Effect of Saikosaponins-d on COX-2 expression and intracellular calcium of human hepatoma carcinoma cell line SMMC-7721

【Objectives】 To observe the effect of Saikosaponins-d(SSd) on COX-2 expression and intracellular calcium in human hepatoma carcinoma cell line SMMC-7721 and to investigate the mechanism of antitumous effect.【Methods】 The human hepatoma carcinoma cell line SMMC-7721 was cultured in vitro and then treated with SSd of various concentrations(2.5,5.0,10.0,20.0 mg/L) for 48 hrs,and the inhibitory rate of cell proliferation was measured by MTT.The cell apoptosis was observed by staining with Hoechst 33342,and the expression of Cyclooxygenase-2(COX-2) protein in the cells was determined by Western bolt.Prostaglandin E2(PGE2) in medium was detected by radioimmunoassay,and the concentration of intracellular calcium was tested with spectrofluorometer.【Results】 SSd could obviously inhibit the growth and proliferation of SMMC-7721 cells,and induced their apoptosis.Meanwhile,SSd could depress the expression of hepatoma carcinoma cell COX-2 protein,cut down PGE2 level and increase intracellular calcium concentration.There was a dose-effect relationship when the SSd concentration was in the range of 2.5 to 10.0 mg/L.【Conclusion】 Improve intracellular calcium concentration might be one of the mechanisms of inhibiting COX-2 activity and inducing SMMC-7721 apoptosis by SSd.