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ObjectiveTo investigate the detoxification mechanism of Chebulae Fructus， Glycyrrhizae Radix et Rhizoma and Prepared Aconiti Kusnezoffii Radix Cocta， and their effective components ellagic acid， liquiritin and aconitine based on cardiac cytochrome P450 （CYP450） system. MethodIn in vivo experiments， rats were randomly divided into control group， prepared Aconiti Kusnezoffii Radix Cocta group （0.25 g·kg-1）， Chebulae Fructus group （0.252 g·kg-1）， Glycyrrhizae Radix et Rhizoma group （0.25 g·kg-1） and combination group （0.25 g·kg-1 Chebulae Fructus+0.25 g·kg-1 Glycyrrhizae Radix et Rhizoma+0.25 g·kg-1 prepared Aconiti Kusnezoffii Radix Cocta， with prepared Aconiti Kusnezoffii Radix Cocta as standard）. After 8 days of administration， creatine kinase （CK） and lactate dehydrogenase （LDH） in rats were detected to observe the pathological changes of heart tissue. Real-time PCR and Western blot were performed to detect the mRNA and protein expressions of CYP2J3， respectively. In in vitro experiments， control group， aconitine group， ellagic acid group， liquiritin group and combination group （aconitine+ellagic acid+liquiritin） were set， and their effects on cell number， DNA content， reactive oxygen species （ROS） and mitochondrial membrane potential （MMP） were detected by high content analysis. The changes in the mRNA and protein expressions of CYP2J3 were also observed. ResultIn vivo experiments， compared with the control group， the prepared Aconiti Kusnezoffii Radix Cocta group had increased CK and LDH in serum （P<0.05， P<0.01）， while the combination group had decreased activities of CK and LDH. Additionally， pathological staining results showed that Chebulae Fructus and Glycyrrhizae Radix et Rhizoma reduced the cardiac toxicity caused by prepared Aconiti Kusnezoffii Radix Cocta. Real-time PCR found that compared with the control group， prepared Aconiti Kusnezoffii Radix Cocta down-regulated the mRNA level of CYP2J3 （P<0.05）， while up-regulated that expression when used in combination with Chebulae Fructus and Glycyrrhizae Radix et Rhizoma （P<0.01）. The protein and mRNA translation levels were basically consistent. In vitro experiments， high content analysis revealed that there was a decrease in the cell number， DNA content and MMP fluorescence value of the aconitine group （P<0.01） and the combination group （P<0.05， P<0.01）， and the fluorescence value of the combination group was higher than that of the aconitine group. Moreover， aconitine down-regulated the mRNA level of CYP2J3 （P<0.05）， but the down-regulating ability of aconitine was reversed in the combination group （P<0.05）. ConclusionThe detoxification mechanism of combined Chebulae Fructus， Glycyrrhizae Radix et Rhizoma and prepared Aconiti Kusnezoffii Radix Cocta is mainly that the combination of ellagic acid， liquiritin and aconitine can up-regulate the expression of CYP2J3， and promote the metabolism of arachidonic acid （AA） to produce epoxyeicosatrienoic acids （EETs）， thus reducing the cardiac toxicity， and this effect may start from the transcriptional link.
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@#To investigate the influential mechanism of total flavonoids from Abelmoschus Manihot (HKZ) on cytochrome P450 (CYP450) isoforms in human liver microsomes and to verify its effect on the most significantly inhibited subtype CYP2C9 in rats.The inhibitory effects of HKZ on human CYP3A4, CYP2C9, CYP2C19, CYP2E1, CYP1A2 and CYP2D6 were evaluated through the cocktail method using ultra-performance liquid chromatography tandem mass spectrometry, then its inhibitory mechanism was investigated and kinetic parameters of enzyme inhibition were calculated By comparing the pharmacokinetic behaviors of tolbutamide after single or multiple administration of 200 mg/kg HKZ and equal dose of CMC-Na in rats, the effects of HKZ on CYP2C11 enzyme (CYP2C9 isoenzyme) was estimated.The results indicated the significant inhibitory effect of HKZ on CYP2C9 and CYP2E1 with IC50 of 3.22 and 8.64 μg/mL, respectively. Also, it showed certain inhibitory ability on other isoforms with IC50 of 20-30 μg/mL.As demonstrated, HKZ may not be a time-dependent inhibitor which competitively inhibited CYP2E1 and CYP2C9 with Ki of 3.84 and 6.33 μg/mL.In contrast, it showed noncompetitive inhibition on CYP3A4 mediated testosterone-6β-hydroxylation and midazolam-4-hydroxylation reaction with Ki of 7.37 and 3.32 μg/mL.It was also a noncompetitive inhibitor of CYP1A2, CYP2D6 and CYPC219 with Ki values of 8.66, 11.49 and 21.94 μg/mL. HKZ did not change the pharmacokinetic parameters of CYP2C11 probe substrate tolbutamide in rat, but it affected the AUC0-t, cmax of 4-hydroxytolubutamide (P < 0.05). Therefore, drug-drug interaction mediated by CYP450 should be considered in clinical study.
