Evaluation of Kampo medicines used to treat rheumatoid arthritis in collagen-induced arthritic and pX transgenic mice.

Abstract To evaluate the usefulness of Kampo medicines (traditional herbal medicines) used clinically for the treatment of rheumatoid arthritis (RA), we selected eight of them and examined their effects on collagen-induced arthritic and pX transgenic mice. Among these, Dai-bofu-to, Kanzo-bushi-to, and Makyo-yokkan-to significantly reduced the severity of arthritis in collagen-induced arthritis (CIA) mice. The onset of arthritis was delayed by three Kampo medicines, but only the effect of Makyo-yokkan-to was statistically significant. In addition, three Kampo medicines suppressed the arthropathy of pX transgenic mice, which had developed spontaneously. The onset of arthritis was delayed by 10.7, 8.3, and 15.4 days following treatment with Dai-bofu-to, Kanzo-bushi-to, and Makyo-yokkan-to, respectively. A study of the underlying mechanism showed that Kanzo-bushi-to decreased serum antitype II collagen antibody levels, suggesting that Kanzo-bushi-to possesses immunomodulating activity. This study shows that some Kampo medicines are effective in an induced or spontaneously developed arthritis animal model of human RA.