UGT1A1 rs4148323 A Allele is Associated With Increased 2-Hydroxy Atorvastatin Formation and Higher Death Risk in Chinese Patients With Coronary Artery Disease.

It is widely accepted that genetic polymorphisms impact atorvastatin (ATV) metabolism, clinical efficacy, and adverse events. The objectives of this study were to identify novel genetic variants influencing ATV metabolism and outcomes in Chinese patients with coronary artery disease (CAD). A total of 1079 CAD patients were enrolled and followed for 5 years. DNA from the blood and human liver tissue samples were genotyped using either Global Screening Array-24 v1.0 BeadChip or HumanOmniZhongHua-8 BeadChip. Concentrations of ATV and its metabolites in plasma and liver samples were determined using a verified ultra-performance liquid chromatography mass spectrometry (UPLC-MS/MS) method. The patients carrying A allele for the rs4148323 polymorphism (UGT1A1) showed an increase in 2-hydroxy ATV/ATV ratio (p = 1.69E-07, false discovery rate [FDR] = 8.66E-03) relative to the value in individuals without the variant allele. The result was further validated by an independent cohort comprising an additional 222 CAD patients (p = 1.08E-07). Moreover, the rs4148323 A allele was associated with an increased risk of death (hazard ratio [HR] 1.774; 95% confidence interval [CI], 1.031-3.052; p = 0.0198). In conclusion, our results suggested that the UGT1A1 rs4148323 A allele was associated with increased 2-hydroxy ATV formation and was a significant death risk factor in Chinese patients with CAD.

Plasma miR-142 predicts major adverse cardiovascular events as an intermediate biomarker of dual antiplatelet therapy.

MicroRNAs (miRNAs) are widely expressed in organisms and are implicated in the regulation of most biological functions. The present study investigated the association of plasma miRNAs with the clinical outcomes of dual antiplatelet therapy in coronary artery disease (CAD) patients who underwent percutaneous coronary intervention (PCI). Plasma miRNA levels were screened using high-throughput Illumina sequencing to evaluate the antiplatelet efficacy of clopidogrel and aspirin. Six plasma miRNAs (miR-126, miR-130a, miR-27a, miR-106a, miR-21, and miR-142) were associated with clopidogrel-treated platelet aggregation. These miRNAs were validated in a prospective cohort of 1230 CAD patients using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). High plasma miR-142 levels were associated with a high risk of major adverse cardiovascular events (MACE), with a hazard ratio (95% confidence interval) of 1.83 (1.30-2.59) at a false discovery rate of <5%. Multivariable Cox regression analysis revealed that diabetes mellitus, heart failure, calcium channel blocker application, and a high plasma miR-142 level were independent risk factors of MACE. The levels of the six plasma miRNAs were not significantly associated with bleeding events during the 3-year follow-up. In conclusion, plasma miR-142 is potential marker to predict MACE in CAD patients after PCI.

Effects of PON1 Gene Promoter DNA Methylation and Genetic Variations on the Clinical Outcomes of Dual Antiplatelet Therapy for Patients Undergoing Percutaneous Coronary Intervention.

INTRODUCTION AND OBJECTIVE: The relationship between either paraoxonase 1 (PON1) gene promoter DNA methylation or genetic variations and bleeding or major adverse cardiac events after dual antiplatelet therapy has been incompletely characterized. We aimed to systematically investigate the role of genetic variations and DNA methylation of the PON1 CpG island promoter on the clinical outcomes of dual antiplatelet therapy for patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). METHODS: This study included 653 patients with CAD undergoing PCI and receiving dual antiplatelet therapy. Genomic DNAs were isolated from whole blood and were genotyped for the three single nucleotide polymorphisms (SNPs) of the PON1 gene. The DNA methylation levels in the PON1 promoter region were determined by bisulfite sequencing or pyrosequencing at five CpG sites (positions -142, -161, -163, -170, and -184 from the transcription start site). Clopidogrel and its metabolites in plasma were examined using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and platelet function analysis was performed using the VerifyNow assay. RESULTS: Statistically significant associations between methylation levels at five PON1 CpG sites and bleeding were observed: -184 [odds ratio (OR) 0.98, 95% confidence interval (CI) 0.96-1.00, p = 0.028]; -170 (OR 0.99, 95% CI 0.97-1.00, p = 0.048); -163 (OR 0.98, 95% CI 0.96-1.00, p = 0.029); -161 (OR 0.98, 95% CI 0.97-1.00, p = 0.026); and -142 (OR 0.98, 95% CI 0.97-1.00, p = 0.042) at a false discovery rate of <5%. Statistical analysis also revealed that aspirin reaction units (ARUs) were significantly associated with PON1 methylation level at CpG site -163 (p = 0.0342). The ARUs of patients with the PON1 126 CC genotype was 527 ± 94, which was higher than the ARUs (473 ± 89) of patients with the 126 CG genotype (p = 0.0163). Multivariate logistic regression analysis indicated that the PON1 methylation level at CpG site -161 (OR 0.95, 95% CI 0.92-0.98, p = 0.002) and the use of angiotensin-converting enzyme inhibitors (OR 0.48, 95% CI 0.26-0.89, p = 0.021) were associated with a decreased risk of bleeding events. CONCLUSIONS: Hypomethylation of CpGs in the PON1 promoter may be a weak, albeit statistically significant, risk factor of bleeding after dual antiplatelet therapy. Further large-scale studies are needed to verify our results.

