Abstract

Cheaper and safer antioxidants of natural origin is the focus of research in recent times due to increased in safety concerns about synthetic antioxidants. The effects of four extracting solvents that is, ethanol, methanol, n-Hexane and pet ether and two extraction techniques that is, simple maceration and hot percolation (Soxhlet apparatus) were investigated on the antioxidant activity of pods, leaves, barks and flowers of Cassia fistula. 1,1-diphenyl-2-picryl-hydrazyl (DPPH) was used as standard free radical while ascorbic acid (Vitamin C) and Quarcetin were used as standard anti oxidants. Experiments revealed that extracts have solvent-dependent and technique-dependent antioxidant effects. Using the simple maceration technique, 70% methanolic v/v leaf extract showed 89% DPPH scavenging activity when ascorbic acid was taken as standard and 84.7% when quercetin was taken as standard. However, the percentage inhibition of a similar concentration of pods, barks and flowers extract were 66, 81 and 83.4%, respectively, using simple maceration and ascorbic acid as a standard. However, extraction carried out by Soxhlets apparatus showed less free radical scavenging activities.

Key words: Cassia fistula, soxhlet apparatus, antioxidant activity.