AIM: To describe the long term follow-up of kidney allograft recipients receiving ketoconazole with calcineurin inhibitors(CNI) alone or combined with everolimus. METHODS: This is an open-label, prospective observatio...AIM: To describe the long term follow-up of kidney allograft recipients receiving ketoconazole with calcineurin inhibitors(CNI) alone or combined with everolimus. METHODS: This is an open-label, prospective observational clinical trial in low immunologic risk patients who, after signing an Institutional Review Board approved consent form, were included in one of two groups. The first one(n = 59) received everolimus(target blood level, 3-8 ng/m L) and the other(n = 114) azathioprine 2 mg/kg per day or mycophenolate mofetyl(MMF) 2 g/d. Both groups also received tapering steroids, the cytochrome P-450 3A4(CYP3A4) modulator, ketoconazole 50-100 mg/d, and cyclosporine with C0 targets in the everolimus group of 200-250 ng/mL in 1 mo, 100-125 ng/m L in 2 mo, and 50-65 ng/m L thereafter, and in the azathioprine or MMF group of 250-300 ng/mL in 1 mo, 200-250 ng/mL in 2 mo, 180-200 ng/m L until 3-6 mo, and 100-125 ng/mL thereafter. Clinical visits were performed monthly the first year and quarterly thereafter by treating physicians and all data was extracted by the investigators.RESULTS: The clinical characteristics of these two cohorts were similar. During the follow up(66 + 31 mo), both groups showed comparable clinical courses, but the biopsy proven acute rejection rate during the full follow-up period seemed to be lower in the everolimus group(20% vs 36%; P = 0.04). The everolimus group did not show a higher surgical complication rate thanthe other group. By the end of the follow-up period, the everolimus group tended to show a higher glomerular filtration rate. Nevertheless, we found no evidence of a consistent negative slope of the temporal allograft function estimated by the modification of the diet in renal disease formula in any of both groups. At 6 years of follow-up, the uncensored and death-censored graft survivals were 91% and 93%, and 91% and 83% in the everolimus plus cyclosporine, and cyclosporine alone groups, respectively. The addition of ketoconazole saved 80% of cyclosporine and 56% of everolimus doses. CONCLUSION: Combining CYP3A4 modulators with CNI or mammalian target of rapamycin inhibitor, in low immunological risk kidney transplant recipients is feasible, effective, safe and affordable even in the long term.展开更多
Aim The present study developed a CYP3A4-expressed Caco-2 monolayer model at which effects of the efflux-metabolism alliance on the transport and uptake of clausenamide（CLA） enantiomers as CYP3A4 substrates were inv...Aim The present study developed a CYP3A4-expressed Caco-2 monolayer model at which effects of the efflux-metabolism alliance on the transport and uptake of clausenamide（CLA） enantiomers as CYP3A4 substrates were investigated. The apparent permeability coefficients （Papp） of （ - ） and （ ＋ ）CLA were higher in the ab- sorptive direction than those in the secretory direction with efflux ratios（ER） of 0. 709 ± 0.411 and 0. 867± 0. 250 （ Х10^-6 -1 cm · s ）, respectively. Their bidirectional transports were significantly reduced by （75.6 ± 87.5）% af- ter treatment with verapamil （ a P-glycoprotein inhibitor） that increased the rate of metabolism by CYP3 A4, whereas the CYP3A4 inhibitor ketoconazole treatment markedly enhanced the basolateral to apical flux of （ - ） and （ ＋ ） CLA with ERs being 2. 934 ± 1. 432 and 1. 877 ± 0. 148 （ Х 10^-6 cm/s） respectively. These changes could be blocked by the duel CYP3A4/P-glycoprotein inhibitor cyclosporine A, consequently, Papp values for CLA enanti- omers in both directions were significantly greater than those obtained by using verapamil or ketoconazole, and their ERs were similar to those following （ - ） or （ ＋ ）-isomer treatment alone. Furthermore, the uptake of （ - ）CLA was more than that of （ ＋ ）CLA in the transfected cells. Incubation with ketoeonazole decreased the intracellular concentrations of the two enantiomers. This effect disappeared in the presence of a CYP3A4 inducer dexametha- sone. These results indicated that CYP3A4 could influence P-gp efflux, transport and uptake of CLA enantiomers as CYP3A4 substrates and that a duel inhibition to CYP3A4/ P-glycoprotein could enhance their absorption and bioavailability, which provides new insight into the efflux-metabolism alliance and will benefit the clinical pharma- cology of （？） CLA as a candidate drug for treatment of Alzheimer＇ s disease.展开更多
