Effects of Gene Polymorphisms, Metabolic Activity, and Content of Alcohol Dehydrogenase and Acetaldehyde Dehydrogenases on Prognosis of Hepatocellular Carcinoma Patients.

Background: Alcohol dehydrogenase and acetaldehyde dehydrogenases have been associated with hepatocellular carcinoma, but how alcohol dehydrogenase and acetaldehyde dehydrogenases alter the prognosis of hepatocellular carcinoma have not been completely elucidated.

Methods: Metabolic activities, gene polymorphisms, and content of alcohol dehydrogenase and acetaldehyde dehydrogenases were determined in 68 fibrotic livers from hepatocellular carcinoma patients. These characteristics were then correlated with clinical features and prognosis in these patients.

Variation in the expression of cytochrome P450-related miRNAs and transcriptional factors in human livers: Correlation with cytochrome P450 gene phenotypes.

Cytochrome P450 (CYP) gene expression exhibits large interindividual variation attributable to diverse regulatory factors including microRNAs (miRNAs) and hepatic transcription factors (TFs). We used real-time qPCR with 106 human liver samples to measure the expression and interindividual variation of seven miRNAs and four TFs that have been reported to regulate the expression of CYPs; we also identified factors that influence their expression. The results show that expression of the seven miRNAs and the four TFs exhibits a non-normal distribution and the expression variability is high (89- to 618-fold for miRNA and 12- to 85-fold for TFs).

From Genotype to Phenotype: Content and Activities of Cytochromes P450 2A6 in Human Liver In Vitro and Predicted In Vivo.

Unraveling the molecular mechanisms by which genetic variants of cytochrome P450 2A6 lead to different metabolic phenotypes remains a long-standing but important challenge. CYP2A6 is an enzyme involved in the metabolism of several clinical drugs as well as the metabolic activation of carcinogenic nitrosamines. Herein, genotypes and phenotypes, as indicated by protein content [by liquid chromatography-mass spectrometry (MS)/MS] and metabolic activities [V, clearance (CL)], were determined for 90 human liver samples.

Inhibition of Rat CYP1A2 and CYP2C11 by Honokiol, a Component of Traditional Chinese Medicine.

Background And Objectives: Honokiol, a major constituent isolated from Magnolia officinalis, is regarded as a phytochemical marker and bioactive substance present in many traditional Chinese medicines. However, the effect of honokiol on cytochrome P450 (CYP) has not been thoroughly investigated. The aim of this study was to investigate the effect of honokiol on CYP1A2 and CYP2C11 in vitro and in vivo.

High CYP2E1 activity aggravates hepatofibrosis by limiting macrophage polarization towards the M2 phenotype.

Cytochrome P450 2E1 (CYP2E1) is an important drug-metabolizing enzyme that has been recognized as one of the risk factors for hepatofibrosis. Macrophages play key roles in regulating hepatofibrosis progression and resolution. However, whether CYP2E1 is involved in the regulation of macrophage polarization during hepatofibrosis is still unclear.

CYP3A4/5 Activity Probed with Testosterone and Midazolam: Correlation between Two Substrates at the Microsomal and Enzyme Levels.

Testosterone (TST) and midazolam (MDZ) are widely used as probes to detect CYP3A4/5 activity, but the data acquired with these two substrates do not correlate well at the microsomal level (per milligram of microsomal protein), and the reason is unclear. In this study, CYP3A4/5 activity was probed with TST and MDZ at the microsomal and enzyme levels (per picomole of CYP3A4/5) in 72 human liver samples. Correlation coefficients were lower in V and CL at the microsomal level, as compared with those at the enzyme level ( V 0.

Intraindividual Variation and Correlation of Cytochrome P450 Activities in Human Liver Microsomes.

We systematically studied and explored intraindividual variation and correlation in the activities of cytochrome P450 (CYP) using 105 normal liver samples. The intraindividual percentage coefficients of variation of relative K, V, and CL were 45.9% (18.

Higher Activity of Alcohol Dehydrogenase Is Correlated with Hepatic Fibrogenesis.

Hepatofibrosis can progress to cirrhosis and hepatocellular carcinoma (HCC). Prevention, stabilization, and reversal of disease progression are vital for patients with hepatofibrosis, and identifying the risk factors for hepatofibrosis is urgently needed. In this study, we examined the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in the fibrotic livers of HCC patients ( = 88) and comparied these results with activities in patients with normal livers ( = 74).

Effect of P450 Oxidoreductase Polymorphisms on the Metabolic Activities of Ten Cytochrome P450s Varied by Polymorphic CYP Genotypes in Human Liver Microsomes.

Unlabelled: Background/ Aims: Little is known about the effect of P450 oxidoreductase (POR) gene polymorphisms on the activities of CYPs with multiple genotypes.

Methods: We genotyped 102 human livers for 18 known POR single nucleotide polymorphisms (SNPs) with allelic frequencies greater than 1% as well as for 27 known SNPs in 10 CYPs. CYP enzyme activities in microsomes prepared from these livers were determined by measuring probe substrate metabolism by high performance liquid chromatograph.

