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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.

Background: There is currently renewed interest in foods based on ancient cereals because consumers oftenconsider such foods to be healthy and sustainable. Interest in ancient cereals is also growing among farmers andin the food industry due to increased demands for adaptability and the urgent need to preserve genetic diversity.Scope and approach: In this review, we attempt to summarise recent findings regarding the content of nutrientsand bioactive compounds in ancient cereals and their potential impact on human health in comparison withmodern varieties. A literature review was conducted by collecting, evaluating and analysing data from publicationsin peer-reviewed scientific journals written in English language. Key findings and conclusions: As indicated in several studies, ancient cereal varieties might have beneficialnutritional profile and consumers appreciate the taste and flavour of foods based on ancient cereals. These cerealshave the potential to contribute to the improved sustainability and resilience of cropping systems. Inaddition, the production and consumption of foods based on ancient cereals indirectly encourages biodiversity,which has become a priority in environmental and organic farming circles. In conclusion, due to their uniquenutritional value and phytochemical profile as well as their sensory characteristics, there is good potential forancient cereals and associated products to become a part of a healthy diet., Sustainable organic bread from heritage cereals: using history to form the future

Rye consumption has shown beneficial effects on prostate cancer tumors, as indicated by slower initial tumor growth in animal models and lowering of prostate-specific antigen (PSA) in humans. This study evaluated the effects of whole grain/bran rye consumption on low-grade inflammation and endothelial function biomarkers in men with prostate cancer.Seventeen men with untreated, low-grade prostate cancer consumed 485 g rye whole grain and bran products (RP) per day or refined wheat products with added cellulose (WP) in a randomized crossover design. Fasting blood samples were taken before and after 2, 4, and 6 weeks of treatment.Concentrations of tumor nuclear factor-receptor 2 (TNF-R2), e-selectin, and endostatin were significantly lower after consumption of the RP diet compared with WP (p 0.05). Cathepsin S concentration was positively correlated to TNF-R2 and endostatin concentrations across all occasions. Strong correlations were consistently found between intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and between interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1RA). No effect of intervention was found in 92 inflammation-related protein biomarkers measured in a proximity extension assay.RP diet lowered TNF-R2, e-selectin, and endostatin, compared with WP in men with prostate cancer. These effects were accompanied by a reduction in PSA.

Monitoring the contamination level in aquatic environments and assessing the impact on aquatic life occurs throughout the world. In the present study, an approach based on a combination of biomarkers and the distribution of various industrial and municipal pollutants was used to investigate the effect of aquatic environmental contamination on fish. Monitoring was performed in ten rivers in the Czech Republic (Berounka, Dyje, Elbe, Lužnice, Odra, Ohře, Otava, Sazava, Svratka, and Vltava rivers, with one or two locations in each river) at the same sites that were regularly monitored within the Czech National Monitoring Program in 2007–2011. Health status, hepatic ethoxyresorufin-O-deethylase (EROD) activity, total cytochrome P450 content, and the plasma vitellogenin concentration were assessed in wild chub (Squalius cephalus) males caught at the monitored sites. The contamination level was the highest in the Svratka River downstream of Brno. Among all measured persistent organic pollutants (POPs), polychlorinated biphenyls and dichlorodiphenyltrichloroethane and its metabolites were the major contributors of POPs in fish muscle. Elbe, Odra, and Svratka rivers were identified as the most polluted. Fish from these locations showed reduced gonad size, increased vitellogenin concentration in male plasma, EROD, and total cytochrome P450 content. These biomarkers can be used for future environmental monitoring assessments. Overall, this study improves our understanding of the relationship between human activities and pollutant loads and further contributes to the decision to support local watershed managers to protect water quality in this region.

Sewage treatment plants (STPs) are one of the major source of pharmaceuticals and personal care products in the aquatic environment. Generally, the effects of individual chemicals on fish are studied under laboratory conditions, which leads to results that are potentially not realistic regarding the effects of these chemicals under environmental conditions. Therefore, in this study, common carps were held in exposed pond that receive water from STP effluents for 360 days under natural conditions. Elimination of xenobiotics starts in the fish intestine, in which the microbial community strongly influences its function. Moreover, the fish intestine functions as crucial organ for absorbing lipids and fatty acids (FA), with consequent transport to the liver where their metabolism occurs. The liver is the primary organ performing xenobiotic metabolism in fish, and therefore, the presence of pollutants may interact with the metabolism of FA. The catalytic activity of CYP1A and CYP3A-like enzymes, their gene expression, FA composition and intestinal microbiome consortia were measured. The catalytic activity of enzymes and their gene and protein expression, were induced in hepatic and intestinal tissues of fish from the exposed pond. Also, fish from the exposed pond had different compositions of FA than those from the control pond: concentration of 18:1 n-9 and 18:2 n-6 were significantly elevated and the longer chain n-3 FA 20:5 n-3, 22:5 n-3 and 22:6 n-3 were significantly lowered. There were clear differences among microbiome consortia in fish intestines across control and exposed groups. Microbiome taxa measured in exposed fish were also associated with those found in STP activated sludge. This study reveals that treated STP water, which is assumed to be clean, affected measured biomarkers in common carp.

