Concomitant administration of a single acute dose of ethanol (4 g/kg) protected mice from the hepatocellular injury observed upon administration of a large dose of acetaminophen (400 mg/kg). This was evidenced by the normal histological appearances of liver sections and by the lowered serum aminotransferase activities in mice treated with ethanol and acetaminophen together. In the mice treated with acetaminophen alone, along with the hepatic necrosis, the hepatic microsomal aminopyrine N-demethylase activity was decreased. However, co-administration of ethanol prevented this acetaminophen dependent inhibition on the microsomal mixed function oxidase activity. Pharmacokinetic studies indicated that the concentration of un-metabolized drug in the blood was increased in the ethanol treated mice. Furthermore, upon co-administration of ethanol, although the biliary levels of acetaminophen metabolites (glucuronide, sulfate and cysteine conjugates) were decreased, the level of unmetabolized acetaminophen was increased. Our findings suggest that co-administration of an acute dose of ethanol reduces the degree of hepatocellular necrosis produced by a large dose of acetaminophen and this ethanol dependent protection is, in major part, afforded by suppression of the hepatic microsomal mixed function oxidase activity catalyzing the metabolic activation of acetaminophen.
Acetaminophen* ; Aminopyrine N-Demethylase ; Animals ; Biotransformation* ; Cysteine ; Ethanol* ; Liver ; Mice* ; Necrosis* ; Oxidoreductases

PURPOSE: This study investigated the effect of reducing cisplatin induced nephrotoxicity with DWP-04 that is the compound of Schizandrin C derivative biphenyldimethyl dicarboxylate (DDB), glutathione and selenium. For the purpose of observation is that how DWP-04 has influence on mechanism of reducing cisplatin induced nephrotoxicity with renal function test, free radical formation and detoxification enzyme system in renal tissue. METHODS: Five groups of rats were dosed with vehicle, cisplatin (2 mg/kg i.p.), cisplatin+DWP-04 (100, 200 mg/kg po), or cisplatin+sodium thiosulfate (200 mg/kg i.p.) daily for 4 weeks. RESULTS: Serum creatinine, lactate dehydrogenase and activity of hydroxy radical increased in the cisplatin group and suppressed in the cisplatin+DWP-04 group compared to the cisplatin group. The renal tissue concentration of lipid peroxidase and lipofuscin were increased in the cisplatin group compared to the other groups. The activity of aminopyrine N-demethylase, aniline hydroxylase, aldehyde oxidase and xanthine oxidase, of which free radical formation system in kidney was also decreased in the cisplatin+DWP-04 group compared to the cisplatin and cisplatin+sodium thiosulfate group. The activity of detoxification system of free radical, such as glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were markedly increased in the cisplatin+DWP-04 group than the cisplatin and the cisplatin+sodium thiosulfate group (p<0.05). CONCLUSION: It can be concluded that the mechanism of decreasing cisplatin-induced nephrotoxicity by DWP-04 is that the decreasing of the amount of lipid peroxide and lipofuscin in the renal tissue by increasing activity of the antioxidant defense system and the decreasing of reactive oxygen species by increasing detoxification enzyme activity.
Aldehyde Oxidase ; Aminopyrine N-Demethylase ; Aniline Compounds ; Aniline Hydroxylase ; Animals ; Antioxidants ; Catalase ; Cisplatin ; Creatinine ; Cyclooctanes ; Glutathione ; Glutathione Peroxidase ; Glutathione Transferase ; Kidney ; L-Lactate Dehydrogenase ; Lignans ; Lipofuscin ; Peroxidase ; Polycyclic Compounds ; Rats ; Reactive Oxygen Species ; Renal Insufficiency ; Selenium ; Superoxide Dismutase ; Xanthine Oxidase

OBJECTIVETo observe the effects of kaempferol and quercetin on the activity of cytochrome P450 in rat hepatocytes.

METHODSPrimarily cultured rat hepatocytes were exposed to kaempferol or quercetin in concentrations of 0.1, 1, 10 micromol/L for 12 h, 24 h and 48 h. Hepatocytes CYP isoemzymes-erythromycin N-demethylase (ERND) and aminopyrine N-demethylase (ADM) activities were determined by Nash methods. Erythromycin (10 micromol/L) was used as positive control and DMSO(0.1%) as solvent control.

RESULTSKaempferol and quercetin inhibited ENRD activity in a dose-and time-dependent manner. In dose-response study, the ENRD activities in kaempferol (0.1,1 and 10 micromol/L) treated groups were (0.088+/-0.008), (0.074+/-0.006) and (0.041+/-0.003)micromol/(mg.min(-1)), respectively. ENRD activity in quercetin treated groups at the same concentrations were (0.082+/-0.007), (0.063+/-0.007) and (0.034+/-0.005) micromol/(mg.min(-1)), respectively. In time-courses study, the ENRD activity exposed to 10 micromol/L kaempferol or quercetin for 12 h and 48 h were (0.053+/-0.006) and (0.037+/-0.007) micromol/(mg.min(-1)), or (0.067+/-0.005) and (0.032+/-0.004) micromol/(mg.min(-1)). ADM activity was inhibited only by kaempferol in 10 mol/L at 24 h, but was not significantly altered by quercetin at any concentration tested.