Content and Activities of UGT2B7 in Human Liver In Vitro and Predicted In Vivo: A Bottom-Up Approach.

UDP-glucuronosyltransferase 2B7 (UGT2B7) is one of the most significant isoforms of UGTs in human liver. This research measured UGT2B7 protein content and activities, including maximum velocity (V) and intrinsic clearance (CL), in human liver at isoform, microsomal, liver tissue, and liver levels and identified the factors that influence expression. We determined absolute protein content by liquid chromatography-tandem mass spectroscopy and activities using the probe drug zidovudine in 82 normal human liver microsomes.

From hepatofibrosis to hepatocarcinogenesis: Higher cytochrome P450 2E1 activity is a potential risk factor.

Hepatofibrosis is an important susceptibility factor for hepatocarcinogenesis. However, only a handful of cases of hepatofibrosis will develop into hepatocellular carcinoma (HCC). As cytochrome P450 2E1 (CYP2E1) is involved in the metabolism and activation of many known environmental toxicants and procarcinogens, this enzyme may play a role in the development of hepatocarcinogenesis subsequent to hepatofibrosis.

Association of CYP3A4*1B genotype with Cyclosporin A pharmacokinetics in renal transplant recipients: A meta-analysis.

Objective: Cyclosporine (CsA) is a substrate of cytochrome P450 (CYP) 3A4 with a narrow therapeutic index and large individual difference. CYP3A4*1B is reported to be associated with CsA pharmacokinetics parameters, but the relevance is still in dispute. Therefore, a meta-analysis was employed to evaluate the influence of CYP3A4*1B on CsA pharmacokinetics at different post-transplantation times in adult renal transplant recipients.

Inhibitory effect of chlormethiazole on the toxicokinetics of diethylnitrosamine in normal and hepatofibrotic rats.

The effect of chlormethiazole (CMZ) at single and multiple doses on the toxicokinetics of diethylnitrosamine (DEN) was investigated in normal rats and those with DEN-induced liver fibrosis. Twelve rats were treated with DEN (50 mg/kg) alone and in combination with a single dose of CMZ (10, 50, or 100 mg/kg) by intraperitoneal (i.p.

Higher CYP2E1 Activity Correlates with Hepatocarcinogenesis Induced by Diethylnitrosamine.

Hepatocellular carcinoma (HCC) is one of the most common types of primary liver cancer and the third most frequent cause of cancer death worldwide. Diethylnitrosamine (DEN) is one of the recognized risk factors for hepatocarcinogenesis likely due to CYP2E1-mediated metabolic activation. However, CYP2E1-mediated DEN metabolic activity in non-neoplastic liver tissue from HCC patients has not been determined; the role of CYP2E1 activity, in particular CYP2E1 constitutive activity and CYP2E1 inhibited activity, with respect to the hepatocarcinogenesis induced by DEN is not yet clear.

High CYP2E1 activity correlates with hepatofibrogenesis induced by nitrosamines.

Hepatofibrosis, which leads to cirrhosis and eventual hepatocellular carcinoma, is a common response to chronic toxin-mediated liver injury. Nitrosamines are potent hepatotoxic agents that cause necrosis and subsequent fibrosis in the liver as a result of cytochrome P450 2E1 (CYP2E1)-dependent metabolism, which generates toxic metabolites that form adducts with nucleic acids, leading to hepatotoxicity and mutagenesis. Herein, CYP2E1 activity and content were determined in fibrotic liver tissue from patients with hepatocellular carcinoma.

Prediction of cytochrome P450-mediated drug clearance in humans based on the measured activities of selected CYPs.

Determining drug-metabolizing enzyme activities on an individual basis is an important component of personalized medicine, and cytochrome P450 enzymes (CYPs) play a principal role in hepatic drug metabolism. Herein, a simple method for predicting the major CYP-mediated drug clearance and is presented. Ten CYP-mediated drug metabolic activities in human liver microsomes (HLMs) from 105 normal liver samples were determined.

From Genotype to Phenotype: Cytochrome P450 2D6-Mediated Drug Clearance in Humans.

How genotypic variation results in phenotypic differences is still a challenge for biology. In the field of drug metabolism, the means by which specific cytochrome P4502D6 (CYP2D6) genotypes yield different phenotypes at various levels (molecular, cellular, and organismal) is an important question, as differences in CYP2D6 activity can contribute to adverse drug reactions. Herein, the genotype of CYP2D6 was determined along with the absolute content of CYP2D6 and microsomal protein per gram of liver in human liver microsomes, the molecular, cellular (microsomal, tissue, organ), and organismal phenotype of CYP2D6 determined; the effect of genotype on each phenotype of CYP2D6-mediated dextromethorphan clearance (CL) was delineated, and the overall genotype-phenotype relationship for CYP2D6 was charted.