Cytochrome P450(CYP)enzymes function to catalyze a wide range of reactions,many of which are critically important for drug response.Members of the human cytochrome P4503A(CYP3A)family are particularly important in dru...Cytochrome P450(CYP)enzymes function to catalyze a wide range of reactions,many of which are critically important for drug response.Members of the human cytochrome P4503A(CYP3A)family are particularly important in drug clearance,and they collectively metabolize more than half of all currently prescribed medications.The ability of these enzymes to bind a large and structurally diverse set of compounds increases the chances of their modulating or facilitating drug metabolism in unfavorable ways.Emerging evidence suggests that individual enzymes in the CYP3A family play discrete and important roles in catalysis and disease progression.Here we review the similarities and differences among CYP3A enzymes with regard to substrate recognition,metabolism,modulation by small molecules,and biological consequence,highlighting some of those with clinical significance.We also present structural perspectives to further characterize the basis of these comparisons.展开更多
RNA interference(RNAi)is useful for selective gene silencing.Cytochrome P4503A4(CYP3A4),which metabolizes approximately 50% of drugs in clinical use,plays an important role in drug metabolism.In this study,we aimed to...RNA interference(RNAi)is useful for selective gene silencing.Cytochrome P4503A4(CYP3A4),which metabolizes approximately 50% of drugs in clinical use,plays an important role in drug metabolism.In this study,we aimed to develop a short hairpin RNA(shRNA)to modulate CYP3A4 expression.Three new shRNAs(S1,S2 and S3)were designed to target the coding sequence(CDS)of CYP3A4,cloned into a shRNA expression vector,and tested in different cells.The mixture of three shRNAs produced optimal reduction(55%)in CYP3A4 CDS-luciferase activity in both CHL and HEK293 cells.Endogenous CYP3A4 expression in HepG2 cells was decreased about 50%at both mRNA and protein level after transfection of the mixture of three shRNAs.In contrast,CYP3A5 gene expression was not altered by the shRNAs,supporting the selectivity of CYP3A4 shRNAs.In addition,HepG2 cells transfected with CYP3A4 shRNAs were less sensitive to Ginkgolic acids,whose toxic metabolites are produced by CYP3A4.These results demonstrate that vector-based shRNAs could modulate CYP3A4 expression in cells through their actions on CYP3A4 CDS,and CYP3A4 shRNAs may be utilized to define the role of CYP3A4 in drug metabolism and toxicity.展开更多
OBJECTIVE： Consuming botanical dietary supplements or herbal drugs along with prescription drugs may lead to potential pharmacokinetic-pharmacodynamic（PK-PD） herb-drug interactions（HDI）. The present study focuses...OBJECTIVE： Consuming botanical dietary supplements or herbal drugs along with prescription drugs may lead to potential pharmacokinetic-pharmacodynamic（PK-PD） herb-drug interactions（HDI）. The present study focuses on the importance of and novel approach for assessing HDI in integrative medicine with case examples of two frequently-used Ayurvedic Rasayana botanicals.METHODS： The aqueous extracts of Asparagus racemosus（ARE） and Gymnema sylvester（GSE） were prepared as per Ayurvedic Pharmacopoeia of India. Chemoprofiling of these extracts was done using high-performance liquid chromatography（HPLC）. Additionally, ARE was characterized for the presence of shatavarins IV and I using HPLC ＆ mass spectroscopy respectively. Effects of ARE and GSE were investigated on rat liver microsome using testosterone probe drug assay. The changes in formation of metabolite（6-β hydroxy testosterone） were monitored on incubation of testosterone alone, testosterone with ketoconazole, ARE and GSE using HPLC. Half inhibitory concentration（IC50） was used to predict plausible HDI.RESULTS： ARE and GSE showed no inhibition with IC50 values 〉1 000 μg/m L while the standard inhibitor ketoconazole completely abolished CYP3A4-dependent activity at 0.531 μg/m L and IC50 was found to be 0.036 μg/m L.CONCLUSION： ARE and GSE prepared as per Ayurvedic Pharmacopoeia of India were found to be safe for CYP3A4-mediated inhibitory HDI in rats. Our in vitro study suggests the need of further in vivo investigation for HDI in order to provide clinical relevance.展开更多
This review highlights therapeutic agents from recent cancer therapeutic trials showing the greatest potential for further clinical use for sunitinib in the near future. In fact, sunitinib is one of multi-tyrosine kin...This review highlights therapeutic agents from recent cancer therapeutic trials showing the greatest potential for further clinical use for sunitinib in the near future. In fact, sunitinib is one of multi-tyrosine kinase inhibitors;tyrosine kinases are enzymes, which transfer phosphate groups from ATP to the hydroxyl group of tyrosine residues on signal transduction molecules. Phosphorylation of signal transduction molecules, in turn, induces dramatic changes in tumor growth, including activation of angiogenesis and DNA synthesis. Therefore, sustain efforts have been directed for developing inhibitors for angiogenesis, which is the marginal process for tumor growth and development through targeting TKs. Almost if not all angiogenesis inhibitors target the vascular endothelial growth factor (VEGF) signaling pathway.展开更多
