IN VITRO ANTIOXIDANT ACTIVITY OF DRYNARIA QUERCIFOLIA L. RHIZOME G Prasanna* and M Chitra PG and Research Department of Biochemistry, Sengamala Thayaar Educational Trust Women’s College, Sundarakkottai, Mannargudi, Thiruvarur Dt, Tamil Nadu, India

Antioxidant activity of methanolic extract of Drynaria quercifolia rhizome at different concentrations (100, 200 and 300μg/ml) were studied in various in vitro models. Results were compared with standard ascorbic acid. Antioxidant activity of extract was increased with the increasing concentration. The order of antioxidant potential according to models were found to be highest in nitric oxide scavenging activity followed by total antioxidant activity, reducing power assay and hydrogen peroxide scavenging activity. IC50 values were found to be 180, 230, 230 and 240μg/ml respectively in nitric oxide scavenging activity, total antioxidant assay, reducing power assay, and hydrogen peroxide scavenging activity. In conclusion, the results of present analysis demonstrated that Drynaria quercifolia rhizome possess potential antioxidant activity, and could be used as a viable source of natural antioxidants. INTRODUCTION: Free radicals play a major role in the development of chronic and degenerative diseases such as cancer, arthritis, autoimmune disorders, aging, cardiovascular and neurodegenerative diseases 1-3 . Imbalance in the formation and neutralization of free radicals generates a condition called oxidative stress, which affect the cell membranes and major biomolecules 4-6 . Oxygen free radical can initiate peroxidation of lipids, which in turn stimulates glycation of protein, inactivation of enzymes and alteration in the structure and function of collagen basement and other membranes, and play a role in the long-term complication of diabetes 7, 8 . QUICK RESPONSE CODE DOI: 10.13040/IJPSR.0975-8232.6(7).3061-66 Article can be accessed online on: www.ijpsr.com DOI link: http://dx.doi.org/10.13040/IJPSR.0975-8232.6(7).3061-66 Antioxidants are radical scavengers which are an important in the prevention of human diseases. Naturally occuring antioxidants possess the ability to reduce the oxidative damage associated with many diseases 9-11 . These natural antioxidants may have free radical scavengers, reducing agents, potential complexes of pro-oxidant metals, quenchers of singlet oxygen etc. 12 . Antioxidant compounds like phenolic acids, polyphenols and flavanoids scavenge free radicals such as peroxide, hydroperoxide or lipidperoxyl and thus inhibit the oxidative mechanism that lead to degerative diseases 13 . The plant based antioxidants can be derived from any part of plant’s like bark, leaves, flowers, roots, fruits etc that is any part of the plant may contain active compounds 14 . Therfore, the importance of search for natural antioxidants has greatly increased in recent years. The researchers have focused on natural antioxidants and numerous crude extracts and pure natural compounds have been reported to possess antioxidant properties 15 . In the current