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*

<p>AIMTo identify the cytochrome P450 (CYP) isoform (s) involved in daidzein mono-hydroxylated metabolites using human liver microsomes.p><p>METHODSKinetic analysis of the rates of formation of mono-hydroxylated metabolites of daidzein, including 7,8,4'-trihydroxyisoflavone (7,8,4'-THI), 7,3',4'-trihydroxyisoflavone (7,3',4'-THI) and 6,7,4'-trihydroxyisoflavone (6,7,4'-THI), was performed using human liver microsomes (HLM) and recombinant enzymes at substrate concentrations ranging from 0.5 to 400 micromol x L(-1). Nine selective inhibitors or substrate probes specific for different CYP isoforms were applied for screening the isoform(s) responsible for mono-hydroxylated metabolism of daidzein.p><p>RESULTSMichaelis-Menten kinetic parameters were best fitted to one-component enzyme kinetic model. The mean Km (micromol x L(-1) ) and V(max) (micromol x g(-1) x min(-1)) values were 27 +/- 10 and 4. 8 +/- 2.1, 54 +/- 22 and 2.3 +/- 1.0, 51 +/- 29 and 2.2 +/- 0.8, for the formation rates of 7,8,4'-THI, 7,3',4'-THI, and 6,7,4'-THI, respectively. Furafylline, the CYP1A2 specific inhibitor, estrogen, and monoclonal antibody raised against human CYP1A2 (MAB-1A2) apparently inhibited the formation of mono-hydroxylated metabolites, The IC50 of Fur for the formation of 7,3',4'-THI, 6,7,4'-THI and 7,8,4'-THI was 1.0, 0.9 and 0. 8 mol x L(-1), respectively. The IC50 of estrogen for the formation of 7,3',4'-THI, 6,7,4'-THI and 7,8,4'-THI were 51, 60 and 64 mol x L(-1) respectively. The IC50 of MAB-1A2 for the formation of the mono-hydroxylated products was 1 mol x L(-1), but neither other selective inhibitor nor substrate probes, including coumarin (CYP2D6), sulphaphenzole ( CYP2C9/10), omeprazole ( CYP2C19), quinidine (CYP2D6), diethyldithiocarbamate (CYP2E1), troleandomycin (CYP3A4) and keteconazole (CYP3A4), did so with human liver microsomes.p><p>CONCLUSIONThe in vitro studies indicated that daidzein mono-hydroxylated products were principally metabolized by CYP1A2 in human.p>
Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP1A2 Inhibitors ; Estrogens ; pharmacology ; Humans ; Hydroxylation ; Isoflavones ; metabolism ; Microsomes, Liver ; metabolism ; Theophylline ; analogs & derivatives ; pharmacology

The inhibition activity of 36 flavonoids against CYP1A2 was determined by our previously developed in vitro method. The Comparative Molecular Similarity Indexes Analysis (CoMSJA) approach was used to probe the quantitative relationships between the flavonoids' molecular structural descriptors and their inhibitory activities. A reliable CoMSIA model with the combined electrostatic and hydrophobic fields was derived with the regression coefficient R2 of 0.948 and the cross-validation regression coefficient q2 of 0.630, separately, which is capable of elucidating the quantitative relationship between the 3D structural descriptors of the flavones and their bioactivities. Comparing with flavone, the larger pi-pi conjugated system of alpha-naphthoflavone significantly improved the biologically inhibitory ability. Based on the core structure of the latter, either electropositive substituents or hydrophobic groups at the 6, 3', and 4' ring positions or electronegative counterparts at the 5 ring position, can enhance the inhibitory potency against CYP1 A2 according to the CoMSIA contour maps.
Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP1A2 Inhibitors ; Flavonoids ; chemistry ; pharmacology ; Humans ; Microsomes, Liver ; metabolism ; Models, Molecular ; Molecular Structure ; Quantitative Structure-Activity Relationship

