Study on bile acid metabolism of sleep-deprived mice regulated by Jiaotai Pills based on LC-MS / 中国中药杂志

To investigate the changes of bile acid(BA) levels in mice with sleep deprivation and the regulatory effect of Jiaotai Pills(JTP) on bile acid metabolism, this study established an ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method for simultaneous determination of 23 BAs in mice. A total of 24 ICR mice were randomized into normal group, model group, and JTP group. Mice in the model group and JTP group were deprived of sleep at 20 h·d~(-1) by sleep deprivation apparatus for 8 consecutive days. Mice in the JTP group were given(ig, qd) JTP 3.3 g·kg~(-1) and those in the normal group and model group received(ig) the same volume of purified water. UPLC conditions are as follows: Waters ACQUITY UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 μm), gradient elution with the mobile phase of 0.1% formic acid in water-methanol. MS conditions are as below: negative-ion electrospray ionization, multiple reaction monitoring(MRM). Thereby, the content of 23 BAs in serum, liver, and ileum was determined and methodological investigation of the method was performed. The results showed that 23 BAs could be accurately determined within 15 min and the correlation coefficients were all higher than 0.99. The precision, accuracy, specificity, reproducibility, matrix effect, and recovery of BAs all met the requirement. The levels of BAs were significantly increased in the serum, liver, and ileum of sleep-deprived mice, but JTP can significantly reduce the levels. The UPLC-MS/MS method is simple, rapid, and accurate, which can be used for the determination of 23 BAs in biological samples, and JTP can adjust the elevated BA levels of sleep-deprived mice.

Inhibition of rutaecarpine on in vitro hepatic metabolism of five Coptis alkaloids in rats / 中草药

Objective: To investigate the inhibition of rutaecarpine, a main component in Evodiae Fructus, on the hepatic metabolism of five Coptis alkaloids, and to provide the basis for further study of compatibility mechanism between Coptidis Rhizoma and Evodiae Fructus. Methods: Using rat liver microsome incubation method, the inhibition of rutaecarpine on hepatic metabolism of five Coptis alkaloids in vitro was investigated. Results: Rutaecarpine could inhibit the in vitro hepatic metabolisms of coptisine, epiberberine, berberine, palmatine, and jatrorrhizine. The half inhibitory concentration (IC50) was all greater than 50 μmol/L which showed rutaecarpine had a weak inhibition on Coptis alkaloids. The differences of inhibition constant (Ki) were statistically significant (P jatrorrhizine > palmatine > epiberberine > coptisine. Conclusion: The results could provide the basis to learn the major role on the links that Evodiae Fructus acted on Coptis alkaloids and reveal the compatibility mechanism between Coptidis Rhizoma and Evodiae Fructus.

Stability study in biological samples and metabolites analysis of astragaloside IV in rat intestinal bacteria in vitro / 中国中药杂志

To figure out the stability and intestinal bacteria metabolites of rats in vitro of astragaloside IV ( AST), this research was done to explore the stability of AST in the artificial gastric juice. artificial intestinal juice and rat liver homogenate and the metabolism in rat intestinal in vitro. HPLC was used to calculate the remaining rate of AST in biological samples by measuring the content of AST, while metabolites were determined by combining the methods of TLC, HPLC and LC-MS/MS. It turned out that AST was difficult to metabolize in the artificial gastric juice, artificial intestinal juice and rat liver. Also, the metabolic pathway of AST was stepped by deglycosylation. Firstly, AST was converted to its secondary etabolites (6-O-β-D-glucopyranosyl- cycloastragenol, CMG) by removal of xylose moiety at C-3, then transformed into cycloastragenol (CAG) after hydrolytic removal of the glucose moiety at C-6. All the results suggested that the metabolism of AST in vivo occurs mainly in the intestinal by hydrolysis of glycosyl. In conclusion, hydrolysis of intestinal flora is the main reason that AST metabolizes.

Identification of metabolites of epiberberine in rat liver microsomes and its inhibiting effects on CYP2D6 / 中国中药杂志

Epiberberine, one of the most important isoquinoline alkaloid in Coptidis Rhizoma, possesses extensive pharmacological activities. In this paper, the liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to study phase I and phase II metabolites. A Thermo HPLC system (including Surveyor AS, Surveyor LC Pump, Surveyor PDA. USA) was used. The cocktail probe drugs method was imposed to determine the content change of metoprolol, dapsone, phenacetin, chlorzoxazone and tolbutamide simultaneously for evaluating the activity of CYP2D6, CYP3A4, CYP1A2, CYP2E1 and CYP2C9 under different concentrations of epiberberine in rat liver microsomes. The result showed that epiberberine may have phase I and phase II metabolism in the rat liver and two metabolites in phase I and three metabolites in phase II are identified in the temperature incubation system of in vitro liver microsomes. Epiberberine showed significant inhibition on CYP2D6 with IC50 value of 35.22 μmol L(-1), but had no obvious inhibiting effect on the activities of CYP3A4, CYP1A2, CYP2E1 and CYP2C9. The results indicated that epiberberine may be caused drug interactions based on CYP2D6 enzyme. This study aims to provide a reliable experimental basis for its further research and development of epiberberine.