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Acetaminophen (APAP, also known as paracetamol)-induced liver injury is the leading cause of drug-induced liver injury in the world. Wuzhi Tablet (WZ, an ethanol extract of Schisandra sphenanthera) is widely used in clinical practice to protect liver function. Our previous studies have shown that pretreatment with WZ for 3 days can significantly protect against APAP-induced liver injury; however, the effect of different intervals between APAP and WZ treatment on APAP-induced liver injury remains unclear. In this study, the change in liver injury indexes, APAP metabolites, and the activity of cytochrome P450 (CYP450) enzymes after treatment with WZ and APAP at different intervals were determined. The animal experiment was reviewed and approved by the Animal Ethics Committee of Sun Yat-sen University. The results show that 0 h, 0.5 h, and 2 h pretreatment with WZ significantly protected against APAP-induced liver injury in mice, as evidenced by a significant decrease in biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malonaldehyde (MDA). WZ inhibited the metabolic activation of APAP mediated by CYP450 enzymes and reduced the formation of APAP metabolites. This study further demonstrates that pretreatment with WZ at different intervals (0 h, 0.5 h, and 2 h before APAP dosing) exerts a significant hepatoprotective effect against APAP-induced liver injury, and a single-dose of WZ inhibits the activity of CYP450 enzymes related to APAP metabolic activation, thereby protecting against APAP-induced hepatotoxicity.
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Objective: To observe the effects of Aconitum carmichaelii on serum metabolites in mice by metabolomics technology, and to explore biomarkers and metabolic pathways and targets related to its treatment of various ailments such as cardiovascular diseases, in order to uncover its molecular mechanism of efficacy. Methods: Twenty male mice were randomly divided into two groups, and A. carmichaelii decoction and distilled water were orally administered with the dose of 15 mL/(kg∙d) for consecutive 4 d respectively. Collected blood samples of each group were analyzed using UPLC-MS/MS technology, and data pattern recognition was performed using PCA, PLS-DA and other analytical methods. Meanwhile, differential metabolites were screened out based on VIP greater than 1 and manual integral calculation. The differential metabolites were used for pathway analysis. Network modular analysis and targets screening were performed by Cytoscape and MetScape. Results: When performing data pattern recognition, the aconite group and the control group could be completely separated. A total of 18 differential metabolites were screened out, and their contents were up-regulated. Pathway analysis was performed to obtain five related pathways, namely linoleic acid metabolism, arachidonic acid metabolism, starch and sucrose metabolism, nicotinate and nicotinamide metabolism, and inositol phosphate metabolism. Fourteen modules were obtained using the network analysis, the largest two of which were arachidonic acid metabolism pathway and linoleic acid metabolism pathway. The degree of arachidonic acid (59), linoleic acid (55), nicotinamide (26), and palmitic acid (11) were greater than the mean value (8.010) in the network, and the related pathways were arachidonic acid metabolism, linoleic acid metabolism, nicotinate and nicotinamide metabolism, and saturated fatty acid beta-oxidation pathway respectively. A total of 26 genes were screened out, all of which belonged to the cytochrome P450 enzyme system. Conclusion: A. carmichaelii may affect arachidonic acid metabolism by acting on CYP450, thereby improving the body's energy metabolism and producing therapeutic effects.
