Inhibition of murine chronic graft-versus-host disease by the chloroform extract of Tripterygium wilfordii Hook f.

The effects of chloroform extract of Tripterygium Wilfordii Hook f (TWH extract) on chronic graft-versus-host disease (GVHD) were examined in a murine experimental model. Chronic GVHD was induced by intravenous transfer of parental DBA/2 spleen cells into unirradiated (C57BL/6 x DBA/2)F1 recipient mice. The effects of TWH extract on GVHD were assessed by measuring both the degree of splenomegaly and the total serum IgE levels 3 weeks after the cell transfer. Subcutaneous administration of TWH extract once a day for 3 weeks suppressed chronic GVHD in a dose-dependent manner. Significant suppression of splenomegaly was first noted in mice treated with 7.5 micrograms/kg of the agent. The maximum inhibition was observed when mice were treated with more than 10.0 micrograms/kg (but not 5.0 micrograms/kg) caused complete suppression of serum IgE hyperproduction. The ability of donor T cells purified from recipient spleen cells to produce interleukin 4 in response to stimulation with anti-CD3 monoclonal antibody was significantly abrogated when recipient mice were treated with 10.0 micrograms/kg of the agent. These results strongly suggest that TWH extract will be an addition to the cohort of immunosuppressive therapies used in solid organ and bone marrow transplantation.