Abstract: BACKGROUND ＆ AIM: To study the inhibiting effects of α-tocopheryl succinate(α-TOS) on the growth of Ehrlich ascitesocarcinoma in vivo and explore the mechanisms. MATERIAL AND METHODS: The mice loaded with Ehrlich ascitesocarcinoma were used as tumor model, all the experimental animals were divided into negative control, tumor model, α-TOS treatment at dose 20, 40 and 80 mg/kg and cyclophosphamide positive groups. The survival ratio of tumor-bearing mice and subsequent hematological changes were measured, NK cytotoxicity and the proportion of T lymphocyte subsets were detected by lactate dehydrogenase method and Flow Cytometer, respectively. Inducibility of Ehrlich cell apoptosis was examined by DNA agarose gel electrophoresis. RESULTS: The survival ratio in α-TOS treatment group at dose 80 mg/kg was 33.09％. The white blood cell counts in α-TOS treatment groups were much higher than in positive control, the platelet counts were much lower than in tumor model. The NK cytotoxicity became much higher in α-TOS treatment groups at dose 40 and 80 mg/kg compared with the tumor model(P<0.05 and P<0.01). The T lymphocyte subset counts were close to negative control in α-TOS treatment groups. The DNA ladder was found in Ehrlich ascitesocarcinoma cells at dose 80 mg/kg. CONCLUSION: α-TOS was capable of prolonging the survival time of mice with Ehrlich ascitesocarcinoma; could alleviate hyperviscosity caused by the increase in the number of platelets, without interfering with the number of leucocytes; was able to activate immune system in the process ofinhibiting the growth of tumor due to improved immune function. The result of DNA agarose gel electrophoresis demonstrated that α-TOS induced apoptosis of Ehrlich ascitesocarcinoma cells at a dose of 80mg/kg.

Key words: α-Tocopheryl succinate, Ehrlich ascitesocarcinoma, antineoplastic effect