Apoptosis of lens epithelial cells induced by cinobufagin in vitro.

Abstract

To investigate the in vitro effects and mechanism of action of cinobufacini on apoptosis of lens epithelial cells (LEC). Rabbit LEC were cultured for 72 hours with cinobufacini at different concentrations(0.0 [control], 0.1, 0.2, 0.3mg/L). The inhibition ratio of cinobufacini acting on LEC was analyzed by ethyl thiazolyl tetrazolium(MTT); the changes in DNA structure, by electrophoresis, and the apoptosis rate, by flow cytometry. The mRNA expression of apoptosis-related genes bcl-2 and bax was examined using the reverse transcription-polymerase chain reaction (RT-PCR). At concentrations of 0.1mg/L-0.3mg/L, cinobufacini inhibited LEC proliferation. The inhibition ratio increased as the concentration of the drug increased. The typical DNA-ladders on electrophoretic gels were observed for extracts of LEC in the treated groups. The higher the drug concentration (0.1, 0.2, and 0.3mg/L) was, the higher the apoptosis rate (20.47±0.65%, 27.14±0.95%, and 33.49±0.77%, respectively) would be. The apoptosis rates in these groups were significantly different from those of the control group (P<0.01). With the drug concentration increasing, the mRNA expression levels of the pro-apoptotic bax increased, whereas those of the anti-apoptotic bcl-2 decreased. Cinobufacini can notably induce apoptosis of LEC by decreasing the ratio of bcl-2 to baxin vitro. With its low toxicity, this medication may be effective in the prevention and treatment of posterior capsule opacification.