High levels of glucose induce "metabolic memory" in cardiomyocyte via epigenetic histone H3 lysine 9 methylation.

Diabetic patients continue to develop inflammation and cardiovascular complication even after achieving glycemic control, suggesting a "metabolic memory". Metabolic memory is a major challenge in the treatment of diabetic complication, and the mechanisms underlying metabolic memory are not clear. Recent studies suggest a link between chromatin histone methylation and metabolic memory. In this study, we tested whether histone 3 lysine-9 tri-methylation (H3K9me3), a key epigenetic chromatin marker, was involved in high glucose (HG)-induced inflammation and metabolic memory. Incubating cardiomyocyte cells in HG resulted in increased levels of inflammatory cytokine IL-6 mRNA when compared with myocytes incubated in normal culture media, whereas mannitol (osmotic control) has no effect. Chromatin immunoprecipitation (ChIP) assays showed that H3K9me3 levels were significantly decreased at the promoters of IL-6. Immunoblotting demonstrated that protein levels of the H3K9me3 methyltransferase, Suv39h1, were also reduced after HG treatment. HG-induced apoptosis, mitochondrial dysfunction and cytochrome-c release were reversible. However, the effects of HG on the expression of IL-6 and the levels of H3K9me3 were irreversible after the removal of HG from the culture. These results suggest that HG-induced sustained inflammatory phenotype and epigenetic histone modification, rather than HG-induced mitochondrial dysfunction and apoptosis, are main mechanisms responsible for metabolic memory. In conclusion, our data demonstrate that HG increases expression of inflammatory cytokine and decreases the levels of histone-3 methylation at the cytokine promoter, and suggest that modulating histone 3 methylation and inflammatory cytokine expression may be a useful strategy to prevent metabolic memory and cardiomyopathy in diabetic patients.

Association between polymorphisms of the renin-angiotensin system and coronary artery disease in Chinese patients with type 2 diabetes.

BACKGROUND: The renin-angiotensin system (RAS) is regarded as one of the most important regulatory systems for cardiovascular homeostasis. In this study, we investigated associations of the five genetic polymorphisms in the RAS and presence of coronary artery disease (CAD) in type 2 diabetes. METHODS: Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism analysis. We used the generalised multifactor dimensionality reduction (GMDR) method to identify gene-gene interactions. RESULTS: The D allele in the ACE gene was significantly more frequent in type 2 diabetic patients with CAD (p = 0.04). In multivariate logistic regression analysis, the DD genotype was associated with a significantly increased risk of CAD (p = 0.044). 1675G/A variant in the AT2R gene was found to be associated with CAD in female subjects with type 2 diabetes (p = 0.025). The three other polymorphisms of the RAS do not seem to influence the development of CAD in type 2 diabetes. No significant gene-gene interaction for any combinations of genotypes was found in the GMDR method. CONCLUSION: The DD variant of the ACE gene polymorphism is associated with increased risk of developing CAD in Chinese patients with type 2 diabetes. A slight impact of AT2R 1675G/A polymorphism on CAD was found only in female diabetic patients.

Effects of Ginkgo biloba extract on the pharmacokinetics of bupropion in healthy volunteers.

