Effect of tert-butyl acetate and ethyl butyrate on the dissolution of gallbladder cholesterol stones / 中华肝胆外科杂志

ABSTRACT

Objective:To compare the effect and biotoxicity of tert-butyl acetate (TBA) and ethyl butyrate (EB) on stone dissolution in vitro.Methods:Ten gallstone samples from patients with multiple gallbladder stones were selected and the cholesterol content was analyzed by HPLC. Stone dissolution tests of TBA and EB were performed on cholesterol gallstone in vitro, and the weight of stone at each time point was recorded, meanwhile, methyl tert-butyl ether (MTBE) was used as the control. The inhibitory effects of MTBE, TBA and EB on proliferation of human normal liver cell line LO2 were analyzed by cell proliferation inhibition assay. Flow cytometry was used to analyze the effects of MTBE, TBA and EB on the early and late apoptosis of LO2 cells, and the changes of reactive oxygen species level in LO2 cells were also analyzed.Results:Of the 10 gallbladder gallstones, 6 were cholesterol gallstones and 4 were non-cholesterol gallstones. Stone dissolution experiment showed that the remaining stones of MTBE, TBA and EB groups were (47.83±3.84)%, (58.12±4.53)% and (75.75±4.61)% 30 minutes later. The remaining stones were (18.38±6.47)%, (33.82±6.22)% and (56.38±3.91)% 90 minutes later. MTBE had the best stone dissolution effect in vitro, the stone dissolution effect of TBA was slightly weaker than MTBE, and the stone dissolution effect of EB was relatively weak in all ( P<0.05). The cell proliferation inhibition experiment showed that the cell viability of the control group, MTBE group and TBA group were (100.00±4.46)%, (96.79±4.32)% and (93.72±3.51)%, respectively, and there were no significant differences among the three groups ( P>0.05). However, the cell viability of EB group (87.57±5.29)% was lower than the above three groups, and the differences were statistically significant ( P<0.001). The early apoptosis and late apoptosis of the control group were (1.67±0.15)% and (1.27±0.06)%, respectively. EB induced early apoptosis (15.90±0.53)% ( P<0.001) and late apoptosis (5.13±0.76)% ( P<0.05). However, MTBE and TBA had no significant effect on cell apoptosis ( P>0.05). Compared with control group, MTBE, TBA and EB all significantly inhibited the level of reactive oxygen species ( P<0.05), and the inhibitory effect of EB was the most obvious. Conclusions:TBA has good stone dissolution effect and biosafety for gallbladder cholesterol stones in vitro, while EB has relatively poor performance. TBA is a potential drug for gallstone dissolution.