Gukang Capsules are often used in combination with drugs to treat fractures, osteoarthritis, and osteoporosis. Cytochrome P450(CYP450) mainly exists in the liver and participates in the oxidative metabolism of a variety of endogenous and exogenous substances and serves as an important cause of drug-metabolic interactions and adverse reactions. Therefore, it is of great significance to study the effect of Gukang Capsules on the activity and expression of CYP450 for increasing its clinical rational medication and improving the safety of drug combination. In this study, the Cocktail probe method was used to detect the changes in the activities of CYP1A2, CYP3A2, CYP2C11, CYP2C19, CYP2D4, and CYP2E1 in rat liver after treatment with high-, medium-and low-dose Gukang Capsules. The rat liver microsomes were extracted by the calcium chloride method, and protein expression of the above six CYP isoform enzymes was detected by Western blot. The results showed that the low-dose Gukang Capsules could induce CYP3A2 and CYP2D4 in rats, medium-dose Gukang Capsules had no effect on them, and high-dose Gukang Capsules could inhibit them in rats. The high-dose Gukang Capsules did not affect CYP2C11 in rats, but low-and medium-dose Gukang Capsules could induce CYP2C11 in rats. Gukang Capsules could inhibit CYP2C19 in rats and induce CYP1A2 in a dose-independent manner, but did not affect CYP2E1. If Gukang Capsules were co-administered with CYP1A2, CYP2C19, CYP3A2, CYP2C11, and CYP2D4 substrates, the dose should be adjusted to avoid drug interactions.
Rats ; Animals ; Cytochrome P-450 CYP1A2/metabolism* ; Cytochrome P-450 CYP2C19 ; Cytochrome P-450 CYP2E1/pharmacology* ; Rats, Sprague-Dawley ; Cytochrome P-450 Enzyme System/metabolism* ; Microsomes, Liver ; Liver ; Cytochrome P-450 CYP3A/metabolism*

This paper aimed to study the six chemical components of Polygoni Multiflori Radix (gallic acid, quercetin, luteolin, kaempferol, resveratrol, apigenin). By the established pregnane X receptor (human pregnant X receptor, PXR) CYP3A4 mediated drug induced rapid screening technique, the effect of chemical components on the cell activity was detected by MTS cell method, and the value of IC₅₀ was calculated. The dual luciferase reporter system was used to co-transfect PXR reporter gene expression vector containing transcriptional regulation and CYP3A4 with HepG2 cells, with 10 μmol·L⁻¹ rifampicin (RIF) as a positive control, and 10 μmol·L⁻¹ of ketoconazole (TKZ) as negative control. Gallic acid, quercetin, luteolin, kaempferol, apigenin, resveratrol(5, 10, 20 μmol·L⁻¹) were used to incubate for 24 h, and the luciferase activity was detected. The results showed that when plasmid pcDNA3.1 was co-transfected with pGL4.17-CYP3A4, gallic acid and resveratrol had an inhibitory effect on the regulation of CYP3A4, and quercetin, luteolin, kaempferol had an inductive effect on CYP3A4; when pcDNA3.14-PXR was co-transfected with pGL4.17-CYP3A4, quercetin, luteolin, kaempferol, apigenin, resveratrol had an inductive effect. To sum up, the 6 reported liver injury components had inhibitory or activating effects on CYP3A4. After PXR plasmid was involved, 5 components had an inductive effect on CYP3A4, and the inductive effects of 2 components were significantly different. In this experiment, we found that 2 kinds of potential liver injury components in Polygoni Multiflori Radix had been induced by CYP3A4, which was achieved through PXR regulation. It suggested that attention shall be paid to potential drug interactions when combined with Polygoni Multiflori Radix, so as to improve the safety and efficacy.
Cytochrome P-450 CYP3A ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Hep G2 Cells ; Humans ; Liver ; Phytochemicals ; pharmacology ; Plant Roots ; chemistry ; Polygonum ; chemistry ; Pregnane X Receptor ; metabolism

