Comparative Analysis of Aqueous Extracts of Amaranth and Coriander in Scavenging Free Radical Activity and Protection of DNA against Oxidative Damage

Green leafy vegetables are considered to be of immense therapeutic potential since ancient days. Amaranth (Amaranthus gangeticus) and coriander (Coriandrum sativum) are green leafy vegetables widely distributed across the world and most of which are consumed as daily diet. Present study was aimed to investigate the antioxidant potential of boiled aqueous extract of leaves of these green vegetables in terms of their total antioxidant capacity, free-radical scavenging using alpha, alpha-diphenyl-beta-picryl hydrazyl (DPPH center dot) and hematoxilin, anti-lipid peroxidation, metal chelating and ability to protect DNA against oxidative damage. Results of all the in vitro free-radical generating assay systems demonstrated positive scavenging efficiency for the extracts of both vegetables. The IC50 values for boiled aqueous extract revealed that DPPH center dot radical scavenging ability were almost same for both the vegetables. The extract showed marked confirmed protective effect on calf thymus genomic DNA against oxidative damage and anti-lipid peroxidation activity against ferrous ions on goat liver homogenates. The extract of amaranth showed better anti-lipid peroxidation activity as compared to coriander extract. The optimum DNA protecting ability against free radical-induced damage was 250 mu g and 350 mu g for aqueous extracts of amaranth and coriander, respectively. The results, which suggest that amaranth and coriander have nutritive as well as medicinal values against free-radical-associated oxidative damage and related degenerative diseases involving metabolic stress, genotoxicity and cytotoxicity, highlight the importance of undertaking scientific studies of the commonly used vegetables with traditional claims of pharmaceutical significance.