[Study on the apoptosis inducing effect of pseudolaric acid B on cervical carcinoma cell line HeLa cells].

Objective: To investigate the biological effect and mechanism of action of pseudolaric acid B (PAB) on the cultured human HeLa cells in vitro.
Methods: MTT and flow cytometric assays were used to detect the cells proliferation inhibitory rate and apoptosis of HeLa cell in exposure to PAB; the morphological changes of apoptosis were observed with electron microscope; and the expressions of p53/bcl-2/bax mRNA were detected by RT-PCR.
Results: (1) HeLa cell proliferation was inhibited by PAB in a dose-dependent manner, the IC50 being about 10 micromol/L; (2) flow cytometry showed that the distribution of HeLa cell cycle was changed time-dependently by 10 micromol/L PAB-treatment, showing decrease of G0/G1 phase cell percentage and increase of G2/M phase cell percentage; (3) the bax mRNA expression elevated and bcl-2 protein expression decreased markedly after being treated by 10 micromol/L PAB for 12 h, 24 h, and 48 h; while the expression of p53 mRNA could not be detected.
Conclusion: PAB can inhibit the proliferation and induce the apoptosis of Hela cells in vitro, and its molecular mechanism may be associated with up-regulating bax mRNA expression and down-regulating bcl-2 mRNA expression.