BACKGROUND: The renal function of individuals is one of the reasons for the variations in therapeutic response to various drugs. Patients with renal impairment are often exposed to drug toxicity, even with drugs that are usually eliminated by hepatic metabolism. Previous study has reported an increased plasma concentration of indoxyl sulfate and decreased plasma concentration of 4β-hydroxy (OH)-cholesterol in stable kidney transplant recipients, implicating indoxyl sulfate as a cytochrome P450 (CYP) inhibiting factor. In this study, we aimed to evaluate the impact of renal impairment severity-dependent accumulation of indoxyl sulfate on hepatic CYP3A activity using metabolic markers. METHODS: Sixty-six subjects were enrolled in this study; based on estimated glomerular filtration rate (eGFR), they were classified as having mild, moderate, or severe renal impairment. The plasma concentration of indoxyl sulfate was quantified using liquid chromatography-mass spectrometry (LC-MS). Urinary and plasma markers (6β-OH-cortisol/cortisol, 6β-OH-cortisone/cortisone, 4β-OH-cholesterol) for hepatic CYP3A activity were quantified using gas chromatography-mass spectrometry (GC-MS). The total plasma concentration of cholesterol was measured using the enzymatic colorimetric assay to calculate the 4β-OH-cholesterol/cholesterol ratio. The correlation between variables was assessed using Pearson's correlation test. RESULTS: There was a significant negative correlation between MDRD eGFR and indoxyl sulfate levels. The levels of urinary 6β-OH-cortisol/cortisol and 6β-OH-cortisone/cortisone as well as plasma 4β-OH-cholesterol and 4β-OH-cholesterol/cholesterol were not correlated with MDRD eGFR and the plasma concentration of indoxyl sulfate. CONCLUSION: Hepatic CYP3A activity may not be affected by renal impairment-induced accumulation of plasma indoxyl sulfate.
Cholesterol ; Cytochrome P-450 CYP3A* ; Cytochrome P-450 Enzyme System* ; Cytochromes* ; Drug-Related Side Effects and Adverse Reactions ; Gas Chromatography-Mass Spectrometry ; Glomerular Filtration Rate ; Humans ; Indican ; Kidney ; Metabolism ; Plasma ; Spectrum Analysis ; Transplant Recipients

Pharmacological activities and adverse side effects of ginkgolic acids (GAs), major components in extracts from the leaves and seed coats of Ginkgo biloba L, have been intensively studied. However, there are few reports on their hepatotoxicity. In the present study, the metabolism and hepatotoxicity of GA (17 : 1), one of the most abundant components of GAs, were investigated. Kinetic analysis indicated that human and rat liver microsomes shared similar metabolic characteristics of GA (17 : 1) in phase I and II metabolisms. The drug-metabolizing enzymes involved in GA (17 : 1) metabolism were human CYP1A2, CYP3A4, UGT1A6, UGT1A9, and UGT2B15, which were confirmed with an inhibition study of human liver microsomes and recombinant enzymes. The MTT assays indicated that the cytotoxicity of GA (17 : 1) in HepG2 cells occurred in a time- and dose-dependent manner. Further investigation showed that GA (17 : 1) had less cytotoxicity in primary rat hepatocytes than in HepG2 cells and that the toxicity was enhanced through CYP1A- and CYP3A-mediated metabolism.
Animals ; Cells, Cultured ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Ginkgo biloba ; chemistry ; Glucuronosyltransferase ; metabolism ; Hepatocytes ; chemistry ; drug effects ; enzymology ; metabolism ; Humans ; Kinetics ; Liver ; chemistry ; drug effects ; enzymology ; metabolism ; Microsomes, Liver ; chemistry ; drug effects ; enzymology ; metabolism ; Plant Extracts ; chemistry ; metabolism ; toxicity ; Rats ; Rats, Sprague-Dawley ; Salicylates ; chemistry ; metabolism ; toxicity

Cardiovascular disease (CVD) is the most common cause of death in patients with non-alcoholic fatty liver disease (NAFLD). New therapeutic strategies which have the potential for slowing down the evolution of NAFLD and reducing CVD-related mortality are urgently needed. Statins are well recognized in the treatment of dyslipidemia, but their use in the treatment of NAFLD is limited due to the safety concerns. Ilexgenin A (IA) is one of the main bioactive compounds in 'Shan-lv-cha', an herbal tea commonly used in China. In the present study, we investigated the possible synergistic therapeutic effects of IA and simvastatin (SV) on NAFLD. IA or SV showed beneficial effects on the rats with NAFLD by lowering the liver weight, liver index and plasma levels of alanine aminotransferase and aspartate aminotransferase, regulating abnormal metabolism of lipids and ameliorating steatosis in liver. IA significantly enhanced the hypolipidemic and anti-inflammation effects of SV. Furthermore, a sensitive, accurate, convenient and reproducible LC-MS method was developed to investigate the effects of IA on the pharmacokinetics of SV. No significant changes were observed in pharmacokinetic parameters of SV and simvastatin hydroxy acid in the IA plus SV co-treated group in comparison with those in the group treated with SV alone. The mRNA levels and activity of CYP3A1 were not altered by IA. In conclusion, the results obtained from the present study should be helpful for further clinical application of SV and IA alone or in combination.
Alanine Transaminase ; metabolism ; Animals ; Aspartate Aminotransferases ; metabolism ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Diet, High-Fat ; Disease Models, Animal ; Drug Synergism ; Drug Therapy, Combination ; Lipids ; blood ; Liver ; metabolism ; pathology ; physiopathology ; Male ; Molecular Structure ; Non-alcoholic Fatty Liver Disease ; blood ; drug therapy ; Rats ; Rats, Sprague-Dawley ; Simvastatin ; analogs & derivatives ; pharmacokinetics ; therapeutic use ; Transcription, Genetic ; Triterpenes ; chemistry ; therapeutic use