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.

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 180 days, 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 90 days) 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.

This is the first in vitro study to investigate gender-related differences in the regulation of human cytochrome P450 by the flavonoids. Activities of CYP2E1 and CYP3A were measured in the presence of quercetin, myricetin, or isorhamnetin in hepatic microsomal pools from male and female donors. Hydroxylation of p-nitrophenol (PNPH) was measured to determine CYP2E1 activity, and O-dealkylation of 7-benzyloxy-4-trifluoromethylcoumarin (BFC) was measured to determine CYP3A activity. Quercetin, but not myricetin or isorhamnetin, competitively inhibited PNPH activity in human recombinant cDNA-expressed CYP2E1 with the Ki=52.1±6.31μM. In the human microsomes, slight inhibition of PNPH activity by quercetin was not considered as physiologically relevant. Quercetin inhibited BFC activity in human recombinant cDNA-expressed CYP3A4 competitively with the Ki=15.4±1.52μM, and myricetin - noncompetitively with the Ki=74.6±7.99μM. The degree of inhibition by quercetin was similar between genders. Myricetin showed somewhat stronger inhibition in female pools, but the Ki values were higher than physiologically relevant concentrations. Isorhamnetin did not affect either PNPH or BFC activity. We concluded that observed inhibition of CYP2E1 and CYP3A by some flavonols were not gender-dependent.

Pigs have often been suggested to be a useful model for humans, when investigating CYP dependent events, like drug metabolism. However, comprehensive knowledge about the constitutive expression of the major CYP and corresponding transcription factors is limited. We compared the constitutive mRNA expression of aryl hydrocarbon receptor, constitutive androstane receptor and pregnane X receptor and CYP1A1, CYP1A2, CYP2A, CYP2E1 and CYP3A in liver, adipose tissue, muscle and small intestine in pigs, as well as the expression along the length of the small intestine and colon. Tissue samples were taken from female pigs, and analyzed for gene expression, as well as CYP dependent activity using qPCR and specific probe substrates, respectively. For all investigated transcription factors and CYPs the mRNA expression and activity was highest in the liver. CYP1A1 and CYP3A mRNA expression and activity was shown in all investigated tissues. Along the small intestine and colon the mRNA expression and activity of CYP1A1 and CYP3A was gradually decreased. The results demonstrated, similarity to that reported for humans, and hence adds to the use of pigs as a model for humans.

Background Despite their vulnerability to the toxic effects of certain metals, biomonitoring data on adolescents are limited. In the present study, we assessed blood concentrations of toxic metals (cadmium [Cd], total mercury [Hg], and lead [Pb] in a national representative sample of Swedish adolescents. We also examined the associations of Cd, total Hg and Pb with habitual intakes of major energy-providing food groups and other possible determinants such as age, sex, household education, Nordic or non-Nordic origin, and smoking. Methods We analysed blood concentrations of Cd, total Hg, and Pb in a sample of 1099 adolescents from the Riksmaten Adolescents 2016–17 study in three age groups (mean age of 12, 15, and 18 years) using inductively coupled plasma mass spectrometry. The participants completed web-based questionnaires on food consumption frequency, sociodemographic factors and health status. Dietary data from two web-based 24-h dietary recalls were used to estimate the habitual intake of 10 major food groups. Results Almost all participants had detectable concentrations of Cd, total Hg, and Pb in whole blood. The median blood concentrations were 0.12 μg/L for Cd, 0.72 μg/L for total Hg, and 7.1 μg/L for Pb. Higher blood concentrations of Cd were observed in girls than in boys, whereas concentrations of total Hg and Pb were higher in boys. We observed an inverse association between Cd and meat intake. Total Hg concentrations were positively associated with intakes of fish, eggs, meat, and vegetables, and Pb concentrations were inversely associated with intakes of dairy products. Furthermore, smokers had higher concentrations of Cd and Pb. Conclusions We found that fish was a potentially important source of exposure to total Hg in Swedish adolescents. No other food group was identified to have a strong impact on the blood levels of Cd, total Hg and Pb. Thirteen per cent of the adolescents had blood Pb concentrations above 12 μg/L, the reference point used in the risk assessment of Pb by the European Food Safety Authority (EFSA).

