Abstract
Withania somnifera (commonly known as "Ashwagandha"), Asparagus racemosus (Shatavari) and Picrorhiza kurroa (Kutki) are conventional herbal drugs used in Indian traditional system of medicine. They have been claimed to possess aphrodisiac, sedative, rejuvenative and life prolonging properties. In he present study, immunomodulatory properties were studied using the three models; viz., delayed type hypersensitivity reaction, neutrophil count and humoral antibody response in mice. The dried roots of W. somnifera, A. racemosus and P. kurroa were powdered and the ethanolic extract was obtained and standardized by High Performances Thin Layer Chromatography (HPTLC) method. The dried extract was administered orally as 0.1% suspension of carboxymethylcellulose at a dose of 100 mg kg(-1) of body weight. After 14 days of oral administration immunomodulatory activity was done in male Swiss albino mice with and without an immunosuppressive agent Cyclophosphamide. The ethanolic extract of these herbs exhibited significant foot pad thickness in Delayed Type Hypersensitivity (DTH) reaction when measured after 24 h of sheep RBC antigen challenge in mice. W. somnifera revealed enhanced neutrophil counts and humoral antibody response. All the three selected herbs have immunostimulatory effects in common however, the overall order of immunostimulatory activity was established as W. somnifera>A. racemosus>P. kurroa.