Abstract: To study the anti-tumor activity of Masson's pine bark extract (MPBE) in vitro and in vivo, MTT assay was used to observe the growth inhibitory effect of MPBE on human colonic cancer cell line VoLo in vitro. The model of transplanted tumor in mice was used to observe the inhibiting effect on S₁₈₀ sarcoma in mice, and the survival time of mice bearing Ehrlich ascites carcinoma (EAC), by calculating thymus and spleen indexes in mice bearing S₁₈₀ sarcoma. Results showed: MPBE could inhibit the growth of LoVo cells in vitro, the inhibitory rates of MPBE at the concentration of 500 mg/L were 19.83%, 33.06% and 58.15% after incubation for 24, 48 and 72 h respectively; MPBE could significantly inhibit the growth of S₁₈₀ sarcoma in mice, the inhibitory rates of MPBE were 30.2%, 37.8% and 42.3% at the dosags of 50, 100 and 200 mg/kg respectively. MPBE at the dose of 200 mg/kg could also increase the thymus and spleen indexes in mice bearing S₁₈₀ sarcoma significantly. However, MPBE could not prolong the survival time of mice bearing Ehrlich ascites carcinoma. MPBE has obvious inhibitory effect on the growth of LoVo cells in vitro and S₁₈₀ sarcoma in mice, it could be a potential chemopreventive or chemotherapeutic agent of cancer.

Key words: Masson's pine bark extract, LoVo cell, S₁₈₀ sarcoma mice, anti-tumor activity