Effects of ursolic acid on the proliferation and apoptosis of human ovarian cancer cells

This study examined the effects of ursolic acid (UA) on the proliferation and apoptosis of a human ovarian cancer cell line, CAOV3. The CAOV3 cells were cultured in the RPMI 1640 media and treated with different concentrations of UA (0, 10, 20, 40 mu mol/L). The proliferation rate of the CAOV3 cells was determined by MTT assay. The apoptosis rate was measured by flow cytometry. ERK activity was detected by immunoprecipitation and the expressions of p-ERK1/2, MKP-1, Bax and Bcl-2 by Western blotting. The results showed that the proliferation rate was significantly decreased in the cells treated with UA as compared with that in the non-treated cells (P < 0.05). The intracellular ERK activity and p-ERK1/2 expression were also reduced in the UA-treated cells, while the MKP-1 expression was elevated. Moreover, the apoptosis was found in the CAOV3 cells exposed to UA; the Bax expression was increased and the Bcl-2 expression decreased. The apoptosis rate in the UA-treated cells was much higher than that in the non-treated cells (P < 0.05). It is concluded that UA can inhibit the proliferation of CAOV3 cells by suppressing the ERK activity and the expression of p-ERK1/2. And it can also induce the apoptosis of the CAOV3 cells by up-regulating the Bax expression and down-regulating the Bcl-2 expression.