Effects of Paeonol on cell proliferation and apoptosis in human colorectal cancer LoVo cells and its mechanisms

Objective To investigate the effect of Paeonol on the proliferation of colorectal cancer line LoVo and discuss its possible mechanisms. Methods LoVo cells were cultured in vitro. After treatment by Paeonol at different concentrations respectively at different time, the cell survival was determined by the CKK-8 method. The changes of cell morphology were observed by inverted microscope. Apoptosis was detected by flow cytometry. The concentration of intracellular calcium was investigated by laser confocal sanning microscope with calcium-flourecent probes-Fluo-3/AM.Reverse transcription-polymerase chain reaction(RT-PCR) was used for mRNA analysis. The change of protein expression of RUNX-3 was detected by western blot. Results From the data of CCK-8, the cell proliferation of human colorectal cancer LoVo cells was inhibited by Paeonol in a dose-dependent and time-dependent manner. Typical apoptosis morphology of LoVo cells was observed by inverted microscope. Flow cytometry assays showed that Paeonol significantly induced apoptosis in LoVo cells. After treated with Paeonol for 48 h, the apoptosis rate of Lovo cells was (12.3±1.3)%,(22.4±1.5)%, and (36.2±2.1)% respectively, which showed an obvious concentration-effect relationship. The Ca2+relative fluorescence intensity of Paeonol group was (41.36±4.62),(57.51±3.83) and (69.43±3.76) respectively, which indicated that the concentration of intracellular calcium was significantly elevated by Paeonol. The data of RT-PCR and western blot showed that Paeonol up-regulated RUNX3 in a dose-dependent manner in LoVo cells. Conclusion Paeonol can inhibit the proliferation of LoVo cells and induce apoptosis, and the mechanism of Paeonol on apoptosis may be related to the up regulation of RUNX3 expression and the increase of concentration of intracellular calcium.