Effect of 1-Oxo-5β, 6β-Epoxy-Witha-2-Ene-27-Ethoxy-Olide Isolated from the Roots of Withania somnifera on Stress Indices in Wistar Rats

Objective: Isolation of biologically active fractions and compounds from the roots of Withania somnifera, a plant used extensively as a constituent of rasayana, in Ayurveda and to test their adaptogenic activity on stress indices using the cold-hypoxia-restraint (C-H-R) model. Design: Bioactivity-guided fractionation of an aqueous extract of the roots of Withania somnifera led to the isolation of a new species of withanolide 1-oxo-5β, 6β-epoxy-witha-2-ene-27-ethoxy-olide. Structure elucidation, was carried out using proton nuclear magnetic resonance, infrared (IR), ultraviolet (UV), and mass spectroscopic analysis. Stress-related indices were evaluated, namely serum creatine phosphokinase (CPK) activity, serum lactate dehydrogenase (LDH) activity, serum corticosterone levels, and serum lipid peroxidation (LPO) levels. Results: There was a significant decrease in a serum CPK, LDH, and LPO levels in animals pretreated with (1) fraction-I (20 mg/kg body weight), (2) 1-oxo-5β, 6β-epoxy-witha-2-ene-27-ethoxy-o...