Comparative study on the antioxidant capacity of wines and other plant-derived beverages.

Consistent epidemiological data point to a reduced morbidity and mortality from coronary heart disease and atherosclerosis in people consuming plant-derived beverages such as tea or wine. We studied the antioxidant capacity of three red wines (W) and compared it those of tea and herbal "mate" tea infusions. The antioxidant capacity was evaluated measuring: (1) the inhibition of the luminol-induced chemiluminescence assay (TRAP); (2) the inhibition of 2.2'-thiobarbituric-reactive substances (TBARS) formation in liposomes by fluorescence; (3) the protection of Jurkat cells from AMVN-induced oxidation, measuring the oxidation of 5-(and-6)-carboxy-2'7'-dichlorodihydrofluorescein diacetate to a fluorescent derivative. The polyphenolic content was estimated spectrophotometrically and by HPLC with electrochemical detection. All three beverages provided antioxidant protection in the three assays in a dose-dependent manner. Significant and positive correlations were found between antioxidant capacity and total polyphenol content, especially in the Jurkat cell oxidation assay (r: 0.96, p < 0.01). Results suggest that these dietary components could be a source of antioxidants that protect from oxidative stress. Further studies of absorption and metabolism of the active compounds will judge the physiological relevance of these results for human health.