Protective roles of Cimin grape tissues on oxidative stress markers in the cellular system model.

AIM To analyze the phenolic composition of the Cimin grape, which is 1 of 2 grape varieties with a protected geographical indication in Turkey and is used locally to treat the symptoms of some disorders such as impotence and cardiovascular diseases, and to investigate its antioxidant potency against oxidant mediators in the models of intra- and extracellular surroundings. MATERIALS AND METHODS Cimin grape samples were classified into 5 groups according to the grape's tissues and the extraction solvents used. Free radical scavenging (DPPH) and antilipid peroxidation product [thiobarbituric acid reactive substance (TBARS) and conjugated diene (CD)] levels of the grape tissues were extrapolated from the measurement of total phenolic and individual monomeric flavanol contents in each extract. RESULTS The seed methanolic extract had the highest total amount of flavanols, with the amount of catechin at 4.034 mM. The DPPH activities of the seed extracts were 2- to 10-fold higher than those of the other samples. The seed extract-treated erythrocyte and unfractionated human plasma also showed lower TBARS and CD values. In addition, regeneration of glutathione was more obvious in grape seed extracts than in the rest of the tissues. CONCLUSION The underlying mechanism of these changes can be related mainly to increased antioxidant status. Cimin grape consumption may have beneficial effects on health maintenance.