Effect of ecdysterone on histamine release from rat peritoneal mast cells

Ecdysterone dose-dependently inhibited anti-IgE-induced histamine release from mast cells. Moreover, the rate and extent of histamine release from mast cells induced by Concanavalin A (Con A) are significantly diminished in samples incubated with ecdysterone. Ecdysterone inhibited both the initial and gradual rise in fluorescent response by anti-IgE and Con A. The effects of ecdysterone on the fluorescence response was correlated with the inhibition of histamine release. These results suggest the possibility that the inhibition of histamine release from rat mast cells by ecdysterone might be due to inhibition of Ca2+ mobilization from intracellular Ca2+ storage.