Background In recent years, it is found that the polymorphisms of genes which are involved in the pharmacokinetic and pharmacodynamic pathways play important roles in the clinical anticoagulation treatment with warfar...Background In recent years, it is found that the polymorphisms of genes which are involved in the pharmacokinetic and pharmacodynamic pathways play important roles in the clinical anticoagulation treatment with warfarin. The aim of the study was to investigate the impact of the genetic polymorphism of r-glutamic acid carboxylase （gamma-glutamyl carboxylase gene, GGCX） on the response of warfarin initial anticoagulant therapy. Methods Seven hundred and ninety-eight Chinese Han patients who received valve replacement surgery and orally taken warfarin in long term for anticoagulant therapy in Guangdong General Hospital from 2000 to 2008 were enrolled in the study, a polymorphic SNPs point （rs699664） of GGCX was selected, and SnaPshot was adopted to perform single nucleotide polymorphism （SNP） test, and by grouping according to genotype, GGCX average daily dose of warfarin, time for PT-INR to reach the target value and differences in the incidence of excessive coagulation between different genotypes were compared respectively. Hardy-Weinberg genetic equilibrium test was applied for population representative test. Results Within the 20 days of warfarin initial therapy, male average daily dose of warfarin （2.92 ± 1.18 mg/d） was apparently higher than that of female （2.64 ± 0.98 mg/d）, while there were no significant differences in the average time required for PT-INR to reach the target value （ 1.8） and the excessive coagulation ratio at the initial therapy stage between male and female. And there were no significant differences in the average daily dose of warfarin, time to reach the target value and excessive coagulation ratio among different GGCX genotypes. Conclusions GGCX genovariation had no significant impact on the warfarin daily dose within the 20-day initial therapy of Chinese Han Population, and for the conventional dosage program, the risk of bleeding in the GGCX mutation individuals did not increase obviously at the initial administration period.展开更多
文摘AIM: To describe the long term follow-up of kidney allograft recipients receiving ketoconazole with calcineurin inhibitors(CNI) alone or combined with everolimus. METHODS: This is an open-label, prospective observational clinical trial in low immunologic risk patients who, after signing an Institutional Review Board approved consent form, were included in one of two groups. The first one(n = 59) received everolimus(target blood level, 3-8 ng/m L) and the other(n = 114) azathioprine 2 mg/kg per day or mycophenolate mofetyl(MMF) 2 g/d. Both groups also received tapering steroids, the cytochrome P-450 3A4(CYP3A4) modulator, ketoconazole 50-100 mg/d, and cyclosporine with C0 targets in the everolimus group of 200-250 ng/mL in 1 mo, 100-125 ng/m L in 2 mo, and 50-65 ng/m L thereafter, and in the azathioprine or MMF group of 250-300 ng/mL in 1 mo, 200-250 ng/mL in 2 mo, 180-200 ng/m L until 3-6 mo, and 100-125 ng/mL thereafter. Clinical visits were performed monthly the first year and quarterly thereafter by treating physicians and all data was extracted by the investigators.RESULTS: The clinical characteristics of these two cohorts were similar. During the follow up(66 + 31 mo), both groups showed comparable clinical courses, but the biopsy proven acute rejection rate during the full follow-up period seemed to be lower in the everolimus group(20% vs 36%; P = 0.04). The everolimus group did not show a higher surgical complication rate thanthe other group. By the end of the follow-up period, the everolimus group tended to show a higher glomerular filtration rate. Nevertheless, we found no evidence of a consistent negative slope of the temporal allograft function estimated by the modification of the diet in renal disease formula in any of both groups. At 6 years of follow-up, the uncensored and death-censored graft survivals were 91% and 93%, and 91% and 83% in the everolimus plus cyclosporine, and cyclosporine alone groups, respectively. The addition of ketoconazole saved 80% of cyclosporine and 56% of everolimus doses. CONCLUSION: Combining CYP3A4 modulators with CNI or mammalian target of rapamycin inhibitor, in low immunological risk kidney transplant recipients is feasible, effective, safe and affordable even in the long term.
