No abstract

Beers are a source of dietary flavonoids; however, there exist differences in composition, alcohol concentration, and beneficial activities. To characterize these differences, three kinds of lager beer of habitual consumption in Spain, dark, blond, and alcohol-free, were assayed for total phenolic content, antioxidant activity, superoxide and hydroxyl radical scavenging activities, and in vitro inhibitory effect on DNA oxidative damage. Furthermore, their melanoidin content and correlation with antioxidant activity were evaluated. Dark beer contained the highest total phenolic (489 +/- 52 mg/L) and melanoidin (1.49 +/- 0.02 g/L) contents with a 2-fold difference observed when compared to the alcohol-free beer. For the three kinds of beer, the antioxidant activity measured as N,N-dimethyl-p-phenylenediamine dihydrochloride concentration was strongly correlated with the total polyphenol content (R(2) = 0.91102, p < 0.005) and with the melanoidin content (R(2) = 0.7999, p < 0.05). The results support a positive effect of beers on the protection of DNA oxidative damage, by decreasing the deoxyribose degradation, DNA scission (measured by electrophoresis), and inhibition of 8-hydroxydeoxyguanosine (8-OH-dG) formation. Furthermore, a correlation between the total melanoidin content (R(2) = 0.7309, p < 0.01) and inhibition of 8-OH-dG was observed.

No abstract

The mandarin juice consumption with a reduced calorie diet positively affects the antioxidant defence and produces a decrease in biomarkers of oxidative stress in obese children.

No abstract

The importance of the antioxidants contained in foods is well recognized both for preserving the foods themselves and for supplying essential antioxidants in vivo. Among these, the melanoidins formed during food processing and storage represent a significant part of our diet, with an average intake of several grams per day. Melanoidins exhibit antioxidant properties in vitro through their protective effect against reactive oxygen species. Here we investigated the protective effect of the model glucose-glycine melanoidins on oxidative stress induced by adriamycin in hepatocytes isolated from rats. The study was performed by examining cell toxicity (lactate dehydrogenase) release in the medium, lipoperoxidation, protein oxidation, GSH and ATP levels. The addition of 50 µg glucose-glycine melanoidins to the hepatocytes treated with 25 and 75 µM of adriamycin decreased the cell oxidative damage. The cell toxicity, lipoperoxidation and the protein oxidation decreased significantly in the presence of melanoidins. The effect of melanoidins on the intracellular antioxidant GSH when co-incubated the adriamycin-hepatocytes with melanoidins resulted in a recovery of GSH levels. Furthermore, from the study of ATP levels we found that the damage to the mitochondria induced by adriamycin is decreased in the presence of melanoidins. According to these results, we suggest that melanoidins are capable of preventing cell oxidation. Based on these mechanisms, the ingestion of melanoidins present in food could be play a role important in the prevention of oxidative damage and prevention the diseases related to free radicals.

Severe childhood obesity is associated with oxidative stress. Thus, providing foods with high antioxidant capacity in addition to a hypocaloric diet is crucial for the treatment of obese children.

The consumption of non-alcoholic beer appears to enhance the antioxidant capacity of breastmilk and decrease oxidative damage in breastfeeding mothers.