Abstract :
The current study was designed to evaluate antioxidant activity of the 50% ethanol extract and ethyl acetate of Polygonum nepalense Meissn. Nitric oxide generated from sodium Nitroprusside in aqueous solution at physiological pH, interact with oxygen to produce nitrite ions which were measured by using a modified Griess-llosvany method. The antioxidant activities of aqueous extract, 95% ethanol extract and ethyl acetate fraction was assessed on the basis of the radical scavenging effect of the stable DPPH free radical.100 mg of the 50% ethanol extract and ethyl acetate fraction was taken and was dissolved separately in 10 volumes of ethanol, the resultant solutions were centrifuged at 10000 rpm for 20 min. The ethyl acetate fraction was prepared in order to enrich phenolic content in the fraction. In nitric oxide radical inhibition method ethyl acetate and 50% ethanol extract showed moderate antioxidant activity with IC50 value 185.05±2.59 and 225.00±3.15 μg/mL respectively. 50% ethanol extract and ethyl acetate fraction exhibited good DPPH radical scavenging activity with IC50 values ranging from 64.13±3.37 to 43.87±2.56μg/mL. Thus this study gives support for expanding future investigations of pharmacological activities associated with free radicals.
Keyword :
Antioxidant; Centrifuged; Griess-llosvany; Radicals; Scavenging