文摘Aim The present study developed a CYP3A4-expressed Caco-2 monolayer model at which effects of the efflux-metabolism alliance on the transport and uptake of clausenamide（CLA） enantiomers as CYP3A4 substrates were investigated. The apparent permeability coefficients （Papp） of （ - ） and （ ＋ ）CLA were higher in the ab- sorptive direction than those in the secretory direction with efflux ratios（ER） of 0. 709 ± 0.411 and 0. 867± 0. 250 （ Х10^-6 -1 cm · s ）, respectively. Their bidirectional transports were significantly reduced by （75.6 ± 87.5）% af- ter treatment with verapamil （ a P-glycoprotein inhibitor） that increased the rate of metabolism by CYP3 A4, whereas the CYP3A4 inhibitor ketoconazole treatment markedly enhanced the basolateral to apical flux of （ - ） and （ ＋ ） CLA with ERs being 2. 934 ± 1. 432 and 1. 877 ± 0. 148 （ Х 10^-6 cm/s） respectively. These changes could be blocked by the duel CYP3A4/P-glycoprotein inhibitor cyclosporine A, consequently, Papp values for CLA enanti- omers in both directions were significantly greater than those obtained by using verapamil or ketoconazole, and their ERs were similar to those following （ - ） or （ ＋ ）-isomer treatment alone. Furthermore, the uptake of （ - ）CLA was more than that of （ ＋ ）CLA in the transfected cells. Incubation with ketoeonazole decreased the intracellular concentrations of the two enantiomers. This effect disappeared in the presence of a CYP3A4 inducer dexametha- sone. These results indicated that CYP3A4 could influence P-gp efflux, transport and uptake of CLA enantiomers as CYP3A4 substrates and that a duel inhibition to CYP3A4/ P-glycoprotein could enhance their absorption and bioavailability, which provides new insight into the efflux-metabolism alliance and will benefit the clinical pharma- cology of （？） CLA as a candidate drug for treatment of Alzheimer＇ s disease.
基金supported,in part,by ALSAC and by the National Institutes of Health grants R35-GM118041 and P30-CA21765.
文摘Cytochrome P450(CYP)enzymes function to catalyze a wide range of reactions,many of which are critically important for drug response.Members of the human cytochrome P4503A(CYP3A)family are particularly important in drug clearance,and they collectively metabolize more than half of all currently prescribed medications.The ability of these enzymes to bind a large and structurally diverse set of compounds increases the chances of their modulating or facilitating drug metabolism in unfavorable ways.Emerging evidence suggests that individual enzymes in the CYP3A family play discrete and important roles in catalysis and disease progression.Here we review the similarities and differences among CYP3A enzymes with regard to substrate recognition,metabolism,modulation by small molecules,and biological consequence,highlighting some of those with clinical significance.We also present structural perspectives to further characterize the basis of these comparisons.
基金This project was supported by the grants from National Natural Science Foundation of China(81173120,81302834)Major Program of National Natural Science Foundation of China(2012ZX09506001-004).
文摘RNA interference(RNAi)is useful for selective gene silencing.Cytochrome P4503A4(CYP3A4),which metabolizes approximately 50% of drugs in clinical use,plays an important role in drug metabolism.In this study,we aimed to develop a short hairpin RNA(shRNA)to modulate CYP3A4 expression.Three new shRNAs(S1,S2 and S3)were designed to target the coding sequence(CDS)of CYP3A4,cloned into a shRNA expression vector,and tested in different cells.The mixture of three shRNAs produced optimal reduction(55%)in CYP3A4 CDS-luciferase activity in both CHL and HEK293 cells.Endogenous CYP3A4 expression in HepG2 cells was decreased about 50%at both mRNA and protein level after transfection of the mixture of three shRNAs.In contrast,CYP3A5 gene expression was not altered by the shRNAs,supporting the selectivity of CYP3A4 shRNAs.In addition,HepG2 cells transfected with CYP3A4 shRNAs were less sensitive to Ginkgolic acids,whose toxic metabolites are produced by CYP3A4.These results demonstrate that vector-based shRNAs could modulate CYP3A4 expression in cells through their actions on CYP3A4 CDS,and CYP3A4 shRNAs may be utilized to define the role of CYP3A4 in drug metabolism and toxicity.
