Sunita Bhatnagar, Sunita Sahoo, Ajay Kumar Mohapatra and Dipti Ranjan Behera
Phytochemical analysis of Combretum roxburghii leaf and bark samples revealed presence of tannins, saponins and flavonoids. Hexane, dichloromethyl, chloroform, acetone and methanol solvent extracts of leaf and bark were tested for their antioxidant and cytotoxic activity. Positive antioxidant activity but with seasonal variation was found for all the extracts using TLC based standard qualitative 2,2 diphenyl-1-picrylhydrazys(DPPH) assay. However, a seasonal variation was observed in all the extracts. February and October were found to be favorable for the presence of antioxidant property. Acetone extract of Combretum roxburghii showed maximum antioxidant bands(25) and promising antioxidant activity at par with the standard antioxidant ascorbic acid(IC50 9.5microgram). Brine shrimp motility assay at the doses of 25 and 50microgram/ml showed variation in leaf extracts activity from 10 to 98%(February), 26-83%(May), 56-100%(July) and 86-100% in October. In comparison, activity of bark extracts varied differently 9-98%(February), 43- 100%(May), 46-100%(July) and 23-100% for October samples. The potency of leaf extracts could be considered ideal in October where as for bark samples May and July months are significant. Acetone extract of the leaf showed 100 percent cytotoxic activity and was also rich in antioxidant properties, so same was fractionated and a pure antioxidant fraction was isolated which showed good antioxidant activity and moderate amount of cytotoxic activity in live cell assay using Jurkat cells (tumor cell line).
