Antioxidant and Antimutagenic Activities of Taif Grape (Vitis vinifera) Cultivars

Extract of grape Vitis vinifera has been reported to exhibit antioxidant and antimutagenic activities and the phenolic compounds play a vital role in determining these activities. Therefore; the objective of the present study was to evaluate the antioxidant and anti-mutagenic activities as well as the phenolic composition of different grape cultivar extracts collected from Taif region. The grape cultivars namely; Italian, American, Lebanese, Taify_b and Taify_e were collected at maturity stage to represent Taif region cultivars. The total concentrations of phenoles were determined for the five cultivar extracts and results indicated that the concentrations ranged from 115-960 mg L^-1 Gallic Acid Equivalent (GAE). Also, HPLC analysis included was carried out of nine important phenolic compounds namely; Cyanidine chloride, Myricetin, Chrysin, Quercetin, Delphinidine chloride, Malvidine chloride, Naringenin, Galangin and Caffeic acid. Significant differences among cultivars were obtained for each compound. However, the highest cultivar for each compound differed from compound to another. At the same time, DPPH was used to estimate antioxidant activity and the data showed that different grape cultivar extracts were able to quench 47-60% of DPPH radical solution and to exhibited potent radical scavenging activity. Also, antimutagenic activity was measured as a decrease of chromosomal aberrations in bone marrow cells of mice treated with the mutagen Endoxan. Results showed that treatment of mice with grape cultivar extracts resulted in a significant decrease in all types of chromosomal aberrations induced by Endoxan. Also, the anticlastogenic effect was measured using micronulei test and results indicated that all grape cultivar extracts reduced significantly the effect of Endoxan on micronulei test. Finally, treatment of mice with grape cultivar extracts enhanced mitotic index of mice bone marrow cells reduced by Endoxan treatment. The relationship between phenolic compound concentrations and antioxidant capacity was discussed.