ANTIOXIDANT STUDIES OF METHANOLIC EXTRACT OF RANDIA DUMETORUM LAM.

Summary Antioxidants, or anti-oxidation agents, reduce the effect of dangerous oxidants by binding together with these harmful molecules, decreasing their destructive power. Antioxidants can also help to repair damage already sustained by cells. Randia dumetorum Lam. is a plant of medicinal important belongs to the family Rubiaceae. Fruit of this plant has been used as a folk medicine to cures abscess, ulcers, inflammations, wounds, tumors, skin diseases, piles and have antibacterial activity. The qualitative and quantitative estimation of major constituents of crude extract was carried out using standard methods and contained total phenol (0.292 mg gallic acid equivalent) and total triterpenoids (17.66%). Keeping in view of the cited activity, it is contemplated to screen the Methanolic extract of fruit for in vitro antioxidant activity using different models viz. reducing power assay, DPPH radical scavenging assay, nitric oxide scavenging assay, super oxide scavenging assay, lipid peroxidation assay, total antioxidant capacity and non-enzymatic haemoglobin glycosylation assay . The results were analyzed statistically by regression method. The % scavenging activity at different concentrations was determined and the IC50 value of the extracts was compared with that of standard, ascorbic acid. Its antioxidant activity was estimated by IC50 value and the values are 50.51 µg/ml (reducing power assay), 41.03 µg/ml, (DPPH scavenging assay), 86.71 µg/ml (nitric oxide scavenging assay), 81.11 µg/ml (super oxide scavenging assay) and 124.39 µg/ml (lipid peroxidation assay). In total antioxidant capacity assay, 1 mg of extract is equivalent to 43 µg of ascorbic acid. It showed 53.74% inhibition of haemoglobin glycosylation. In all the testing, a significant correlation existed between concentrations of the extract and percentage inhibition of free radicals, metal chelation. The antioxidant property may be related to the polyphenols present in the extract. These results clearly indicate that Randia dumetorum is effective against free radical mediated diseases.