance of optimal intakes of these substances. However, unlike antioxidant micronutrients, phytochemicals have no defined recommended intake levels. A diet should be based on consuming various plant foods (fruit, vegetables, legumes, whole grains, seeds, nuts), antioxidant-rich beverages, and a moderate intake of animal food products to fully exploit the health-promoting effects of dietary antioxidants.

Modulation of Oxidative Stress and Antioxidant Response by Different Polyphenol Supplements in Five-a-Side Football Players.

Oxidative stress is associated with playing soccer. The objective of the present report was to study the influence of different polyphenolic antioxidant-rich beverages in five-a-side/futsal players. The study was performed with a no supplemented control group (CG) and two supplemented groups with an almond-based beverage (AB) and the same beverage fortified with Lippia citriodora extract (AB + LE). At day 22, participants played a friendly futsal game. Blood extractions were performed at the beginning of intervention (day 1), before and after match (day 22) to determine oxidative stress markers and antioxidant enzyme activities in plasma, neutrophils and peripheral blood mononuclear cells (PBMCs). Malondialdehyde increased significantly in controls after the match in neutrophils, PBMCs and plasma compared to pre-match. Protein carbonyls also increased after the match in plasma in CG. In addition, malondialdehyde levels in neutrophils were significantly lower in the supplemented groups compared to controls. Post-match samples showed significant increases in neutrophil antioxidant activities in CG. Supplemented groups displayed variable results regarding neutrophil antioxidant activities, with superoxide dismutase activity significantly lower than in controls. Finally, post-match myeloperoxidase activity increased significantly in controls compared to pre-match and supplemented groups. In conclusion, polyphenolic antioxidant and anti-inflammatory supplements could be instrumental for optimal recovery after high intensity futsal games.

Microplate ORAC-pyranine spectrophotometric assay for high-throughput assessment of antioxidant capacity

Antioxidant activity assessment is crucial to establish the protective role of bioactive compounds against free radical-induced oxidative damage, a serious threat to health and food quality. For oxygen radical absorbance capacity (ORAC) assays, the target molecule employed has been indicated as a key factor to characterize free-radical scavenging mechanisms. The combined use of target molecules such as pyranine (PYR) and pyrogallol red (PGR) allows to distinguish between the stoichiometry and the chemical reactivity of free radical scavenging by antioxidants. In this work, a high-throughput microplate-based ORAC-PYR method was developed for the estimation of antioxidant capacity (stoichiometry) in a miniaturized fashion. Kinetic studies of pyranine consumption by AAPH-derived radicals were carried out to achieve high sensitivity, reduced consumption of reagents, and low generation of waste. The use of low amounts of target molecule and radical generator (2.5 ng and 2.5 µg, respectively) was feasible with a maximum time to result of 3 h for 96 simultaneous determinations. The limit of detection was 1 µM for Trolox and RSD values were <5.4% and <6.4% for intra- and inter-assay precision, respectively. A dual-probe approach (ORAC-PGR and ORAC-PYR) was implemented in microplate format and a comparative study of structure-antioxidant activity of catechol-derived compounds was performed. This strategy was also extended to the analysis of antioxidant-rich beverages for assessing the applicability of the proposed method to complex matrices.

Nutraceuticals and blood pressure control: a European Society of Hypertension position document.

: High-normal blood pressure (BP) is associated with an increased risk of cardiovascular disease, however the cost-benefit ratio of the use of antihypertensive treatment in these patients is not yet clear. Some dietary components and natural products seems to be able to significantly lower BP without significant side effects. The aim of this position document is to highlight which of these products have the most clinically significant antihypertensive action and wheter they could be suggested to patients with high-normal BP. Among foods, beetroot juice has the most covincing evidence of antihypertensive effect. Antioxidant-rich beverages (teas, coffee) could be considered. Among nutrients, magnesium, potassium and vitamin C supplements could improve BP. Among nonnutrient-nutraceuticals, soy isoflavones could be suggested in perimenopausal women, resveratrol in insulin-resistant patients, melatonin in study participants with night hypertension. In any case, the nutracutical approach has never to substitute the drug treatment, when needed.

