127ANTI-OXIDANT ACTIVITY OF METHANOL EXTRACT OF CHAETOMORPHA LITOREA HARVEY (GREEN SEAWEED) IN KOOTHANKUZHI COAST, TAMIL NADU, INDIAThe present study was undertaken to assess the antioxidant activity of methanol extract of Chaetomorpha litorea Harvey collected from Koothankuzhi coast in the south east coast of Tamil Nadu, India. Free radical scavenging activity was evaluated using 1,1-diphenyl2-picryl hydrazyl (DPPH) free radical by the method of Mensor et al., and a reducing power by Cupric Reducing Antioxidant Capacity (CUPRAC) assay. The percentage of scavenging activity of DPPH by methanol extract at 100μg, 200μg, 300μg, 400μg and 500μg were 48.14, 59.38, 76.58, 87.27 and 94.64% respectively. At a concentration of 100μg, 200μg, 300μg, 400μg and 500μg of methanol extract, the absorbance were 0.215, 0.272, 0.312, 0.329 and 0.349 respectively. These results similar to those obtained from the DPPH assay in which 500μg showed the highest total antioxidant capacity, followed by 400μg, 300μg and 200μg, and lastly 100μg. The results showed that both DPPH scavenging activity and absorbance were increased when the concentration of methanol extract was also increased. Vitamin C, a strong anti-oxidant was also used as control, and the anti-oxidant potential was compared to all tested samples.johnarock2008@yahoo.comResearch712017Chaetomorpha litorea,DPPH,Antioxidant,Cupric Reducing Antioxidant CapacityJohn Peter Paul, J.,Muthu Sheeba, MCentre for Advanced Research in Plant Sciences (CARPS), Research Department of Botany, St. Xavier’s College (Autonomous), Palayamkottai – 627 002, Tamil Nadu, India,Centre for Advanced Research in Plant Sciences (CARPS), Research Department of Botany, St. Xavier’s College (Autonomous), Palayamkottai – 627 002, Tamil Nadu, India