AIMTo evaluate the effect of in vitro and in vivo treatment with mitomycin C (MMC) on activities of CYP2D1/2, CYP2C1 , and CYP1A2 in the liver of male rats.

METHODSUsing HPLC to determine the activities of the three isoenzymes in rat liver microsomes by detecting the specific metabolites of their substrates after treatment with inducers in vivo or inhibitors in vitro.

RESULTSIn vitro, MMC inhibited the activity of CYP2D1/2, CYP2C11, and CYP1A2 in dexamethasone-induced microsomes by (19 +/- 6)% (P < 0.05), (85 +/- 10)% (P < 0.01), and (36 +/- 6)% (P < 0.05), respectively, and decreased the activity of CYP1A2 in beta-naphthoflavone-induced microsomes by (58 +/- 6)% (P < 0.01). Rats were injected intraperitoneally with 20% of the LD50 of MMC for 3 or 6 d. The treatment showed no significant effect on microsomal activities of CYP2D1/2, CYP2C11 or CYP1A2.

CONCLUSIONMMC can inhibit the activities of CYP2D1/2, CYP2C11, and CYP1A2 in rat liver microsomes in vitro, but it showed no significant effect on the activities of the three isoenzymes in vivo.

Alcohol Oxidoreductases ; Animals ; Antibiotics, Antineoplastic ; pharmacology ; Aryl Hydrocarbon Hydroxylases ; metabolism ; Biotransformation ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P450 Family 2 ; Male ; Microsomes, Liver ; enzymology ; Mitomycin ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Steroid 16-alpha-Hydroxylase ; metabolism

Effects of constituents from Schisandra chinensis (Wuweizi) on six liver microsomal CYP450 isozymes (CYP1A2, CYP2C6, CYP2C11, CYP2D2, CYP2E1 and CYP3A1/2) were studied in rats in vivo and in vitro. The in vitro incubation was conducted using liver microsomes of rats after multiple dosing of alcoholic/water extract from Schisandra chinensis. A HPLC-MS method was applied to determine the metabolites formation of six CYP450s probe substrates (phenacetin-CYP1A2, dextromethorphan-CYP2D2, diclofenac sodium-CYP2C6, mephenytoin-CYP2C11, chlorzoxazone-CYP2E1 and midazolam-CYP3A1/2) in rat liver microsomal incubations. The activity of CYP450 isozymes were represented by the formation of metabolites. Alcoholic extract of Schisandra chinensis (28-120 microg x mL(-1)) showed significant inhibitory effect on six CYP450 isozymes to a certain extent in vitro. Multiple dosing of Schisandra chinensis alcoholic extract (1.5 g x kg(-1), qd x 7d) had significant induction on CYP2E1 and CYP3A1/2, inhibition on CYP2D2 and CYP2C11, and no effect on CYP2C6 and CYP1A2. Water extract of Schisandra chinensis (100-500 microg x mL(-1)) also exhibited inhibition on the activity of CYP450 isozymes in vitro, whereas multiple administrations (1.5 g x kg(-1), qd x 7d) had significant induction of CYP2E1 and inhibition on CYP2D2, no effect on CYP2C6, CYP3A1/2, CYP1A2 or CYP2C11. The results suggested that the constituents from Schisandra chinensis exhibited the inhibition and induction on six rat liver microsomal CYP450 isozymes to a certain extent in vivo and in vitro. The possibility of interaction between Schisandra chinensis and coadministrative drugs will be considered base on the levels and subtype of CYP450 involved in the drug metabolism.
Animals ; Aryl Hydrocarbon Hydroxylases ; metabolism ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP2E1 ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Cytochrome P450 Family 2 ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Isoenzymes ; metabolism ; Lignans ; isolation & purification ; pharmacology ; Microsomes, Liver ; enzymology ; Plants, Medicinal ; chemistry ; Rats ; Rats, Sprague-Dawley ; Schisandra ; chemistry ; Steroid 16-alpha-Hydroxylase ; metabolism ; Steroid 21-Hydroxylase ; metabolism ; Substrate Specificity

