This study examined the ability of several human pharmaceuticals to modulate hepatic piscine CYP-mediated monooxygenase activities. Effects of six pharmaceuticals: diclofenac, sulfamethoxazole, tramadol, carbamazepine, venlafaxine and nefazodone, were investigated in vitro in rainbow trout hepatic microsomes. The reactions of 7-ethoxyresorufin-O-deethylase (EROD) and benzyloxy-4-trifluoromethylcoumarin-O-debenzyloxylase (BFCOD), were used as markers for hepatic CYP1A and CYP3A-like activities, respectively. Our results showed that EROD and BFCOD activities were both affected by nefazodone. Nefazodone inhibited EROD in a dose dependent manner and was found to be a potent non-competitive inhibitor of EROD with a Ki value of 6.6 μM. BFCOD activity was inhibited non-competitively in the presence of nefazadone with Ki value of 30.7 μM. BFCOD activity was slightly reduced only by the highest concentration of carbamazepine. Diclofenac, sulfamethoxazole, tramadol, and venlafaxine did not affect the activity of either EROD or BFCOD. We further exposed microsomal fraction to mixtures of six pharmaceuticals to investigate potential inhibition. The results showed that EROD and BFCOD activity was inhibited on 94% and 80%, respectively at higher tested concentration. To our knowledge, this is the first report to demonstrate an inhibitory effect of nefazodone on hepatic CYP1A and CYP3A-like proteins in rainbow trout.

• MeSH
• Water Pollutants, Chemical MeSH
• Cytochrome P-450 CYP1A1 metabolism   MeSH
• Cytochrome P-450 CYP3A metabolism   MeSH
• Microsomes, Liver enzymology   metabolism   MeSH
• Liver metabolism   MeSH
• Pharmaceutical Preparations metabolism   MeSH
• Humans MeSH
• Oncorhynchus mykiss metabolism   MeSH
• Triazoles pharmacology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Sesquiterpenes, the main components of plant essential oils, are often taken in the form of folk medicines and dietary supplements. Several sesquiterpenes possess interesting biological activities but they could interact with concurrently administered drugs via inhibition of drug-metabolizing enzymes. Therefore, the present study was designed to test the potential inhibitory effect of tree structurally relative sesquiterpenes β-caryophyllene (CAR), β-caryophyllene oxide (CAO) and α-humulene (HUM) on the activities of the main drug-metabolizing enzymes. For this purpose, rat and human hepatic subcellular fractions were incubated with CAR, CAO or HUM together with specific substrates for oxidation, reduction and conjugation enzymes and their coenzymes. HPLC, spectrophotometric and spectrofluorimetric analyses of product formations were used. All tested sesquiterpenes significantly inhibited cytochromes P4503A (CYP3A) activities in rats as well as in human hepatic microsomes, with CAO being the strongest inhibitor. A non-competitive type of inhibition was found. On the other hand, none of the tested sesquiterpenes significantly affected the activities of carbonyl-reducing enzymes (CBR1, AKRs, NQO1) or conjugation enzymes (UGTs, GSTs, SULTs, COMT). As CYP3A enzymes metabolize many drugs, their inhibition by CAO, CAR and HUM might affect the pharmacokinetics of concurrently administered drugs. Similar results obtained in rat and human hepatic microsomes indicate that rats could be used for further testing of possible drug-sesquiterpenes interactions in vivo.

