Int Immunopharmacol. 2001 Sep; 1(9-10): 1669-77.

Protective effect of a traditional Japanese medicine Hochu-ekki-to (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in infant mice.

Yamaoka Y, Kawakita T, Nomoto K.

Kampo (Traditional Japanese Medicine) and Healthcare Research Laboratories, Kanebo Co. Ltd, Takaoka, Japan.

In this study, the effect of traditional Japanese (Chinese) medicine, Hochu-ekki-to, HOT (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in postneonatal infant mice was examined. Numbers of bacteria in infant mice (infected at 4 weeks of age) were significantly higher than those in adult mice (infected at 8 weeks of age) on day 3 (non-specific resistance phase) and day 5 (specific resistance phase) after infection. Oral administration of 1,000 mg/kg of HOT for 7 days to infant mice reduced bacterial numbers in the liver and spleen at 5 days after the infection. The amount of IFN-gamma and the number of IFN-gamma-producing CD4+ T cells were lower in infant mice than adult mice but those in infant mice enhanced by HOT treatment. HOT also enhanced the antigen-presenting function along with the expression of MHC class II in infant macrophages induced by heat-killed L. monocytogenes. Further, HOT enhanced the IFN-gamma production from infant CD4+ T cells independent of the deficiency in the antigen-presenting function. These findings suggest that HOT induced simultaneously functional maturation of both infant antigen-presenting cells and T cells, and consequently developed an anti-listerial Th1 response.