Antioxidant activity and antigenotoxicity of seeds and berries extracts from the red, anthocianin-rich Vitis vinifera variety Vinhão and from the white variety Loureiro from the northwestern region of Portugal

Abstract

Introduction: Vitis vinifera grape berries are rich in polyphenols, mainly in seeds1 and the skin. Red varieties are richer due to the presence of anthocianins but there are also considerable differences also among red grape varieties2. The red variety Vinhão from the Northwest of Portugal is highly concentrated in these compounds3, conferring a great potential for biological activities usually associated to polyphenols. Material & Methods: Ethanolic extracts were prepared from seeds and berries from the red variety Vinhão and the white variety Loureiro. Antioxidant analysis was performed with the reducing power, DPPH and iron chelating assays and genotoxicity/antigenotoxicity were assessed with the DNA topology assay and the comet assay with human lymphocytes. Results: Seed extracts from both varieties displayed strong reducing power and DPPH scavenging activities, while red Vinhão berries displayed higher activities than the white variety (Loureiro). Interestingly, all samples did not chelate iron, suggesting that this property is not involved in antioxidant activity. In addition, all extracts were antigenotoxic in the DNA topology assay and the comet assay with human lymphocytes. Conclusion: As antioxidant and antigenotoxic activities were not coincident in some of the extracts (eg, Loureiro berries), different compounds and mechanisms are probably involved in these bioactivities.