• MeSH
• Anti-Inflammatory Agents, Non-Steroidal chemistry   metabolism   MeSH
• Cytochrome P-450 CYP1A2 chemistry   metabolism   MeSH
• Cytochrome P-450 CYP3A chemistry   metabolism   MeSH
• Inhibitory Concentration 50 MeSH
• Microsomes, Liver enzymology   MeSH
• Liver enzymology   MeSH
• Kinetics MeSH
• Rats MeSH
• Humans MeSH
• Rats, Wistar MeSH
• Sesquiterpenes chemistry   metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Rocuronium is a neuromuscular blocking agent acting as a competitive antagonist of acetylcholine. Results of an inhibition of eight individual liver microsomal cytochromes P450 (CYP) are presented. As the patients are routinely premedicated with diazepam, possible interaction of diazepam with rocuronium has been also studied. Results indicated that rocuronium interacts with human liver microsomal CYPs by binding to the substrate site. Next, concentration dependent inhibition of liver microsomal CYP3A4 down to 42% (at rocuronium concentration 189 μM) was found. This effect has been confirmed with two CYP3A4 substrates, testosterone (formation of 6β-hydroxytestosterone) and diazepam (temazepam formation). CYP2C9 and CYP2C19 activities were inhibited down to 75-80% (at the same rocuronium concentration). Activities of other microsomal CYPs have not been inhibited by rocuronium. To prove the possibility of rocuronium interaction with other drugs (diazepam), the effect of rocuronium on formation of main diazepam metabolites, temazepam (by CYP3A4) and desmethyldiazepam, (also known as nordiazepam; formed by CYP2C19) in primary culture of human hepatocytes has been examined. Rocuronium has caused inhibition of both reactions by 20 and 15%, respectively. The results open a possibility that interactions of rocuronium with drugs metabolized by CYP3A4 (and possibly also CYP2C19) may be observed.

• MeSH
• Androstanols metabolism   pharmacology   MeSH
• Cytochrome P-450 CYP3A metabolism   physiology   MeSH
• Cytochrome P-450 CYP2C19 metabolism   physiology   MeSH
• Cytochrome P-450 CYP2C9 metabolism   MeSH
• Cytochromes metabolism   MeSH
• Diazepam pharmacology   MeSH
• Hepatocytes metabolism   MeSH
• Cytochrome P-450 Enzyme Inhibitors MeSH
• Microsomes, Liver enzymology   MeSH
• Cells, Cultured MeSH
• Drug Interactions MeSH
• Humans MeSH
• Neuromuscular Nondepolarizing Agents pharmacology   MeSH
• Cytochrome P-450 Enzyme System metabolism   MeSH
• Binding Sites MeSH
• Dose-Response Relationship, Drug MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The effects of clotrimazole (CLO) and dexamethasone (DEX), both detected in the aquatic environment, were assessed on inhibition of cytochrome P450 (CYP450) in hepatic microsomes of rainbow trout. Activity of three CYP450 isoforms: ethoxyresorufin O-deethylase (EROD; CYP1A), 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD; CYP3A) and p-nitrophenol hydroxylase (PNPH; CYP2E1-like protein) was investigated in the presence of four concentrations of CLO and DEX. Clotrimazole in a concentration range of 1-100μM decreased the activity of EROD and BFCOD. The inhibition was reversible, as pre-incubation of the microsomes with CLO, before addition of the substrate, had no effect. EROD activity was non-competitively inhibited with a Ki of 0.5μM, and BFCOD activity revealed competitive inhibition with a Ki of 0.04μM. The relatively low Ki for CLO inhibition of EROD and BFCOD activity may indicate that the ability of CYP1A and CYP3A to metabolize xenobiotics is reduced in the presence of CLO. PNPH activity was not affected by CLO. DEX showed no inhibitory potency on any investigated reaction. CLO, but not DEX, inhibited EROD and BFCOD activity by different mechanisms.