Preclinical Pharmacokinetics, Tissue Distribution, and Plasma Protein Binding of Sodium (±)-5-Bromo-2-(α-Hydroxypentyl) Benzoate (BZP), an Innovative Potent Anti-ischemic Stroke Agent.

Sodium (±)-5-bromo-2-(α-hydroxypentyl) benzoate (BZP) is a potential cardiovascular drug and exerts potent neuroprotective effect against transient and long-term ischemic stroke in rats. BZP could convert into 3-butyl-6-bromo-1(3H)-isobenzofuranone (Br-NBP) in vitro and in vivo. However, the pharmacokinetic profiles of BZP and Br-NBP still have not been evaluated.

Correlation of Cytochrome P450 Oxidoreductase Expression with the Expression of 10 Isoforms of Cytochrome P450 in Human Liver.

Human cytochrome P450 oxidoreductase (POR) provides electrons for all microsomal cytochromes P450 (P450s) and plays an indispensable role in drug metabolism catalyzed by this family of enzymes. We evaluated 100 human liver samples and found that POR protein content varied 12.8-fold, from 12.

Significant change of cytochrome P450s activities in patients with hepatocellular carcinoma.

The lack of information concerning individual variation in drug-metabolizing enzymes is one of the most important obstacles for designing personalized medicine approaches for hepatocellular carcinoma (HCC) patients. To assess cytochrome P450 (CYP) in the metabolism of endogenous and exogenous molecules in an HCC setting, the activity changes of 10 major CYPs in microsomes from 105 normal and 102 HCC liver tissue samples were investigated. We found that CYP activity values expressed as intrinsic clearance (CLint) differed between HCC patients and control subjects.

Physiological Content and Intrinsic Activities of 10 Cytochrome P450 Isoforms in Human Normal Liver Microsomes.

Due to a lack of physiologic cytochrome P450 (P450) isoform content, P450 activity is typically only determined at the microsomal level (per milligram of microsomal protein) and not at the isoform level (per picomole of P450 isoform), which could result in the misunderstanding of variations in P450 activity between individuals and further hinder development of personalized medicine. We found that there were large variations in protein content, mRNA levels, and intrinsic activities of the 10 P450s in 100 human liver samples, in which CYP2E1 and CYP2C9 showed the highest expression levels. P450 gene polymorphisms had different effects on activity at two levels: CYP3A5*3 and CYP2A6*9 alleles conferred increased activity at the isoform level but decreased activity at the microsomal level; CYP2C9*3 had no effect at the isoform level but decreased activity at the microsomal level.

Changes in cytochrome P450s-mediated drug clearance in patients with hepatocellular carcinoma in vitro and in vivo: a bottom-up approach.

Hepatocellular carcinoma (HCC) accompanied by severe liver dysfunction is a serious disease, which results in altered hepatic clearance. Generally, maintenance doses depend upon drug clearance, so individual dosage regimens should be customized for HCC patients based on the condition of patients. Based on clearance of CYP isoform-specific substrates at the microsomal level (CLM), microsomal protein per gram of liver (MPPGL), liver weight, hepatic blood flow, hepatic clearance values (CLH) for 10 CYPs in HCC patients (n=102) were extrapolated using a predictive bottom-up pharmacokinetic model.

Inhibition of baicalin on metabolism of phenacetin, a probe of CYP1A2, in human liver microsomes and in rats.

Baicalin has been used as mainly bioactive constituent of about 100 kinds of traditional Chinese medicines in Chinese pharmacopoeia. The effect of baicalin on cytochrome P450 should be paid more attention because baicalin was used widely. The aim of this study was to investigate whether baicalin could inhibit CYP1A2 in pooled human liver microsomes (HLMs) and in rats in vivo and the gene polymorphisms could affect inter-individual variation in IC50 in 28 human livers.

Contribution of baicalin on the plasma protein binding displacement and CYP3A activity inhibition to the pharmacokinetic changes of nifedipine in rats in vivo and in vitro.

Baicalin purified from the root of Radix scutellariae is widely used in clinical practices. This study aimed to evaluate the effect of baicalin on the pharmacokinetics of nifedipine, a CYP3A probe substrate, in rats in vivo and in vitro. In a randomised, three-period crossover study, significant changes in the pharmacokinetics of nifedipine (2 mg/kg) were observed after treatment with a low (0.

Pharmacokinetic changes of unbound theophylline are due to plasma protein binding displacement and CYP1A2 activity inhibition by baicalin in rats.

Ethnopharmacological Relevance: Baicalin is one of the major bioactive constituents of Scutellariae Radix, the root of Scutellariae baicalensis Georgi and possesses a wide variety of pharmacological properties.

Aim Of The Study: To elucidate the effect of baicalin on the pharmacokinetics of theophylline in rats, focusing on plasma protein binding displacement and inhibition effect on CYP1A2 in vivo and in vitro.

Materials And Methods: The study was a randomized, three-period crossover design.