<p>OBJECTIVETo observe the effect of ketoconazole on the activity of cytochrome P450 (CYP) 1A2 and 3A4 in hepatic microsomes of healthy adults.p><p>METHODSHuman hepatic microsomes obtained from healthy adults were randomly divided into control group and ketoconazole-treatment groups at different concentrations. After 15 min of culture, the substrates (testosterone for CYP3A4 and phenacetin for CYP1A2) were added and incubated for another 20 min. The metabolites (6-testosterone and acetaminophen) were then measured with high-performance liquid chromatography (HPLC) to assess the activities of CYP3A4 and 1A2.p><p>RESULTSSignificant difference was found between the groups in the quantity of 6-testosterone and the relative activity of CYP3A4 (P<0.05). The IC(50) of ketoconazole for CYP3A4 was 0. 16 mg/L. Both the quantity of 6-testosterone and the relative activity of CYP3A4 were reduced gradually with the increment of ketoconazole concentration. Significant differences were found between the ketoconazole groups and the control group in both the quantity of acetaminophen and the relative activity of CYP1A2 (P<0.05). Ketoconazole at low doses reduced CYP1A2 activity and but increased the activities at high doses (P<0.05).p><p>CONCLUSIONIn the range of maximum clinical blood concentration, ketoconazole can inhibit the activity of CYP3A4, but not that of CYP1A2, in the hepatic microsomes in healthy adults.p>
Adult ; Antifungal Agents ; pharmacology ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Dose-Response Relationship, Drug ; Female ; Humans ; Ketoconazole ; pharmacology ; Male ; Microsomes, Liver ; drug effects ; enzymology

<p>OBJECTIVETo study the effects of salvianolic acid A on content of cytochrome P450,cytochrome b5 and CYP1A2, CYP2E1 activities of rats.p><p>METHODThe rats were randomly divided into two groups and each group contained 5 male rats and 5 female rats. One is control group, another is dosage group. The dosage group was injected salvianolic acid A into a rat tail vein at doses of 20 mg x kg(-1) x d(-1) for 5 days. The control group was injected placebo into a rat tail vein at the same doses as the dosage group. The content of cytochrome P450 and cytochrome b5 of rats were assayed using UV and CYP1A2, CYP2E1 activities were evaluated using probe substrate.p><p>RESULTAfter salvianolic acid A was injected into rats tail vein for 5 days, the total content of cytochrome P450 and cytochrome b5 and CYP1A2 and CYP2E1 activities have no statistical significance of differences than the control group.p><p>CONCLUSIONSalvianolic acid A has no effects on CYP1A2 and CYP2E1 activities, indicating that there is no internation between salvianolic acid A and the drugs metabolized by CYP1A2 or CYP2E1.p>
Animals ; Caffeic Acids ; pharmacology ; Chromatography, High Pressure Liquid ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP2E1 ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Cytochromes b5 ; metabolism ; Female ; Lactates ; pharmacology ; Male ; Microsomes, Liver ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley

This study was carried out to investigate the effect of oral administration of Dendrobium huoshanense on the expressions and activities of hepatic microsomal cytochrome P450s in mice, and to provide a reference for the evaluation of drug-drug interactions between D. huoshanense and clinical drugs. The C57BL/6 mice were randomly divided into blank control group, D. huoshanense low dose group (crude drug 1.25 g·kg⁻¹), D. huoshanense high dose group (crude drug 7.5 g·kg⁻¹), and phenobarbital positive control group (0.08 g·kg⁻¹). Each group was intragastrically administered with drugs for 2 weeks. The mice were sacrificed and their liver microsomes were prepared. The expressions of major subtypes of P450 enzyme were determined by Western blot and the probe drugs were used to detect the enzyme activities of P450 subtypes with protein expression changes. Western blot analysis showed that the protein expressions of CYP1A1, CYP1A2 and CYP2B in liver tissues were up-regulated in D. huoshanense-treated group. In vitro enzyme activity tests showed that there were no significant difference in metabolism of 7-ethoxyresorufin (a probe drug for CYP1A1) and bupropion (a probe drug for CYP2B) between D. huoshanense group and control group. The metabolism of phenacetin (a probe drug for CYP1A2) showed a statistical difference in rate Vmax, and it was significantly increased by approximately 20% in D. huoshanense group as compared with the blank control group, and the clearance CLint in treated group was also increased by about 32%. Therefore, oral administration of D. huoshanense had no effects on the activities of most hepatic P450 enzymes in mice, with no drug-drug interaction related to the P450 enzyme system in most clinical drugs theoretically. However, oral administration of D. huoshanense may accelerate the metabolism of CYP1A2-catalyzed drugs, which needs to be considered in clinical practice.
Animals ; Cytochrome P-450 CYP1A1 ; metabolism ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Dendrobium ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; Mice ; Mice, Inbred C57BL ; Microsomes, Liver ; drug effects ; enzymology ; Random Allocation