Effect of Stevia rebaudiana Bert. Addition on the Antioxidant Activity of Red Raspberry (Rubus idaeus L.) Juices

The demand for antioxidant-rich beverages is steadily expanding. At the same time, the possibility of manufacturing products with reduced sugar content, sweetened with natural ingredients, represents a decisive aspect of obtaining quality products with health benefits. Stevia rebaudiana Bertoni (stevia) is a natural sweetener that can help to control caloric intake and is also a good source of antioxidant compounds. The present study was designed to assess the feasibility of producing high-quality berry juices sweetened with dry-grinded stevia leaves or their crude extract. The effect of the stevia supplementation on the antioxidant activities of raspberry juices was determined at two different production steps by means of the Folin–Ciocalteu, the oxygen radical absorbance capacity (ORAC), and the cellular antioxidant activity (CAA) assays. The addition of stevia significantly increased the antioxidant activity of the juices and resulted in significantly higher ascorbic acid and total phenolic content. A positive correlation was observed between ORAC, CAA, and total phenolic values. These findings show that supplementation with stevia not only promotes a healthy diet by reducing sugar intake but may also enhance the antioxidant potential of the beverage.

Design of lemon–mustard nutraceutical beverages based on synergism among antioxidants and in vitro antioxidative, hypoglycaemic and hypocholesterolemic activities: characterization and shelf life studies

The present study has endeavoured a unique application of the sleep hormone, melatonin as a food antioxidant in synergism with other antioxidants. Two lemon–mustard based nutraceutical beverages, brown mustard beverage (BMB) and yellow mustard beverage (YMB), were formulated using brown and yellow mustard seed extracts based on highest synergistic combination of four antioxidants (melatonin and ɣ-tocopherol from mustard seeds; ascorbic acid and citric acid from lemon). Evaluation of microbial load, sensory attributes, physicochemical properties, antioxidant activities, hypocholesterolemic and antidiabetic properties (in vitro) of the beverages revealed that YMB had a shelf life over 360 days and BMB over 240 days, vis-a-vis 21 days for the control sample at 4 ± 1 °C. The beverages retained considerable amount of melatonin even after 360 days (87.13 ± 0.92% for BMB and 91.97 ± 0.89% for YMB) of storage in amber-colored glass bottles at 4 ± 1 °C. These antioxidant-rich beverages could be novel designer nutraceutical foods. Besides, this methodology of formulation of the beverages based on synergistic activities of multiple antioxidants could be successfully adopted industrially in development of innovative antioxidant-rich food products.

Improved Lipid Profile Associated with Daily Consumption of Tri-Sura-Phon in Healthy Overweight Volunteers: An Open-Label, Randomized Controlled Trial.

Tri-Sura-Phon (TSP), a traditional Thai polyherbal formula renowned for its rejuvenating properties, is commonly used as a blood tonic. It comprises Cinnamomum bejolghota, Cinnamomum parthenoxylon, and Aquilaria crassna. The aim of this study is to evaluate the beneficial properties of TSP tea consumption on blood glucose regulation and serum lipid profiles of healthy overweight volunteers. This open-label, randomized controlled trial was conducted in 70 healthy overweight adults. Two groups of 35 subjects took a TSP infusion or a placebo (cornstarch) twice daily for 8 weeks. The blood glucose regulation, serum lipid profiles, BMI, and liver function tests of the subjects were determined at the baseline, 4th week, and endpoint (8th week). Significant decreases in the average fasting levels of total cholesterol (p = 0.013), triglyceride (p = 0.001), and low-density lipoprotein (LDL, p = 0.017) were observed in the TSP group at the 8th week compared to those at the baseline. The average HDL level in the TSP group at the beginning of the study was 65.2 mg/dL, and it increased significantly (p = 0.005) to 72.4 mg/dL after 8 weeks of TSP intake. This study showed that the intake of TSP tea as an antioxidant-rich beverage might be safe and improve lipid profiles in overweight adults.

