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.

• Klíčová slova
• 7-benzyloxy-4-trifluoromethylcoumarin, 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase, 7-benzyloxyquinoline, BFC, BFCOD, BQ, BzRes, CLO, CYP1A, CYP2E1-like protein, CYP3A, Clotrimazole, DBF, DEX, Dexamethasone, EROD, P450, PNP, PNPH, Rainbow trout, benzyloxyresorufin, clotrimazole, cytochrome P450, dexamethasone, dibenzylfluorescein, ethoxyresorufin O-deethylase, p-nitrophenol, p-nitrophenol hydroxylase,
• MeSH
• cytochrom P-450 CYP1A1 antagonisté a inhibitory   metabolismus   MeSH
• cytochrom P-450 CYP2E1 metabolismus   MeSH
• cytochrom P-450 CYP3A metabolismus   MeSH
• dexamethason chemie   farmakologie   MeSH
• inhibitory cytochromu P450 CYP2E1 MeSH
• inhibitory cytochromu P450 CYP3A MeSH
• inhibitory cytochromu P450 MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• kinetika MeSH
• klotrimazol chemie   farmakologie   MeSH
• Oncorhynchus mykiss metabolismus   MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP2E1 MeSH
• cytochrom P-450 CYP3A MeSH
• dexamethason MeSH
• inhibitory cytochromu P450 CYP2E1 MeSH
• inhibitory cytochromu P450 CYP3A MeSH
• inhibitory cytochromu P450 MeSH
• klotrimazol MeSH
• systém (enzymů) cytochromů P-450 MeSH

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.

• Klíčová slova
• Antidepressant, Cytochrome P450, Fish microsomes, Inhibition, Mixture of compounds,
• MeSH
• chemické látky znečišťující vodu MeSH
• cytochrom P-450 CYP1A1 metabolismus   MeSH
• cytochrom P-450 CYP3A metabolismus   MeSH
• jaterní mikrozomy enzymologie   metabolismus   MeSH
• játra metabolismus   MeSH
• léčivé přípravky metabolismus   MeSH
• lidé MeSH
• Oncorhynchus mykiss metabolismus   MeSH
• piperaziny MeSH
• triazoly farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP3A MeSH
• léčivé přípravky MeSH
• nefazodone MeSH Prohlížeč
• piperaziny MeSH
• triazoly 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.

• Klíčová slova
• CYP inhibitors, CYP1A1, CYP3A, Catalytic activity, P450,
• MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• játra enzymologie   MeSH
• messenger RNA genetika   metabolismus   MeSH
• mozek enzymologie   MeSH
• myokard enzymologie   MeSH
• Oncorhynchus mykiss metabolismus   MeSH
• pohlavní dimorfismus MeSH
• regulace genové exprese enzymů fyziologie   MeSH
• střeva enzymologie   MeSH
• žábry enzymologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP3A MeSH
• messenger RNA MeSH

Flavonoids are known to have effects on cytochrome P450 enzymatic activity. However, little effort has been made to examine species differences and the relevance of studies on mammalian and fish microsomes so that extrapolations can be made to humans. Therefore, the effects of several naturally occurring flavonoids on the activity of CYP3A-dependent 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD) were evaluated in human, pig, mouse, and juvenile rainbow trout sources of hepatic microsomes. Each was exposed to three concentrations (1, 10, and 100μM) of diosmin, naringin, and naringenin. Naringenin competitively inhibited BFCOD activity (Ki values were 24.6μM in human, 15.6μM in pig, and 19.6μM in mouse microsomes). In fish, BFCOD activity was inhibited in a noncompetitive manner (Ki=7μM). Neither diosmin nor naringenin affected BFCOD activity in hepatic microsomes from the studied model organisms. These results suggest that dietary flavonoids potentially inhibit the metabolism of clinical drugs.

