Clinical and immunomodulatory effects of fun-boi, an herbal medicine, on collagen-induced arthritis in vivo.

OBJECTIVE Crude preparations of Fun-boi (Stephania tetrandra), a traditional antirheumatic herb, have been reported to have immunomodulatory effects on both cell-mediated and humoral immunity in vitro, but little is known about the mode of action in vivo. The objective of this study was therefore to evaluate the efficacy of Fun-boi against arthritis and its effect on the immune system. METHODS Mice were divided into the following 3 groups of 7 mice each: 1) a normal group, not treated to cause collagen-induced arthritis (CIA), received water orally; 2) a control group with CIA received water orally; and 3) the Fun-boi group with CIA, received Fun-boi (3 mg/g body weight/day) orally. We analyzed the arthritis score, the serum anti-type II collagen (CII) antibody level, and the percentage of the following lymphocyte subsets from lymphoid organs: B220, CD3/CD4, CD3/CD8 and CD40L/CD4 lymphocytes from blood or lymph nodes; and CD4-CD8-, CD4+CD8+, CD4+CD8- and CD4-CD8+ from the thymus. RESULTS Fun-boi therapy markedly reduced the severity of arthritis (p < 0.001) and tended to reduce the serum anti-CII antibody level (p = 0.06). Whereas CII immunization of DBA/1J mice caused a significant redistribution of CD3/CD8 lymphocytes from blood or lymph nodes, Fun-boi therapy caused significant normalization of the same types of lymphocyte subsets from lymph nodes, but did not affect the CD4 or CD4/CD40L lymphocyte subsets. CONCLUSION These results demonstrate that Fun-boi therapy exerts therapeutic effects in CIA mice, possibly by causing immunomodulatory effects at specific sites.