[Pharmacological mechanisms of ethyl acetate extraction of Tongbiheji for active T cell signaling molecules].

Aim: To confirm extracts of activity from Traditional Chinese Medicine TongBiHeJi, study effect on two signaling pathways of T cells and clarify the pharmacological mechanisms of TongBiHeJi.

Methods: Concanavalin(ConA) were added successively into rats lymphocytic culture with different extracts of activity from Traditional Chinese Medicine. After 24 hours, CD71 expression rate on rat T lymphocytes activated with ConA was analyzed by flow cytometry. TCR, CD28 and ICOS on T cells were detected after T lymphocytes of rat activated by ConA were cultivated with various EthylAcetate extraction of TongBiHeJi(TBHJ) and Methotrexate (MTX) for 48 hours.

Results: CD71 expression rate on rat T lymphocytes induced by ConA was increased to 69.7%. TBHJ inhibited the rate of CD3(+);CD71(+); expression(32.5%); ConA up-regulated TCR, CD28 and ICOS expression on T cells obviously. There was different between ConA and positive control significantly(P<0.001). TBHJ could down-regulate obviously TCR, CD28 and ICOS expression on ConA-activated T lymphocytes with Concentration-dependent, especially ICOS. MTX inhibited CD3(+);CD71(+); and CD3(+);TCR(+); expression also.

Conclusion: TBHJ inhibited T cells activation by adjusting two signaling pathways. That implied TBHJ could block CD28-ICOS signaling molecules to induce immunological tolerance. This study provided an experimental basis for application of TongBiHeJi to treatment of rheumatoid arthritis.