Antioxidants from defatted Indian Mustard (Brassica Juncea) protect biomolecules against in vitro oxidation

Indian mustard seeds were defatted by distillation with hexane and the residue extracted with methanol was analyzed for potential antioxidants; ascorbate, riboflavin, and polyphenols. Gallic acid (129.796 mu g), caffeic acid (753.455 mu g), quercetin (478.352 mu g) and kaempferol (48.060 mu g)/g dry seeds were identified by HPLC analysis of the extract. DPPH free radical scavenging activity and protection of lipids, proteins and DNA against metal induced oxidation was examined. Defatted mustard seed remnant had excellent free radical scavenging activity and protects biomolecules with IC50 value 2.0-2.25 mg dry seed weight. Significant content of polyphenols in methanol extract of defatted seeds accounts for high antioxidant potential. We are the first to report the detailed analysis of antioxidant composition and protection of biomolecules against oxidative damage by methanol extract of mustard seed remnant after oil extraction.