The metabolic characteristics of ligustrazin (TMPz) in liver microsomes were investigated in the present study. The reaction phenotyping of TMPz metabolism was also identified by in vitro assessment using recombinant human cytochrome P450 enzymes (CYP) and UDP glucuronosyltransferases (UGT). TMPz was incubated at 37 degrees C with human (HLM) and rat liver microsomes (RLM) in the presence of different co-factors. The metabolic stability and enzyme kinetics of TMPz were studied by determining its remaining concentrations with a LC-MS/MS method. TMPz was only metabolically eliminated in the microsomes with NADPH or NADPH+UDPGA. In the HLM and RLM with NADPH+UDPGA, t1/2, K(m) and V(max) of TMPz were 94.24 +/- 4.53 and 105.07 +/- 9.44 min, 22.74 +/- 1.89 and 33.09 +/- 2.74 micromol x L(-1), 253.50 +/- 10.06 and 190.40 +/- 8.35 nmol x min(-1) x mg(-1) (protein), respectively. TMPz showed a slightly higher metabolic rate in HLM than that in RLM. Its primary oxidative metabolites, 2-hydroxymethyl-3, 5, 6-trimethylpyrazine (HTMP), could undergo glucuronide conjugation. The CYP reaction phenotyping of TMPz metabolism was identified using a panel of recombinant CYP isoforms (rCYP) and specific CYP inhibitors in HLM. CYP1A2, 2C9 and 3A4 were found to be the major CYP isoforms involved in TMPz metabolism. Their individual contributions were assessed b) using the method of the total normalized rate to be 19.32%, 27.79% and 52.90%, respectively. It was observed that these CYP isoforms mediated the formation of HTMP in rCYP incubation. The UGT reaction phenotyping of HTMP glucuronidation was also investigated preliminarily by using a panel of 6 UGT isoforms (rUGT). UGT1A1, 1A4 and 1A6 were the predominant isoforms mediated the HTMP glucuronidation. The results above indicate that the metabolism of TMPz involves multiple enzymes mediated phase I and phase II reactions.
Animals ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP2C9 ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme Inhibitors ; Cytochrome P-450 Enzyme System ; metabolism ; Drug Interactions ; Glucuronosyltransferase ; metabolism ; Humans ; Ligusticum ; chemistry ; Microsomes, Liver ; enzymology ; NADP ; metabolism ; pharmacology ; Pyrazines ; metabolism ; pharmacokinetics ; Rats ; Uridine Diphosphate Glucuronic Acid ; metabolism ; pharmacology

To study the enzyme kinetics of ligustilide metabolism and the effects of selective CYP450 inhibitors on the metabolism of ligustilide in liver microsomes of rat, a LC-MS method was established for quantitative analysis of ligustilide in liver microsomes incubation system with nitrendipine as internal standard. The determination m/z for ligustilide was 173, and for nitrendipine, 315. An optimum incubation system was found and various selective CYP inhibitors were used to investigate their inhibitory effects on the metabolism of ligustilide. The results showed that enzyme kinetics of ligustilide could be significantly inhibited by ketoconazole, trimethoprim and a-naphthoflavon but scarcely inhibited by omeprazole, 4-methylpyrazole and quinidine. Therefore, CYP3A4, CYP2C9 and CYP1A2 are the major isoenzyme participated in in vitro metabolism of ligustilide.
4-Butyrolactone ; analogs & derivatives ; metabolism ; Animals ; Benzoflavones ; pharmacology ; Cytochrome P-450 CYP1A2 ; Cytochrome P-450 CYP3A ; Cytochrome P-450 Enzyme Inhibitors ; Cytochrome P-450 Enzyme System ; Cytochromes ; antagonists & inhibitors ; Ketoconazole ; pharmacology ; Kinetics ; Male ; Microsomes, Liver ; metabolism ; Rats ; Rats, Sprague-Dawley ; Trimethoprim ; pharmacology