Ginsenoside Rh2 (Rh2) is one of the major bioactive ginsenosides in Panax ginseng. However, the oral bioavailability of Rh2 is low, with P-glycoprotein (P-gp) and CYP3A4 being reported to be the main factors. The purpose of the present study was to determine the enhancing effect of piperine on the oral bioavailability as well as bioactivity of Rh2. The inhibitory effect of piperine on P-gp and CYP3A4 was determined using a Caco-2 monolayer model and a recombinant CYP3A4 metabolic system, respectively. The pharmacokinetics of oral Rh2 (10 mg·kg) administered alone or in combination with piperine (10 and 20 mg·kg) was performed in rats. The immune boosting effect of Rh2 was assessed in rats by measuring IL-12 level after treated by Rh2 alone or co-administered with piperine. The results indicated that piperine significantly increased the permeability of Rh2 and inhibited the metabolism of Rh2. The pharmacokinetic study results showed that the AUC of Rh2 was significantly increased in combination with piperine at high dose (20 mg·kg) when compared to the control group, with relative bioavailability of 196.8%. The increase of Rh2 exposure led to increased serum levels of IL-12. In conclusion, piperine may be used as a bioenhancer to improve pharmacological effect of Rh2 when given orally.
Administration, Oral ; Alkaloids ; administration & dosage ; Animals ; Benzodioxoles ; administration & dosage ; Biological Availability ; Caco-2 Cells ; Cytochrome P-450 CYP3A ; metabolism ; Drugs, Chinese Herbal ; administration & dosage ; Ginsenosides ; administration & dosage ; pharmacokinetics ; Humans ; Interleukin-2 ; metabolism ; Panax ; chemistry ; Piperidines ; administration & dosage ; Polyunsaturated Alkamides ; administration & dosage ; Rats ; Rats, Sprague-Dawley

In adult liver, CYP3A4 plays an important role in the metabolism of a wide range of endogenous and exogenous compounds. To investigate whether there is a single nucleotide polymorphism (SNP) of CYP3A4 intron 2 in the liver and its effects on the mRNA expression and enzymatic activity of CYP3A4, genomic DNA was extracted from 96 liver tissue samples obtained from patients who had undergone liver surgery. An SNP of CYP3A4 intron 2 was identified by polymerase chain reaction (PCR)-single-strand confirmation polymorphism and DNA sequencing. The mRNA expression of CYP3A4 was determined by the fluorescence quantitative PCR technique. The enzymatic activity of CYP3A4 was measured using erythromycin and testosterone as probe substrates. Twelve patients were found to have the SNP/T4127G CYP3A4 within intron 2. The mRNA levels of CYP3A4 in wild-type and SNP/T4127G samples were 2.62±1.09 and 2.79±1.63, respectively (P>0.05). Erythromycin N-demethylase activity in wild-type and SNP/T4127G samples were 121.2±32.8 and 124.7±61.6 nmol·mg(-1)·min(-1), respectively (P>0.05). The activity of testosterone 6β-hydroxylase was significantly different between wild-type (648±173 pmol·mg(-1)·min(-1)) and SNP/T4127G samples (540±196 pmol·mg(-1)·min(-1); P<0.05). In conclusion, the SNP/T4127G of CYP3A4 intron 2 exists in the liver. This SNP does not affect the mRNA expression of CYP3A4 but significantly decreases the hepatic microsomal testosterone 6β-hydroxylase activity of CYP3A4. Furthermore, this study indicates that the appropriate selection of probe substrates is very important in studying the relationship between the genotype and phenotype of CYP3A4.
Adult ; Asian Continental Ancestry Group ; genetics ; China ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Erythromycin ; metabolism ; Genotype ; Humans ; Introns ; Liver ; enzymology ; Phenotype ; Polymorphism, Single Nucleotide ; RNA, Messenger ; genetics ; Sequence Analysis, DNA ; methods ; Testosterone ; metabolism

