Effect and mechanism of miR-206/miR-613 on expression of OATP1B1 / 药学学报

This study was designed to explore the effect and mechanism of miR-206/miR-613 on the expression of OATP1B1 gene. Bioinformatic analysis was used to predict the potential miRNAs target sites in 3'-untranslated region (3'-UTR) of OATP1B1 mRNA. The expression level of miR-206/miR-613 and OATP1B1 mRNA and protein was determined with RT-qPCR and Western blot, respectively. Luciferase assay was used to explore the exact mechanism of the effect of miR-206/miR-613 on the expression of OATP1B1 mRNA and protein. The results showed that the seed sequences of miR-206/miR-613 has perfect complementary with 3'-UTR of OATP1B1 mRNA in terms of sequence specificity. The secondary structure between miR-206/miR-613 and 3'-UTR of OATP1B1 mRNA was rather stable. The OATP1B1 protein level was down-regulated by 24.7%, 38.8% by overexpression of miR-206/miR-613. The expression was up-regulated by 25%, 38.2% by inhibition of miR-206/miR-613. However, overexpression or inhibition of miR-206/miR-613 had no effect on the expression of OATP1B1 mRNA. The luciferase activity of pMIR/OATP1B1-WT luciferase reporter gene was decreased by 35% and 30% through overexpression of miR-206/miR-613. The expression was increased by 33.1% and 32.5% through inhibition of miR-206/miR-613. When the binding sites in the 3'-UTR of OATP1B1 mRNA complementary with miR-206/miR-613 was mutated, overexpression or inhibition of miR-206/miR-613 had no effect on the luciferase activity. Collectively, miR-206/miR-613 post-transcriptionally regulates the expression of OATP1B1 protein by directly targeting the 3'-UTR of OATP1B1 mRNA.

OATP1B1 in drug-drug interactions between traditional Chinese medicine Danshensu and rosuvastatin / 药学学报

The study was designed to explore the drug-drug interactions mechanisms mediated by OATP1B1 between traditional Chinese medicine Danshensu and rosuvastatin. First, the changes of rosuvastatin pharma­cokinetics were investigated in presence of Danshensu in rats. Then, the primary rat hepatocytes model was established to explore the effects of Danshensu on the uptake of rosuvastatin by hepatocytes. Finally, HEK293T cells with overexpression of OATP1B1*1a and OATP1B1*5 were established using a lentiviral delivery system to explore the effects of Danshensu on the uptake of rosuvastatin. Rosuvastatin pharmacokinetic parameters of Cmax, AUC0-t, AUC0-∞ were increased about 123%, 194% and 195%, by Danshensu in rats, while the CLz/F value was decreased by 60%. Uptake of rosuvastatin in the primary rat hepatocytes was decreased by 3.13%, 41.15% and 74.62%, respectively in the presence of 20, 40 and 80 μmol·L-1 Danshensu. The IC50 parameters was (53.04 ± 2.43) μmol·L-1. The inhibitory effect of Danshensu on OATP1B1 mediated transport of rosuvas­tatin was related to the OATP1B1 gene type. In OATP1B1*5-HEK293T mutant cells, transport of rosuvastatin were reduced by (39.11 ± 4.94) % and (63.61 ± 3.94) %, respectively, by Danshensu at 1 and 10 μmol·L-1. While transport of rosuvastatin was reduced by (8.22 ± 2.40) % and (11.56 ± 3.04) % and in OATP1B1*1a cells, respectively. Danshensu significantly altered the pharmacokinetics of rosuvastatin in rats, which was related to competitive inhibition of transport by OATP1B1. Danshensu exhibited a significant activity in the inhibition of rosuvastatin transport by OATP1B1*5-HEK293T, but not by OATP1B1*1a, suggesting a dependence on OATP1B1 sequence.