The present study was performed to investigate the effect of bicyclol on hepatic microsomal cytochrome P450 (CYP) activity, as well as gene and protein expressions in rats after partial hepatectomy (PH). Bicyclol (300 mg x kg(-1)) was given to rats subjected to 70% hepatectomy three times before operation. At 6 and 48 h after PH, blood and liver tissue samples were collected for the measurement of serum alanine aminotransferase (ALT), hepatic microsomal malondialdehyde (MDA) and total hepatic CYP content. The activities of four CYP isozymes were detected with liquid chromatography-mass spectrometry (LC-MS) and the gene and protein expressions were determined by RT-PCR and Western blotting assay. As a result, bicyclol pretreatment markedly inhibited the elevation of serum ALT and hepatic microsomal MDA, and prevented the decrease of total hepatic CYP content in PH rats. In addition, bicyclol significantly attenuated the reduction of CYP2C6 activity and mRNA expression, as well as the reduction of CYP2C11 activity in PH rats. Bicyclol can inhibit the decrease of CYP3A1/2 activity, and up-regulate the mRNA and protein expressions of CYP3A1 and CYP2E1. These results showed that bicyclol pretreatment might ameliorate abnormality in CYP450 isoforms during liver regeneration after PH, and this protective effect was likely due to its anti-oxidative property and enzyme induction.
Alanine Transaminase ; blood ; Animals ; Antioxidants ; pharmacology ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Biphenyl Compounds ; pharmacology ; Cytochrome P-450 CYP2E1 ; genetics ; metabolism ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Cytochrome P450 Family 2 ; Enzyme Activation ; drug effects ; Enzyme Induction ; drug effects ; Hepatectomy ; Male ; Malondialdehyde ; metabolism ; Membrane Proteins ; genetics ; metabolism ; Microsomes, Liver ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Steroid 16-alpha-Hydroxylase ; genetics ; metabolism ; Steroid 21-Hydroxylase ; genetics ; metabolism

The paper is to report the study of the effect of Shenfu injection on the enzyme activity of liver CYP450 and its mRNA level of rat liver. Microsome of rat liver was prepared after intravenous administration of Shenfu injection for 7 days. The enzyme activity was quantified by Cocktail method. Meanwhile, the mRNA expression of CYP1A2, CYP2B1/2, CYP2C11 and CYP3A1 in the liver was detected by RT-PCR. Shenfu injection obviously induced the enzyme activities of CYP2B and CYP2C. Meantime Shenfu injection decreased the enzyme activities of CYP1A2 and CYP3A. The mRNA levels of CYP2B and CYP2C were also induced in rats treated with Shenfu injection. But it obviously inhibited the mRNA level of CYP1A2 and CYP3A. Since the enzyme activity and mRNA level were obviously changed after administration, the potential effect of drug-drug interaction should be concerned.
Aconitum ; chemistry ; Animals ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Cytochrome P-450 CYP1A2 ; genetics ; metabolism ; Cytochrome P-450 CYP2B1 ; genetics ; metabolism ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Cytochrome P-450 Enzyme System ; genetics ; metabolism ; Cytochrome P450 Family 2 ; Drug Combinations ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Injections ; Male ; Microsomes, Liver ; enzymology ; Panax ; chemistry ; Plants, Medicinal ; chemistry ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Steroid 16-alpha-Hydroxylase ; genetics ; metabolism

OBJECTIVETo investigate the effects of the ethyl acetate extract of Semen Hoveniae (ESH) on liver microsomal cytochrome P450 isoenzyme in rats.

METHODThe rats were given orally the ESH in the doses of 0.14, 0.17, 0.2 g x kg (equivalent to the crude herb) for 10 days respectively. Rat liver microsomal cytochrome P450, NADPH-Cyt C reductase, erythromycin N-demethylase (ERD), Aniline hydroxylase (ANH), aminopyrine N-demethylase (ADM) activities were quantitated by UV chromatography. The levels of mRNA expression of CYP1A1, CYP2C11, CYP2E1 and CYP3A1 were detected by semi-quantitative reverse transcripatase-polymerase chain reaction (RT-PCR).

RESULTThe cytochrome P450 content, NADPH-Cyt C reductase activities and erythromycin N-demethylase (ERD) activities were not affected. Aniline hydroxylase (ANH) activities in liver were decreased by up to35.1%; aminopyrine N-demethylase (ADM) activitiesin liver were increased by up to 42.4%. The mRNA expression of CYP1A1, CYP2C11 and CYP3A1 were found to be increased markedly.

CONCLUSIONA specific effect of ESH on liver microsomal cytochrome P450 isoenzyme in rats was observed in this investigation. ESH had various effects on liver microsomal cytochrome P450 isoenzyme.

Acetates ; chemistry ; Aminopyrine N-Demethylase ; metabolism ; Aniline Hydroxylase ; genetics ; metabolism ; Animals ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Cytochrome P-450 CYP1A1 ; genetics ; metabolism ; Cytochrome P-450 CYP2E1 ; genetics ; metabolism ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Cytochrome P-450 Enzyme System ; genetics ; metabolism ; Cytochrome P450 Family 2 ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; pharmacology ; Gene Expression Regulation, Enzymologic ; drug effects ; Male ; Microsomes, Liver ; drug effects ; enzymology ; NADPH-Ferrihemoprotein Reductase ; genetics ; metabolism ; Plants, Medicinal ; chemistry ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Rhamnaceae ; chemistry ; Seeds ; chemistry ; Steroid 16-alpha-Hydroxylase ; genetics ; metabolism

