In vitro antioxidative activity of withania somnifera aqueous root extract

The present study was undertaken to evaluate the antioxidant and radical scavenging potentials of Withania somnifera aqueous root extract (WRE) by 3 different assays: DPPH Free radical scavenging assay, Fe²⁺ chelating assay and reducing power assay. The results showed that DPPH scavenging activity increased with increase in concentration of WRE when compared to standard antioxidant, butylated hydroxytoulene (BHT). Reducing power of WRE was significantly less when compared to BHT but increased dose dependently with maximum activity at highest concentration (1 mg/ml). The aqueous extract of WRE disrupted ferrous-ferrozine complex and showed increase in chelating activity in a dose dependent manner. WRE contains phenolic compounds and glycowithanolides (Sitoindosides VII-X and Withaferin A) which donates electron and hydrogen to protect against free radical mediated autoxidation of unsaturated lipids. It is, therefore, inferred that WRE possess in vitro antioxidant activity.