Suppressive effects of the Chinese herbal remedy Tripterygium wilfordii Hook f on eosinophilia and IgE hyperproduction in mice

The effects of chloroform extract of Tripterygium wilfordii Hook f (TWH extract) on eosinophilia and IgE hyperproduction induced by Mesocestoides cortii infection were examined in BALB/c mice. Mice were infected with M. cortii by intraperitoneal injection of 500 tetrathyridia. The number of peripheral blood eosinophils and IgE levels were examined 21 days after infection. Oral administration of TWH extract once per day for three weeks dose-dependently suppressed peripheral blood eosinophilia and serum IgE levels, which are enhanced by M. cortii infection. Significant suppression of both eosinophilia and serum IgE levels were first noted in mice treated with 300 μg/kg of the extract. The maximum inhibition was observed when mice were treated with 410 μg/kg TWH extract. The ability of spleen cells to produce interleukin (IL)-4 and IL-5 in response to M. cortii somatic antigen was also significantly suppressed when donor mice were treated with more than 400 μg/kg of the extract. Extraxct treatment at a daily dose of 400 μg/kg suppressed costimulatory molecule (CD40 and CD86) expression on spleen cells induced by M. cortii infection. These results may suggest that TWH extract will be a good candidate for immunotherapy in allergic diseases.