Fig. 4

Validation of the effects of each gallstone-dissolving compound in the hamster model of gallstones. a Effects of intracystic infusion of each solvent on the release of pro-inflammatory mediators in hamsters with gallstones. ELISA shows that while MTBE significantly increased the levels of IL-6, MMP did not in both hamster models of cholesterol [Left] and pigmented gallstones [Right]. b Effects of intracystic injection of each solvent on the release of TNF-α in hamsters with gallstones. In contrast with MTBE, MMP decreased the serum levels of TNF-α in both hamster models of cholesterol [Left] and pigmented gallstones [Right]. c Representative pictures demonstrating the development of cholesterol [Left] and pigmented [Right] gallstones in the experimental hamsters following their respective protocol diets. Yellow circles indicate the gallbladder and gallstones within the gallbladder. d Demonstration of in vivo gallstone dissolubility of each solvent. After infusing each solvent into the gallbladders of hamsters with gallstones for 24 h, gallstone dissolubility was determined by comparing the weights of the residual gallstones. The in vivo gallstone dissolubility (%) of each solvent was defined as (the average weight of DMSO-treated gallstones − the average weight of gallstones after solvent treatment)/the average weights of DMSO-treated gallstones. MMP demonstrated significantly higher dissolubility than MTBE in both hamster models of cholesterol [Left] and, especially, pigmented [Right] gallstones. The dissolubility of each solvent (MTBE and MMP) for pigmented gallstones was 32.0% and 54.3%, respectively (P < 0.05). *P < 0.05. DMSO, dimethyl sulfoxide; MMP, 2-methoxy-6-methylpyridine; MTBE, methyl tert-butyl ether