Antiasthmatic property of polyherbal preparation E-721 B.

E-721B and its aqueous extract were studied for its antiasthmatic effect in various experimental models using rats and guinea pigs. E-721B produced significant and dose-dependent inhibition of peritoneal mast-cell degranulation induced by compound 48/80 and egg-albumin in sensitised rats. The inhibition was comparable to that with disodium cromoglycate, ketotifen, and prednisolone. E-721B administered 2 h before the experiment and once daily for seven days significantly increased the preconvulsion time of acetylcholine and histamine aerosol-induced bronchospasm. It also significantly reduced mortality in guineapigs produced by egg albumin-induced anaphylactic shock and also reduced bronchoalveolar fluid eosinophil count in the same animals. E-721B significantly inhibited the acetylcholine and histamine-induced contraction of different isolated smooth muscle preparations from rats and guinea pigs. Contrary to these findings E-721B produced dose-dependent contraction of the rat anococcygeus muscle which was blocked by prazosin. Thus our observations establish the antiasthmatic potential of this herbal formulation.