Objective: To explore the effects of paeoniflorin on the proliferation and apoptosis of HeLa cells.
Methods: HeLa cells treated with paeoniflorin at different concentrations for different hours were assessed by the method of methyl thiazolyl tetrazolium (MTT). Cell apoptosis rate and cycle change were detected by flow cytometry with annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI). The morphological change of HeLa cells was observed by transmission electron microscope (TEM). The expressions of Bcl-2, Bax and Caspase-3 in HeLa cells induced by paeoniflorin were detected by immunocytochemistry.
Results: After treatment with different concentrations of paeoniflorin for different hours, the proliferation of HeLa cells was inhibited in a dose and time-dependent manner with an IC50 value of 5054, 2965, 2459 µg/ml at 24, 48 and 72 hours respectively (P < 0.05). After treated by different concentrations of paeoniflorin (control group, 1000 and 2000 µg/ml), apoptosis was induced in HeLa cells at a rate of 0.94%, 10.94% and 13.95% respectively. Such effects were dose-dependent (P < 0.05) and the proportion of HeLa cells in Sphase was under a rising trend. Typical apoptotic changes of HeLa cells under the exposure to paeoniflorin were observed under TEM. There was a lowered expression of Bcl-2 and an elevated expression of Bax and Caspase-3 genes versus the control group after a 48-hour paeoniflorin treatment (P < 0.05).
Conclusion: Paeoniflorin can significantly induce the apoptosis of HeLa cells through a down-regulation of anti-apoptotic gene Bcl-2 and an up-regulation of pro-apoptotic genes Bax and Caspase-3.