Antioxidant Properties of Aqueous Extract of Roasted Hulled Barley in Bulk Oil or Oil‐in‐Water Emulsion Matrix

Antioxidant properties of the aqueous extracts of hulled barley (Hordeum vulgare L.) that had been roasted at 210 °C for 20 min were determined in bulk oil and oil-in-water (O/W) emulsions. Bulk oils were heated at 60, 100, and 180 °C, and O/W emulsions were oxidized under riboflavin photosensitization. The content of phenolic compounds was analyzed by high-performance liquid chromatography, and in vitro antioxidant assays were also conducted. The major phenolics contained in the aqueous extract of roasted hulled barley (AERB) were p-coumaric, ferulic, protocatechuic, chlorogenic, 4-hydroxybenzoic, and vanillic acids. Depending on the concentration and oxidation temperature, AERB had antioxidant or prooxidant properties in bulk oil. At 60 °C, AERB at a concentration of 0.5% acted as a prooxidant, whereas at 1.0% it acted as an antioxidant. At 100 °C, AERB acted as an antioxidant irrespective of concentration. In 180 °C conditions, 0.5% AERB acted as a prooxidant, whereas other concentrations of AERB acted as antioxidants. In the case of riboflavin photosensitized O/W emulsions, AERB showed antioxidant properties irrespective of concentration. Antioxidant abilities of AERB are affected by the food matrix, including bulk oil and O/W emulsions, and concentrations of AERB, even though diverse phenolic compounds may display high antioxidant properties in in vitro assays. Roasted barley has been widely used as a tea ingredient in East Asian countries such as Korea, China, and Japan. The highly antioxidative properties of the aqueous extracts of roasted barley have been confirmed in bulk oil and O/W emulsions as well as in vitro assays because of the presence of phenolic compounds. The results of this study can contribute to the development of antioxidant-rich beverages using roasted barley by aiding in the selection of proper food matrix-containing extracts of high phenolic compounds, as well as by expanding consumers’ choices for healthy beverages.

Soluble Antioxidant Compounds Regenerate the Antioxidants Bound to Insoluble Parts of Foods

This study aimed to investigate the regeneration potential of antioxidant capacity of an insoluble food matrix. Investigations were performed in vitro with several food matrices rich in dietary fiber (DF) and bound antioxidants. After removal of the soluble fraction, the antioxidant capacity (AC) of the insoluble fraction was measured by the QUENCHER procedure using ABTS(•+) or DPPH(•) radicals. After measurement, the insoluble residue was washed out to remove the excess of radicals and treated with pure antioxidant solution or antioxidant-rich beverage to regenerate depleted antioxidants on the fiber. Results revealed that the antioxidant capacity of compounds chemically bound to the insoluble moiety could be reconstituted in the presence of other hydrogen-donating substances in the liquid phase. Regeneration efficiency was found to range between 21.5 and 154.3% depending on the type of insoluble food matrix and regeneration agent. Among the food matrices studied, cereal products were found to have slightly higher regeneration efficiency, whereas antioxidant-rich beverages were more effective than pure antioxidants as regeneration agents. Taking wheat bran as reference insoluble material, the regeneration abilities of beverages were in the following order: green tea > espresso coffee > black tea > instant coffee > orange juice > red wine. These results highlighted the possible physiological relevance of antioxidants bound to the insoluble food material in the gastrointestinal tract. During the digestion process they could react with the free radicals and at the same time they can be regenerated by other soluble antioxidant compounds present in the meal.

