Immunomodulating effect of a traditional Japanese medicine, hachimi-jio-gan (ba-wei-di-huang-wan), on Th1 predominance in autoimmune MRL/MP-lpr/lpr mice.

Hachimi-jio-gan (Ba-Wei-Di-Huang-Wan, HMG), a traditional Japanese herbal medicine, has been used for disorders accompanying aging. Oral administration of HMG from 8 to 16 weeks of age to MRL/lpr mice as a lupus-like autoimmune model ameliorated significantly some nephritis parameters, proteinuria and immune complex deposition in the kidney. Further, HMG reduced significantly the degree of lymphadenopathy and the serum level of immunoglobulin (Ig) G2a anti-dsDNA specific auto-antibody, even at 12 weeks of age. Simultaneously, interferon (IFN)-gamma production from anti-CD3 stimulated B220- T cells was suppressed by HMG, whereas interleukin (IL)-4 production was promoted. Examination of cytokine mRNA expressions in CD4 positive cells showed clearly that T cell differentiation was shifted from T helper (Th)1 to Th2 predominance by HMG. Furthermore, we demonstrated that HMG suppressed IL-12 mRNA expression in spleen cells which is a marker of Th1 predominance in MRL/lpr mice. These results suggested that HMG modulated an imbalance toward Th1 predominance in MRL/lpr mice through inhibition of IL-12 production and ameliorated autoimmune disorders.