RESUMEN
To predict the mechanism of liver injury induced by Genkwa Flos, we investigated the effect of chloroform extract on UGTs and UGT1A1 activities of the liver microsomes in rat and human. In the present study, 4-nitrophenol(4-NP) and ß-estradiol were elected as substrates to determine activities of UGTs and UGT1A1 by UV and HPLC. The results showed that there were 1.00% of apigenin, 6.40% of hydroxygenkwanin and 18.38% of genkwanin in chloroform extract; and total diterpene mass fraction was 31.40%. Compared with the control group, chloroform extract could significantly inhibit the activity of UGTs in rat liver microsomes(RLM) system, while the inhibitory effect was not obvious in human liver microsomes(HLM) system. UGT1A1 activity was inhibited by chloroform extract in rat liver microsomes and human liver microsomes (based on genkwanin, IC50=8.76, 10.36 µmolâ¢L⻹). The inhibition types were non-competitive inhibition(RLM) and uncompetitive inhibition(HLM). In conclusion, the results indicated that chloroform extract showed different inhibitory effects on UGTs and UGT1A1 activity, which may be one of the mechanisms of liver injury induced by Genkwa Flos.
Asunto(s)
Daphne/química , Medicamentos Herbarios Chinos/farmacología , Glucuronosiltransferasa/metabolismo , Microsomas Hepáticos/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Apigenina/análisis , Cromatografía Líquida de Alta Presión , Estradiol , Flavonas/análisis , Flavonoides/análisis , Glucuronosiltransferasa/antagonistas & inhibidores , Humanos , Microsomas Hepáticos/enzimología , Nitrofenoles , RatasRESUMEN
In the present study, the effects of six Coptidis alkaloids (berberine, epiberberine, coptisine, jatrorrhizine, palmatine and magnoflorine) on liver microsomes UGTs and UGT1A1 activities in rats and mice were investigated in vitro and in vivo to study the mechanism of metabolic drug-drug interactions of Coptidis Rhizoma with other drugs. In vitro rat and mice liver microsomal incubation systems combined with UDPGA were applied, as well as mice liver microsomes after administration of six Coptidis alkaloids. 4-Nitrophenol and ß-estradiol were selected as substrates to determine activities of UGTs and UGT1A1 by UV and HPLC, respectively. According to the in vitro rat study, berberine, epiberberine, coptisine and jatrorrhizine significantly inhibited rat liver microsome UGTs activity, particularly epiberberine showed the strongest inhibition. UGT1A1 activity was lowly inhibited by jatrorrhizine, with IC50 at about 227 µmolâ¢L⻹, whereas coptisine and magnoflorine significantly activated UGT1A1. According to the in vitro mice study, berberine, coptisine, jatrorrhizine and palmatine significantly inhibited mice liver microsome UGTs activity, and the six alkaloids all significantly activated UGT1A1. According to the in vivo mice study, UGTs activity was significantly activated only in berberine group, while UGT1A1 activity was significantly activated only in jatrorrhizine group. In conclusion, the effects of Coptidis alkaloids on UGT activity showed significant differences in species and between in vitro and in vivo. Meanwhile, the changes in structures of Coptidis alkaloids also have a big impact on UGT activity, which may be one of the causes for the drug-drug interactions between Coptidis Rhizoma and other drugs.
Asunto(s)
Alcaloides/administración & dosificación , Coptis/química , Medicamentos Herbarios Chinos/administración & dosificación , Glucuronosiltransferasa/metabolismo , Microsomas Hepáticos/enzimología , Animales , Cromatografía Líquida de Alta Presión , Medicamentos Herbarios Chinos/química , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/química , Glucuronosiltransferasa/antagonistas & inhibidores , Glucuronosiltransferasa/química , Glucuronosiltransferasa/genética , Masculino , Ratones , Microsomas Hepáticos/efectos de los fármacos , RatasRESUMEN
To predit the mechanism of metabolic drug-drug interactions of hydroxygenkwanin with other drugs, we investigated the inhibition inhibitory effect of hydroxygenkwanin on UGTs and UGT1A1 activities of different liver microsomes. In the present study, 4-nitrophenol (4-NP) and ß-estradiol were elected as substrates to determine activities of UGTs and UGT1A1 by UV and HPLC, respectively. The results showed that, hydroxygenkwanin significantly inhibited UGTs activity in rat, mouse and human liver microsomes. UGT1A1 activity was inhibited by hydroxygenkwanin to varying degrees, with IC50 about 190, 10.93, 20.07, 76.31 µmolâ¢L⻹ in mouse liver microsome(MLM), rat liver microsome (RLM) and recombinant UGT1A1, and human liver microsome (HLM), respectively. The inhibition types were competitive inhibition (RLM, HLM) and linear mixed-typed linear inhibition (recombinant UGT1A1). The order for the inhibitory intensity was RLM>rUGT1A1>HLM>MLM. In conclusion, hydroxygenkwanin has an inhibitory effect on UGTs and UGT1A1 activities of different liver microsomes, with differences in species, indicating its potential drug interactions based on UGT1A1 enzyme. This study aims to provide a reliable experimental basis for its further research and development of hydroxygenkwanin, and provide theoretical reference for the clinic drug combination research.
