Effect of hachimi-jio-gan on immunoglobulin A producing cells in Peyer's patch by oral administration.

We investigated here the effect of Hachimi-jio-gan (HJ), a Japanese and Chinese herbal medicine, on immunoglobulin A (IgA) producing cells in Peyer's patch. The oral administration of HJ (0.1, 0.2, 1.0 g/kg for 2 d) enhanced the IgA producing cells almost 2-fold compared with the control group on days 4 and 5 after the administration. Furthermore, HJ augmented antigen-specific IgA (anti-SRBC IgA) production. These results suggested that HJ acted as a polyclonal B cell activator. To characterize its active ingredients, HJ was fractionated by ethanol precipitation. The crude polysaccharide fraction (EP fraction) showed the ability to augment IgA production, but low molecular weight fraction (ES fraction) did not. These results suggest that the crude polysaccharide fraction might be responsible for the augmentation of IgA production by HJ.