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EVALUATION OF ANTI-OXIDANT AND FREE RADICAL SCAVENGING POTENTIAL OF WITHANIA SOMNIFERA WATER EXTRACT

This study aimed to evaluate the active phytoconstituents and in vitro anti-oxidant as well as free radical scavenging activity of aqueous root extract of Withania somnifera, commonly known as aswagandha. Phytochemical constituents were measured both by qualitatively and quantitatively using spectrophotometric assays. Total antioxidant capacity by phosphomolybdenum reduction, ferric reducing power, cupric ion reducing power and ferrous chelation assays were measured for determination of anti-oxidant activity. In vitro DPPH radical, superoxide radical, hydrogen peroxide, hydroxyl radical and nitric oxide scavenging activities were also estimated using spectrophotometry. Our study showed that the root extract of W. somnifera contains active phytoconstituents like polyphenols, tannins and alkaloids, terpenoids, saponin and reducing sugars. Furthermore, it showed cupric as well as ferric ion reducing capability and selective scavenging ability towards free radicals such as superoxide anion, nitric oxide and hydrogen peroxide. This study elucidated that root extract of W. somnifera possesses concentration dependent superoxide, nitric oxide and hydrogen peroxide scavenging activity. These results suggested the potentials of W. somnifera as a preventive medicine against free radical associated oxidative assault.