꾸지 뽕나무 휘발성 향기성분의 항산화활성

The antioxidant activities of volatile aroma extracts from Cudrania tricuspidata (Carr.) Bureau were examined using two antioxidant assays. Ten volatile aroma compounds identified in this plant were also tested for antioxidant activity. The volatile aroma extracts of stem and root from C. tricuspidata exhibited antioxidant activities with a clear dose response relationship in both aldehyde/carboxylic acid and lipid/malonaldehyde assays. Antioxidant activities of volatile aroma extracts from C. tricuspidata at were (stem) and (root) in the aldehyde/carboxylic acid assay. Antioxidant activities of volatile aroma extracts from C. tricuspidata at were (stem) and (root) in the lipid/malonaldehyde assay. Positively identified volatile aroma components in extracts of stem and root from C. tricuspidata were seven terpenes and terpenoides, 14 alkyl compounds, 11 nitrogen containing heterocyclic compounds, three oxygen containing heterocyclic compounds, 12 aromatic compounds, nine lactones, and seven miscellaneous compounds (possible contaminants). Among the positively identified compounds, eugenol, isoeugenol, and 2,4-bis (1,1-dimethylethyl)phenol exhibited antioxidant activities comparable to those of BHT and -tocopherol. Vanillin and 2-acetylpyrrole showed moderate activities in the lipid/malonaldehyde assay. These results suggest that consumption of antioxidant-rich beverages prepared from C. tricuspidata could have beneficial effects on human health by preventing diseases caused by oxidative damage.

Antioxidant Activities of Extracts from Teas Prepared from Medicinal Plants, Morus alba L., Camellia sinensis L., and Cudrania tricuspidata, and Their Volatile Components

The antioxidant activity of essences of teas prepared from mulberry ( Morus alba L.), Camellia sinensis L., and Cudrania tricuspidata (Carr.) Burea plant was examined using two antioxidant assays. Selected volatile chemicals identified in these plants were also tested for antioxidant activity. All extracts exhibited antioxidant activity with a clear dose response in the aldehyde/carboxylic acid and the malonaldehyde/gas chromatography (MA/GC) assays. Antioxidant activity of extracts at the level of 500 μg/mL ranged from 77.02 ± 0.51% (stems of Burea plant) to 52.57 ± 0.92% (fermented tea of Camellia and stems of Mulberry tea) in the aldehydes/carboxylic acid assay. Their antioxidant activity at the level of 160 μg/mL ranged from 76.17 ± 0.27% (roots of Burea plant) to 59.32 ± 0.27% (stems of Mulberry tea) in the MA/GC assay. Among the positively identified compounds (11 terpenes and terpenoids, 15 alkyl compounds, 26 nitrogen containing heterocyclic compounds, 9 oxygen containing heterocyclic compounds, 18 aromatic compounds, 7 lactones, 6 acids, and 4 miscellaneous compounds), eugenol, 2,5-dihydroxyl acetophenone, and isoeugenol exhibited antioxidant activity comparable to that of BHT in both assays. Vanillin and 2-acetylpyrrole showed potent antioxidant activity in the aldehydes/carboxylic acid assay but only moderate activity in the MA/GC assay. These results suggest that consumption of antioxidant-rich beverages prepared from these plants may be beneficial to human health.

Effects of a Hypersaline Sodium-rich Carbonated Natural Mineral Water on Structure and Expression of VEGF, VEGFR1, VEGFR2, Ang1, Ang2 and Tie2 of Fructose-treated Rat Corpus Cavernosum