CONCLUSIONIn the present condition, kaempferol and quercetin act as potential CYP3A4 inhibitors as they can significantly inhibit ENRD in primarily cultured rat hepatocytes.

Aminopyrine N-Demethylase ; metabolism ; Animals ; Carcinoma, Hepatocellular ; enzymology ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Dose-Response Relationship, Drug ; Hepatocytes ; metabolism ; Kaempferols ; pharmacology ; Liver Neoplasms ; enzymology ; pathology ; Quercetin ; pharmacology ; Rats ; Tumor Cells, Cultured

This study was designed to test the effect of Korean traditional tea materials on oxygen-free radical metabolism in lead (Pb) -administered rats. Male rats were divided into normal, Pb-control (Pb-Con) and Pb-water extract of green tea (Camellia sinensis; GT) , persimmon leaf (Diospyros kaki; PL) , safflower seed (Carhamus tinctorius: SS) , Du-Zhong (Eucommia ulmoides; EU) groups, respectively. Pb intoxication was induced by administration of lead acetate (25 mg/kg. B.W., oral) weekly. The extract was administered based on 1.26 g of raw material/kg B.W./day for 4 weeks. When the GT, PL, SS and EU were supplemented to the Pb-administered rats, hepatic lipid peroxide levels were significantly lower compared to the Pb-Con group. Hepatic cytochrom P-450 content and aminopyrine N-demethylase activity was lower in the Pb-Con group than in the normal group, whereas xanthine oxidase activity was significantly elevated in Pb-administered rats. The water extract of GT, PL, SS and EU supplementation attenuated changes in enzyme activities generating reactive oxygen species in the liver. Hepatic superoxide dismutase, catalase and glucose 6-phosphate dehydrogenase activities were significantly higher in the Pb-Con group than in the normal group, while monoamine oxidase activity also tended to increase in the Pb-administered rats. However, glutathione peroxidase and glutathione S-transferase activities, and glutathione content significantly decreased through Pb intoxication. The supplementation of GT, PL, SS and EU induced alleviation changes of hepatic antioxidant enzyme activity.
Aminopyrine N-Demethylase ; Animals ; Carthamus tinctorius ; Catalase ; Diospyros ; Eucommiaceae ; Glucose ; Glutathione ; Glutathione Peroxidase ; Glutathione Transferase ; Humans ; Liver ; Male ; Metabolism ; Monoamine Oxidase ; Oxidoreductases ; Oxygen* ; Rats* ; Reactive Oxygen Species ; Superoxide Dismutase ; Tea* ; Water* ; Xanthine Oxidase

Ischemia causes tissue necrosis in a wide variety of pathologic conditions. Permanent deprivation of blood flow is lethal to any tissue and the prudent therapy for ischemia unquestionably is reperfusion. While reperfusion is necessary to reverse the progression towards ischemic death, reperfusion is also thought to be accompanied by its own component of injury. Oxygen free radicals, formed during ischemia/reperfusion, have been proposed as one of the main causes of reperfusion injury. Free radical attacks on biological membrane, such as mitochondria and endoplasmic reticulum, and can lead to the oxidative destruction of the polyunsaturated fatty acids of the membranes through lipid peroxidation. However, direct association between microsomal lipid peroxidation in vivo after ischemia/reperfusion and changes in secretory function and drug metabolism on the liver have not been established. Therefore, present study was performed to evaluate the hepatic secretory function and the hepatic microsomal drug metabolizing enzyme activity after ischemia/reperfusion preparation in rat liver. Further, the effect of oxygen free radical scavengers was investigated. The animals were divided into sham operation group and ischemia/reperfusion group. The ischemia/reperfusion group was subdivided into non-treated control and treated (with superoxide dismutase, allopurinol, alpha-tocopherol, deferoxamine) groups. Hepatic ischemia was produced by clamping the left branches of portal vein and hepatic artery, resulting in complete ischemia to the median and left lobes while the right lobes remained per Fused to prevent intestinal congestion. Reperfusion was permitted by declamping after 1 hour. After 1 or 5 hours of reperfusion, bile was collected, blood was obtained from abdominal aorta, and liver microsomes were isolated. The results are as follows. Serum aminotransferase was increased 15~20 times by ischemia/reperfusion. However, this increase was attenuated by free radical scavengers, especially 5 hours of reperfusion. The wet weight-to-dry weight ratio of the liver was significantly increased by ischemia/reperfusion. alpha-tocopherol pretreatment minimized the increase of ratio. Malondialdehyde level in the liver microsomal fraction was significantly increased after ischemia/reperfusion, but this increase was attenuated by scavenger pretreatment, especially alpha-tocopherol. Bile flow and cholate output but not the bilirubin output, were decreased after ischemia/reperfusion. The free radical scavenger pretreahnent restored the secretion significantly. Cytochrome P-450 content was significantly decreased after ischemia/reperfusion and ameliorated by free radical scavenger pretreatment. NADPH cytochrome P-450 reductase activity and aminopyrine N-demethylase activity were also decreased and improved by free radical scavengers pretreatment. These results indicate that ischemia/reperfusion deteriorates the hepatic secretory function as well as hepatic microsomal drug metabolizing enzyme activity, and the oxygen free radical scavengers attenuate the functional changes of the liver induced by ischemia/reperfusion.
Allopurinol ; alpha-Tocopherol ; Aminopyrine N-Demethylase ; Animals ; Aorta, Abdominal ; Bile ; Bilirubin ; Cholates ; Constriction ; Cytochrome P-450 Enzyme System ; Endoplasmic Reticulum ; Estrogens, Conjugated (USP) ; Fatty Acids, Unsaturated ; Free Radical Scavengers ; Free Radicals ; Hepatic Artery ; Ischemia ; Lipid Peroxidation ; Liver ; Malondialdehyde ; Membranes ; Metabolism* ; Microsomes, Liver ; Mitochondria ; NADPH-Ferrihemoprotein Reductase ; Necrosis ; Oxygen ; Portal Vein ; Rats* ; Reperfusion ; Reperfusion Injury ; Superoxide Dismutase

