Evaluation Of The Physicochemical Stability And Biological Activity Of Withanolide Rich Fraction From Withania Somnifera Root By Hptlc And Cyclic Voltammetry: A Simple, Reliable, And Cost-Effective Approach

Stability testing of plant extract is an important part during developing new therapeutic alternatives for array of maladies. Withanolides, an active phytoconstituents from Withania somnifera, are susceptible to various experimental conditions. The aim was to evaluate the physicochemical stability and biological activity of the standardized extract of Withania somnifera (ashwagandha) root over a six months. Withanolide Rich Fraction (WRF) was prepared from ashwagandha root and characterized by using HPTLC method. The stability of WRF was determined with half-life (t(1/2)) and shelf-life (t(99)). The total antioxidant capacity was also determined by using a cyclic voltammeter over a six months. Additionally, the anti-inflammatory potential of fresh and stored WRF (200 mg/kg) were evaluated using carrageenan-induced rats paw edema model. The HPLTC analysis suggested WRF exhibits 5 withanolides components viz., withanoside V (WS V), withaferin A (WF A), 1,2 deoxywithastramonolide (1,2 DWM), withanone (WNN), withanolide A (WN A), and withanolide B (WN B). The stability of WRF decreased over six months reflected by decreased in area under curve (AUC), t(1/2), and t(99) of these 5 withanolides components. The cyclic voltammeter analysis suggest that six-month storage moderately reduces antioxidant capacity of WRF and followed 1st order kinetics. Additionally, six-month storage of WRF showed significant inhibition in carrageenan-induced paw inflammation, however, there was no any significant difference in the percent inhibition of inflammation as compared to freshly prepared extract. Findings of present investigation suggests that withanolides components from ashwagandha showed sensitivity towards physicochemical stability and biological activity. The antioxidant and anti-inflammatory potential of Withania somnifera reduces via first order kinetics over a six months when it stored at room temperature.