Solanum lyratum inhibits anaphylactic reaction and suppresses the expression of L-histidine decarboxylase mRNA.

We investigated the effect of aqueous extract of Soloanum lyratum THUNB. (Solanaceae) (SLAE) on anaphylactic reaction. The mast cell is widely thought to contribute to the acute changes associated with anaphylaxis. SLAE inhibited skin mast cells-mediated anaphylactic reaction activated by anti-dinitrophenyl (DNP) IgE. SLAE dose-dependently inhibited histamine release in mouse peritoneal mast cells activated by anti-DNP IgE or substance P. Substance P increased steady state levels of L-histidine decarboxylase (HDC) mRNA in mouse mastocytoma P-815 cells. Northern-blot analysis demonstrated that significantly reduced level of the mRNA of HDC was expressed in mast cells treated with SLAE, compared to that without SLAE. We conclude that SLAE directly affect IgE-mediated anaphylactic reaction and substance P-induced HDC mRNA over-expression.