Effect of ganhuangenin obtained from Scutellaria radix on the chemical mediator production of peritoneal exudate cells and immunoglobulin E level of mesenteric lymph node lymphocytes in Sprague-Dawley rats.

We previously showed that ganhuangenin (GHG) has beneficial antioxidative properties against lipid peroxidation in tissues of Sprague-Dawley (SD) rats. In this study, the effect of GHG on immunoglobulin E (IgE), histamine and leukotriene B(4) (LTB(4)) levels of cells isolated from SD rats was examined with regard to the manifestation of the type I allergic reaction. We showed that GHG inhibited the IgE production of mesenteric lymph node (MLN) lymphocytes. In the presence or absence of concanavalin A (ConA), the concentration used did not exert a toxic effect against MLN lymphocytes. Interestingly, the increase in the IgE content and lipid peroxidation induced by ConA was alleviated in the presence of GHG. Moreover, GHG also inhibited histamine release from the peritoneal exudate cells stimulated with a calcium ionophore, A23187, or with the histamine releaser, compound 48/80. In the case of LTB(4), GHG markedly inhibited its release at a concentration of 100 microM. Thus, it is concluded that GHG may block the common pathway for the release of histamine and LTB(4), and that the IgE level is responsible for the lipid peroxidation induced by ConA. Copyright 2002 John Wiley & Sons, Ltd.