Immunomodulatory and CNS effects of sitoindosides IX and X, two new glycowithanolides from <i>Withania somnifera</i>

Abstract

Abstract Two new glycowithanolides, sitoindoside IX (1) and sitoindoside X (2), isolated from Withania somnifera Dun., were evaluated for their immunomodulatory and CNS effects (anti‐stress, memory and learning) in laboratory animals, because the plant extract is used by practitioners of the Indian systems of medicine for similar purposes. The two compounds, in doses of 100–400 μg/mouse, produced statistically significant mobilization and activation of peritoneal macrophages, phagocytosis and increased activity of the lysosomal enzymes secreted by the activated macrophages. Both these compounds (50–200 mg/kg p.o.) also produced significant anti‐stress activity in albino mice and rats and augmented learning acquisition and memory retention in both young and old rats. These findings are consistent with the use of W. somnifera , in Ayurveda, to attenuate cerebral function deficits in the geriatric population and to provide non‐specific host defence.