Abstract: AIM: To study the effects of theasinesin (TS) on proliferation and apoptosis of murine lympho-cytes.METHODS: MTT method was employed to inves-tigate the proliferatory response of murine splenocytes. Cellular morphological observation, DNA agarose gel elec-trophoresis and flow cytometry analysis were used to study the effects of TS on apoptosis of murine thymocyte and splenocyte.RESULTS: 50, 150 and 500 mg·L^-1 TS could markedly promote ConA-induced splenocyte prolif-eration in mice.In the cellular morphologic observation and DNA biochemical analysis, murine thymocytes cul-tured for 20 h in vitro showed keryopyk-nosis, condensa-tion of cell, typical “ladder” on gel electrophoresis and typical apoptotic peak (AP) by FACS analysis.After treatment with 50, 150 and 500 mg·L^-1 TS, DNA lad-der and apoptotic peak were decreased gradually and apoptotic rates were reduced to 12.14%, 9.49%, 6.71%respectively from 19.87%in control group.But the apoptosis of murine splenocytes induced by 10-5 mol·L-1 DEX was not affected by TS.CONCLUSION: TS can significantly promote splenocyte prolifera-tion in mice and has an inhibitory effect on spontaneous apoptosis of murine thymocytes.

Key words: theasinesin, apoptosis, thymocyte, splenocyte, mouse