Immunomodulatory and CNS Effects of Sitoindosides IX and X, Two New Glycowithanolides from zyxw Withania somnifera zy t Shibnath Ghosal,S Jawahar La1 and Radheyshyam Srivastava Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutics, Institute of Technology, Banaras Hindu University, Varanasi-221005, India Sali K. Bhattacharya, Sachidananda N. Upadhyay and Arun K. Jaiswal Department of Pharmacology, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005, India Utpala Chattopadhyay Department of Tumour Immunobiology, Chittaranjan National Cancer Research Centre, Calcutta-700026, India zyx ~ Two new glycowithanolides, sitoindoside zyxwvut IX (1) and sitoindoside X (Z), isolated from Withuniu somniferu 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 zyxwvutsr two compounds, in doses of 100-400 & n o u s e , 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.0.) 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. somniferu, in Ayurveda, to attenuate cerebral function deficits in the geriatric population and to provide non-specific host defence. Keywords: Withuniu somniferu Dun.; C-27-glycowithanolides; sitoindoside-IX, -X, immunostimulatory activity; anti-stress activity; augmenting effects on learning and memory. INTRODUCTION Withania somnifera (L) Dun. (Ashwagandha in Sanskrit), popularly known as the Indian ginseng, is used in Ayurvedic medicine to attenuate cerebral function deficits in the geriatric population, to augment the faculty of learning and memory retention in normal individuals, and to provide non-specific host defence (Sharma, 1978; Pandey, 1986; Ghosal, 1986). Withaferin-A (H in place of glucosyl at C-27 in str. 1) was the first active principle isolated from W. somniferu and also constituted the first member of a new class of phytosteroids, the withanolides (Lavie et af., 1965). Withaferin-A, however, produced immunological effects reminiscent of immunosuppression and not immunostimulation for which Ashwagandha is re- puted. Thus, withaferin-A produced suppression of adjuvant-induced arthritis in rats and locally induced graft (lymphocytes) zyxwvutsr us host reaction in chicks (Fiigner, 1973); it also caused depletion of murine splenic cells zyxwvu in uitro in the presence or absence of a mitogenic stimulant (e.g. PHA; Bahr and Hansel, 1982). Other withanolides, related to withaferin-A, also produced f Part 7 in the series ‘Bioactive Phytosterol Conjugates’. For Part $ Author to whom correspondence should be addressed. 6. see Ghosal er al. (1988). similar immunosuppressant effects (Cassady et af., 1981; BIask6 and Cordell, 1988). The similarity in structure of withaferin-A and analogues with the glucocorticoid, prednisolone, was considered to be responsible for the immunosuppressant activities of the withanolides (Fugner, 1973). Recently, we reported, for the first time, the occurrence of two glycowithanolides, viz. sitoindoside IX (withaferin-A-G7-O-/3-D-g1ucoside) (1) and sitoin doside X (6’-O-palmitoyl-withaferin-A-C2,-O-/3-~- glucoside) (2), in the roots of several cultivated varieties of zyxwvu W. sornnifera (Ghosal et af., 1988). Our earlier observations that free and 0-glycosylated low M, organic compounds, e.g. sitoindosides I-VIII, produced, respectively, immunosuppressant and im- munostimulant effects (Chattopadhyay et al., 1984; Ghosal, 1985; Bhattacharya et af., 1987; Chat- topadhyay et af., 1987a,b) prompted us to evaluate the immunological profile of activity of the newly isolated withanolide glycosides (1 and 2) uis-&uis withaferin-A (the withanolide aglycone). Furthermore, since immunomodulators are also known to influence CNS activity (JankoviC, 1985), the effects of these compounds on some selected CNS parameters w;re evaluated. This was done with a view also to validating or ruling out the claimed therapeutic properties of Ashwagandha as an adaptogenic agent and an augmentor of learning and memory. CCC-095 1-418X/89/0201-02O6 $03.00 zyxwvu 0 Heyden & Son Limited, 1989 PHnOTHERAPY RESEARCH, VOL. 3. NO. 5, 1989 201