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Parenteral nutrition-associated liver disease (PNALD) is a liver dysfunction caused by various risk factors presented in patients receiving total parenteral nutrition (TPN). Omega-6 rich Intralipid® and omega-3 rich Omegaven® are two intravenous lipid emulsions used in TPN. TPN could affect the hepatic expression of genes in anti-oxidative stress, but it's unknown whether TPN affects genes in drug metabolism. In this study, either Intralipid®- or Omegaven®-based TPN was administered to mice and the expression of a cohort of genes involved in anti-oxidative stress or drug metabolism was analyzed, glutathione (GSH) levels were measured, and protein levels for two key drug metabolism genes were determined. Overall, the expression of most genes was downregulated by Intralipid®-based TPN ( and ). Omegaven® showed similar results as Intralipid® except for preserving the expression of and and increasing . Total GSH levels were decreased by Intralipid®, but increased by Omegaven®. CYP3A11 protein levels were increased by Omegaven®. In conclusion, TPN reduced the expression of many genes involved in anti-oxidative stress and drug metabolism in mice. However, Omegaven® preserved expression of , suggesting another beneficial effect of Omegaven® in protecting liver functions.
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Objective: To investigate the metabolic stability, the main CYP450 enzymes phenotypes and metabolites of Diosbulbin B based on in vitro metabolism model. Methods: For metabolic stability study, UPLC-MS/MS was used to detect the remaining Diosbulbin B content in the incubation solution after being incubated with human and rat liver microsomes, respectively. Ten recombinant human CYP450 enzymes (1A1, 1A2, 1B1, 2A13, 2A6, 2B6, 2D6, 2C9, 2C19, 3A4) were used for identifying the metabolic enzyme phenotypes of Diosbulbin B. Moreover, the major metabolic enzyme phenotype for the metabolism of Diosbulbin B was confirmed and verified by the rat isolated hepatic perfusion model. The metabolites of Diosbulbin B in human and rat liver microsomes were determined by LC-MS/MS. Results: The metabolic percentage of Diosbulbin B in human and rat liver microsomes were 37% and 59%, respectively. Its half-lives t1/2 in human and rat liver microsomes were 97.4 and 52.3 min, respectively. The intrinsic clearance rates CLint in human and rat livers were 8.23 and 23.9 mL/(min•kg), and liver clearance CLh in human and rat livers were 5.89 and 16.8 mL/(min•kg). It can be found that the metabolic rate of Diosbulbin B in rat liver microsomes was faster than in human liver microsomes. There were five CYP enzymes, including 3A4, 2C19, 2C9, 1A13 and 1A1, related to the metabolism of Diosbulbin B, especially CYP3A4. The hepatic perfusion experimental results showed that the metabolism of Diosbulbin B was inhibited by ketoconazole, and the inhibitory effect was enhanced along with the increasing dosage of ketoconazole, which confirmed that CYP3A4 played an important role in metabolism of Diosbulbin B. There was one metabolite (M1) of Diosbulbin B has been found in both human and rat liver microsomes incubation. Conclusion: The metabolic rate of Diosbulbin B in rat liver microsomes was faster than human liver microsomes. The CYP3A4 plays a leading role in the metabolism of Diosbulbin B. And a demethylated metabolite of Diosbulbin B was appeared in both human and rat liver microsomes incubation.
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Cytochrome P450 family is a kind of biocatalyst widely existing in nature. It has many functions such as catalyzing the biosynthesis of plant secondary metabolites and regulating phytoremediation. Based on the analysis of proteome data of Tripterygium wilfordii,the CYP450 gene of T. wilfordii was preliminarily analyzed and predicted by various bioinformatics methods. The results showed that after the expression of T. wilfordii suspension cells was induced by methyl jasmonate,the proteomic data of T. wilfordii were obtained and analyzed,and 10 CYP450 proteins of T. wilfordii were finally screened out. By analyzing the phylogenetic tree constructed with CYP450 gene of Arabidopsis family,the 10 CYP450 proteins were clustered into 6 different CYP450 families. The physical and chemical properties of CYP450 proteins in different families were different. The secondary structure of CYP450 proteins was mainly composed of irregular curls. Eight subcellular localization results of CYP450 proteins were chloroplasts and the rest were plastids. Subsequently,the conserved domains( heme active sites) shared by CYP450 genes were found by analyzing the results of multiple sequence alignment. Finally,by analyzing the transcriptome data of T. wilfordii,the expression distribution of T. wilfordii in different tissues was preliminarily confirmed,which verified its correlation with the biosynthesis of active components of T. wilfordii,and provided important genetic resources for the analysis of biosynthesis pathway of active components of T. wilfordii.
