ANTIOXIDANT ACTIVITY OF HALOPHILA OVALIS AND HALOPHILA BECCARII (HYDROCHARITACEAE): TWO IMPORTANT SEAGRASS SPECIES OF CHILIKA LAGOON, INDIA

Objective: The present study was undertaken to evaluate the total phenolic and flavonoid content and the antioxidant property of two important seagrass species namely, Halophila ovalis and Halophila beccarii occurring in Chilika lagoon, Odisha, India. Methods: Total Phenolic Content (TPC) of the extracts of Halophila species was determined by Folin-Ciocalteu method with little modifications and the total flavonoid content (TFC) was measured by aluminum chloride colorimetric assay. The antioxidant activity of different extracts was investigated by DPPH and ABTS radical scavenging activity. IC50 values were calculated for the DPPH and ABTS methods. Result: The study revealed that the methanol extract of H. ovalis has greater antioxidant activity than H. beccarii. Methanol extract of both the species (H. ovalis and H. beccarii) was found to possess high phenolic content at value of 70.25 mg GAE/g of extract and 48.53 mg GAE/g of extract respectively. Similarly flavonoid contents was found highest in methanol extract for both H. ovalis (76.82 mg quercetin equivalent/ g of extract) and H. beccarii (64.28 mg quercetin equivalent/ g of extract). The antioxidant activity of different extracts of these two species were evaluated using DPPH and ABTS radical assay. The methanol extract of both H. ovalis and H. beccarii showed high radical scavenging activity with IC50 values of 37.77 μg/ml and 52.25 μg/ml for DPPH and 25.62 μg/ml and 45.45 μg/ml for ABTS respectively. Conclusion: The study revealed the potential of the Halophila species as natural sources of antioxidants having considerable commercial importance.