Evaluation of E-721B, an indigenous herbal combination in experimental models of immediate hypersensitivity

E-721B, an indigenous herbal combination was investigated for its usefulness in immediate hypersensitivity using different animal models. The drug inhibited the mast cell degranulation induced both by antigen and compound 48/80, the Schultz-Dale response in sensitized guinea pig ileum smooth muscle preparation and the production of precipitating antibodies in 50% of tested rats. It also inhibited the mast cell degranulation in passively sensitized rats indicating its suppressive action on production of reaginic antibody (IgE). However, the drug did not inhibit the 48 hours passive cutaneous anaphylaxis reaction in rats, indicating that a single dose of the drug does not have cromoglycate like properties. All the above results indicate the inhibitory effect of E-721B on immediate hypersensitive reactions such as asthma.