Abstract
Withania somnifera Dunal (Solanaceae) (WS), a well known Indian herbal drug, was examined for its effect on downregulation of antigen-specific IgE antibody response in mice. The extract prepared from the dried roots of WS (WSE) was administered intraperitoneally along with ovalbumin (OVA), a classical allergen, in the presence of aluminum hydroxide as an adjuvant. It exerted a significant suppression of OVA-specific IgE antibody production in BALB/c mice (H-2 d) as determined by passive cutaneous anaphylaxis (PCA). The extract also inhibited the production of OVA-specific IgE antibody, when administered 24 h prior to, and 6 h after, immunization. Further, WSE not only down-regulated OVA-specific IgE antibody response in other haplotypes of mice such as C57Bl/6 (H-2 b) and SWR/J (H-2 q), but it also suppressed the antigen-specific IgE antibody response against other allergens tested in BALB/c mice. Thus, the basic concept for its appli cation in the alleviation of different IgE mediated immunopathological conditions is supported.