Abstract:

Abstract:Objective
To observe the effect of diterpenoid B derived from Rabdosia excise (DB) on the cell line of cervical cancer (Hela) and its related mechanism.Methods Hela cells at logarithmic growth phase were divided into control group and 0.5,1.0,2.0,4.0,8.0,16, 0 and 32.0 mg•L^-1 DB experimental groups,MTT  assay was used to detect the  inhibitory rate of cell growth at 24 and 48 h,and the morphologic changes of cells were observed by phase contrast microscope. RT-PCR was exploited to observe the mRNA expressions of p53,p21 and CDK2 of Hela cells.Immunocytochemical  staining was utilized to detect the protein expressions of P53,P21 and CDK2.Results  MTT result  showed that the inhibitory rate of cell growth at 24 h in 2.0,4.0 and 8.0 mg?mL-1 DB groups were 18.18%,28.89%,and 32.84%;the inhibitory rates  of cell  growth  at 48 h in  2.0,4.0,and 8.0  μg•mL^-1DB groups were 26.64%,47.03%, and 51.90%;DB  inhibited Hela cell growth in a dose- and time- dependent manner（P<0.05 or P<0.01）.Hela cells after treated with DB  manifested retarded proliferation,and became round and smaller in size,with some cells floating;the RT-PCR  and Western blotting results showed that after  treated with DB (2.0,4.0,8.0  μg•mL^-1) for 24 and 48 h,the mRNA and protein expressions of P53 and P21 in DB  groups were significantly higher than those in control group（P<0.01）,meanwhile the mRNA and protein levels of CDK2 were lower than those in control group（P<0.01）.Conclusion  DB can inhibit the  proliferation of Hela cells,its mechanism  may be related to  up-regulating the expressions of P53 and P21,down-regulating the expression of  CDK2,and  furthermore influencing the transition from G1 to S phase.

Key words: diterpenoid compound B；Rabdosia excise； uterine cervical neoplasms；cell cycle