The aim of this study was to explore the regulating effects of hyperoside (Hyp) on lipid metabolism in high-fat diet mice. The high-fat diet mouse model was established by high-fat diet induction. After 5 weeks of Hyp intragastric administration in high-fat diet mice, the serum lipid levels before and after Hyp administration were measured by the corresponding kits. The tissue structure of mouse liver was observed by HE staining before and after Hyp administration. The changes of intestinal flora and transcriptome were measured by Illumina platforms. Liquid chromatography-mass spectrometry (LC-MS) was used to determine non-targeted metabolites. The results showed that Hyp significantly reduced lipid levels in the high-fat diet mice and effectively restored the external morphology and internal structure of liver tissue. Hyp changed the species composition of the intestinal flora in high-fat diet mice, increased the abundance of beneficial flora such as Ruminococcus, and decreased the abundance of harmful flora such as Sutterella. Combined multi-omics analysis revealed that the effect of retinoic acid on lipid metabolism was significant in the high-fat diet mice treated with Hyp, while the increase of retinoic acid content was significantly negatively correlated with the expression of genes such as cyp1a2 and ugt1a6b, positively correlated with AF12 abundance, and significantly negatively correlated with unidentified_Desulfovibrionaceae abundance. These results suggest that Hyp may modulate the abundance of AF12, unidentified_Desulfovibrionaceae and inhibit the expression of genes such as cyp1a2 and ugt1a6b, thus increasing the content of retinoic acid and regulating lipid metabolism in the high-fat diet mice.
Animals ; Mice ; Diet, High-Fat/adverse effects* ; Lipid Metabolism ; Cytochrome P-450 CYP1A2/pharmacology* ; Multiomics ; Liver ; Lipids/pharmacology* ; Tretinoin/pharmacology* ; Mice, Inbred C57BL

Effects of six kinds of Chinese herb extracts, including Folium Crataegi extract, Herba Epimedii extract, Folium Acanthopanacis Senticosi extract, Trifolium pratense L. extract, Folium Ginkgo extract and Radix Puerariae extract, on the activities of CYP450 isozymes (CYP1A2, CYP2C, CYP2E1, CYP2D, CYP3A) in rat hepatic microsomals were studied by using a UPLC-MS/MS (MRM) and cocktail probe substrates method. The results showed that effects of six kinds of Chinese herb extracts on each CYP450 isozyme activity were inhibitory. The IC50 of Folium Crataegi extract for the inhibition of rat microsomal CYP2D activity was only for 4.04 microg x mL(-1), which showed the highest inhibition; Trifolium pratense L. extract had strong inhibitory action to CYP2D, the IC50 value was 5.73 microg x mL(-1); Folium Crataegi extract also had strong inhibitory action on CYP2E1, the IC50 value was 10.91 microg x mL(-1). Furthermore, the IC50 of Folium Ginkgo extract for the inhibition of rat microsomal CYP3A, 2D, 2E1 activities were 45.12, 35.45 and 22.41 microg x mL(-1), respectively, and the IC50 of Folium Acanthopanacis Senticosi extract on the inhibition of rat microsomal CYP2E1 activity was 32.89 microg x mL(-1). In addition, mechanism of inhibition experimental results showed that the inhibiting abilities of Folium Crataegi extract and Radix Puerariae extract on each CYP450 isozyme increased with the increasing of the preincubation time, therefore, the inhibitory effects were a mechanism-based inhibition.
Animals ; Chromatography, High Pressure Liquid ; Crataegus ; chemistry ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP2E1 ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Eleutherococcus ; chemistry ; Epimedium ; chemistry ; Ginkgo biloba ; chemistry ; Inhibitory Concentration 50 ; Male ; Microsomes, Liver ; enzymology ; Plants, Medicinal ; chemistry ; Pueraria ; chemistry ; Rats ; Rats, Sprague-Dawley ; Tandem Mass Spectrometry ; Trifolium ; chemistry