Antioxidant Activities of Two Medicinal Vegetables: Parkia Javanica and Phlogacanthus Thyrsiflorus

Antioxidant activity of aqueous, ethanolic and methanolic extracts of two common vegetables of North-eastern states of India, Parkia javanica and Phlogacanthus thyrsiflorus have been estimated by three different methods: DPPH free radical scavenging, FRAP and Ascorbate-Iron (III) induced lipid peroxidation inhibition assay. The activity was expressed as both mg trolox and ascorbic acid equivalent (TE and AAE) per gram of extract for DPPH and FRAP assay. Methanolic extract of P.thyrsiflorus showed highest value of 61.07 and 77.29 mg TE/gm of extract in DPPH and FRAP assay respectively whereas its ethanolic extract caused maximum inhibition of lipid peroxidation. The extracts were also tested for its total phenol content (TPC) and correlated with antioxidant activity. In data analysis it was found that there was a positive correlation between TPC and antioxidant activity of the extracts (DPPH, R2 = 0.6247; FRAP, R2 = 0.785; Lipid peroxidation inhibition, R2 = 0.3606). From this study it can be concluded that these two medicinal vegetables has high antioxidant property and should further be investigated for novel drug discovery.