Abstract: The activities of four CYP450 enzymes (CYP3A, 1A2, 2El and 2C) and the mRNA expression levels of CYP1A2, 2El, 2Cll and 3A1 in rat liver were determined after Wistar rats were orally administered with brucine (BR) at three dosage levels (3, 15 and 60 mg.kg-1 per day) and the high dose of BR combined with glycyrrhetinic acid (GA, 25 mg.kg-1 per day) or liquiritin (LQ, 20 mg.kg-1 per day) for 7 consecutive days. Compared with the control, brucine caused 24.5% and 34.6% decrease of CYP3A-associated testosterone 6beta-hydroxylation (6betaTesto-OH) and CYP2C-associated tolbutamide hydroxylation (Tol-OH), respectively, and 146.1% increase of CYP2El-associated para-nitrophenol hydroxylation (PNP-OH) at the high dose level. On the other hand, (BR+GA) caused 51.4% and 33.5% decrease, respectively, of CYP2El-associated PNP-OH and CYP1A2-associated ethoxyresorufin-O-de-ethylation (EROD) as compared with the high dose of BR group. Meanwhile, (BR+LQ) caused 41.1% decrease of CYP2El-associated PNP-OH and 37.7% increase of CYP2C-associated Tol-OH. The results indicated that the co-administration of BR with GA or LQ had effect on mRNA expression and activities of the CYP450 enzymes mentioned above to some extent, and the in vivo antagonism of LQ on BR-induced CYPs adverse effects and the in vivo inhibitory action of GA on CYP2E1 and 1A2 might play an important role in the detoxification of Radix Glycyrrhizae against Strychnos nux-vomica L.
Animals ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Cytochrome P-450 CYP1A1 ; metabolism ; Cytochrome P-450 CYP1A2 ; genetics ; metabolism ; Cytochrome P-450 CYP2E1 ; genetics ; metabolism ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Cytochrome P-450 Enzyme System ; genetics ; metabolism ; Cytochrome P450 Family 2 ; Flavanones ; pharmacology ; Gene Expression Regulation, Enzymologic ; Glucosides ; pharmacology ; Glycyrrhetinic Acid ; pharmacology ; Hydroxylation ; Liver ; enzymology ; metabolism ; Male ; Nitrophenols ; metabolism ; Plants, Medicinal ; chemistry ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Steroid 16-alpha-Hydroxylase ; genetics ; metabolism ; Steroid Hydroxylases ; metabolism ; Strychnine ; analogs & derivatives ; isolation & purification ; pharmacology ; Strychnos nux-vomica ; chemistry ; Tolbutamide ; metabolism

Triptolide (TP) is a major active component in Tripterygium root, but its therapeutic window was very narrow due to its severe multi-organ toxicity. In this work, the effect of TP combined with glycyrrhetic acid (GA) on mRNA expression and activity of four cytochrome P450 (CYP) enzymes in rat liver was studied after intragastric administration of TP (0.05, 0.3 and 0.6 mg x kg(-1) x day(-1)) and TP (0.6 mg x kg(-1) x day(-1)) combined with GA (30 mg x kg(-1) x day(-1)) for 7 consecutive days. Compared with the control, the high dose of TP significantly up-regulated the mRNA expression levels of CYP2E1, 1A2, 3A1 and 2C11, the co-administration of TP and GA further up-regulated the mRNA expression levels of CYP3A1, 2C11 and 2E1 as compared with the high dose of TP. Meanwhile, TP at high dose and combined with GA significantly increased CYP3A-associated testosterone 6beta-hydroxylation activity (2.2-fold and 4.1-fold, respectively) as compared with the control. Because TP is mainly metabolized by CYP3A2 in male rats, the present work indicated that TP-induced increase of CYP3A activity might be an important reason for the rapidly metabolic clearance of TP in rat liver, and GA can reduce the hepatotoxicity of TP by promoting its hepatic metabolic clearance. Furthermore, the results also suggest that the drug interactions might be occurred when TP and GA were co-administered with other CYP3A substrate drug.
Animals ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Cytochrome P-450 CYP1A2 ; genetics ; metabolism ; Cytochrome P-450 CYP2E1 ; genetics ; metabolism ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Cytochrome P-450 Enzyme System ; genetics ; metabolism ; Cytochrome P450 Family 2 ; Diterpenes ; administration & dosage ; isolation & purification ; pharmacology ; Dose-Response Relationship, Drug ; Drug Combinations ; Drug Interactions ; Enzyme Activation ; Epoxy Compounds ; administration & dosage ; isolation & purification ; pharmacology ; Glycyrrhetinic Acid ; isolation & purification ; pharmacology ; Liver ; enzymology ; Male ; Phenanthrenes ; administration & dosage ; isolation & purification ; pharmacology ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Steroid 16-alpha-Hydroxylase ; genetics ; metabolism ; Tripterygium ; chemistry