IMMUNOSTIMULATORY ACTIVITY OF PICRORHIZA-KURROA LEAF EXTRACT

A 50% ethanolic extract of Picrorhiza kurroa Royle ex Benth. (Scrophul ariaceae) leaves (PKLE) was found to stimulate the cell-mediated and h umoral components of the immune system as well as phagocytosis in expe rimental animals. PKLE elicited a dose-related increase in SRBC, induc ed 4 h (early) and 24 h (delayed) hypersensitivity reactions in mice a nd rats, and horse serum induced Arthus reaction in guinea pigs. It al so enhanced the humoral immune responses in mice and rats and phagocyt ic function of the cells of the reticuloendothelial system in mice. PK LE exhibited no mitogenic activity but augmented the responsiveness of murine splenocytes to T cell mitogens phytohaemagglutinin (PHA) and c oncanavalin A (Con A) and B cell mitogen lipopolysaccharide (LPS E. co il).