[Effects of triptolide on T lymphocyte functions in mice]

Triptolide (Tri) is an active principle of Tripterygium hypoglaucum Hutch, which has been used to treat cancers and autoimmune diseases in folk medicine. The lymphocyte proliferation (LP) induced by Con A or Lipopolysaccharide (LPS) was suppressed by Tri at 50 and 500 ng/ml. At 5 ng/ml the suppressive effect on LP induced by Con A was much stronger than that by LPS. The humoral immune reaction monitored by quantitative hemolysis spectrophotometry (QHS) was suppressed by Tri 0.75 and 1 mg/kg ip. IL-2 production by mouse spleen cells were suppressed by Tri 5, 50,500 ng/ml in vitro and 0.5, 0.75 and 1 mg/kg ip. IL-2 activity was assayed by assessing its ability to support proliferation of selected IL-2-dependent T cell line, measured by colorimetric method which is based on the ability of viable cells to cleave MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide). Ts cells induced by supraoptimal immune (SOI) were suppressed by Tri 0.5 and 0.75 mg/kg ip. These results suggest T or its subpopulations and B lymphocytes may be the target cells of Tri.