• Klíčová slova
• CYP3A, Diosmin, Diosmin (PubChem CID: 5353588), Inhibition, Naringenin, Naringenin (PubChem CID: 932), Naringin, Naringin (PubChem CID: 25075),
• MeSH
• Citrus chemie   MeSH
• cytochrom P-450 CYP3A genetika   metabolismus   MeSH
• diosmin farmakologie   MeSH
• druhová specificita MeSH
• exprese genu MeSH
• flavanony farmakologie   MeSH
• hydrolýza MeSH
• inhibitory enzymů farmakologie   MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• játra účinky léků   enzymologie   MeSH
• kinetika MeSH
• kumariny metabolismus   MeSH
• lidé MeSH
• myši inbrední ICR MeSH
• myši MeSH
• Oncorhynchus mykiss MeSH
• prasata MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 7-benzyloxy-4-trifluoromethylcoumarin MeSH Prohlížeč
• cytochrom P-450 CYP3A MeSH
• diosmin MeSH
• flavanony MeSH
• inhibitory enzymů MeSH
• kumariny MeSH
• naringenin MeSH Prohlížeč
• naringin MeSH Prohlížeč

Naturally- and anthropogenically-produced cresols could pose serious risks to fish health. In this study, three piscine CYP isoforms were investigated for their abilities to interact with p-cresol. Therefore, the activity of 7-ethoxyresorufin-O-deethylase (EROD), 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD), and p-nitrophenol hydroxylase (PNPH) were evaluated in the hepatic microsomes of juvenile rainbow trout. Results showed that EROD activity was inhibited in a competitive manner, BFCOD activity was inhibited in presence the highest tested p-cresol concentration and PNPH activity was not affected. These results indicate that p-cresol might affect the ability of fish to metabolize numerous aromatic hydrocarbons and dioxin compounds, which are present in the aquatic environment.

• Klíčová slova
• CYP1A1, CYP2E1-like, CYP3A-like, Fish, p-Cresol,
• MeSH
• chemické látky znečišťující vodu toxicita   MeSH
• cytochrom P-450 CYP1A1 antagonisté a inhibitory   metabolismus   MeSH
• kresoly toxicita   MeSH
• Oncorhynchus mykiss metabolismus   MeSH
• rybí proteiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 4-cresol MeSH Prohlížeč
• chemické látky znečišťující vodu MeSH
• cytochrom P-450 CYP1A1 MeSH
• kresoly MeSH
• rybí proteiny 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.

• Klíčová slova
• CYP1A, CYP2E1-like protein, CYP3A, Dexamethasone, Rainbow trout,
• MeSH
• chemické látky znečišťující vodu toxicita   MeSH
• cytochrom P-450 CYP1A1 metabolismus   MeSH
• dexamethason toxicita   MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• Oncorhynchus mykiss metabolismus   MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• tandemová hmotnostní spektrometrie MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• cytochrom P-450 CYP1A1 MeSH
• dexamethason MeSH
• systém (enzymů) cytochromů P-450 MeSH

1. This study examined hepatic cytochrome P450 (CYP450) response to dietary sesamin in combination with different n-6/n-3 fatty acid ratios in fish diet. Over a period of 4 months, fish were fed seven different experimental diets an n-6/n-3 FA ratio of either 0.5 or 1.0 in combination with two sesamin levels: low sesamin = 1.16 g/kg feed and high sesamin = 5.8 g/kg feed. Control diets did not contain sesamin. 2. The CYP450-associated activities of ethoxyresorufin O-deethylase (EROD), 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylation (BFCOD), pentoxyresorufin O-depentylase (PROD), coumarin hydroxylase (COH), methoxyresorufin O-deethylase (MROD) and p-nitrophenol hydroxylase (PNPH) were significantly induced by dietary sesamin in a dose-related manner. 3. Expressions of the genes CYP1A1, CYP1A3, CYP3A, AhR1α, AhR2β, AhR2δ and PXR involved in the regulation of CYP450 activities, was not the primary source of this induction.

• Klíčová slova
• Fish, induction, xenobiotic metabolizing enzymes,
• MeSH
• dioxoly farmakologie   MeSH
• játra účinky léků   enzymologie   MeSH
• lignany farmakologie   MeSH
• oleje rostlin farmakologie   MeSH
• regulace genové exprese účinky léků   MeSH
• rybí oleje farmakologie   MeSH
• Salmo salar metabolismus   MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• xenobiotika metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dioxoly MeSH
• lignany MeSH
• oleje rostlin MeSH
• rybí oleje MeSH
• sesamin MeSH Prohlížeč
• systém (enzymů) cytochromů P-450 MeSH
• xenobiotika MeSH