Asunto(s)
Inhibidores Enzimáticos/química , Flavonoides/química , Glucuronosiltransferasa/antagonistas & inhibidores , Animales , Cromatografía Líquida de Alta Presión , Glucuronosiltransferasa/metabolismo , Humanos , Cinética , Ratones , Microsomas Hepáticos/química , Microsomas Hepáticos/enzimologíaRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Scutellariae radix (Scutellaria baicalensis Georgi) and Coptidis rhizoma (Coptis chinensis Franch), known as traditional Chinese medicine (TCM), have been widely used with the effects of suppressing fever, dispelling dampness, purging fire and removing toxicosis. Owing to their unimaginable complexity, it is difficult to understand their pharmacokinetic properties in detail. The aim of this study was to develop an optimal proteomics approach to analyze the protein profiling related with ADME/Tox in rat liver treated with S. radix and C. rhizoma as well as their compatibility. MATERIALS AND METHODS: Male rats were respectively administered the extracts of S. radix, C. rhizoma and their mixture for 7 days, and their liver tissue samples were prepared for the comparative proteomic analysis. The significantly differentially expressed proteins between the experimental groups and the control group were found and identified by 2-DE and MALDI-TOF-MS analyses. To validate the proteomic analysis results, glutathion peroxidase, catalase and betaine homocysteine methyl transferase were selected and confirmed by western blotting. RESULTS: Seventy eight significantly differentially expressed proteins between the experimental groups and the control group were found and identified. By querying the relational databases, the identified differentially expressed proteins were summarized and classified into three groups, phase I drug metabolic enzymes, phase II drug metabolic enzymes and the rest proteins which mainly involve in energy metabolism, signal transduction and cytoskeleton. These proteins involved in ADME/Tox may be the targets for metabolic studies or markers for toxicity. CONCLUSIONS: Our findings indicated S. radix and C. rhizoma as well as their compatibility can assuredly influence the expression of the proteins in rat liver. After administration, the majority of these expressions presented a downward trend, which may be closely related to the pharmacological properties of the medicine. The method in this study may open up a new road for the complementary tests for ADME/Tox properties of S. radix and C. rhizoma as well as their compatibility.
Asunto(s)
Coptis , Hígado/efectos de los fármacos , Extractos Vegetales/farmacología , Scutellaria baicalensis , Animales , Betaína-Homocisteína S-Metiltransferasa/metabolismo , Catalasa/metabolismo , Glutatión Peroxidasa/metabolismo , Hígado/metabolismo , Masculino , Medicina Tradicional China , Raíces de Plantas , Proteoma/efectos de los fármacos , Proteómica , Ratas Sprague-DawleyRESUMEN
Epiberberine, one of the most important isoquinoline alkaloid in Coptidis Rhizoma, possesses extensive pharmacological activities. In this paper, the liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to study phase I and phase II metabolites. A Thermo HPLC system (including Surveyor AS, Surveyor LC Pump, Surveyor PDA. USA) was used. The cocktail probe drugs method was imposed to determine the content change of metoprolol, dapsone, phenacetin, chlorzoxazone and tolbutamide simultaneously for evaluating the activity of CYP2D6, CYP3A4, CYP1A2, CYP2E1 and CYP2C9 under different concentrations of epiberberine in rat liver microsomes. The result showed that epiberberine may have phase I and phase II metabolism in the rat liver and two metabolites in phase I and three metabolites in phase II are identified in the temperature incubation system of in vitro liver microsomes. Epiberberine showed significant inhibition on CYP2D6 with IC50 value of 35.22 µmol L(-1), but had no obvious inhibiting effect on the activities of CYP3A4, CYP1A2, CYP2E1 and CYP2C9. The results indicated that epiberberine may be caused drug interactions based on CYP2D6 enzyme. This study aims to provide a reliable experimental basis for its further research and development of epiberberine.
Asunto(s)
Berberina/análogos & derivados , Inhibidores del Citocromo P-450 CYP2D6/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Medicamentos Herbarios Chinos/metabolismo , Microsomas Hepáticos/enzimología , Animales , Berberina/química , Berberina/metabolismo , Cromatografía Líquida de Alta Presión , Inhibidores del Citocromo P-450 CYP2D6/química , Medicamentos Herbarios Chinos/química , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Espectrometría de Masas en TándemRESUMEN
To figure out the stability and intestinal bacteria metabolites of rats in vitro of astragaloside IV ( AST), this research was done to explore the stability of AST in the artificial gastric juice. artificial intestinal juice and rat liver homogenate and the metabolism in rat intestinal in vitro. HPLC was used to calculate the remaining rate of AST in biological samples by measuring the content of AST, while metabolites were determined by combining the methods of TLC, HPLC and LC-MS/MS. It turned out that AST was difficult to metabolize in the artificial gastric juice, artificial intestinal juice and rat liver. Also, the metabolic pathway of AST was stepped by deglycosylation. Firstly, AST was converted to its secondary etabolites (6-O-ß-D-glucopyranosyl- cycloastragenol, CMG) by removal of xylose moiety at C-3, then transformed into cycloastragenol (CAG) after hydrolytic removal of the glucose moiety at C-6. All the results suggested that the metabolism of AST in vivo occurs mainly in the intestinal by hydrolysis of glycosyl. In conclusion, hydrolysis of intestinal flora is the main reason that AST metabolizes.