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Computational Biology , Cytochrome P-450 Enzyme System , Chemistry , Phylogeny , Plant Proteins , Chemistry , Proteomics , Tissue Distribution , TripterygiumABSTRACT
<p><b>OBJECTIVE</b>The purpose of this study was to screen for frequencies of different CYP450 genotypes in the Chinese population and explore the relationship between sorafenib toxicity and CYP450 polymorphism.</p><p><b>METHODS</b>A total of 600 peripheral blood samples were obtained from two groups for this study. The first group of 300 samples were from Chinese patients with HBV/HCV-associated HCC, while the remaining 300 samples were from a healthy population of recruited subjects. Allele-specific PCR and long-fragment gene sequencing was used to identify the frequencies of CYP450 polymorphism. Aflatoxin-induced HCC rat models expressing CYP3A4*1, CYP3A5*3, CYP2C19*2, and CYP2D6*10 were established and treated with sorafenib at certain time points. Hepatic and renal function, along with plasma concentration of sorafenib, were monitored regularly.</p><p><b>RESULTS</b>The most common forms of CYP mutations in the Chinese population were identified. The levels of sorafenib plasma concentration, as well as damage to hepatic and renal function in aflatoxin-induced HCC rat models varied significantly across the different CYP genotypes.</p><p><b>CONCLUSION</b>The mutational frequencies of CYP3A5, CYP3A4, CYP2C19, and CYP2D6 genotypes varied among different ethnic groups and populations. Individuals with CYP3A5*3 demonstrated minimal sorafenib metabolism, which led to severe hepatic and renal damage. Inter-individual variability in sorafenib-toxicity may be interpreted by CYP450 genetic polymorphisms, suggesting that identification of CYP polymorphism within a certain population should be considered in sorafenib therapy.</p>
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Schisandra chinensis is a commonly used hepatoprotective medicine in clinic. Previous studies have showed that Schisandrae Chinensis Fructus has dual effects on the activity of CYPs. Short-term administration of Schisandrae Chinensis Fructus may inhibit CYP450s activity, while long-term administration may up-regulate CYP activity. High CYP450s activity level may increase the frequency of reactive metabolites-induced liver injury. It remains unclear how long-term administration of Schisandrae Chinensis Fructus may affect acetaminophen-induced acute hepatotoxicity. After oral administration of Schisandrae Chinensis Fructus extract (0.5-2.0 g·kg⁻¹) for 21 d, the activity of CYPs, Nrf2, HO-1, GST expressions, SOD and GST activity as well as glutathione level of SD rats were up-regulated. Besides, Schisandrae Chinensis Fructus extract ameliorated APAP (500 mg·kg⁻¹)-induced acute hepatotoxicity in a dose-dependent manner, as evidenced by decrease in ALT, AST, and MDA level and increase in GSH level (<0.05). What's more, the liver histopathology was alleviated, and cleaved caspase-3 expression was decreased. Besides, the increase of N-acetyl-p-benzoquinoneimine-GSH (reactive metabolite of acetaminophen) formation was observed in Schisandrae Chinensis Fructus extract groups. In conclusion, the present study indicated that the effects of Schisandrae Chinensis Fructuson acetaminophen-induced hepatotoxicity may rely on the Nrf2 signal pathway activation, and less depends on the increase in CYP450s activity.
