[Determination of sulfonate ether in grapes, grape juice, wine and water by means of thin-layer chromatography].
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Chromatography, Thin Layer↗
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[Hygienic assessment of grape juice obtained by the electrohydraulic effect on grape pulp].
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Animals↗
[Nutritional characteristics of grape juice made from Belyĭ Kruglyĭ grapes].
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Animals↗
Effects of different grape formulations on antioxidative capacity, lipid peroxidation and oxidative DNA damage in aged rats.
In this study, the freeze-dried powders from whole grapes, pomace and juice of Campbell Early (Vitis labruscana Bailey) were prepared to determine the amount of total flavonoids, vitamins A, C, and E, and dietary fiber. Effects of whole grape, pomace, or juice intakes on their antioxidative capacity and DNA damage were investigated in Sprague-Dawley male rats. A total of 120 rats at 13 mo old and weighing 549 +/- 4 g were blocked into 8 groups according to body weight and raised for 3, 5, or 7 mo with diets containing 2% (w/w) dry powder of three different parts of grapes and 0.02% (w/w) CdCl2. The contents of flavonoids, antioxidant vitamins A and E, and dietary fiber in freeze-dried powder were the highest in grape pomace, but the vitamin C contents were similar among the three powders. In all the 16, 18, and 20-mo-old animals, plasma and liver thiobarbituric acid reactive substances levels of grape-ingesting groups were lower than those of the controls and that of the grape pomace group was the lowest among the groups. Cd administration increased plasma and liver thiobarbituric acid reactive substances levels remarkably; however, Cd+grape groups were lower than the Cd-control group. Red blood cell superoxide dismutase activity of 18- and 20-mo-old rats was higher than that of 16-mo-olds, showing an age-related increase; however, red blood cell catalase and glutathione peroxidase activities decreased with age. Grape diets promoted superoxide dismutase, catalase, glutathione peroxidase activities, and the grape pomace increased the activities most significantly among three different parts of the grape. Cd decreased superoxide dismutase, catalase, glutathione peroxidase activities; however Cd+grape groups showed similar activities to the non-Cd control group. Liver superoxide dismutase activity was decreased with age but catalase activity of 18-mo-old rats was higher than those of 16- and 20-mo-old groups, and glutathione peroxidase activities of 16- and 18-mo-old groups were similar but that of 20-mo-old groups decreased markedly. Grape intake increased these three antioxidative enzyme activities while Cd administration decreased catalase and glutathione peroxidase activities except superoxide dismutase activity. The concentration in the kidney of 8-hydroxy-2'-deoxyguanosine in the 18- and 20-mo-old rats was higher than that in the 16-mo-old groups, and grape intake showed a protecting effect on DNA from age-related or Cd-induced oxidative damage. In conclusion, grape intakes, especially grape pomace with the highest content of flavonoids, beta-carotene, tocopherols and dietary fiber among the three parts, showed the prominent antioxidative capacity of inhibiting age-related or Cd-induced increase of lipid peroxidation and DNA damage effectively, promoting liver and red blood cell antioxidant enzyme activities.
Aging↗
Study of amine composition of botrytized grape berries.
Aliphatic primary and biogenic amines of grape varieties from two vintages were studied. We established that appearance and/or increase of both primary aliphatic and biogenic amines is due to microbiota living in/on grape berries. Aszú, gray rotten grapes infected mainly with Botrytis cinerea, grape berries infected mainly with Penicillium species, and intact grape berries were compared on the basis of amine composition using t-test, analysis of variance, and multivariate statistical analysis (principal component analysis and linear discriminant analysis). The amine composition and amine content of Aszú grapes were significantly different (p < 0.05) from those of intact grapes despite the effect of the vineyards and the vintages. Grape samples coming from the same growing location, intact, Aszú grapes, and grape berries infected mainly with Penicillium species could be separated from each other with multivariate statistical analysis. We distinguished intact, Aszú (noble rotten), and gray rotten berries from each other as well. Evaluating amine values of grape samples independently of the place of origin, the Aszú and green rotten berries could not be differentiated. The varieties and vineyards have affected the amine composition of Aszú grapes, while these effects on intact grapes appeared only slightly.
Biogenic Amines↗
Origin of (-)-geosmin on grapes: on the complementary action of two fungi, botrytis cinerea and penicillium expansum.
One of the consequences of rot on grapes is the development of volatile compounds giving fungal, mouldy or earthy odours. Among these compounds, (-)-geosmin (trans-1,10-dimethyl-trans-9-decalol), a powerful aromatic compound with an earthy smell is a persistent defect in grape juice and wines made with at least partially rotten grapes. A microbiota analysis of rotten grapes containing (-)-geosmin was carried out on sites from four French regions from 1999 to 2002, to clarify the involvement in geosmin appearance of Streptomyces spp. and Penicillium spp., two types of microorganisms present on grape, that are known for their ability to produce geosmin. In earthy grapes, Botrytis cinerea was largely present. Different species of Streptomyces were also isolated, but their pH sensitivity was an extremely limiting parameter for their development on grape juice, grapes or stem, and consequently for their potentiality to generate geosmin in the vineyard. Penicillium expansum, producing geosmin on a model medium, was omnipresent. Penicillium carneum, which is also a geosmin producer, was represented by a single colony during the 4 years of this study. P. expansum alone was able to produce geosmin on a model medium but not on grapes. However, after 7 days' pre-culture of some B. cinerea strains on grape juice, this juice became favourable to geosmin production by P. expansum. We demonstrated the necessary and complementary action of B. cinerea and P. expansum in geosmin production in grape juice and in crushed grape berries.
Beverages↗
Environmental conditions during vegetative growth determine the major proteins that accumulate in mature grapes.
Despite recent reports in the literature that chitinases comprise approximately 50% of the soluble proteins present in mature Vitis vinifera L. (cv. Moscatel) grapes, with the other major proteins being thaumatin-like proteins, a careful inspection of the published data reveals inconsistencies as to which proteins actually accumulate in mature grapes. Mature Moscatel grapes were harvested in the same vineyard in two consecutive years, 1999 and 2000. The grapes exhibited widely distinct polypeptide patterns when analyzed by either FPLC cation exchange chromatography or two-dimensional electrophoresis: whrereas the 2000 grapes possessed a much higher protein content (1.96 versus 1.11 mg g(-)(1) of fresh weight), the 1999 grapes contained a greater heterogeneity of polypeptides. In addition, highly specific antibodies that recognize the pathogenesis-related proteins present in the grapes demonstrated that the 2000 harvest grapes had a wider variety of pathogenesis-related polypeptides. N-Terminal sequencing of the major polypeptides revealed differences in the relative abundance and amino acid sequence of thaumatin-like and osmotin-like polypeptides present in the 1999 and 2000 harvest Moscatel grapes and did not detect the presence of chitinase. As a whole, the data indicate that the expression and accumulation of the major proteins in grapes is essentially determined by the environmental and/or pathological conditions prevailing during grape development and maturation. The potential physiological and technological implications are discussed. The results of the present work suggest that it is not possible to base varietal differentiation of grapes on the profile of the pathogenesis-related polypeptides present in the mature berries.
Amino Acid Sequence↗
Grape extracts suppress the formation of preneoplastic foci and activity of fatty acid synthase in rat liver.
This study was conducted to examine the effects of dietary grape extracts on preneoplastic foci formation in rat hepatocarcinogenesis, and related hepatic enzymes. Male Sprague-Dawley rats were fed basal diet or grape diet containing 15% concentrated grape extracts (68 bricks). The grape diet groups were divided into whole-period grape diet group (DEN-GW; grape diet group fed throughout experimental period) and postinitiation grape diet group (DEN-GP; grape diet group fed from post initiation stage) according to the starting time point of the grape diet. Hepatocarcinogenesis was induced by diethylnitrosamine (DEN; 200 mg/kg bw) and 2/3 partial hepatectomy (DEN-B; DEN-treated basal diet group, DEN-GW, and DEN-GP groups), while the control group treated with saline and sham operation (Control group). The formation of placental glutathione (GSH) S-transferase positive (GST-P+) foci in DEN-GW group was moderately but significantly suppressed, however, not in DEN- GP group. Thiobarbituric acid reactive substances content of DEN-GW group was significantly lower than that of DEN-B group. The activity of fatty acid synthase (FAS) in the grape diet groups was decreased about 1/2 of the DEN-B group. The content of GSH and GSH peroxidase activity were increased by carcinogen treatment, but not modulated by grape diet. The activities of GSH S-transferase, p-nitrophenol hydroxylase, and catalase were not affected by diet or treatment. Conclusively, the grape diet-induced reduction of FAS activity that was expressed highly in neoplastic tissues, might be one of the contributing mechanisms of hepatic cancer prevention.
Administration, Oral↗
Allergic rhinitis, asthma, and atopy among grape farmers in a rural population in Crete, Greece.
STUDY OBJECTIVE: To measure the prevalence of allergic rhinitis, atopy, and asthma among grape farmers, and to compare the respiratory and atopic status in grape farmers with those of nonexposed control subjects. DESIGN: Cross-sectional study. SETTING: Malevisi region in northern Crete, Greece. SUBJECTS AND METHODS: One hundred twenty grape farmers and 100 control subjects living in the Malevisi region were examined. The protocol comprised a questionnaire, skin prick tests for 16 common allergens, measurement of specific IgE antibodies against 8 allergens, and spirometry before and after bronchodilation. RESULTS: Grape farmers were found to have an excess of respiratory symptoms. The comparison with the control group, after adjusting for age, sex, and smoking status, showed that the differences were statistically significant for rhinorrhea (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.5 to 5.1; p < 0.001), sneezing (OR, 2.2; 95% CI, 1.2 to 4.0; p < 0.01), and nasal itching (OR, 1.9; 95% CI, 1.0 to 3.6; p < 0.05), but were nonsignificant for asthma-related symptoms. In the multiple logistic regression model, grape farmers were found to have increased work-related symptoms, such as sneezing (OR, 2.9; 95% CI, 1.3 to 6.6; p < 01), rhinorrhea (OR, 2.9; 95% CI, 1.3 to 6.6; p < 0.01), cough (OR, 3.7; 95% CI, 1.2 to 11.4; p < 0.05), and dyspnea (OR, 3.8; 95% CI, 1.1 to 1.3; p < 0.05). The prevalence of allergic rhinitis was 40.8% in grape farmers and 26% in control subjects (OR, 2.0; 95% CI, 1.1 to 3.5; p < 0.02). Increased but statistically nonsignificant values of asthma prevalence were found in grape farmers (6.7%) compared with the control group (2.0%). The prevalence of atopy was 64.2% in grape farmers and 38.0% in the control group (OR, 2.2; 95% CI, 1.2 to 3.5; p < 0.01). Mean FEV1 was significantly lower in grape farmers than in control subjects (p < 0.05), after adjusting for age, sex, and smoking status. Bronchial obstruction was reversible in 23 grape farmers (19.2%) and in 6 control subjects (6%; p < 0.01). CONCLUSIONS: The study mainly demonstrated the high prevalence of allergic rhinitis and work-related respiratory symptoms in grape farmers compared to control subjects. It also suggested that grape farming is possibly associated with increased allergic sensitization to specific pollens, low baseline FEV1, and increased bronchial hyper-responsiveness. Further studies are needed to determine the potential risk factors for these disorders among the farming population.
Adult↗
Grape anaphylaxis: a study of 11 adult onset cases.
Reports of immunoglobulin E (IgE)-mediated allergic reactions to grapes and wine are limited in the literature. Nevertheless, grapes are widely grown and consumed in Mediterranean countries. The object of this prospective study was to present clinical features, in vivo and in vitro allergy testing, and human leukocyte antigen (HLA) serotyping in patients with recurring reactions to grapes and grape products. Eleven unrelated Greek patients, six men and five women (aged 16-44 years; mean, 26.9 years) were enrolled based on a documented history of IgE-mediated reactions to grapes, wine, or other grape products. Their evaluation included full history, reaction severity, clinical examination, skin-prick tests with food allergens and molds, serum IgE, specific IgEs to the same allergen battery, and HLA typing. Patients reported 35 grape-induced anaphylaxis episodes ranging from moderate (more than one system involved but not prominent respiratory or cardiovascular symptoms; 45.5%) to severe (serious respiratory obstruction and/or hypotension and loss of consciousness; 54.5%). A causative agent was identified: wine, 10/35 (28.6%); red grapes, 9/35 (25.7%); stuffed vine leaves, 8/35 (22.9%); raisins, 3/35 (8.6%); white grapes, 2/35 (5.7%); wine vinegar, 2/35 (5. 7%); and grape juice, 1/35 (2.9%). Other foods that induced anaphylaxis were apples (54.5%), cherries (18.6%), peaches (18.6%), and bananas (9.3%). Specific IgE values were in accordance with skin-prick tests reactivity. Concerning HLA typing, 9/11 possessed HLA-DR11(5) and -DQ7(3) and the remaining two possessed HLA-DR17(3) and -DQ2 antigens. Grapes, wine and other grape products might cause serious allergic reactions in sensitized individuals. The cosensitization and reaction incidence to other fruit allergens could be a basis for further investigation of panallergens of fruits. HLA class II antigens may contribute in genetic predisposition to these allergic reactions.
Adolescent↗
Purple grape juice inhibits 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumorigenesis and in vivo DMBA-DNA adduct formation.
There has been considerable interest in identifying specific foods and phytochemicals that may have breast cancer preventive properties. Concord grapes are rich in polyphenolic chemicals and anthocyanin pigments that may have biological properties which could suppress cancer such as having antioxidant, antiproliferative, and proapoptotic actions. To determine the potential breast cancer protective action of purple grape juice, we examined the effect of grape juice consumption on the initiation stage of 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumorigenesis and on the in vivo formation of rat mammary DNA adducts in female Sprague-Dawley rats. Consumption of grape juice significantly inhibited mammary tumor mass at termination and the growth of tumors for the first 5 weeks of detectable tumor development. Consumption of grape juice phenolics by rats also significantly inhibited in vivo mammary DMBA-DNA adduct formation by 34 and 56% for animals fed phenolics at 346 and 692 mg/dL, respectively, compared to controls. Mammary 8-oxo-deoxyguanosine (8-oxo-dG) levels decreased by 25 and 37%, respectively, but the differences were not statistically significant. Liver DMBA-DNA adducts decreased by 10-30%, while 8-oxo-dG adducts remained unchanged, following grape juice intake. Liver glutathione S-transferase activity was significantly increased following grape juice consumption, but only at the highest level of intake. In addition, liver activities of catalase increased and xanthine oxidase decreased significantly, but only at the highest grape juice dose. Thus, these studies indicate that specific constituents or combinations of phytochemicals in purple grape juice can block the initiation stage of DMBA-induced rat mammary tumorigenesis. This tumor inhibitory effect was associated with a suppression of mammary DMBA-DNA adduct formation, which in part may be explained by increased liver activity of the phase II metabolizing enzyme, glutathione S-transferase. Mammary and liver 8-oxo-dG levels were not significantly altered by grape juice consumption. Thus, grape juice constituents appear to have benefit in decreasing susceptibility of the rat mammary gland to the tumor-initiating action of DMBA.
8-Hydroxy-2'-Deoxyguanosine↗
Yeasts isolated from three varieties of grapes cultivated in different locations of the Dolenjska vine-growing region, Slovenia.
The number and diversity of yeasts on grape berry surfaces are influenced by several factors, such as grape variety, degree of grape maturity at harvest, climatological conditions, geographic location, physical damage of grapes, the intensity of pest management etc. Cvicek is a typical Slovene wine, which has obtained a special protection under the Slovene Wine Law for its geographical origin. This blended red wine is produced from different grape varieties (Vitis vinifera L.), mostly from red grapes of Zametovka and Modra frankinja and from white grapes of Kraljevina. The aim of this study was to evaluate the impact of geographical locations in the Dolenjska vine-growing region and to obtain precise information about the influence of different grape varieties on the composition of yeast community on grape berries. The restriction fragment length polymorphism of PCR-amplified fragments from the rDNA gene cluster (PCR RFLP of rDNA) has been used for the differentiation of yeast species. The standard identification procedure has been performed on representative strains that shared identical RFLP profiles. The number of yeasts and yeast species isolated varied according to different grape varieties, Zametovka, Modra frankinja and Kraljevina (V. vinifera L.) and according to different sampling location. On the surface of grape berries 13 different yeast species have been identified. Saccharomyces cerevisiae has not been found.
Cluster Analysis↗
Severe immediate allergic reactions to grapes: part of a lipid transfer protein-associated clinical syndrome.
BACKGROUND: Grape allergy is considered rare; grape lipid transfer protein (LTP; Vit v 1), an endochitinase and a thaumatin-like protein (TLP) have been reported as grape allergens. A considerable number of patients have referred to our department for severe reactions to grapes, and several IgE binding proteins were detected. OBJECTIVES: The aim of this study was to identify and characterise the allergens involved in severe allergic reactions to grapes and describe the population in which they occur. METHODS: Patients with reported severe allergic reactions to grapes (n = 37) are described. Grape allergens were purified/fractionated by a combination of chromatographic techniques, identified by proteomic analysis and biochemically characterised. Immunoreactivity was assessed by blot (inhibitions) and RAST (inhibitions), and skin prick tests were performed with the isolated allergens. RESULTS: All subjects were polyallergic, sensitised and reactive to several additional foods and pollen. All patients were sensitised to grape LTP. A 28-kDa expansin, a 37.5-kDa polygalacturonase-inhibiting protein, a 39-kDa beta-1,3-glucanase and a 60-kDa protein were identified as minor grape allergens. Endochitinase and TLP did not play a role. Inhibition experiments revealed the possible cross-reactive role of LTP for clinical sensitivities to other LTP-containing plant foods, but also the involvement of cross-reactive carbohydrate determinants of minor allergens in IgE cross-reactivity. CONCLUSIONS: LTP is the major grape allergen, while additional minor allergens may contribute to clinical reactivity. Severe grape allergy presents in atopic patients who frequently react to other LTP-containing, plant-derived foods. The 'LTP syndrome' is the appropriate term to describe this condition.
Adolescent↗
Yeasts associated to Malbec grape berries from Mendoza, Argentina.
AIMS: The aims of this work were to evaluate different pre-isolation treatments applied to complete yeast extraction from grapes and to identify the yeast microflora associated to Malbec grapes from two vineyards located in Mendoza, Argentina. METHODS AND RESULTS: The pre-isolation treatments evaluated were shaking, jet streaming with pressurized water and grape blending. The overall results clearly indicated that when a more vigorous and disruptive pre-isolation treatment was applied; larger numbers of yeast species were recovered. The yeast population on healthy and ripe Malbec grapes was in the order of 10(5)-10(6) CFU g(-1). Eight different yeast species were isolated from berries, including Kloeckera apiculata, Metschnikowia pulcherrima, Pichia membranifaciens, Saccharomycodes ludwigii, Candida species (Candida stellata and Candida raghi), Issatchenkia orientalis and Rhodotorula spp. CONCLUSIONS: Grape blending gave the highest yeast counts. Rainfall near grape harvest time quantitatively and qualitatively modifies the yeast microflora. The yeast species identified on ripe grapes from the Mendoza region, partially match those previously documented in different parts of the world related. S. ludwigii has not been previously reported in grapes. SIGNIFICANCE AND IMPACT OF THE STUDY: The report is on yeast microbiota in grapes from Mendoza, Argentina. Saccharomycodes ludwigii was found in high percentage (17%), this species has not been described before on grapes surface. The importance of pre-isolation steps to the recovery of high number of yeasts was shown. Influence of climatic conditions near harvest time on microflora was confirmed.
Argentina↗
Biological traits of Xylella fastidiosa strains from grapes and almonds.
Xylella fastidiosa is a xylem-limited bacterium that causes various diseases, among them Pierce's disease of grapevine (PD) and almond leaf scorch (ALS). PD and ALS have long been considered to be caused by the same strain of this pathogen, but recent genetic studies have revealed differences among X. fastidiosa isolated from these host plants. We tested the hypothesis that ALS is caused by PD and ALS strains in the field and found that both groups of X. fastidiosa caused ALS and overwintered within almonds after mechanical inoculation. Under greenhouse conditions, all isolates caused ALS and all isolates from grapes caused PD. However, isolates belonging to almond genetic groupings did not cause PD in inoculated grapes but systemically infected grapes with lower frequency and populations than those belonging to grape strains. Isolates able to cause both PD and ALS developed 10-fold-higher concentrations of X. fastidiosa in grapes than in almonds. In the laboratory, isolates from grapes overwintered with higher efficiency in grapes than in almonds and isolates from almonds overwintered better in almonds than in grapes. We assigned strains from almonds into groups I and II on the basis of their genetic characteristics, growth on PD3 solid medium, and bacterial populations within inoculated grapevines. Our results show that genetically distinct strains from grapes and almonds differ in population behavior and pathogenicity in grapes and in the ability to grow on two different media.
Culture Media↗
[Characterization of cookies made with deseeded grape pomace].
Characterization of cookies made with deseeded grape pomace. The objective of this study was to evaluate deseeded grape pomace as a potential ingredient to elaborate some food products. Cookies were made with flour containing four levels of deseeded grape pomace (0, 5, 7.5 and 10%). Moisture, protein, ashes, fat, tannins and dietary fiber contents were determined in both the deseeded of grape pomace and the cookies. Besides, color, sensorial acceptability and biological evaluations of Net Protein Ratio (NPR), Apparent Digestibility (AD) and True Digestibility (TD) of Protein were determined to the cookies. Substantial amounts of dietary fiber and ashes were found in both the deseeded grape pomace and the cookies. Total dietary fiber increased while adding more deseeded grape pomace. Cookies were well accepted as observed in the sensory evaluation, showing no significative differences among the four levels of deseeded grape pomace addition. The addition of deseeded grape pomace imparted a darker color to the cookies. The dark color was greater in the samples containing more fiber which was indicated by the lower L color value. Regarding nutritional analysis, the higher the deseeded grape pomace addition, the lower the NPR, AD, and TD values. The NPR was affected in greater degree, although these differences were not significant. It is possible to use deseeded grape pomace as an ingredient to make high fiber cookies with acceptable sensorial attributes.
Dietary Fiber↗
Potential health benefits from the flavonoids in grape products on vascular disease.
In the dog, monkey, a nd human we have shown that 5 ml/kg of red wine or 5-10 ml/kg of purple grape juice but not orange or grapefruit juice inhibits platelet activity, and protects against epinephrine activation of platelets. Red wine and purple grape juice enhances platelet and endothelial production of nitric oxide (Fitzpatrick et al., 1993, Parker et al., 2000). This is thought to be one of the mechanisms whereby purple grape juice significantly improved endothelial function in 15 patients with coronary artery disease. The consumption of purple grape juice by the patients also offered increased protection against LDL cholesterol oxidation, even though all the patients were also taking another antioxidant vitamin E, 400 IU/day. The number of people and animals in these studies was small; however, each one acted as their own control as measurements were made in each before, and then after consumption of red wine or purple grape juice. Thus these studies are thought to be significant. We feel that the results of these studies are encouraging and justify further research on larger numbers of subjects. This suggests that the flavonoids in purple grape juice and red wine may inhibit the initiation of atherosclerosis by one or more of the mechanisms described above. It will take years to fully characterize the potential benefits of daily consumption of red wine or purple grape juice for maintaining a healthy heart. Based on the existing evidence of antiplatelet and antioxidant benefits and improved endothelial function from red wine and purple grape juice, it seems reasonable to suggest that moderate amounts of red wine or purple grape juice be included among the 5-7 daily servings of fruits and vegetables per day as recommended by the American Heart Association to help reduce the risk of developing cardiovascular disease.
Adult↗
Activity of grape extracts from Greek varieties of Vitis vinifera against mutagenicity induced by bleomycin and hydrogen peroxide in Salmonella typhimurium strain TA102.
Several in vivo and in vitro studies have shown that grape extracts could prevent certain steps in carcinogenesis and a few mechanisms have been proposed for this activity. In this study, the potential antimutagenic activity of methanolic and aqueous extracts from two Greek grape varieties of Vitis vinifera against DNA damage induced by reactive oxygen species (ROS) was assessed as a potential novel chemopreventive mechanism, using Salmonella typhimurium strain TA102. The two grape varieties were Assyrtiko (white grapes) and Mandilaria (red grapes), while the oxidant mutagens used were bleomycin (BLM) and hydrogen peroxide (H(2)O(2)). Since it has been considered that polyphenols present in grapes are their most potent biologically active compounds, we also tested the effects of polyphenol-rich fractions as well as some of the more common grape polyphenols on the activity of the two test mutagens. These polyphenols were quercetin, (+)-catechin, (-)-epicatechin, trans-resveratrol, gallic acid and protocatechuic acid. Almost all extracts showed inhibitory activity against both mutagens. On the other hand, polyphenol-rich fractions as well as individual polyphenols at concentrations found in the extracts either did not diminish or did enhance the activity of the mutagens. These results suggest that the protection of DNA from mutations induced by ROS may be one of the mechanisms accounting for the chemopreventive activity of grape extracts. However, it seems that this protective activity may not be attributed to polyphenols but rather to a synergism of many compounds in the grapes.
Antimutagenic Agents↗