Biliary excretion characteristics of berberine, palmatine and jateorhizine in sandwich-cultured rat hepatocytes / 中国药理学通报

Aim To study the biliary excretion characteristics of berberine,palmatine and jateorhizine in rat hepatocytes.Methods Berberine,palmatine and jateorhizine were incubated with the sandwich-cultured rat hepatocytes (SCRH) in standard Ca2+ buffer or Ca2+ free buffer.The accumulation of the three compounds under different conditions were measured by UPLC-MS/MS.The biliary excretion index and biliary clearance were calculated,and the effect of P-gp or Mrp2 inhibitor on the transport of three compounds was also investigated.Results While the incubation time increased,the accumulation of the three compounds also increased.There were obvious differences in accumulation of berberine,palmatine and jateorhizine in incubations treated with standard buffer and calcium-free buffer.The P-gp inhibitors ciclosporin A and verapamil could inhibit the biliary excretion of berberine,palmatine and jateorhizine.However,the Mrp2 inhibitors MK571 and probenecid had no effect on biliary excretion of the three compounds.Conclusions The biliary excretion of berberine,palmatine and jateorhizine is mainly through an active process.They are all the P-gp substrates other than Mrp2 substrates.

Simultaneous determination of 8 constituents of Desmodii Styracifolii Herba in rat bile with HPLC-MS/MS and their excretion pharmacokinetics / 中国中药杂志

To establish a HPLC-MS/MS quantitative method for analysis of 8 constituents in rat bile. The method was applied in the biliary excretion study after oral administration of Desmodii Styracifolii Herba extract. The rat bile samples were collected during 0-1, 1-2, 2-4, 4-6, 6-8, 8-12, 12-24 h. Diamonsil C₁₈column (4.6 mm×150 mm, 5 μm) was adopted and eluted with methanol and 0.01% acetic acid in a gradient mode. The flow rate was 0.8 mL•min⁻¹, and the column temperature was set at 40 ℃. The detection was carried out by a triple quadrupole linearion trap mass spectrometer in the negative ion mode with an electrospray source. Multiple reactions monitoring (MRM) mode was employed. The calibration curves showed a good linearity, with correlation coefficients (r≥0.991 5) for all of the analytes within the concentration range. The intra-day and inter-day precisions (RSD) were both less than 15%, and the accuracies (RE) ranged from -15% to 15%. The method had a good stability, and was suitable for the content determination of 8 constituents in rat bile. The extraction recoveries of the 8 analytes were more than 63.2%, and the RSD of IS-normalized matrix factors were no more than 15%, which met the requirements for analysis. According to the biliary excretion study, the bile excretion rates of the 8 analytes were relatively low, with great difference among the individuals. The results showed that the established method was simple, selective and specific, thus could be applied in the biliary excretion study of the 8 analytes in rat bile.

Screening and verifying potential NTCP inhibitors from herbal medicinal ingredients using the LLC-PK1 cell model stably expressing human NTCP / 中国天然药物

NTCP is specifically expressed on the basolateral membrane of hepatocytes, participating in the enterohepatic circulation of bile salts, especially conjugated bile salts, to maintain bile salts homeostasis. In addition, recent studies have found that NTCP is a functional receptor of HBV and HDV. Therefore, it is important to study the interaction between drugs and NTCP and identify the inhibitors/substrates of NTCP. In the present study, a LLC-PK1 cell model stably expressing human NTCP was established, which was simple and suitable for high throughput screening, and utilized to screen and verify the potential inhibitors of NTCP from 102 herbal medicinal ingredients. The results showed that ginkgolic acid (GA) (13 : 0), GA (15 : 1), GA (17 : 1), erythrosine B, silibinin, and emodin have inhibitory effects on NTCP uptake of TCNa in a concentration-dependent manner. Among them, GA (13 : 0) and GA (15 : 1) exhibited the stronger inhibitory effects, with IC50 values being less than 8.3 and 13.5 μmol·L(-1), respectively, than the classical inhibitor, cyclosporin A (CsA) (IC50 = 20.33 μmol·L(-1)). Further research demonstrated that GA (13 : 0), GA (15 : 1), GA (17 : 1), silibinin, and emodin were not substrates of NTCP. These findings might contribute to a better understanding of the disposition of the herbal ingredients in vivo, especially in biliary excretion.

THE PHARMACOKINETICS AND BILIARY EXCRETION OF PRAZIQUANTEL IN RATS BY DIFFERENT ROUTE OF ADMINISTRATION / 中国药理学通报

Praziquantel ( PQT ) concentrations in plasma after iv 20 mg/kg decayed rapidly with tip of 0.36 h. The absorption of PQT was rapid following the intramuscular doses of 10,20,40mg/kg or intragastic dose of 100mg/kg, but the phase of elimination was much longer than that after iv. Both of MAT1m and MATig were greater than MRTiv. The bioavailability of ig was 13.2%, suggesting a strong first-pass effect. The kinetics of PQT elimination was linear after intramuscular dose of either 10 or 20 mg/kg, but nonlinear process was found when the dose was increased to 40mg/kg.By any route of iv, im and ig administration, the concentrations of PQT in the bile were much lower than the peripheral plasma concentrations and changed in parallel to the later with high levels after iv, medium levels after im and much low levels after ig.