OBJECTIVETo study the effects of Angelica sinensis Polysaccharides (ASP) on the hepatic drug metabolism enzymes activities in normal mice and those prednisolone (PSL)-induced liver injury.

METHODThe activities of phase II enzymes (GSH-related enzymes) and cytochrome P450 enzymes were measured by biochemical method.

RESULTASP increased the activities of glutathione S-transferase in liver microsomes and mitochondria. The cytochrome P450 content, NADPH-cytochrome c reductase, aminopyrine N-demethylase, and aniline hydroxylase activities in liver microsomes were also increased. PSL significantly increased serum ALT levels, and decreased the liver mitochondrial glutathione content. At the same time, other enzymes activities were all increased. When mice were treated with ASP 2.0 g.kg-1, the PSL-induced changes on cytochrome P450 enzymes, glutathione S-transferase, and GSH content were restored.

CONCLUSIONASP can modulate the activities of drug metabolism enzymes.

Aminopyrine N-Demethylase ; metabolism ; Angelica sinensis ; chemistry ; Aniline Hydroxylase ; metabolism ; Animals ; Chemical and Drug Induced Liver Injury ; enzymology ; etiology ; Cytochrome P-450 Enzyme System ; metabolism ; Glutathione Transferase ; metabolism ; Male ; Mice ; Microsomes, Liver ; enzymology ; Mitochondria, Liver ; enzymology ; NADPH-Ferrihemoprotein Reductase ; metabolism ; Plants, Medicinal ; chemistry ; Polysaccharides ; isolation & purification ; pharmacology ; Prednisolone

OBJECTIVETo study the modulatory effect of Panax gingseng and coadministration with Veratrum nigrum on the activity and mRNA expression of cytochrome P450 isoenzymes in rat liver.

METHODRat liver microsomal cytochrome P450, b5, aminopyrine N-demethylase(APND), p-nitrophenol-hydroxylase(pNPH)activities were quantitated by UV chromatography. The mRNA expression level of five CYP isoenzymes CYP1A1, CYP2B1/2, CYP2C11, CYP2E1 and CYP3A1 were detected by semi-quantitative reverse transcriptase-polymerase chain reaction(RT-PCR).

RESULTP. gingseng coadministrated with V. nigrum obviously decreased the P450 contents of liver microsomes, and the b5 contents. Both single and combined used inhibited the activities of aminopyrine N-demethylase. At the mRNA level, the expression of CYP2C11 markedly induced exposure to V. nigrum, but combinative groups decreased the expression of CYP2C11. The combination of P. gingseng and V. nigrum induced the expression of CYP1A1. P. gingseng has inhibitory effect on CYP2B1/2 and inductive effect used with V. nigrum. The combination of P. gingseng with V. nigrum also induced the expression of CYP3A1.

CONCLUSIONP. gingseng used singly has some different modulation effects compared with combinative used, which may occur because of drug-drug interaction based on cytochrome P450. To elucidate the drug-drug interaction, it needs further analysis and metabolism research.

Aminopyrine N-Demethylase ; metabolism ; Animals ; Cytochrome P-450 Enzyme System ; biosynthesis ; genetics ; Cytochromes b5 ; metabolism ; Drug Incompatibility ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; In Vitro Techniques ; Isoenzymes ; biosynthesis ; genetics ; Male ; Microsomes, Liver ; metabolism ; Panax ; chemistry ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Veratrum ; chemistry

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