• MeSH
• Cytochrome P-450 CYP1A1 antagonists & inhibitors   metabolism   MeSH
• Cytochrome P-450 CYP2E1 metabolism   MeSH
• Cytochrome P-450 CYP3A metabolism   MeSH
• Dexamethasone chemistry   pharmacology   MeSH
• Cytochrome P-450 CYP2E1 Inhibitors MeSH
• Cytochrome P-450 CYP3A Inhibitors MeSH
• Cytochrome P-450 Enzyme Inhibitors MeSH
• Microsomes, Liver drug effects   enzymology   MeSH
• Kinetics MeSH
• Clotrimazole chemistry   pharmacology   MeSH
• Oncorhynchus mykiss metabolism   MeSH
• Cytochrome P-450 Enzyme System metabolism   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Piscine cytochrome P450 (CYP) enzymes play an important role in the metabolism of xenobiotics. Xenobiotics often act as inducers of CYP1A1 and CYP3A expression and activity in fish. We compared constitutive mRNA expression of CYP1A1, CYP3A27, and CYP3A45 and catalytic activity of CYP1A (7-ethoxyresorufin-O-deethylation, EROD) and CYP3A-like (benzyloxy-4-trifluoromethylcoumarin-O-debenzyloxylation, BFCOD) enzymes in the following six rainbow trout tissues: liver, gill, heart, brain, intestine, and gonad. mRNA expression and activity were present in all investigated tissues. The CYP1A1 mRNA expression was higher in the liver, gill, heart, and brain compared to gonad and intestine. The intestine was the main site of CYP3A27 and CYP3A45 expression. The highest EROD and BFCOD activity was observed in liver tissue followed in descending order by heart, brain, gill, intestine, and gonad. Such differences might be related to the role of CYP physiological functions in the specific tissue. Rainbow trout exposure to 50 mg/kg of β-naphthoflavone for 48 h resulted in a 7.5- and 5.9-fold increase in liver EROD and BFCOD activity, respectively. In vitro EROD activity inhibition with ellipticine showed tissue-specific inhibition, while ketoconazole decreased BFCOD activity by 50-98 % in all tissues. Further studies are needed to identify all CYP isoforms that are responsible for these activities and modes of regulation.

• MeSH
• Cytochrome P-450 CYP1A1 genetics   metabolism   MeSH
• Cytochrome P-450 CYP3A genetics   metabolism   MeSH
• Liver enzymology   MeSH
• RNA, Messenger genetics   metabolism   MeSH
• Brain enzymology   MeSH
• Myocardium enzymology   MeSH
• Oncorhynchus mykiss metabolism   MeSH
• Sex Characteristics MeSH
• Gene Expression Regulation, Enzymologic physiology   MeSH
• Intestines enzymology   MeSH
• Gills enzymology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

The aim of this study was to characterize biomarker responses, haematological profiles, structural changes and uptake in juvenile rainbow trout exposed to clotrimazole (CLO) at three concentrations (0.01 - [lowest environmentally relevant concentration], 1.0 [highest environmentally relevant concentration] and 10 μg L(-1)) in a semi-static system over a period of 42 days. Antioxidant defence enzymes, which responded to CLO exposure, changed the oxidative stress status of cells, but no differences were observed in lipid peroxidation. Clotrimazole triggered a biphasic response of CYP3A-like activity in liver microsomes, which may indicate a detoxification process in the liver. Histopathological alterations were most pronounced in kidneys and testes in the group exposed to 10 μg L(-1). Structural changes in the kidney included tubulonephrosis and hyaline droplet degeneration in the tubular epithelial cells. The relative proportions of germ cells in testes were changed: The number of spermatozoa was reduced, and the spermatogonia and spermatocytes were increased. The highest CLO concentration was detected in fish liver (3710 ng per gram wet tissue) and kidney (4280 ng per gram wet tissue). Depuration half-life was estimated to be 72, 159, and 682 h in liver, muscle, and kidney, respectively. Taken together, these results provide valuable toxicological data on the effects of CLO on aquatic non-target organisms, which could be useful for further understanding of the potential risks in the real aquatic environment.

