Acorus calamus Linn. (Acoraceae) is a medicinal plant widely distributed in India and other eastern countries. The root, rhizome extracts and aromatic oil from the plant has been previously screened for its antioxidant potential. But whole plant extract is yet to be screened for its possible bioactivity and antioxidant property to the best of our knowledge. Therefore, screening of antioxidant property of whole plant extract of A. calamus was chosen for the study. The antioxidant property of ethanol, hydro-ethanol and aqueous extracts was determined by phytochemical screening, estimation of total phenolics and flavonoids and in vitro antioxidant screening models viz. DPPH scavenging activity, nitric oxide scavenging activity, hydroxyl radical scavenging activity, superoxide radical scavenging activity, reductive ability and ferric reducing antioxidant power (FRAP) along with HPTLC analyses. The antioxidant activity of the extracts was compared to standard ascorbic acid to assess its free radical scavenging potential. The ethanol extract showed marked quantity of phenolics and flavonoids and promising antioxidant activity followed by hydro-ethanol and aqueous extracts. IC50 values for the scavenging activities of DPPH, nitric oxide, hydroxyl radical, superoxide radical exhibited by the ethanol extract were 54.82μg/mL, 118.802 μg/mL, 109.85 μg/mL, 38.3 μg/mL respectively. The reductive ability and FRAP values of the extracts were found to increase in a concentration dependent manner. The ethanol extract of A. calamus showed promising in vitro antioxidant activity indicating its potency for therapeutic applications.
