Suppressive effect of hochu-ekki-to on collagen induced arthritis in DBA1J mice.

Abstract

To investigate the effect of hochu-ekki-to (HET) decoction on the development of collagen-induced arthritis (CIA) in mice. CIA was induced in male DBA/IJ mice by immunization with 2 injections of bovine type II collagen (CII). HET was orally administered at different doses and with different schedules. The incidence of arthritis, arthritis index, levels of anti-CII antibody, interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) and lymphocyte subsets were examined. HET caused suppression of CIA development in a dose dependent fashion and exerted a suppressive effect on CIA when administered from the first CII immunization or from the onset of CIA, but not when administered for 2 weeks before CII immunization. HET inhibited the production of specific anti-CII antibody, IL-6, and TNF-alpha, and tended to normalize the proportions of cells in lymphocyte subsets. HET suppresses the development of CIA, and HET redistributes the population of lymphocytes in lymph node and blood and inhibits IL-6 and TNF-alpha secretion in CIA mice.