• MeSH
• Water Pollutants, Chemical pharmacokinetics   toxicity   MeSH
• Microsomes, Liver metabolism   MeSH
• Liver metabolism   MeSH
• Clotrimazole pharmacokinetics   toxicity   MeSH
• Kidney drug effects   metabolism   pathology   MeSH
• Oncorhynchus mykiss * anatomy & histology   metabolism   MeSH
• Oxidative Stress drug effects   MeSH
• Sperm Count MeSH
• Half-Life MeSH
• Spermatozoa cytology   drug effects   MeSH
• Muscles metabolism   MeSH
• Testis drug effects   pathology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Imunosupresívne lieky cyklosporín (CsA) a takrolimus (Tac) sú široko užívané k zabráneniu akútnej rejekcii štepu po orgánovej transplantácii. Klinické použitie týchto inhibítorov kalcineurínu je komplikované mnohými vedľajšími účinkami. CsA a Tac majú úzky terapeutický index a vykazujú značnú interindividuálnu variabilitu vo farmakokinetike. Nízka biologická dostupnosť CsA a Tac je sčasti pripisovaná interindividuálnej variabilite v expresii metabolického enzýmu cytochrómu P450 3A. Gény pre CYP 450 3A4 a 3A5 podliehajú genetickému polymorfizmu. Výsledky jednotlivých štúdií zaoberajúcich sa dopadom CYP3A polymorfizmu na farmakokinetiku CsA a Tac sú jednoznačné u Tac, kde bol preukázaný vzťah medzi CYP3A polymorfizmom a zmenou farmakokinetiky Tac, u CsA sú výsledky štúdií kontroverzné.

The calcineurin inhibitors cyclosporine (CsA) and tacrolimus (Tac) are widely used in the prevention of acute rejection after solid organ transplantation. However, their clinical use is associated with many adverse reactions. The calcineurin inhibitors CsA and Tac have a narrow therapeutic index and show highly variable pharmacokinetics. The low CsA and Tac bioavailability has been attributed to interindividual differences in the expression of the metabolizing enzyme cytochrome P450 3A. The genes for CYP3A4 and 3A5 undergo genetic polymorphism. The results of many studies focusing on the impact of CYP 3A polymorphism on CsA and Tac pharmacokinetics are clear with Tac, where an association between CYP 3A polymorphism and the pharmacokinetic consequences has been shown. However, the results with CsA are controversial

• MeSH
• Cyclosporine pharmacology   therapeutic use   MeSH
• Cytochrome P-450 CYP3A pharmacology   therapeutic use   MeSH
• Immunosuppressive Agents pharmacology   classification   therapeutic use   MeSH
• Calcineurin Inhibitors MeSH
• Calcineurin pharmacology   therapeutic use   MeSH
• Humans MeSH
• Polymorphism, Genetic genetics   drug effects   MeSH
• Graft Survival drug effects   radiation effects   MeSH
• Graft vs Host Reaction radiation effects   MeSH
• Tacrolimus pharmacology   therapeutic use   MeSH
• Check Tag
• Humans MeSH

Effects of aquatic pollutants on fish are of increasing concern. Pharmaceutical-based contaminants are prioritized for further study in environmental risk assessment using several approaches. Dexamethasone (DEX) was one such contaminant recognised for its effect on fish health status. Thus, we carried out an in vivo experiment to identify potential effects of DEX on rainbow trout. Fish were exposed to 3, 30, 300 and 3000ngL(-1) DEX in a semi-static system over a period of 42d. The concentrations of DEX that fish were exposed to was confirmed by LC-LC-MS/MS. Using hepatic microsomes, we determined cytochrome P450 content, activities of ethoxyresorufin O-deethylase (EROD), p-nitrophenol hydroxylase (PNPH), 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD) and benzyloxyquinoline O-debenzylase (BQOD), as well as protein expression. Our results showed that fish do not change the catalytic activity of CYP450-mediated reactions after high DEX concentration exposure. These results disagree with mammalian studies, where DEX is a well-known inducer of CYP450. We showed a significant effect of DEX exposure on CYP450-mediated reactions (EROD, BCFOD, BQOD and PNPH) when expressed as amount of product formed per min per nmol total CYP450 at 3, 30 and 300ngL(-1) after 21d exposure. Moreover, BFCOD and BQ activities showed matching trends in all groups. Western blot analysis showed induction of CYP3A-like protein in the presence of the lowest environmentally relevant concentration of DEX. Based on these findings, continued investigation of the effect of DEX on fish using a battery of complementary biomarkers of exposure and effect is highly relevant.