AIMS: To assess the effects of Ginkgo biloba extract on the pharmacokinetics of bupropion in healthy volunteers. METHODS: Fourteen healthy male volunteers (age range 19-25 years) received orally administered bupropion (150 mg) alone and during treatment with G. biloba 240 mg day(-1) (two 60-mg capsules taken twice daily) for 14 days. Serial blood samples were obtained over 72 h after each bupropion dose, and used to derive pharmacokinetic parameters of bupropion and its CYP2B6-catalysed metabolite, hydroxybupropion. RESULTS: Ginkgo biloba extract administration resulted in no significant effects on the AUC(0-infinity) of bupropion and hydroxybupropion. Bupropion mean AUC(0-infinity) value was 1.4 microg.h ml(-1)[95% confidence interval (CI) 1.2, 1.6] prior to G. biloba treatment and 1.2 microg.h ml(-1) (95% CI 1.1, 1.4) after 14 days of treatment. Hydroxybupropion mean AUC(0-infinity) value was 8.2 microg.h ml(-1) (95% CI 6.5, 10.4) before G. biloba administration and 8.7 microg.h ml(-1) (95% CI 7.1, 10.6) after treatment. The C(max) of hydroxybupropion increased from 221.8 ng ml(-1) (95% CI 176.6, 278.6) to 272.7 ng ml(-1) (95% CI 215.0, 345.8) (P = 0.038) and the t(1/2) of hydroxybupropion fell from 25.0 h (95% CI 22.7, 27.5) to 21.9 h (95% CI 19.9, 24.1) (P = 0.000). CONCLUSIONS: Ginkgo biloba extract administration for 14 days does not significantly alter the basic pharmacokinetic parameters of bupropion in healthy volunteers. Although G. biloba extract treatment appears to reduce significantly the t(1/2) and increase the C(max) of hydroxybupropion, no bupropion dose adjustments appear warranted when the drug is administered orally with G. biloba extract, due to the lack of significant change observed in AUC for either bupropion or hydroxybupropion.

Effects of Ginkgo biloba extract ingestion on the pharmacokinetics of talinolol in healthy Chinese volunteers.

BACKGROUND: Ginkgo biloba extract (GBE), the best selling herbal medicine in the world, has been reported to inhibit P-glycoprotein in vitro. However, the effects of GBE on P-glycoprotein activity in humans have not been clarified. OBJECTIVE: To investigate the effects of single and repeated GBE ingestion on the oral pharmacokinetics of talinolol, a substrate drug for P-glycoprotein in humans. METHODS: Ten unrelated healthy male volunteers were selected to participate in a 3-stage sequential study. Plasma concentrations of talinolol from 0 to 24 hours were measured by high-performance liquid chromatography after talinolol 100 mg was administrated alone, with a single oral dose of GBE (120 mg), and after 14 days of repeated GBE ingestion (360 mg/day). RESULTS: A single oral dose of GBE did not affect the pharmacokinetics of talinolol. Repeated ingestion of GBE increased the talinolol maximum plasma concentration (C(max)) by 36% (90% CI 10 to 68; p = 0.025), the area under the concentration-time curve (AUC)(0-24) by 26% (90% CI 11 to 43; p = 0.008) and AUC(0-infinity) by 22% (90% CI 8 to 37; p = 0.014), respectively, without significant changes in elimination half-life and the time to C(max). CONCLUSIONS: Our results suggest that long-term use of GBE significantly influenced talinolol disposition in humans, likely by affecting the activity of P-glycoprotein and/or other drug transporters.

Lack of effect of Ginkgo biloba on voriconazole pharmacokinetics in Chinese volunteers identified as CYP2C19 poor and extensive metabolizers.