Subject(s)
Animals , Rats , Acetaminophen , Chemical and Drug Induced Liver Injury , Cytochrome P-450 Enzyme System , Drugs, Chinese Herbal , Liver , NF-E2-Related Factor 2 , Rats, Sprague-DawleyABSTRACT
ABSTRACT Interactions between herbs and drugs may increase or decrease the pharmacological or toxicological effects of either component. Experimental data on the pharmacokinetic interactions between herbal products and drugs are limited. This study attempted to investigate the effect of Bacopa monnieri Linn. (Brahmi) formulation on the pharmacokinetics of amitriptyline in rats. In this study, rats were randomly divided into two groups (n = 6 each) which were served as a control (amitriptyline alone) and treatment group (amitriptyline with B. monnieri), respectively. Rats in the treatment group received B. monnieri (31 mg/kg/day) whereas the control group received normal saline by oral gavage for seven days before a single intragastric administration of 25 mg/kg amitriptyline. Plasma concentrations of amitriptyline were measured up to 24 h after its administration by a developed and validated high-performance liquid chromatography method. Pretreatment with B. monnieri produced a significant increase in the maximum plasma concentration (Cmax), area under the curve (AUC0-t) and elimination half-life (t1/2) of amitriptyline by 16.8%, 26.5%, and 15.5%, respectively, compared to amitriptyline alone. Moreover, oral clearance and volume of distribution (Vss) were decreased by 26.2% and 15.5% respectively. This study concluded that B.monnieri significantly enhanced the oral bioavailability of amitriptyline in rats.
Subject(s)
Animals , Male , Rats , Bacopa/adverse effects , Drug Interactions , Amitriptyline/pharmacokinetics , Plants, Medicinal/classification , Biological Availability , Chromatography, High Pressure Liquid/methodsABSTRACT
Objective: To investigate the protective effects of matrine combined with glycyrrhizic acid on chronic liver injury induced by carbon tetrachloride, and explore the protective mechanism from the points of energy metabolism and CYP enzyme.Methods: The chronic hepatic injury model of rats was induced by CCl4.The changes of activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were measured to observe the protective effect of the two drugs and their combination.The contents of glutamate dehydrogenase (GLDH) in serum and adenine nucleoside three phosphate (ATP), adenosine diphosphate (ADP) and adenine monophosphate (AMP) in liver tissue were determined to evaluate the regulation effect on hepatic energy metabolism and mitochondrial function.The levels of CYP1A2, CYP2E1 mRNA and protein in liver tissue were detected by real-time PCR and Western Blot to evaluate the two drugs and their combination on the regulation function of liver CYP enzyme.Results: Matrine (72.8 mg×kg-1)and glycyrrhizic acid(43.4 mg·kg-1)could decrease the serum activities of ALT and ALT in chronic hepatic injury model, and the combination (matrine 36.4 mg·kg-1+glycyrrhizic acid 21.7 mg·kg-1) had the most significant protective effect (P＜0.05).Matrine (72.8 mg·kg-1)and glycyrrhizic acid(43.4 mg·kg-1)could decrease GLDH in serum,and restore the content of ATP in liver (P＜0.05).Matrine (72.8 mg·kg-1) had no effect on the expression of CYP1A2 and CYP2E1mRNA, and glycyrrhizin (43.4 mg·kg-1) could inhibit the expression of CYP1A2, CYP2E1mRNA and protein (P＜0.05).Conclusion: Matrine combined with glycyrrhizin has obvious regulation effect on mitochondrial function and liver protective effect in chronic hepatic injury model.
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OBJECTIVE: To compare the effect on CYP450 isoenzyme in rats with acute liver injury induced by different chemicals. METHODS: Acute liver injury model of rats induced by tetrachloromethane(CCl4), D-aminogalactose(D-GalN)/lipopolysaccharide(LPS), α-naphthyl isothiocyanate(ANIT) respectively whereas the normal Wistar rats were used as controls. After the tail vein injection with Cocktail probe solutions prepared with five CYP450s probe substrates (phenacetin-CYP1A2, omeprazole-CYP2C9, tolbutamide-CYP2C19, dextromethorphan-CYP2D6, midazolam-CYP3A4), the blood samples were collected from the fundus venous plexus of rat at different time point, the blood drug concentration of the five probe substrates were determined by LC-MS/MS, and the pharmacokinetic parameters were calculated by PK Solutions 2™. Compared with normal rats, the changes of the probe drug pharmacokinetics in different rat models were used as the basis for the evaluation of the metabolic activity of CYP450 isoenzyme. RESULTS: Compared with normal rats, the activities of CYP1A2, CYP2C9, CYP2C19, CYP2D6 of CCl4 group rats were significantly inhibited, and the activities of CYP3A4 was slightly inhibited; the activities of CYP2C9, CYP2D6 and CYP3A4 of D-GalN/LPS group rats were significantly induced, and the activity of CYP2D6 and CYP3A4 was slightly induced, and the activity of CYP1A2 was not significantly affected, but the activity of CYP2C19 was significantly inhibited; the activities of CYP2C9, CYP2C19 and CYP3A4 of ANIT group rats were significantly induced, the activity of CYP3A4 were slightly induced, and the activity of CYP2D6 was not significantly affected, but the activity of CYP1A2 was significantly inhibited. CONCLUSION: There are significant differences in the activities of CYP450 isoenzyme in the rat model of acute liver injury induced by different chemicals.