OATP1B1 in drug-drug interactions between traditional Chinese medicine Danshensu and rosuvastatin / 药学学报

The study was designed to explore the drug-drug interactions mechanisms mediated by OATP1B1 between traditional Chinese medicine Danshensu and rosuvastatin. First, the changes of rosuvastatin pharmacokinetics were investigated in presence of Danshensu in rats. Then, the primary rat hepatocytes model was established to explore the effects of Danshensu on the uptake of rosuvastatin by hepatocytes. Finally, HEK293T cells with overexpression of OATP1B1*a and OATP1B1*5 were established using a lentiviral delivery system to explore the effects of Danshensu on the uptake of rosuvastatin. Rosuvastatin pharmacokinetic parameters of C(max0, AUCO(0-t), AUC(0-∞) were increased about 123%, 194% and 195%, by Danshensu in rats, while the CL z/F value was decreased by 60%. Uptake of rosuvastatin in the primary rat hepatocytes was decreased by 3.13%, 41.15% and 74.62%, respectively in the presence of 20, 40 and 80 μmol x L(-1) Danshensu. The IC50 parameters was (53.04 ± 2.43) μmol x L(-1). The inhibitory effect of Danshensu on OATP1B1 mediated transport of rosuvastatin was related to the OATP1B1 gene type. In OATP1B1*5-HEK293T mutant cells, transport of rosuvastatin were reduced by (39.11 ± 4.94)% and (63.61 ± 3.94)%, respectively, by Danshensu at 1 and 10 μmol x L(-1). While transport of rosuvastatin was reduced by (8.22 ± 2.40)% and (11.56 ± 3.04)% and in OATP1B1*1a cells, respectively. Danshensu significantly altered the pharmacokinetics of rosuvastatin in rats, which was related to competitive inhibition of transport by OATPJBI. Danshensu exhibited a significant activity in the inhibition of rosuvastatin transport by OATP1B1*5-HEK293T, but not by OATP1B1*1a, suggesting a dependence on OATP1B1 sequence.

Research progress of the atypical kinetic profiles of cytochrome P450 enzymes / 药学学报

Cytochrome P450 enzymes are composed of many isozymes and involved in the biotransformation of both exogenous and endogenous substances. A growing number of studies have found that the P450 enzymes do not always follow the classical Michaelis-Menten kinetics, but show atypical kinetic behavior, which is also the current research hotspot. In this paper, the category and mechanisms of atypical kinetics of the P450 enzyme were reviewed, providing theoretical basis for the research of enzyme kinetics.

Effect of pravastatin on transportation of scutellarin in mouse liver and its mechanism / 药学学报

This study is to investigate the transportation of scutellarin in cell and live models and study on mechanism of absorption and transport of scutellarin in mouse liver. The concentration of scutellarin in plasma and liver from control and pretreated groups was determined by high performance liquid chromatography. The uptake of scutellarin was examined in control hepatocytes group, induced hepatocytes group and induced hepatocytes plus pravastatin group. Pravastatin can affect the pharmacokinetics of scutellarin in mouse: CL is decreased while AUC is increased. The scutellarin absorption of hepatocyte induced group was higher than that of control group, but was decreased in the group with pravastatin added. The research showed that there was potential drug interaction between pravastatin and scutellarin. The drugs may compete for oatp2 mediated transport pathway consisted in the uptake of scutellarin in liver.

Effect of OATP1B1 521T --> C heterogenesis on pharmacokinetic characterstics of rosuvastatin in Chinese volunteers / 药学学报

This study is to report the effect of OATP1B1 gene mutation in the 521T --> C in Chinese human on the pharmacokinetics of rosuvastatin and guide the reasonable clinical application of rosuvastatin by the feature of genetic polymorphism of OATP1B1. Plasma samples were determined with LC-MS: the analyte and internal standard pitavastatin were both analyzed by MS in the ESI, m/z was 480.0 for rosuvastatin and 420.0 for the IS, separately. Genotyping of OATP1B1 was determined with the method of polymerase chain reaction--amplification refractory mutation system targeted at 40 healthy volunteers and showed that there were 7 subjects with 521T --> C mutant, accounting to 17.5% of total and wild type homozygote accounted to 82.5%. It was found that there were significant differences between OATP1B1 mutation in the 521T --> C and wild type homozygote for rosuvastatin pharmacokinetic process in Chinese human. In contrast to OATP1B1 wild type group, OATP1B1 mutation group's absorption degree increased, elimination process decreased. The OATP1B1 mutation should be noted for guiding the reasonable application of rosuvastatin during its clinical use.