Metabolic Syndrome (MS) definition is based on a cluster of metabolic risk factors that identifies subjects at high risk for forthcoming type 2 diabetes mellitus and atherosclerotic cardiovascular diseases (CVD). Although the exact aetiology of the MS still remains unclear, it is known to involve complex interactions between genetic, metabolic and environmental factors, with diet and oxidative stress playing important roles. Regular increased fructose consumption has been associated to some metabolic adverse changes observed in the MS and, thus, fructose-fed is considered a suitable animal model of diet-induced MS. On the other hand, calcium, magnesium and potassium, generally deficient in MS-inducing diets, and abundant in natural mineral-rich waters, have been proposed protective against the MS. Although their exact effects are not yet fully clarified, natural mineral-rich waters present some antioxidant properties that exert protection against reactive oxygen species that are chief contributors to the increase of CVD risk, considering their reactivity to nitric oxide (NO). Such waters also improve some MS metabolic risk factors. Degradation of NO seriously compromises the vasodilatation mechanism leading to endothelial dysfunction, which always precedes atherosclerosis — the main contributor to CVD and erectile dysfunction. Penis erection is a vascular process that strongly depends on NO-induced smooth muscle relaxation. Moreover, NO mediates indirectly the vascular endothelial growth factor (VEGF)-induced angiogenesis, which is fundamental to maintain endothelium integrity in the cavernous tissue. VEGF binds specifically to VEGF tyrosine kinase membrane receptors (VEGFR1 and VEGFR2), and crosstalk in vivo with other angiogenic factors such as angiopoietins that compete for binding to the endothelial-specific Tie2 receptor. Previous work from our group demonstrated that long-term consumption of antioxidant-rich beverages modifies the expression of VEGF, Ang1, Ang2 and their receptors VEGFR1, VEGFR2 and Tie2 in the cavernous tissue of the rat, preventing atherosclerosis progression.

Consumption of Antioxidant-Rich Beverages and Risk for Breast Cancer in French Women

The objective of the study is to evaluate the relation between antioxidant-rich beverages and the incidence of breast cancer. This prospective study consisted of 4396 women without a history of cancer who were participants in the French Supplémentation en Vitamines et Minéraux Antioxydants Study. Beverage consumption was estimated by using three nonconsecutive 24-hour recalls. Incident cancer cases were identified through clinical examinations performed every other year, including, e.g., a screening mammogram, and through a monthly health questionnaire. During the median 6.6 years of follow-up, 95 breast cancers were diagnosed. In a multivariate model, an inverse association between herbal tea consumption and risk for breast cancer was observed (compared with nondrinkers, drinking 1 to 149 mL/d; relative risk [RR], 0.93; 95% confidence interval [CI], 0.48-1.80, and for > or =150 mL/d; RR, 0.43; 95% CI, 0.20-0.94; p for trend = 0.04). Consumption of coffee, tea, fruit juices, or wine was not associated with risk for breast cancer. Results of this study suggest that consumption of herbal tea may have a role in the prevention of breast cancer.

Rose Petal Tea as an Antioxidant‐rich Beverage: Cultivar Effects

ABSTRACT Twelve rose cultivars were selected by field tasting as potential sources of edible flowers. Hot water infusions (teas) of air‐dried petals of these cultivars were assayed for antioxidant activity, total phenols, and total anthocyanins contents. Their composition was analyzed by high‐performance liquid chromatography (HPLC). Green tea was tested in parallel as a reference antioxidant‐rich beverage. Rose petal teas from different cultivars exhibited scavenging capacity toward 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline)‐6‐sulfonate cation radical (ABTS+) ranging between 712.7 and 1770.7 μM Trolox equivalents (TE) per gram of dry petals, as compared with 1227.6 μM TE/g dry weight in the green tea. The range of total phenols content in rose teas was 50.7 to 119.5 mg gallic acid equivalents (GAE) per gram of dry matter, as compared with 62.1 mg GAE/g dry weight in the green tea. The rose teas were rich in free gallic acid. The highest values of antioxidant activity, total phenols, and gallic acid contents were found in the cultivars San Francisco, Katharina Zeimet, and Mercedes and in the essential‐oil‐bearing rose Rosa damascena. The correlation coefficients between antioxidant activity, on the 1 hand, and the contents of total phenols and of gallic acid in various rose cultivars, on the other hand, were 0.79 and 0.81, respectively. No clear relationship between anthocyanin level and radical‐scavenging activity was revealed. Teas from different rose cultivars significantly differed in their sensory properties. It was concluded that dried rose petals may be used for preparing antioxidant‐rich caffeine‐free beverages, either separately or in combination with other herbal materials.