<p>OBJECTIVEConsuming 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.p><p>METHODSThe 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.p><p>RESULTSARE and GSE showed no inhibition with IC50 values >1 000 μg/mL while the standard inhibitor ketoconazole completely abolished CYP3A4-dependent activity at 0.531 μg/mL and IC50 was found to be 0.036 μg/mL.p><p>CONCLUSIONARE 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.p>
Animals ; Asparagus Plant ; Chromatography, High Pressure Liquid ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 CYP3A Inhibitors ; pharmacology ; Gymnema sylvestre ; Herb-Drug Interactions ; Isoenzymes ; antagonists & inhibitors ; Plant Extracts ; pharmacology ; Rats ; Rats, Wistar

<p>OBJECTIVETo evaluate the effect of a 10-day course of triptolide (TP) on rat cytochrome (CY) P3A4 activity, and on the pharmacokinetics of cyclophosphamide (CPA).p><p>METHODSIn the pharmacokinetics experiment, rats were orally given 0.9% NaCl solution (n=5) and TP [1.2 (mg/kg·d)] for 10 days and a single dose of CPA was administered intravenously (100 mg/kg) to rats on day 11. Blood samples were collected up to 4 h at predetermined time intervals, the plasma concentration of CPA was determined by high performance liquid chromatography (HPLC) and pharmacokinetic parameters were determined. In the in vitro CYP3A4 activity inhibition research, rat blank liver microsomes were divided into 3 groups: a control group, a TS (5 μL, 200 μmol/L) with TP (5 μL, 12.5 μmol/L) group, a TS with ketoconazole (5 μL, 1 μmol/L) group. Concentration of 6β-hydroxylated testosterone (6β-OHT) in liver microsomes was measured by HPLC and the activity of CYP 3A4 was calculated through the following formula: Einhibitor/Econtrol × 100%=Cinhibitor/Ccontrol × 100%.p><p>RESULTSCompared with the control group, the area under the plasma concentration-time curve (AUC0-∞) of CPA was significantly increased by 229.05% pretreated with TP (P<0.01). Peak plasma concentrations (Cmax) of CPA was significantly increased and plasma half-life was correspondingly extended. The CYP3A4 activity was significantly inhibited by ketoconazole 93.5%±0.2% and TP 84.6%±0.3% compared with the control group (P<0.01 and P<0.05, respectively).p><p>CONCLUSIONOur results strongly suggested that long-term oral intake of TP can distinctly inhibit the CYP3A4 activity and this inhibition evidently decrease the formation of toxic metabolites of CPA.p>
Animals ; Cyclophosphamide ; pharmacokinetics ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 CYP3A Inhibitors ; pharmacology ; Diterpenes ; pharmacology ; Epoxy Compounds ; pharmacology ; Herb-Drug Interactions ; Hydroxytestosterones ; metabolism ; Immunosuppressive Agents ; pharmacokinetics ; Injections, Intravenous ; Ketoconazole ; pharmacology ; Male ; Microsomes, Liver ; drug effects ; metabolism ; Phenanthrenes ; pharmacology ; Rats, Sprague-Dawley

Multidrug regimens and corresponding drug interactions cause many adverse reactions and treatment failures. Drug efflux transporters: P-glycoprotein (P-gp), multidrug resistance associated protein (MRP) and breast cancer resistance protein (BCRP) in conjunction with metabolizing enzymes (cytochrome P450, CYP450) are major factors in such interaction. In recent years, a large number of studies have shown that P-gp plays a role in the oxidative metabolism of its substrates that are also substrates of CYP3A4. Combined actions of P-gp and CYP3A could account in some part for the low oral bioavailability determined for many of these dual substrates. P-gp along with efflux transporters (MRP and BCRP) having overlapping substrate specificity plays critical role in drug disposition. The relationship between MRP or BCRP and CYP3A is similar to that between P-gp and CYP3A. In this paper, we summarize the classification of efflux transporters, the main metabolizing enzymes CYP3A, clinical significance interactions mediated by efflux transporters and CYP450 enzymes and in vitro studies.
ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Biological Availability ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Drug Interactions ; Humans ; Multidrug Resistance-Associated Proteins ; metabolism ; Neoplasm Proteins ; metabolism ; Substrate Specificity