Free Radical Scavenging Activity ofGrangea maderaspatanaPoir.

The present study was aimed to investigate the antioxidant activities of the methanolic extract of Grangea maderaspatana Poir (Compositae). The antioxidant activity of the extract was evaluated using fi ve in vitro assays and was compared to standard antioxidant (Ascorbic acid). Further, Total phenolic contents of the extract were determined by using Folin-Ciocalteu method in order to evaluate a relationship between the antioxidant activity and the phytochemical constituents. The total phenolic content was found to be 121.45 ± 2.56 μg Gallic acid equivalent of phenol. The extract and ascorbic acid were found to have different levels of antioxidant activity in the systems tested. Methanolic extract of Grangea maderaspatana (GMME) exhibited significant (p<0.05) reducing power ability, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, nitric oxide radical scavenging activity, hydrogen peroxide (H 2 O 2 ) scavenging activity and inhibition of β-carotene bleaching. In DPPH radical scavenging activity NO scavenging activity,H 2 O 2 scavenging activity, and β-carotene bleaching assay the IC 50 values obtained for GMME were found to be 46.55 ± 1.67 μg/mL,120.73 ± 0.694 μg/mL, 30.54 ± 1.11 μg/mL and 209.73 ± 4.63 μg/mL respectively and for Ascorbic acid the IC 50 values were found to be 24.96 ± 1.95 μg/mL, 236.37± 1.394 μg/mL, 57.34± 1.29 μg/mL and 339.16 ± 5.30 μg/mL respectively. The antioxidant property depends upon concentration and increased with increasing amount of the extract. The free radical scavenging and antioxidant activities may be attributed to the presence of phenolic and flavonoid compounds present in the extract. The results obtained in the present study indicate that Grangea maderaspatana is a potential source of natural antioxidants.