BACKGROUND: Ginkgo biloba is one of the most popular herbal supplements in the world. The supplement has been shown to induce the enzymatic activity of CYP2C19, the main cytochrome P450 isozyme involved in voriconazole metabolism. Because this enzyme exhibits genetic polymorphism, the inductive effect was expected to be modulated by the CYP2C19 metabolizer status. OBJECTIVE: To examine the possible effects of Ginkgo biloba as an inducer of CYP2C19 on single-dose pharmacokinetics of voriconazole in Chinese volunteers genotyped as either CYP2C19 extensive or poor metabolizers. METHODS: Fourteen healthy, nonsmoking volunteers-7 CYP2C19 extensive metabolizers (2C19(*)1/2C19(*)1) and 7 poor metabolizers (2C19(*)2/2C19(*)2)-were selected to participate in this study. Pharmacokinetics of oral voriconazole 200 mg after administration of Ginkgo biloba 120 mg twice daily for 12 days were determined for up to 24 hours by liquid chromatography-electrospray tandem mass spectrometry in a 2-phase randomized crossover study with 4-week washout between phases. RESULTS: For extensive metabolizers, the median value for voriconazole area under the plasma concentration-time curve from zero to infinity (AUC(0-)(infinity)) was 5.17 microg.h/mL after administration of voriconazole alone and 4.28 microg.h/mL after voriconazole with Ginkgo biloba (p > 0.05). The other pharmacokinetic parameters of voriconazole such as AUC(0-24), time to reach maximum concentration, half-life, and apparent clearance also did not change significantly for extensive metabolizers in the presence of Ginkgo biloba. Pharmacokinetic parameters followed a similar pattern for poor metabolizers. CONCLUSIONS: The results suggest that 12 days of treatment with Ginkgo biloba did not significantly alter the single-dose pharmacokinetics of voriconazole in either CYP2C19 extensive or poor metabolizers. Therefore, the pharmacokinetic interactions between voriconazole and Ginkgo biloba may have limited clinical significance.

Induction of cytochrome P450 2B6 activity by the herbal medicine baicalin as measured by bupropion hydroxylation.

PURPOSE: This study investigated the effect of the herbal medicine baicalin on bupropion hydroxylation, a probe reaction for CYP2B6 activity related to different CYP2B6 genotype groups. METHOD: Seventeen healthy male volunteers (6 CYP2B6*1/*1, 6 CYP2B6*1/*6, and 5 CYP2B6*6/*6) received orally administered bupropion alone and during daily treatment with baicalin. Blood samples were taken up to 72 h after each bupropion dose, and pharmacokinetics profiles were determined on days 1 and 25 for bupropion and hydroxybupropion. RESULT: Baicalin administration increased hydroxybupropion maximum plasma concentration (C(max)) by 73% [90% confidence interval (CI), 44-108%; P < 0.01] and the area under the concentration time curve extrapolated to infinity (AUC(0-infinity)) of hydroxybupropion by 87% (90% CI, 48-137%; P < 0.01), with no change in the elimination half-life of hydroxybupropion. Baicalin increased the AUC(0-infinity) ratio of hydroxybupropion to bupropion by 63% (90% CI, 38-92%; P < 0.01). CONCLUSION: Baicalin significantly induced CYP2B6-catalyzed bupropion hydroxylation, and the effects of baicalin on other CYP2B6 substrate drugs deserve further investigation.

The CYP2C19 ultra-rapid metabolizer genotype influences the pharmacokinetics of voriconazole in healthy male volunteers.

AIM: To study the pharmacokinetic characteristics of voriconazole in healthy Chinese male volunteers in relation to cytochrome P450 (CYP) 2C19 genotype status, including ultra-rapid metabolizers (URMs), homozygous extensive metabolizers (EMs), and poor metabolizers (PMs). METHOD: Twenty healthy Chinese male volunteers were recruited for the study. Of these, four were CYP2C19 heterozygous URMs (*1/*17), eight were CYP2C19 homozygous EMs (*1/*1), and eight were CYP2C19 PMs (*2/*2). After a single oral dose of 200 mg voriconazole, plasma concentrations of voriconazole were determined for a 24-h period by liquid chromatography-mass spectrometry/mass spectrometry. RESULT: In Chinese male subjects, the allele frequencies of the CYP2C19*17 and CYP2C19*2 alleles were 0.64 and 35.6%, respectively, and both alleles were in Hardy-Weinberg equilibrium. The area under the concentration-time curve (AUC) from predose to 24 h (AUC(0-24)) and from predose to infinity (AUC(0-infinity)), and apparent oral clearance (CL/F) of voriconazole were statistically different among all three genotypic groups (P < 0.001, respectively). The maximum plasma concentration (C(max)) value of URMs also showed statistically significant differences from those of EMs and PMs (P = 0.036 and P = 0.035, respectively). The elimination half-life (t(1/2)) in URMs was 87% (P = 0.58) of that in EMs and 51% (P= 0.002) of that in PMs. CONCLUSION: Our data indicate that the presence of the CYP2C19*17 allele results in ultra-rapid metabolism of voriconazole after a single oral dose.