• MeSH
• Water Pollutants, Chemical toxicity   MeSH
• Cytochrome P-450 CYP1A1 metabolism   MeSH
• Dexamethasone toxicity   MeSH
• Microsomes, Liver drug effects   enzymology   MeSH
• Oncorhynchus mykiss metabolism   MeSH
• Cytochrome P-450 Enzyme System metabolism   MeSH
• Tandem Mass Spectrometry MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

OBJECTIVES: The aim of the study was to find whether probiotic Escherichia coli Nissle 1917 O6:K5:H1 (EcN) influences the expression of cytochromes P450 (CYP) in the rat intestine. DESIGN: Live bacterial suspension of EcN was administered to healthy male Wistar rats daily for 7 days. Control group of rats was stressed by oral application of the saline solution daily for 7 days as well. Sections of the duodenum, jejunum, ileum, caecum and colon have been taken from each experimental animal. With all individual samples, microsomal fraction has been prepared and expression of selected CYPs was determined by Western blotting. The levels of expression of CYPs were also evaluated by mRNA using real-time PCR. RESULTS: It was found that there are changes in expression of CYP enzymes studied along the intestine. CYP1A1, 2B1/2 and 2E1 are present mainly in the duodenum and jejunum; on the other hand, CYP2C6 is expressed mainly in the caecum and colon. CYP3A was found all over the rat intestine. The results show that there are no prominent differences between control samples and samples with EcN, only the expression of CYP3A protein in the duodenum appears to exhibit a clear tendency to decrease. In the case of the colon, a significant increase in the expression of CYP3A (most likely CYP3A1) after treatment of rats with EcN was found. CONCLUSION: This in vivo study revealed that the levels of colon CYP3A could be significantly increased in rats treated with probiotic EcN. On the contrary, the expression of CYP3A in the duodenum decreased. However, the changes in the expression of CYP enzymes are probably not as extensive to be clinically important in man; hence, most likely the probiotic EcN has little influence on the intestinal drug metabolism by CYP enzymes.

• MeSH
• Aryl Hydrocarbon Hydroxylases metabolism   MeSH
• Cytochrome P-450 CYP3A metabolism   MeSH
• Duodenum enzymology   MeSH
• Escherichia coli MeSH
• Gastrointestinal Tract enzymology   MeSH
• Colon enzymology   MeSH
• Rats MeSH
• Models, Animal MeSH
• Rats, Wistar MeSH
• Probiotics pharmacology   MeSH
• Cytochrome P-450 Enzyme System metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

INTRODUCTION: We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years. METHODS: We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics. RESULTS: We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P(trend) = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P(trend) = 0.005) but not cases (P(trend) = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P(het) = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age ≥15 years (OR(het) = 0.84, 95% CI 0.75, 0.94; OR(hom) = 0.81, 95% CI 0.51, 1.30; P(trend) = 0.002) but not for those who had their menarche age ≤11 years (OR(het) = 1.06, 95% CI 0.95, 1.19, OR(hom) = 1.07, 95% CI 0.67, 1.72; P(trend) = 0.29). CONCLUSIONS: To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels.

• MeSH
• White People MeSH
• Cytochrome P-450 CYP3A genetics   MeSH
• Adult MeSH
• Genetic Predisposition to Disease MeSH
• Genetic Association Studies * MeSH
• Genotype MeSH
• Polymorphism, Single Nucleotide MeSH
• Middle Aged MeSH
• Humans MeSH
• Menarche genetics   MeSH
• Breast Neoplasms genetics   pathology   MeSH
• Premenopause genetics   MeSH
• Reproductive History MeSH
• Risk Factors MeSH
• Aged MeSH
• Age of Onset MeSH
• Age Factors MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, N.I.H., Intramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH