Scutellaria baicalensis is one of the most widely used herbal medicines in East Asia. Because baicalein and baicalin are major components of this herb, it is important to understand the effects of these compounds on drug metabolizing enzymes, such as cytochrome P450 (CYP), for evaluating herb-drug interaction. The effects of baicalin and baicalein on activities of ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), benzyloxyresorufin O-debenzylase (BROD), p-nitrophenol hydroxylase and erythromycin N-demethylase were assessed in rat liver microsomes in the present study. In addition, the pharmacokinetics of caffeine and its three metabolites (i.e., paraxanthine, theobromine and theophylline) in baicalin-treated rats were compared with untreated control. As results, EROD, MROD and BROD activities were inhibited by both baicalin and baicalein. However, there were no significant differences in the pharmacokinetic parameters of oral caffeine and its three metabolites between control and baicalin-treated rats. When the plasma concentration of baicalin was determined, the maximum concentration of baicalin was below the estimated IC50 values observed in vitro. In conclusion, baicalin had no effects on the pharmacokinetics of caffeine and its metabolites in vivo, following single oral administration in rats.
Administration, Oral ; Animals ; Caffeine* ; Cytochrome P-450 CYP1A1 ; Cytochrome P-450 CYP2B1 ; Cytochrome P-450 CYP3A ; Cytochrome P-450 Enzyme System ; Drug Interactions ; Far East ; Herb-Drug Interactions ; Inhibitory Concentration 50 ; Microsomes, Liver ; Pharmacokinetics* ; Plasma ; Rats* ; Scutellaria baicalensis ; Theobromine

The effects of styrene on the induction of cytochrome P-450s (P450), (P4501A1/2, P4502B1/2 and P4502El) and activities of other related enzymes were investigated in the male Sprague Dawley rats which were treated with styrene 500 (S1), 1,000 (S2) 1,500 (S3) mg/kg in olive oil intraperitoneally once a day for two days and sacrificed for the preparation of liver microsomes after 24 hrs. 1. The contents of total protein and P450 in the microsomes derived from the styrene treated groups were slightly higher than those from the control group except those from the 53 group (1,500 mg styrene/kg body weight) . The decreases in microsomal protein contents was prominent in the S3 (p<0.05), but the P450 contents was increased significantly in the S2 (p<0.05). 2. The activities of NADPH-P450 and NADH b5 reductase in hepatic microsomes derived from the treated groups were significantly increased in the treated groups(p<0.05). 3. The activities of PROD were also prominently increased with the treatment of styrene except in 53 group, but the activity of EROD was decreased by styrene treatment. The activities of pNPH in the styrene treated groups were higher than that of the control group (p<0.05). 5. Western blotting with monoclonal antibodies against P4502B1/2 isozymes showed the presence of P4502B1/2 in hepatic microsomes from the rats treated with styrene, and the increase in the densities of immunoblots were corelated with the dosages of styrene. The blot densities against P4501A1/2 and P4502El were slightly increased in the styrene treated groups compared with the control group. These results suggested that styrene could primarily induce P4502B1/2 as major and P4501A1/2 and P4502El in minor forms for the metabolism of styrene in rats.
Animals ; Antibodies, Monoclonal ; Blotting, Western ; Cytochrome P-450 CYP1A1 ; Cytochrome P-450 CYP2B1 ; Cytochrome P-450 Enzyme System* ; Cytochromes* ; Humans ; Isoenzymes ; Male ; Metabolism ; Microsomes ; Microsomes, Liver ; NAD ; Olea ; Oxidoreductases ; Rats* ; Rats, Sprague-Dawley ; Styrene*

The effects of styrene on the induction of cytochrome P-450s (P450), (P4501A1/2, P4502B1/2 and P4502El) and activities of other related enzymes were investigated in the male Sprague Dawley rats which were treated with styrene 500 (S1), 1,000 (S2) 1,500 (S3) mg/kg in olive oil intraperitoneally once a day for two days and sacrificed for the preparation of liver microsomes after 24 hrs. 1. The contents of total protein and P450 in the microsomes derived from the styrene treated groups were slightly higher than those from the control group except those from the 53 group (1,500 mg styrene/kg body weight) . The decreases in microsomal protein contents was prominent in the S3 (p<0.05), but the P450 contents was increased significantly in the S2 (p<0.05). 2. The activities of NADPH-P450 and NADH b5 reductase in hepatic microsomes derived from the treated groups were significantly increased in the treated groups(p<0.05). 3. The activities of PROD were also prominently increased with the treatment of styrene except in 53 group, but the activity of EROD was decreased by styrene treatment. The activities of pNPH in the styrene treated groups were higher than that of the control group (p<0.05). 5. Western blotting with monoclonal antibodies against P4502B1/2 isozymes showed the presence of P4502B1/2 in hepatic microsomes from the rats treated with styrene, and the increase in the densities of immunoblots were corelated with the dosages of styrene. The blot densities against P4501A1/2 and P4502El were slightly increased in the styrene treated groups compared with the control group. These results suggested that styrene could primarily induce P4502B1/2 as major and P4501A1/2 and P4502El in minor forms for the metabolism of styrene in rats.
Animals ; Antibodies, Monoclonal ; Blotting, Western ; Cytochrome P-450 CYP1A1 ; Cytochrome P-450 CYP2B1 ; Cytochrome P-450 Enzyme System* ; Cytochromes* ; Humans ; Isoenzymes ; Male ; Metabolism ; Microsomes ; Microsomes, Liver ; NAD ; Olea ; Oxidoreductases ; Rats* ; Rats, Sprague-Dawley ; Styrene*

<p>OBJECTIVETo observe the effects of ginkgolides on gene expression of hepatic cytochrome P-450 in rats.p><p>METHODSprague-Dawley rats were administered ginkgolides (100 mg x kg(-1) body weight) through oral gavage once daily for four consecutive days. The level of gene expression in liver tissues was analyzed by competitive reverse transcription-polymerase chain reaction (competitive RT-PCR).p><p>RESULTA single and prospective band of CYP1A1, CYP1A2, CYP2B1/B2, CYP2C11, CYP2E1, CYP4A1 and cyclophilin was observed after polymerase chain reaction (PCR) when the reactive system of reverse transcription (RT) had no target RNA, which confirmed the competitor had a specific capacity to bind to the CYP or cyclophilin primer. CYP1A1 mRNA was not dectectable in the livers of untreated control rats and ginkgolides-treated rats. The levels of CYP2C11 and CYP2E1 were not changed by ginkgolides treatment. In contrast, the levels of gene expression for CYP1A2 and CYP2B1/B2 were decreased, however, the levels of gene expression for CYP3A1 and CYP4A1 in ginkgolides group were distinctly increased compared with the control.p><p>CONCLUSIONA specific effect of ginkgolides on cytochrome P-450 gene expression was observed in this investigation. Ginkgolides had various effects on different cytochrome P-450 isoforms.p>
Animals ; Aryl Hydrocarbon Hydroxylases ; biosynthesis ; genetics ; Cytochrome P-450 CYP1A1 ; biosynthesis ; genetics ; Cytochrome P-450 CYP1A2 ; biosynthesis ; genetics ; Cytochrome P-450 CYP2B1 ; biosynthesis ; genetics ; Cytochrome P-450 CYP3A ; Cytochrome P-450 Enzyme System ; biosynthesis ; genetics ; Cytochrome P450 Family 4 ; Gene Expression Regulation ; Ginkgo biloba ; chemistry ; Ginkgolides ; isolation & purification ; pharmacology ; Liver ; metabolism ; Male ; Plants, Medicinal ; chemistry ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley

The present study was firstly undertaken in an attempt to compare simultaneously EMG(electromyography) and two new ACC(accelerography) reponses in the both hand following vecuronium administration in 26 ASA 1 or 2 adult patients undergoing general anesthesia. In the three NMT monitors, stimulating electrodes are applied similarly over the ulnar nerve on the volar side of the wrist, but the evoked EMG(Relaxograph, Datex Co.) responses obtained from the hypothenar muscles, TOFGUARD(Biometer Co.) responses from adductor pollicis and ParaGraph(Utah Med. Prod. Co.) responses from both muscles of hypothenar and thenar muscle of the hand respectively. Following induction of anesthesia with thiopental sodium(5 mg/kg) and vecuronium(0.08 mg/kg) intravenously, endotracheal intubation was facilitated and anesthesia was maintained with a mixture of enflurane(1~2%) and N2O(50%) . After loss of consciousness, the assessment of the neuromuscular blockade was started. We compared simultaneously TR(train-of-four ratio) responses of EMG at the one hand, and two new ACC named TOF-GUARD and ParaGraph at the other hand respectively during evoked recovery from vecuronium induced neuromuscular blockade. The result was the greater depression of TR response in TOF-GUARD and the lesser depression of TR response in ParaGraph than those in EMG. But test for parallelism did not show a statistically significant difference between the slope of these regression lines. Conclusively, the regression line for TR seems to be tend to give an impression that two new ACC named TOF-GUARD and ParaGraph would be suitable in the assessment of neuromuscular blockade in clinical anesthesia.
Adult ; Anesthesia ; Anesthesia, General ; Cytochrome P-450 CYP2B1 ; Depression ; Electrodes ; Hand ; Humans ; Intubation, Intratracheal ; Muscles ; Neuromuscular Blockade ; Thiopental ; Ulnar Nerve ; Unconsciousness ; Vecuronium Bromide* ; Wrist

OBJECTIVES: In order to gain a better understanding of the mechanism of DMF toxicity, recent studies have focused on hepatic drug metabolizing enzymes. In this study, we investigated the effects of DMF on the induction of P450 and the activities of other related enzymes in rat liver microsomes. METHODS: DMF was administered to male Sprague Daweley rats by intraperitoneal injection at 0(control), 450(D1), 900(D2), 1,800(D3) mg DMF/kg body weight in olive oil once a day for three days. Hepatic P450 was measured by method of Omura and Sato. We evaluated selective assays for the three drug metabolizing cytochrome P450 isoenzymes 1A1, 2B1 and 2E1. RESULTS: The content of microsomal protein, P450 and b5 were tended to be decreased in DMF treated group, but they were not statistically significant. The activity of NADPH-cytochrome P450 reductase was significantly increased dose dependently(p<0.01), but the activity of NADH-b5 reductase was decreased in the treated group(p<0.01). The activities of PROD and EROD were not significant between control and treated group. The activities of pNPH in the DMF treated groups were higher than that of the control group(p<0.01). When Western immunoblottings were carried out utilizing three monoclonal antibodies which were specific against P4501A1/1, P4502B1/2 and P4502E1, the strong density band corresponding to P4502E1 was observed with the microsomes obtained from the rats treated with DMF. But there were no significant increased in the P4501A1/2 and P4502B1/2 band densities in immunoblotting. CONCLUSIONS: These result suggested that P4502E1 was inducible by DMF and P4502E1 isozyme might be responsible for the hydroxylation of DMF to HMMF.
Animals ; Antibodies, Monoclonal ; Blotting, Western ; Body Weight ; Cytochrome P-450 CYP1A1 ; Cytochrome P-450 CYP2B1 ; Cytochrome P-450 Enzyme System* ; Cytochromes* ; Dimethylformamide* ; Humans ; Hydroxylation ; Immunoblotting ; Injections, Intraperitoneal ; Isoenzymes ; Male ; Microsomes ; Microsomes, Liver ; NADPH-Ferrihemoprotein Reductase ; Olea ; Oxidoreductases ; Rats ; Rats, Sprague-Dawley* ; Olive Oil

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

Whole or partial liver transplantation has become one of the main treatment strategies for hepatic failure. The availability of a donor liver is the single most limiting factor in liver transplantation. In cell therapy, liver cells have been used clinically to bridge patients to whole organ transplantation and/or as an alternative to whole organ transplants. The crucial property that defines a stem cell is its ability to give rise to a large family of descendants, and at least some hepatocytes do exhibit this pleuripotency. Thus hepatocyte-like cells derived from the bone marrow, embryonal stem cells, or placental sources can also be used. Stem cells of many types have been prodded and cajoled by combinations of growth factors, matrix and culture modifications to identify conditions that favor differentiation or transdifferentiation of stem/progenitor cells into hepatocytes. Additional studies are needed to determine whether hepatocyte-like cells derived from the bone marrow or other sources express the full complement of hepatic functions. If a sufficient number of differentiated hepatocytes can be produced from these stem cells, they could be useful in clinical transplantation programs.
Bone Marrow ; Cell- and Tissue-Based Therapy ; Complement System Proteins ; Cytochrome P-450 CYP2B1 ; Hepatocytes ; Humans ; Intercellular Signaling Peptides and Proteins ; Liver Failure* ; Liver Transplantation ; Liver* ; Organ Transplantation ; Stem Cell Transplantation* ; Stem Cells* ; Tissue Donors ; Transplants

<p>OBJECTIVETo detect the effect of deltamethrin (DM) on benzyloxyresorufin O-dealkylatase (BROD) activity and the expression of CYP2B1/2B2 in rat brain.p><p>METHODSBROD activity was determined by fluorophotometry under the treatment of DM in vivo and vitro. Western-blot analysis was used to detect the expression of CYP2B1/2B2.p><p>RESULTSIn vivo, DM could markedly inhibit BROD activity in rat brain microsome after rats had been treated with DM (12.5 mg.kg-1.d-1, i.p.) for 5 days. The inhibitory rate in whole brain, cerebral cortex and cerebellum were 26.7%, 23.8% and 33.3% respectively(P < 0.05). However, in vitro, under the concentration of 2 x 10(-8)-2 x 10(-4) mol/L of DM, there was no obvious change of BROD activity in rat brain. Moreover, Western-blot analysis indicated that DM could significantly reduce the expression of CYP2B1/2B2 in vivo, the inhibitory rate of protein synthesis was 42.6%.p><p>CONCLUSIONDM could inhibit BROD activity in rat brain and this effect may be related to the reduction of CYP2B1/2B2 protein synthesis.p>
Animals ; Aryl Hydrocarbon Hydroxylases ; antagonists & inhibitors ; biosynthesis ; Blotting, Western ; Brain ; drug effects ; enzymology ; Cytochrome P-450 CYP2B1 ; antagonists & inhibitors ; biosynthesis ; Enzyme Inhibitors ; toxicity ; Insecticides ; toxicity ; Nitriles ; toxicity ; Pyrethrins ; toxicity ; Rats ; Steroid Hydroxylases ; antagonists & inhibitors ; biosynthesis