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Objective To characterize the metabolic kinetics of aloe emodin in human liver microsomes(HLM)and rat liver microsomes(RLM)and identify the CYP phenotyping of phase-metabolism. Methods Aloe emodin was incubated at 37° with HLM and RLM in the presence or absence of NADPH, UDGPA or NADPH+UDGPA. The remaining aloe emodin was determined with a validated LC-MS/MS method to assess the metabolic stability and enzymatic kinetics. A panel of rCYP isoforms(CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 and 3A4)and HLM with specific inhibitors of CYP isoforms were used to identify the CYP phenotyping of aloe emodin. Results In HLM and RLM, aloe emodin was metabolically eliminated in the presence of NADPH, with 85.8% and 81.7% of the parent compounds eliminated in 30 min, respectively. The t1/2 were(10.3±0.3)and(11.5±3.3)min, and the CLint were(420.1±10.9) and(573.4±188.2)ml/(min·kg), respectively. The apparent Km and Vmax for HLM and RLM were obtained and found to be(2.4±0.9) and(3.9±1.4)µmol/L, (1492±170.5)and(2783±595.8)nmol/(min·g protein), respectively. In RLM with UDPGA, 38.5% of aloe emodin was metabolized in 30 min with t1/2 of 31.6 min and CLint of(197.1±15.5)ml/(min·kg). The results of CYP phenotyping indicated that CYP1A2, 2B6, 2C19 and 3A4 were the major enzymes involved in the metabolism of aloe emodin. By using the method of total normalized rate, the contributions of the major enzymes were assessed to be 35.4%, 6.6%, 2.2% and 21.9%, respectively. Conclusion Aloe emodin is mainly eliminated by CYP mediated metabolism in HLM and RLM. CYP1A2 and 3A4 are the major responsible enzymes of aloe emodin, and the contributions are above 20%. Species differences in liver metabolism of aloe emodin are observed. It undergoes notable glucuronidation in RLM only.
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The aim of this study is to establish the in vitro methods for the study of induction and inhibition on CYP450 by drugs, and to validate the analytical method and incubation system. A method for the simultaneous determination of eight metabolites of seven subtypes of CYP450 enzymes probe substrates in human liver microsomes (HLM) was established and validated. The incubation system was optimized to confirm the incubation time and protein concentration of HLM, the enzyme activity of seven subtypes of CYP450 enzymes in HLM was determined, and the inhibition effects on each CYP450s were checked by positive controls. The method for the simultaneous determination of three metabolites of subtypes of CYP450 enzymes was established and validated in human primary cultured hepatocytes (HPCH) using the incubation medium. The enzyme activity of three subtypes of CYP450 enzymes in HPCH was determined, and the total RNA was extracted from HPCH after incubation. The expression of CYP450 enzymes were measured by Taqman fluorescence probe method. The induction effects on each CYP450s were examined using the positive controls. The established methods for the determination of metabolites of probe substrates were fully validated, and the results were conformed to the requirements of bioanalytical method validation. The induction and inhibition effects on each CYP450s were checked by positive controls. The established in vitro methods for the study of drug induction and inhibition on CYP450 were simple and reliable, which could be used in the investigation of enzyme induction or inhibition properties of new drug candidates and to evaluation the metabolic interactions of concomitant medication in clinical.
