Abstract: Objective To investigate the anti-rejection effect of triptolide (TPT) on xenogenic skin transplantation in mice. Methods The tergal skin transplantation model was achieved by an operation (BALB/c mice as donors and C57 BL/6 mice as acceptors). Then acceptors were divided randomly into 5 groups, namely model, TPT ( 200 μg·kg^-1) , ciclosporin A (CsA) ( 10 mg·kg^-1) , combination of TPT and CsA (TPT 200 μg·kg^-1 and CsA 5 mg·kg^-1) and sham. All acceptor mice were administered intraperitoneally once a day for ten days. The survival days of skin graft were documented in all groups. The levels of IL-2, IL-4, IL-10 and IFN-γ in plasma were detected by ELISA ten days after the operation. The quantity of CD4⁺ CD25⁺ T cells in spleen were analyzed by flow cytometry. Results The survival days of skin graft in groups administered with drugs were all significantly prolonged compared with that of model group (P < 0.01) . Combination of TPT and CsA group showed a longer survival days than TPT or CsA group (P < 0.05 or P < 0.01) . Compared with those of model group, Th1 cytokines (IL-2 and IFN-γ)in plasma in groups treated with TPT or combination of TPT and CsA were significantly decreased. (P < 0.01)while Th2 cytokines (IL-4 and IL-10) were significantly increased (P < 0.01) . The amount of CD4⁺ CD25⁺ T cells in spleen in groups administered with TPT or combination of TPT and CsA were all significantly increased compared with that of model group (P <0.01) . Conclusion TPT has an immunosuppressive effect on mice with xenogenic skin transplantation. The effectiveness of TPT appears to be associated with balance of Th1/Th2 cytokines, induction of immune tolerance and stimulation of expression of CD4⁺ CD25⁺ T cells, etc.

Key words: triptolide, immunosuppressive effect, skin transplantation, Th1/Th2, CD4⁺ CD25⁺ T cells