Comparison of the inhibition potentials of icotinib and erlotinib against human UDP-glucuronosyltransferase 1A1

UDP-glucuronosyltransferase 1A1 (UGT1A1) plays a key role in detoxification of many potentially harmful compounds and drugs. UGT1A1 inhibition may bring risks of drug-drug interactions (DDIs), hyperbilirubinemia and drug-induced liver injury. This study aimed to investigate and compare the inhibitory effects of icotinib and erlotinib against UGT1A1, as well as to evaluate their potential DDI risksUGT1A1 inhibition. The results demonstrated that both icotinib and erlotinib are UGT1A1 inhibitors, but the inhibitory effect of icotinib on UGT1A1 is weaker than that of erlotinib. The ICvalues of icotinib and erlotinib against UGT1A1-mediated NCHN--glucuronidation in human liver microsomes (HLMs) were 5.15 and 0.68 μmol/L, respectively. Inhibition kinetic analyses demonstrated that both icotinib and erlotinib were non-competitive inhibitors against UGT1A1-mediated glucuronidation of NCHN in HLMs, with thevalues of 8.55 and 1.23 μmol/L, respectively. Furthermore, their potential DDI risksUGT1A1 inhibition were quantitatively predicted by the ratio of the areas under the concentration-time curve (AUC) of NCHN. These findings are helpful for the medicinal chemists to design and develop next generation tyrosine kinase inhibitors with improved safety, as well as to guide reasonable applications of icotinib and erlotinib in clinic, especially for avoiding their potential DDI risksUGT1A1 inhibition.

Influence of CYP3A and MDR1 genetic polymorphisms on the pharmacokinetics of ciclosporin A / 国际药学研究杂志

Ciclosporin A (CsA), an immunosuppressive macrolide antibiotics, is widely applied to prevent rejections after organ transplants. CsA is mainly transported by P-glycoprotein (P-gp) and metabolized by cytochrome P450 (CYP450) 3A.Genetic polymorphisms of CYP3A and MDR1 probably influence the expressions and bioactivity of CYP3A and P-gp,and may affect the pharmacokinetics of CsA.This issue summarizes the correlation between genetic polymorphisms of CYP3A and MDR1 and the pharmacokinetics of CsA to guide the rational and individualized medication.

Determination of cefoperazone and sulbactam by LC-MS/MS in plasma and ultrafiltrate of patients undergone continuous renal replacement therapy / 国际药学研究杂志

Objective To establish a sensitiv e and specific LC-MS/MS method for the simultaneous determination of cefoperazone and sulbactam in plasma and ultrafiltrate of patients undergone continuous renal replacement therapy(CRRT). Methods Cefuroxime axetil was used as the internal standard,the plasma samples were separated on an WatersAtlantis dC18 column (150 mm× 4.6 mm, 5.0 μm). A tandem mass spectrometer equipped with ESI was used as the detector and operated in the mode of multiple reaction monitoring.Quantitive analysis of[M-H]-ions were m/z 644.1→528.1(cefoperazone), m/z 231.8→188.0(sulbactam) and m/z 509.3→206.9(the internal standard, IS), respectively. Results The linear range of cefoperazone and sulbactam in human plasma and ultrafiltrate were(10-500) and(6-300)μg/ml, respectively. Extraction recoveries were more than 90.0%, and intra- and inter-day relative standard deviation was less than 15%. The matrix effect of plasma and ultrafiltrate showed that the matrix effect of the two media had little influence on the measurement of cefoperazone, sulbactam and IS. Conclusion The method is simple, fast, and highly sensitive. The two drugs can be detected simultaneously in the same sample. It is appropriate to monitor drug concentration in plasma and ultrafiltrate of the patients undergone CRRT. Sieving coefficient could be calculated and provide an accurate basis for dose adjustment.

Protective effects of TAT-tCNTF fusion protein on SH-SY5Y cells induced by β-amyloid peptide(25-35) / 中国药理学通报

Aim To determine TAT-Tcntf penetration ability and to investigate the effects of the fusion protein on SH-SY5Y cells against toxicity induced by β-amyloid peptide 25-35(Aβ_(25-35) ).Methods The conjugate(TAT-tCNTF)of TAT(47-57)of HIV-1 and the truncated human CNTF active fragment was genetic engineered and expressed in E.Coli.Immunofluorescence was used to identify cell permeation ability across membrane.MTT assay was used to measure the survival of SH-SY5Y cells injured by Aβ_(25-35).And Hoechst 33342/PI double staining was used to observe the morphology of cell apoptosis and necrosis.LDH was measured by spectrophotometric method.Results The expression vector of pBV220-TAT-tCNTF was constructed successfully.Western blot showed the recombinant fusion protein could bind specifically with CNTF antibody.The immunofluorescence assay clearly demonstrated that TAT-tCNTF did penatrate into the cells while little rhCNTF pass across the cells.Double staining and LDH release assay demonstrated that TAT-tCNTF could promote significantly the survival of the cells.Conclusion sTAT-tCNTF with high activities and effective transmembrane ability is obtained for the first time.The fusion protein protects SH-SY5Y cells from death after Aβ25-35 exposure.

Protective effects of TAT-tCNTF fusion protein on SH-SY5Y cells induced by ?-amyloid peptide(25-35) / 中国药理学通报

Aim To determine TAT-tCNTF penetration ability and to investigate the effects of the fusion protein on SH-SY5Y cells against toxicity induced by ?-amyloid peptide 25-35(A?25-35 ).Methods The conjugate(TAT-tCNTF)of TAT(47-57)of HIV-1 and the truncated human CNTF active fragment was genetic engineered and expressed in E.Coli.Immunofluorescence was used to identify cell permeation ability across membrane.MTT assay was used to measure the survival of SH-SY5Y cells injured by A?25-35.And Hoechst 33342/PI double staining was used to observe the morphology of cell apoptosis and necrosis.LDH was measured by spectrophotometric method.Results The expression vector of pBV220-TAT-tCNTF was constructed successfully.Western blot showed the recombinant fusion protein could bind specifically with CNTF antibody.The immunofluorescence assay clearly demonstrated that TAT-tCNTF did penatrate into the cells while little rhCNTF pass across the cells.Double staining and LDH release assay demonstrated that TAT-tCNTF could promote significantly the survival of the cells.Conclusions TAT-tCNTF with high activities and effective transmembrane ability is obtained for the first time.The fusion protein protects SH-SY5Y cells from death after A?25-35 exposure.