Role of grape extracts of different cultivars in radioprotection

Abstract

Radiation therapy uses ionizing radiation (IR) to kill cancer cells. But during radiotherapy normal cells are also damaged and killed. IR causes oxidative stress through the generation of reactive oxygen species (ROS) in the living cells leading to further oxidative damage to biomolecules such as DNA, RNA, protein, lipid and ultimately causes apoptosis. Polyphenolic compounds are known to mitigate the damaging effects induced by radiation. Grape (Vitis vinifera) contains a variety of bioactive phytochemicals. newlineIn this study, we determine and compare few phytochemicals and antioxidants and the free radical scavenging activities and antioxidant activities of grape extracts of different cultivars with the potential for radiation protection. We also evaluate and compare the radioprotective effect of skin, pulp and seed extracts of different grape cultivars against and#61543;-radiation induced oxidative stress in goat liver tissue ex-vivo; membrane damage on red blood cells (RBCs); oxidative stress, DNA damage, apoptosis and gene expression in human lymphocytes. newlinePolyphenols, flavonoids and antioxidants are known to mitigate radiation induced damage by scavenging free radicals. In our study, we found that the total phenolics, flavonoids and ascorbic acid content significantly (Plt0.05) differed among extracts (skin, pulp and seed) within the same grape cultivar and also varied among different cultivars (Thompson seedless, Kishmish chorni, Flame seedless and Red globe). Seed extracts contain maximum amount of total polyphenols, total flavonoids and ascorbic acid, followed by skin and then followed by pulp. Among the seed of different cultivars, Kishmish chorni seed possesses maximum amount of total polyphenols, flavonoids and ascorbic acid. Among the grape skin of different cultivars, Flame seedless cultivar showed highest concentration of polyphenols, flavonoids and ascorbic acid. The amount of glutathione (GSH) and activities of catalase, glutathione S-transferase (GST) and superoxide dismutase (SOD) significantly