基金BSDT’s Ayurvedic College, Synapse Laboratory Pvt. Ltd., National Toxicology Center, & National Centre for Cell Science, Pune for extending their kind support to carry out this work
文摘OBJECTIVE： Consuming botanical dietary supplements or herbal drugs along with prescription drugs may lead to potential pharmacokinetic-pharmacodynamic（PK-PD） herb-drug interactions（HDI）. The present study focuses on the importance of and novel approach for assessing HDI in integrative medicine with case examples of two frequently-used Ayurvedic Rasayana botanicals.METHODS： The aqueous extracts of Asparagus racemosus（ARE） and Gymnema sylvester（GSE） were prepared as per Ayurvedic Pharmacopoeia of India. Chemoprofiling of these extracts was done using high-performance liquid chromatography（HPLC）. Additionally, ARE was characterized for the presence of shatavarins IV and I using HPLC ＆ mass spectroscopy respectively. Effects of ARE and GSE were investigated on rat liver microsome using testosterone probe drug assay. The changes in formation of metabolite（6-β hydroxy testosterone） were monitored on incubation of testosterone alone, testosterone with ketoconazole, ARE and GSE using HPLC. Half inhibitory concentration（IC50） was used to predict plausible HDI.RESULTS： ARE and GSE showed no inhibition with IC50 values 〉1 000 μg/m L while the standard inhibitor ketoconazole completely abolished CYP3A4-dependent activity at 0.531 μg/m L and IC50 was found to be 0.036 μg/m L.CONCLUSION： ARE and GSE prepared as per Ayurvedic Pharmacopoeia of India were found to be safe for CYP3A4-mediated inhibitory HDI in rats. Our in vitro study suggests the need of further in vivo investigation for HDI in order to provide clinical relevance.
文摘This review highlights therapeutic agents from recent cancer therapeutic trials showing the greatest potential for further clinical use for sunitinib in the near future. In fact, sunitinib is one of multi-tyrosine kinase inhibitors;tyrosine kinases are enzymes, which transfer phosphate groups from ATP to the hydroxyl group of tyrosine residues on signal transduction molecules. Phosphorylation of signal transduction molecules, in turn, induces dramatic changes in tumor growth, including activation of angiogenesis and DNA synthesis. Therefore, sustain efforts have been directed for developing inhibitors for angiogenesis, which is the marginal process for tumor growth and development through targeting TKs. Almost if not all angiogenesis inhibitors target the vascular endothelial growth factor (VEGF) signaling pathway.
基金supported by National Natural Science Foundation of China (No.30772620)Guangdong Medical Science and Technology Research Foundation (NO.A2007048)
文摘Background In recent years, it is found that the polymorphisms of genes which are involved in the pharmacokinetic and pharmacodynamic pathways play important roles in the clinical anticoagulation treatment with warfarin. The aim of the study was to investigate the impact of the genetic polymorphism of r-glutamic acid carboxylase （gamma-glutamyl carboxylase gene, GGCX） on the response of warfarin initial anticoagulant therapy. Methods Seven hundred and ninety-eight Chinese Han patients who received valve replacement surgery and orally taken warfarin in long term for anticoagulant therapy in Guangdong General Hospital from 2000 to 2008 were enrolled in the study, a polymorphic SNPs point （rs699664） of GGCX was selected, and SnaPshot was adopted to perform single nucleotide polymorphism （SNP） test, and by grouping according to genotype, GGCX average daily dose of warfarin, time for PT-INR to reach the target value and differences in the incidence of excessive coagulation between different genotypes were compared respectively. Hardy-Weinberg genetic equilibrium test was applied for population representative test. Results Within the 20 days of warfarin initial therapy, male average daily dose of warfarin （2.92 ± 1.18 mg/d） was apparently higher than that of female （2.64 ± 0.98 mg/d）, while there were no significant differences in the average time required for PT-INR to reach the target value （ 1.8） and the excessive coagulation ratio at the initial therapy stage between male and female. And there were no significant differences in the average daily dose of warfarin, time to reach the target value and excessive coagulation ratio among different GGCX genotypes. Conclusions GGCX genovariation had no significant impact on the warfarin daily dose within the 20-day initial therapy of Chinese Han Population, and for the conventional dosage program, the risk of bleeding in the GGCX mutation individuals did not increase obviously at the initial administration period.