Quantification of pentoxyverine citrate in human plasma by LC-ESI/MS method and its application / 药学学报

A rapid and sensitive liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI/ MS) method for quantification of pentoxyverine citrate in human plasma has been developed and applied for the bioequivalence and pharmacokinetics study. After extracted from plasma samples with ethyl acetate, analysis was performed in selected ion monitoring (SIM) mode with a positive electrospray ionization (ESI) interface with a mobile phase consisted of methanol and water (0.4% glacial acetic acid and 4 mmol x L(-1) ammonium acetate, 43 : 57, v/v). The linear concentration range of the calibration curves was 1.0-160.0 ng x mL(-1) for pentoxyverine citrate, inter- and intra-precision (RSD) was less than 12.5%, accuracy (RE) was in +/- 13.5% and absolute recovery was more than 80%. The method was proved simple, rapid, sensitive, specific and suitable for pharmacokinetic and bioequivalence study of Yufenweilin capsule containing pentoxyverine citrate.

Study on metabolism of tetramethylpyrazine in system of rat liver microsomes / 中国中药杂志

<p><b>OBJECTIVE</b>The metabolic character of tetramethylpyrazine (TMPz) in rat liver microsomes was studied in vitro and in vivo to identify which isoforms of cytochrome P450 were responsible for TMPz metabolism in rats, offer the theoretical foundation for the fact that it is rational to use medicine in clinic.</p><p><b>METHOD</b>Set up UV- HPLC method of TMPz, determine concentration of TMPz and its formation in rat plasma and liver microsomes incubation solution, analyze the correlation between TMPz's metabolic eliminate rate and each inducer. Erythromycin( ERY) N-demethylase activity of each sample in rat liver microsomes was measured using N-demethylation reaction of ERY as probe. The correlation between the rate of TMPz metabolite formation and the demethylase activity was analysed. After the SD rats who had been treated with inducer, inhibitor, or untreated, received administration of TMPz in vein, the plasma concentration of TMPz were determined by HPLC. Pharmacokinetic parameters of TMPz were computed and compared.</p><p><b>RESULT</b>The disppearing rate of TMPz in the incubation solutions of the rats liver microsomes, which treated with DEX, were markedly quicker than that of control group (P < 0. 01) , while no obvious difference between P-NF group or PB and control group was observed (P > 0. 05). The activity of ERY-N-demethylase in DEX-induced group was corespondingly enhanced, was much higer than that in control group. The correlation between the rate of TMPz metabolic product formation and the activity of N-demethylase was significant. After using Ket, the CYP3A inhibitor, the metabolism of TMPz could be significantly inhibited the metabolism of TMPz in rat liver microsomes. In vivo, CL( s) were larger than that of the control group,t,/2 were smaller than the control group in DEX group; By contrary, CL(s) was smaller than the control group,t1/2 was larger than the control group in Ket group.</p><p><b>CONCLUSION</b>Results suggest that CYP3A plays a major role in TMPz metabolism in rats, TMPz lie in the possibility of Interaction among the medicines between TMPz and CYP3A inducers or inhibitors when they are used in clinic.</p>

Bioequivalence of domestic nimodipine capsules and toblets / 中国临床药理学与治疗学

0.05). The relative bioavailability of tested capsules to reference tablets was (99.3?13.1)% Conclusion Both formulations are of bioequivalence.