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To observe the effect of processed Polygonum multiflorum on mRNA expression levels of five subtypes of CYP450 enzymes in rat liver. SD rats were randomly divided into the normal control group, processed P. multiflorum high dose and low dose groups (5.40 g•kg⁻¹ and 1.08 g•kg⁻¹). The rats in administration groups were continuously given with processed P. mutiflorum for 7 days by ig administration, and the rats in normal control group were given with the same volume of distilled water. After successive administration of 7 days, the serum biochemical indications were detected, and Real-time quantitative PCR technology was used to detect the mRNA expression levels of five subtypes of CYP450 enzymes in rat liver. Experimental results showed that AST was decreased significantly in both low and high dose groups. ALT was significantly decreased in low dose group and significantly increased in high dose group. The mRNA expression levels of five subtypes of CYP450 enzymes in rat liver were decreased in high dose and low dose groups in a dose-dependent manner. Especially the high dose processed P. multiflorum could significantly inhibit CYP1A2 and CYP2E1 mRNA expression levels in rats. The study showed that high dose P. multiflorum water extract had hepatotoxicity, and the degree of liver damage was increased with the increase of dose. It shall be noted that 5.40 g•kg⁻¹ water extract of P. multiflorum could significantly inhibit CYP1A2 and CYP2E1 mRNA expression levels in the liver of rats.
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Aim To develop a sensitive,rapid and ac-curate LC-MS /MS method for the simultaneous deter-mination of cytochrome P450 probe substrates,inclu-ding caffeine and its metabolite paraxanthine for CYP1 A2,omeprazole and its metabolite 5-hydroxyome-prazole for CYP2C1 9,dextromethorphan and its metab-olite dextrorphan for CYP2D6,midazolam and its me-tabolite 1 ′-hydroxymidazolam for CYP3A4.Methods Probe drugs with the IS diazepam were extracted using ethyl acetate.Gradient elution was performed on an Agilent Eclipse Plus-C1 8 column (50 mm ×2.1 mm, 3.5 μm).The mobile phase consisted of 0.01 % for-mic acid(1 mmol·L -1 ammonium formate)and aceto-nitrile.The flow rate was 0.3 mL·min -1 ,and the in-jection volume was 1 0 μL.The analyte was detected u-sing electrospray ionization(ESI)in positive multiple reaction monitoring(MRM+)mode.The reaction se-lected ions were 1 95.0 /1 38.1 m /z for caffeine, 1 81 .1 /1 24.1 m /z for paraxanthine,346.1 /1 98.1 m /z for omeprazole,362.1 /21 4.1 m /z for 5-hydroxyome-prazole, 272.2 /1 47.1 m /z for dextromethorphan, 258.1 /1 57.1 m /z for dextrorphan,326.1 /291 .1 m /z for midazolam,342.1 /324.1 m /z for 1 ′-hydroxymid-azolam and 285.1 /1 54.0 m /z for diazepam as internal standard.Results The linear ranges of caffeine,pa-raxanthine,omeprazole,5-hydroxyomeprazole,dextro-methorphan, dextrophan, midazolam and 1 ′-hydroxymidazolam were 1 .95 ~2 000,0.98 ~250, 0.48 ~2 000,0.98 ~250,0.98 ~2 000,0.48 ~1 25,1 .95 ~2 000 and 1 .95 ~250 μg·L -1 respec-tively.The RSD of all probe drugs was less than 1 5%and matrix effects in plasma on the ionization of probe drugs were negligible.Conclusion This sensitive and rapid LC-MS /MS method is suitable for determination of the drug/metabolite concentrations in plasma,so as to study the metabolism of CYP1 A2, CYP2C1 9, CYP2D6 and CYP3A4 in depth.