Aqueous extract ofIlex paraguariensisattenuates the progression of atherosclerosis in cholesterol-fed rabbits

Ilex paraguariensis aqueous extract (mate) is an antioxidant-rich beverage widely consumed in South American countries. Here we questioned whether mate could reduce the progression of atherosclerosis in 1% cholesterol-fed rabbits. New Zealand White male rabbits (n = 32) were divided into four groups: control (C, n = 5), control-mate (CM, n = 5), hypercholesterolemic (HC, n = 11) and hypercholesterolemic-mate (HCM, n = 11). The daily water and mate extract consumption was approximately 400 ml. After 2 months of treatment, mate intake did not change the lipid profile or hepatic cholesterol content of control or hypercholesterolemic rabbits (p < 0.05). However, the atherosclerotic lesion area was considerably smaller in the hypercholesterolemic-mate group (HCM, 35.4% vs. HC, 60.1%; p < 0.05). In addition, the aortic cholesterol content was around half that of the HC group (HCM, 36.8 vs. HC, 73.9 microg/mg of protein, p < 0.05). In spite of this, the thiobarbituric acid-reactive substances (TBARS) in the atherosclerotic aorta, liver and serum, and the activity of the antioxidant enzymes in liver and aorta did not differ among groups (p > 0.05). The results showed that Ilex paraguariensis extract can inhibit the progression of atherosclerosis in cholesterol-fed rabbits, although it did not decrease the serum cholesterol or aortic TBARS and antioxidant enzymes.

A buccal cell model comet assay: Development and evaluation for human biomonitoring and nutritional studies

The comet assay is a widely used biomonitoring tool for DNA damage. The most commonly used cells in human studies are lymphocytes. There is an urgent need to find an alternative target human cell that can be collected from normal subjects with minimal invasion. There are some reports of buccal cells, collected easily from the inside of the mouth, being used in studies of DNA damage and repair, and these were of interest. However, our preliminary studies following the published protocol showed that buccal cells sustained massive damage and disintegrated at the high pH [O. Ostling, K.J. Johanson. Microelectrophoretic study of radiation-induced DNA damages in individual mammalian cells. Biochem. Biophys. Res. Commun. 123 (1984) 291–298] used, but that at lower pH were extremely resistant to lysis, an essential step in the comet assay. Therefore, the aims of this study were to develop a protocol than enabled buccal cell lysis and DNA damage testing in the comet assay, and to use the model to evaluate the potential use of the buccal cell model in human biomonitoring and nutritional study. Specifically, we aimed to investigate intra- and inter-individual differences in buccal cell DNA damage (as strand breaks), the effect of in vitro exposure to both a standard oxidant challenge and antioxidant treatment, as well as in situ exposure to an antioxidant-rich beverage and supplementation-related effects using a carotenoid-rich food. Successful lysis was achieved using 0.25% trypsin for 30 min followed by proteinase K (1 mg/ml) treatment for 60 min. When this procedure was performed on cells pre-embedded in agarose on a microscope slide, followed by electrophoresis (in 0.01 M NaOH, 1 mM EDTA, pH 9.1, 18 min at 12 V), a satisfactory comet image was obtained, though inter-individual variation was quite wide. Pre-lysis exposure of cells to a standard oxidant challenge (induced by H 2O 2) increased DNA strand breaks in a dose related manner, and incubation of cells in Trolox ® (a water soluble Vitamin E analogue) conferred significant protection ( P < 0.05) against subsequent oxidant challenge. Exposure of buccal cell in situ (i.e. in the mouth) to antioxidant-rich green tea led to an acute decrease in basal DNA strand breaks. In a controlled human intervention trial, buccal cells from 14 subjects after 28 days’ supplementation with a carotenoid-rich berry ( Fructus barbarum L.) showed a small but statistically significant ( P < 0.05) decrease in DNA strand breaks. These data indicate that this buccal cell comet assay is a feasible and potentially useful alternative tool to the usual lymphocyte model in human biomonitoring and nutritional work.