Effect of Schizonepeta tenuifolia extract on mast cell-mediated immediate-type hypersensitivity in rats

We investigated the effect of an aqueous extract of Schizonepeta tenuifolia (STAE) on mast cell-mediated immediate-type hypersensitivity. STAE inhibit ed systemic allergic reaction induced by compound 48/80 in rats dose-depend ently. STAE also inhibited plasma histamine levels induced by compound 48/8 0. STAE inhibited local allergic reaction activated by anti-dinitrophenyl ( DNP) IgE. In addition, STAE does-dependently inhibited histamine release fr om rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. However, STAE had a significant enhancing effect on anti-DNP IgE-indu ced tumor necrosis factor-alpha (TNF-alpha) production from RPMC. These res ults indicate that STAE inhibits immediate-type hypersensitivity and sugges t that STAE can selectively activate the TNF-alpha production from RPMC.