In vitro antioxidant and free radical scavenging activities of Galega purpurea root

Abstract

This study was designed to determine the antioxidant and free radical scavenging properties of methanol extract of Galega purpurea (MEGP) (Papilionaceae) root in various in vitro systems. DPPH radical, superoxide anion radical, nitric oxide radical and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of methanolic extract increased in a dose dependent manner. About 50, 100, 200, 300, 400 and 500 µg of methanol extract of Galega purpurea (MEGP) showed 38.11, 45.71, 51.32, 58.04, 63.44 and 70.28 % inhibition respectively on peroxidation of linoleic acid emulsion. Like antioxidant activity, the effect of MEGP on reducing power increases in a dose dependent manner. In DPPH radical and nitric oxide radical scavenging assays, MEGP exhibited maximum activity of 71.32 and 76.14 % inhibition respectively at the concentration of 125 µg/mL. Moreover, the MEGP was found to scavenge the superoxide generated by PMS/NADH-NBT system. MEGP was also found to inhibit the hydroxyl radical generated by Fenton's reaction, where the IC50 value of MEGP was found to be 61.36 µg/mL and for catechin the IC50 value was found to be 5.27 µg/mL, which indicates the prooxidant activity of MEGP. The amounts of total phenolic compounds were also determined in this study. The results obtained in the present study indicate that the MEGP can be a potential source of natural antioxidant.

Keywords: Galega purpurea; Antioxidant activity; DPPH assay