In vitro impacts of five organic solvents on cytochrome P450 (CYP450) enzyme activity were investigated using hepatic microsomes of rainbow trout. The rates of several CYP450-mediated reactions were investigated at solvent concentrations ranging from 0.01% to 3%. The solvents greatly affected all tested reactions. In at least 0.8% ethanol, 2% methanol or acetone, 1% acetonitrile or 3% dimethyl sulfoxide (DMSO), 7-ethoxyresorufin-O-deethylase (EROD) activity decreased and at 3% acetonitrile or ethanol, it was undetected. At 3%, all tested solvents except methanol reduced 7-benzyloxy-4-trifluoromethylcoumarin-O-debenzylase (BFCOD) activity, but at low concentrations of ethanol (2% and lower) or DMSO (1% and lower), it was induced. This was not seen with the inclusion of a pre-incubation step. p-Nitrophenolhydroxylase (PNPH) activity was not affected at concentrations below 1% DMSO, and at 2% acetonitrile it was reduced, as it was above 1% methanol or 0.5% ethanol. Acetone did not affect PNPH activity with or without a pre-incubation step. In general, the degree of inhibition was similar with and without the pre-incubation step. We conclude that the concentration of organic solvent for solubilizing the substrate and inhibitor in in vitro microsomal studies should be minimized.

• Klíčová slova
• CYP1A1, CYP2E1, CYP3A, enzyme activity, organic solvent,
• MeSH
• aceton farmakologie   MeSH
• acetonitrily farmakologie   MeSH
• dimethylsulfoxid farmakologie   MeSH
• ethanol farmakologie   MeSH
• izoenzymy MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• játra účinky léků   enzymologie   MeSH
• kinetika MeSH
• methanol farmakologie   MeSH
• Oncorhynchus mykiss metabolismus   MeSH
• rozpouštědla farmakologie   MeSH
• substrátová specifita MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aceton MeSH
• acetonitrile MeSH Prohlížeč
• acetonitrily MeSH
• dimethylsulfoxid MeSH
• ethanol MeSH
• izoenzymy MeSH
• methanol MeSH
• rozpouštědla MeSH
• systém (enzymů) cytochromů P-450 MeSH

Concerns about the effect of sewage treatment plant (STP) effluent on the health of freshwater ecosystems have increased. In this study, a unique approach was designed to show the effect of an STP effluent-dominated stream on native wild brown trout (Salmo trutta L.) exposed under fully natural conditions. Zivny stream is located in South Bohemia, Czech Republic. The downstream site of Zivny stream is an STP-affected site, which receives 25% of its water from Prachatice STP effluent. Upstream, however, is a minimally polluted water site and it is considered to be the control site. Native fish were collected from the upstream site, tagged, and distributed to both upstream and downstream sites. After 30, 90, and 180days, fish were recaptured from both sites to determine whether the downstream site of the Zivny stream is associated with the effects of environmental pollution. Several biomarkers indicating the oxidative stress and antioxidant enzyme activities, cytochrome P450 activity, xenoestrogenic effects, bacterial composition, and lipid composition were investigated. Additionally, polar chemical contaminants (pharmaceuticals and personal care products (PPCPs)) were quantified using polar organic chemical integrative samplers (POCIS). Fifty-three PPCPs were detected in the downstream site; 36 of those were constantly present during the 180-day investigation period. Elevated hepatic 7-benzyloxy-4-trifluoromethylcoumarin-O-debenzyloxylase (BFCOD) (after 90days) and blood plasma vitellogenin concentrations in males were detected in fish downstream of the STP effluent during all sampling events. An increase in the fishes' total fat content was also observed, but with low levels of ω-3 fatty acid in muscle tissue. Two bacterial taxa related to activated sludge were found in the intestines of fish from downstream. Our results show that Prachatice STP is a major source of PPCPs in the Zivny stream, which has biological consequences on fish physiology.

• Klíčová slova
• Bacterial consortia, Fatty acid composition, Fish, STP, Vitellogenin,
• MeSH
• biologické markery metabolismus   MeSH
• ekosystém MeSH
• látky znečišťující vodu toxicita   MeSH
• monitorování životního prostředí * MeSH
• odpad tekutý - odstraňování * MeSH
• odpadní vody MeSH
• pstruh mikrobiologie   fyziologie   MeSH
• řeky chemie   MeSH
• střevní mikroflóra fyziologie   MeSH
• vitelogeniny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• biologické markery MeSH
• látky znečišťující vodu MeSH
• odpadní vody MeSH
• vitelogeniny MeSH