A novel function of red wine polyphenols in humans: prevention of absorption of cytotoxic lipid peroxidation products

Abstract

Current evidence supports a contribution of polyphenols to the prevention of cardiovascular disease, but their mechanisms of action are not understood. We investigated the impact of red wine polyphenols on postprandial cytotoxic lipid peroxidation products (MDA) levels in humans. In a randomized, crossover study, the effect of red wine polyphenols on postprandial levels of plasma and urine MDA was investigated. Three meals of 250 g turkey cutlets supplemented by water (A); soaked in red wine after heating plus 200 ml of red wine (B); or soaked in red wine prior to heating plus 200 ml of red wine (C) were administered to 10 healthy volunteers. Subject baseline plasma levels of MDA were 50 +/- 20 nM. After a meal of turkey meat cutlets, plasma MDA levels increased by 160 nM (P<0.0001); after (B) there was a 75% reduction in the absorption of MDA (P<0.0001). However, after (C), the elevation of plasma MDA was completely prevented (P<0.0001). Similar results were obtained for MDA accumulation in urine. Our study suggests that red wine polyphenols exert a beneficial effect by the novel new function, absorption inhibition of the lipotoxin MDA. These findings explain the potentially harmful effects of oxidized fats found in foods and the important benefit of dietary polyphenols in the meal.

Hypoglycaemic activity of four plant extracts traditionally used in South Africa for diabetes

“…Tshikalange (2007) isolated various triterpenoides such as lup-20(30)-ene-3,29-diol, (3␣)-(9Cl), lup-20(29)-ene-30-hydroxy-(9Cl), taraxastanonol and ␤-sitosterol and a phenolic derivative and depside namely ataric acid and atranorin from Elaeodendron transvaalense, these substances were however not tested for their anti-diabetic activity, except ␤-sisosterol that demonstrated ␣-glucosidase and ␣-amylase inhibition (Nkobole, 2009). Drewes and Mashimbye (1993) isolated the phenolic compound, elaeocyanidin as well as the gallotannins and ouratea proanthocyanidin A from Elaeodendron transvaalense and it is likely that these compounds are responsible for the hypoglycaemic activity (Gruendel et al, 2007;Gorelik et al, 2008). In literature the use of Schkuhria pinnata as an anti-diabetic agent is numerous but no literature could be found on the chemical analysis and testing for it's hypoglycaemic activity.…”

Heme Iron Intake, Dietary Antioxidant Capacity, and Risk of Colorectal Adenomas in a Large Cohort Study of French Women

“…Oxidation leads to the formation of secondary reactive end products, such as malondialdehyde or 4-hydroxynonenal, that are cytotoxic and genotoxic (5). The heme-induced lipid peroxidation can be inhibited in the gastrointestinal tract by some polyphenols and vitamins, redox components of plant origin, that are able to hamper the damaging effect of free radicals (15)(16)(17)(18)(19)(20)(21). To consider the global antioxidant capacity as well as synergistic interactions between dietary antioxidants, the assessment of dietary non-enzymatic antioxidant capacity (NEAC) has been applied to epidemiologic studies as well as human intervention trials (22,23).…”

Health Aspects of Thermal Food Processing

“…Pří-kladně taurin obsažený především v neutrofilech a erytrocytech, sítnici a nervové tkáni (32). Taurin má navíc hypoglykemický efekt (33). Dipeptid karnosin obsahující histidin a β-alanin, snižuje tvorbu malondialdehydu (MDA) a brání lipooxidaci, a tedy snižuje tvorbu ALE a též i AGE (34).…”