Inhibitory effect of 20(s)-protopanaxdiol on proliferation of Siha cells in vitro and its mechanism

Objective To observe the effect of 20(s)-protopanaxadiol(PPD)on the cell cycle of Siha cells in vitro and to detect the transcription and expressions of p53,p21and cyclin-E,and to clarify the mechanism of its inhibitory effect on proliferation of Siha cells.Methods The Siha cells cultivated in vitro were treated with alcohol(negative control group)and 20μg·L-1 PPD(PPD group),respectively.The cell cycle was detected by FCM 48h after treatment.The mRNA and protein expressions of p53,p21and cyclin-E in Siha cells were analyzed by Real time PCR and Western blotting.Results Compared with negative control group,after treated with 20μg·L-1 PPD for 48h,the ratio of Siha cells at G0 /G1 phase was increased(P0.01),the blockage of G1 phase was obviously enhanced;the transcription and protein expressions of p53and p21were up-regulated(P0.01);while the transcription and expression of cyclin-E were significantly decreased(P0.01).Conclusion PPD may inhibit the proliferation of Siha cells,and its mechanism may be related to up-regulating the expressions of p53and p21and down-regulating the expression of cyclin-E.