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Objective To characterize the metabolic kinetics of aloe emodin in human liver microsomes(HLM)and rat liver microsomes(RLM)and identify the CYP phenotyping of phaseⅠmetabolism. Methods Aloe emodin was incubated at 37℃ with HLM and RLM in the presence or absence of NADPH,UDGPA or NADPH+UDGPA. The remaining aloe emodin was determined with a validated LC-MS/MS method to assess the metabolic stability and enzymatic kinetics. A panel of rCYP isoforms(CYP1A2,2B6,2C8, 2C9,2C19,2D6 and 3A4)and HLM with specific inhibitors of CYP isoforms were used to identify the CYP phenotyping of aloe emo?din. Results In HLM and RLM,aloe emodin was metabolically eliminated in the presence of NADPH,with 85.8%and 81.7%of the parent compounds eliminated in 30 min,respectively. The t1/2 were(10.3±0.3)and(11.5±3.3)min,and the CLint were(420.1±10.9) and(573.4±188.2)ml/(min·kg),respectively. The apparent Km and Vmax for HLM and RLM were obtained and found to be(2.4±0.9) and(3.9±1.4)μmol/L,(1492±170.5)and(2783±595.8)nmol/(min·g protein),respectively. In RLM with UDPGA,38.5%of aloe emodin was metabolized in 30 min with t1/2 of 31.6 min and CLint of(197.1±15.5)ml/(min·kg). The results of CYP phenotyping indi?cated that CYP1A2,2B6,2C19 and 3A4 were the major enzymes involved in the metabolism of aloe emodin. By using the method of total normalized rate,the contributions of the major enzymes were assessed to be 35.4%,6.6%,2.2%and 21.9%,respectively. Con?clusion Aloe emodin is mainly eliminated by CYP mediated metabolism in HLM and RLM. CYP1A2 and 3A4 are the major responsi?ble enzymes of aloe emodin,and the contributions are above 20%. Species differences in liver metabolism of aloe emodin are observed. It undergoes notable glucuronidation in RLM only.
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The incidence of polypharmacy-which can result in drug-drug interactions-has increased in recent years. Drug-metabolizing enzymes and drug transporters are important polypharmacy modulators. In this study, the effects of bosentan and rifampin on the expression and activities of organic anion-transporting peptide (OATP) and cytochrome P450 (CYP450) 2C9 and CYP3A4 were investigated in vitro. HEK293 cells and primary human hepatocytes overexpressing the target genes were treated with bosentan and various concentrations of rifampin, which decreased the uptake activities of OATP transporters in a dose-dependent manner. In primary human hepatocytes, CYP2C9 and CYP3A4 gene expression and activities decreased upon treatment with 20 μM bosentan+200 μM rifampin. Rifampin also reduced gene expression of OATP1B1, OATP1B3, and OATP2B1 transporter, and inhibited bosentan influx in human hepatocytes at increasing concentrations. These results confirm rifampin- and bosentan-induced interactions between OATP transporters and CYP450.
Subject(s)
Humans , Cytochrome P-450 CYP2C9 , Cytochrome P-450 CYP3A , Cytochrome P-450 Enzyme System , Cytochromes , Gene Expression , HEK293 Cells , Hepatocytes , In Vitro Techniques , Incidence , Organic Anion Transporters , Polypharmacy , RifampinABSTRACT
Aim To study the effect of emodin in Po-lygonum multiflorum on the expression of CYP450 isoenzymes in L02 hepatocytes and explore its mecha-nism of cytotoxicity. Methods L02 cells were treated with different concentrations of emodin. Cell viability was examined by MTS assay kit, and cell membrane injury was examined by detecting the release rate of lactate dehydrogenase( LDH) . The expression of cyto-chrome P450 mRNA was detected by real time PCR. Results The result of MTS assay showed that L02 cells viability was significantly reduced following expo-sure to emodin in a concentration and time dependent manner. The LDH release rate of L02 cells significant-ly increased after exposure to emodin for 48 h com-pared with the control group. On the mRNA level, compared with the control group,emodin had inductive effects on mRNA of each CYP450 enzyme, while had significant inductive effects on mRNA of CYP1 A1 and CYP1 B1 in a concentration and time dependent man-ner. Conclusion Emodin in Polygonum multiflorum may generate significant liver injury in L02 cells and has inductive effects on CYP450 enzyme activity.
ABSTRACT
Drug-induced liver injury ( DILI) is a significant rea-son of acute liver failure and is the main cause of therapeutic drugs withdrawal from the market .Multiple mechanisms can cul-minate in DILI , but metabolism and genetics play distinct roles in this process .This review will cover papers we consider have addressed these mechanisms of DILI in commonly used medica-tions for adults , and discuss the hot issues .The aim is to gener-ate discussion about the potential clinical significance among these researchs and point out the key areas for further study of DILI.