In this study we evaluated and applied an HPLC coulometric array (HPLC-CoulArray) method for simultaneous determination of flavonols and phenolic acids in bilberry, lingonberry, cloudberry and sea-buckthorn berry. Berry samples purchased from local supermarkets were freeze-dried, hydrolysed and extracted with 50% aqueous methanol containing TBHQ antioxidant and 1.2 M HCL, and analysed with HPLC-CoulArray. We found that phenolic profiles differed between berries. Quercetin was found in almost all berries, with the highest concentrations observed in lingonberry. Myricetin and isorhamnetin were only detected in bilberry and sea-buckthorn, respectively. Hydroxycinnamic acids (caffeic, ferulic, p-coumaric) were also detected in all berries, but hydroxybenzoic acids (gallic, vanillic) were not found in sea-buckthorn. Total concentration of phenolic compounds was highest in sea-buckthorn berry (270.5 mg/100 g DW), followed by bilberry (253.6 mg/100 g DW), lingonberry (219.7 mg/100 g DW) and cloudberry (121.7 mg/100 g DW).

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.

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.

The fate of pharmaceuticals in aquatic environments is an issue of concern. Current evidence indicates that the risks to fish greatly depend on the nature and concentrations of the pharmaceuticals and might be species-specific. Assessment of risks associated with the presence of pharmaceuticals in water is hindered by an incomplete understanding of the metabolism of these pharmaceuticals in aquatic species. In mammals and fish, pharmaceuticals are primarily metabolized by cytochrome P450 enzymes (CYP450). Thus, CYP450 activity is a crucial factor determining the detoxification abilities of organisms. Massive numbers of toxicological studies have investigated the interactions of human pharmaceuticals with detoxification systems in various fish species. In this paper, we review the effects of pharmaceuticals found in aquatic environments on fish hepatic CYP450. Moreover, we discuss the roles of nuclear receptors in cellular regulation and the effects of various groups of chemicals on fish, presented in the recent literature.

Higher accumulation of skatole in the fat of male pigs compared with female pigs might be due to gender-related differences in the rate of skatole degradation. In the present study, skatole metabolites and cytochrome P450 (CYP450) isoforms involved in skatole metabolism were for the first time investigated in hepatic S9 fractions from six male and four female pigs (crossbred Landrace× Yorkshire dams and Duroc boar). Surprisingly, the rates of production of major skatole metabolites were similar in male and female pigs. The most abundant metabolite of skatole was 3-hydroxy-3-methyloxindole (HMOI) followed by 3-methyloxindole and indole-3-carbinol in both male and female S9 fractions. Concentrations of formed HMOI and 3-methyloxindole did not differ between the genders (P = 0.124 for HMOI, and P = 0.575 for 3-methyloxindole). Indole-3-carbinol formation was higher in S9 fractions from the females compared with male pigs (P = 0.0001). Enzyme kinetic parameters were similar for both genders (P> 0.05). In both male and female pigs, ellipticine, diallyl sulphide (DAS) and quercetin inhibited HMOI formation, confirming the involvement of CYP1A1 and CYP2E1. The formation of 3-methyloxindole was reduced in the presence of the CYP2E1 inhibitor DAS, and formation of indole-3-carbinol was reduced in the presence of CYP1A1 and CYP2A19 inhibitors. We found only minor differences in skatole metabolism between male and female pigs, particularly the involvement of CYP2C and CYP3A in indole-3-carbinol formation in female but not in male pigs. This is a very essential finding, suggesting the involvement of larger number of CYP450 isoforms in female pigs. On the other hand, indole-3-carbinol is a minor skatole metabolite, and the physiological significance of CYP2C and CYP3A involvement in its formation in female pigs, but not in male pigs, needs to be elucidated. Our results, however, should be interpreted with caution because of the low number of animals and possibility of breed and age effects on skatole metabolism. info:eu-repo/semantics/publishedVersion

Due to limited availability of human liver tissue for the study of cytochrome P450 (CYP450), porcine liver tissue has been suggested as an alternative source to prepare microsomes and hepatocytes. The porcine liver is made by four different lobes. The present study investigated the expression and activity of specific CYP450 isoforms in the four lobes, with the purpose to examine if one lobe of the porcine liver resembles the human more than others. Samples from the four major lobes were taken from female pigs and mRNA expression and activity of CYP1A, 2A, 2C, 2D, 2E and 3A determined. The results showed no differences in specific mRNA expression and activity of any of the investigated CYP450 isoforms. In conclusion, the study shows that all parts of the porcine liver are equally useful as model tissue.

Cytochrome P450 (CYP450) is the major family of enzymes involved in the metabolism of several xenobiotic and endogenous compounds. Among substrates for CYP450 is the tryptophan metabolite skatole (3-methylindole), one of the major contributors to the off-odour associated with boar-tainted meat. The accumulation of skatole in pigs is highly dependent on the hepatic clearance by CYP450s. In recent years, the porcine CYP450 has attracted attention both in relation to meat quality and as a potential model for human CYP450. The molecular regulation of CYP450 mRNA expression is controlled by several nuclear receptors and transcription factors that are targets for numerous endogenously and exogenously produced agonists and antagonists. Moreover, CYP450 expression and activity are affected by factors such as age, gender and feeding. The regulation of porcine CYP450 has been suggested to have more similarities with human CYP450 than other animal models, including rodents. This article reviews the available data on porcine hepatic CYP450s and its implications for boar taint.

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 1–100 μM 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 K i of 0.5 μM, and BFCOD activity revealed competitive inhibition with a K i of 0.04 μM. The relatively low K i 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.

The objective of this study was to investigate how color stability of beef is affected by vacuum skin packaging (VSP) compared with vacuum packaging (VP) and high-oxygen modified atmosphere packaging (MAP; 80% O₂ and 20% CO₂). Longissimus lumborum muscles were aged in vacuum for 7 days and then cut into 2-cm-thick slices and repacked using VSP, VP and MAP for another 7 days. Color stability was measured during the next 5 days in air and samples for α-tocopherol and NADH analyses were obtained at the beginning and end of aerobic storage. Color stability, α-tocopherol and NADH of steaks were affected by packaging methods and storage time in air (P0.05). Higher a* value was obtained in VSP on day 5 compared with VP. Steaks packed in VSP had better color stability than in VP and their color was similar to MAP at the end (day 5) of storage.

Hepatic cytochrome P450 expression and activity are dependent on many factors, including dietary ingredients. In the present study, we investigated the in vivo and in vitro effect of chicory root on hepatic CYP3A and 2C in male pigs. Chicory feeding increased the expression of CYP3A29 mRNA but not CYP2C33.Correspondingly, CYP3A activity was increased by chicory feeding, while CYP2C activity was not affected. Additionally, the in vitro effect of chicory extract on the CYP3A activity was investigated. It was shown that CYP3A activity in the microsomes from male pigs was inhibited, but this effect was eliminated bypre-incubation. In both male and female pigs the CYP3A activity was increased in the presence of chicory after pre-incubation. Furthermore, gender-related differences in mRNA expression and activity were observed. CYP3A mRNA expression was greater in female pigs; this was not reflected on activity. ForCYP2C, no difference in mRNA expression was observed, while CYP2C activity was greater in female pigs. Surprisingly, the expression of the constitutive androstane receptor, pregnane X receptor and aryl hydrocarbon receptor did not differ with feed or gender. In conclusion, chicory root modifies the expression and activity of CYP3A in vivo and in vitro, while CYP2C is not affected.

In the present study, we investigated hepatic mRNA expression and activities of CYP3A and 2C in entire, surgically castrated and pigs vaccinated with Improvac. Additionally, we examined the mRNA expression of the two nuclear receptors pregnane X receptor (PXR) and constitutive androstane receptor (CAR), known to regulate CYP3A and 2C mRNA expression, respectively. Activities of CYP3A and 2C were estimated as a rate of 7-benzyloxy-4-trifluoromethylcoumarin and 7-benzyloxyquinoline metabolism (CYP3A) and tolbutamide metabolism (CYP2C). We found no effect of Improvac treatment or surgical castration on either CYP3A or 2C activities. Similarly, the mRNA expressions of CYP3A29, 2C33 and PXR were not changed. CAR mRNA expression differed only between entire and surgically castrated male pigs (p=0.005), being greater in surgically castrated pigs. Our results indicated that neither CYP3A nor 2C are affected by Improvac.

Little is known about the effects of the cardiovascular drug verapamil (VRP) on metabolic processes in fish. Most calcium channel blockers including VRP are metabolized by cytochrome P450 (CYP450) enzymes. In this study we investigated the in vivo effect of VRP on some CYP450-mediated reactions in juvenile rainbow trout ( Oncorhynchus mykiss ). Fish were exposed to sublethal concentrations of VRP (0.5, 27 and 270 μg l −1 ) for 0, 21, and 42 day. The following CYP450-mediated reactions were studied in hepatic microsomes: O-dealkylation of ethoxyresorufin, methoxyresorufin, and pentoxyresorufin, hydroxylation of coumarin, tolbutamide, and p-nitrophenol, and O-debenzylation of 7-benzyloxy-4-trifluoromethylcoumarin. The amounts of products of these reactions did not differ among fish exposed to different levels of VRP and control fish. This suggests that the levels of VPR used did not alter catalytic activity of the selected CYP450 enzymes. In conclusion, none of the investigated CYP450-mediated reactions has potential as a biomarker to monitor VRP contamination of the aquatic environment.

The present study investigated the in vivo effect of chicory root on testicular steroid concentrations and androstenone metabolizing enzymes in entire male pigs. Furthermore, the effect on skatole and indole concentrations in plasma and adipose tissue was investigated. The pigs were divided into two groups; one receiving experimental feed containing 10% dried chicory root for 16 days before slaughter, the control group was fed a standard diet. Plasma, adipose and liver tissue samples were collected at slaughter. Plasma was analyzed for the concentration of testosterone, estradiol, insulin-like growth factor 1 (IGF-1), skatole and indole. Adipose tissue was analyzed for the concentration of androstenone, skatole and indole, while the liver tissue was analyzed for mRNA and protein expressions of 3β-hydroxysteroid dehydrogenase (3β-HSD), sulfotransferase 2A1 and heat-shock protein 70 (HSP70). The results showed that the androstenone concentrations in the adipose tissue of chicory fed pigs were significantly (p

We investigated in vitro inhibitory effects of ketoconazole (KTZ) on cytochrome P450 activity in microsomes from pigs and Atlantic salmon. The following enzymatic reactions were studied: 7-benzyloxyresorufin and 7-ethoxyresorufin O-dealkylation (BROD and EROD, respectively), 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylation (BFCOD) and 7-benzyloxyquinoline O-debenzylation (BQOD). KTZ was a potent non-competitive inhibitor of BROD and BQOD in the microsomes from pigs, whereas in the microsomes from Atlantic salmon, these reactions were competitively inhibited by KTZ. BFCOD activity was inhibited by KTZ in a non-competitive manner in both species. KTZ non-competitively inhibited EROD in Atlantic salmon, but not in porcine microsomes. The activity of BROD and BQOD was higher in male than that in female pigs, but the activity of BFCOD showed no sex-related differences.

The aim of this study was to investigate the effect of a vaccine against gonadotropin-releasing hormone (GnRH), Improvac(®) (Pfizer Ltd), administered at a pre- or early pubertal stage on boar taint, hormonal status and reproductive organs. Crossbred male pigs (Swedish Yorkshire dams×Swedish Landrace sires or Swedish Yorkshire sires, n=192) were at birth randomly allocated to four groups: one group of pigs surgically castrated without anaesthesia before age 1 week, a second group of early vaccinated pigs given Improvac at ages 10 and 14 weeks, a third group of standard vaccinated pigs given Improvac at ages 16 and 20 weeks, and a fourth group of entire male pigs. Following the second vaccine injection, antibody titres increased rapidly, accompanied by a rapid decrease in testosterone and a slower decrease of skatole in plasma to the same low levels as for surgically castrated pigs. At slaughter, the levels of androstenone and skatole in adipose tissue were low in surgically castrated and vaccinated pigs, whereas entire male pigs had elevated levels (p

The objective of this study was to evaluate the long-term effect of a gonadotropin-releasing hormone (GnRH) vaccine, Improvac (Pfizer Ltd.), on the levels of GnRH antibodies, testosterone, estrone sulphate (E1S) and androstenone, as well as skatole and indole in male pigs. Additionally, the long-term effect of immunocastration on social and sexual behaviour was studied. Male pigs were assigned to two treatment groups: a treatment group given two doses of Improvac (n=12) and a control group of entire male pigs (n=12). The pigs were kept either 16 or 22 weeks after vaccination. Blood samples were collected five or six times; prior to both first and second vaccination, then three or four times during the 16 or 22 week period after second vaccination. Immunocastration significantly reduced levels of testosterone and E1S in plasma, and levels of androstenone in fat (P

A total of 96 entire male pigs were used to evaluate the effects of feeding raw potato starch (RPS) and live weight (LW; 90, 100 or 115 kg) on skatole, indole and androstenone levels in fat and plasma. Different methods to analyse the compounds were compared. Fat levels of skatole analysed by HPLC and colorimetric methods, and androstenone analysed by HPLC and ELISA, were highly correlated. However, androstenone values obtained by ELISA were overestimated. Feeding RPS reduced skatole levels in plasma and fat but did not affect indole levels. Androstenone levels in plasma measured by direct ELISA were not altered by diet, whereas the levels measured by ELISA with extraction were lower in the pigs fed RPS. Feeding RPS did not reduce androstenone levels in fat. Androstenone levels in fat were higher at 115 than at 90 kg, whereas skatole and indole levels were not affected by LW.

Cytochromes P4502E1 (CYP2E1) and P4502A6 (CYP2A6) catalyse metabolic reactions of skatole and indole metabolism. The objectives of this study were as follows: to evaluate whether activities of CYP2E1 and CYP2A6 in pigs of two live weights (LW) differ between males and females; to investigate whether activities of CYP2E1 and CYP2A6 are affected by hCG stimulation; and to investigate whether the levels of skatole and indole in the liver and the activities of CYP2E1 and CYP2A6 are affected by raw potato starch (RPS). Female pigs expressed higher CYP2A6 activity at 90 kg LW, and higher CYP2E1 activity at 115 kg LW compared to male pigs. Skatole levels in the liver were higher in male pigs than in female pigs at both LW, whereas indole levels were higher in males only at 115 kg LW. Neither levels of indolic compounds in the liver nor enzyme activities were affected by hCG stimulation. The inclusion of RPS in the diet reduced skatole levels in the liver in both sexes and increased CYP2A6 activity in female pigs. It was concluded that the incidence of boar taint may depend on both skatole amount, which reach the liver, and the activities of enzymes involved in skatole metabolism, which may vary depending on sex, live weight, and diet.

This study evaluated the effect of supplement of raw potato starch (RPS) on the levels of skatole, androstenone, testosterone and oestrone sulphate in plasma from entire male pigs. The study also evaluated relationships between plasma levels of skatole and testicular steroids at three different live weights (LW) of approximately 90, 100 and 115 kg. A total of 111 entire male pigs of a crossbred (Yorkshire dams×Swedish Landrace sires) were used. Animals were raised either in mixed pens, with females and males, or single-sex pens. Each pen contained seven or nine pigs. The most fast-growing three pigs from the pens with nine pigs were slaughtered when they reached 90 kg LW, and the remaining pigs were slaughtered at 115 kg LW. All pigs were fed the same commercial diet until the average pen weight reached 100 kg. Then, 33 out of 80 remaining pigs received RPS, 0.6 kg per pig and day, for 2 weeks prior to slaughter. Blood samples were taken from the pigs at three occasions: first, the day prior to first slaughter occasion, low-weight group; second, the day prior to change in diet, middle-weight group; and third, the day prior to second slaughter occasion, high-weight group. Plasma was analysed for the levels of skatole, androstenone, testosterone and oestrone sulphate. Fat samples were taken at slaughter and analysed for the levels of skatole and androstenone. The levels of skatole and testicular steroids in plasma were significantly higher in entire male pigs from the high-weight group fed no RPS compared to those from low- and middle-weight groups. The levels of the investigated compounds did not differ between low- and middle-weight groups (P>0.1). The diet with RPS induced a decline in skatole levels in plasma and fat (P 0.05). Skatole levels were positively correlated to testosterone and oestrone sulphate levels in the middle- and high-weight pigs fed no RPS as well as to testosterone in the low-weight group. In the high-weight group fed RPS, skatole levels were not correlated to any of the analysed compounds. Approximately 26% of the entire male pigs (11 out of 43) from the high-weight group fed no RPS produced skatole levels in fat above 0.20 μg/g, whereas the pigs from the low- and high-weight group fed RPS did not produce skatole levels above 0.20 μg/g in fat. Androstenone levels in fat were high in all groups. In total 47% (52 out of 111) pigs expressed androstenone levels above the rejection levels in fat of 1.0 μg/g and 88% (98 out of 111) had androstenone levels above 0.5 μg/g. It was concluded that a lower slaughter weight and the supplement of raw potato starch to the diet could be used to reduce skatole levels in entire male pigs. Androstenone levels in fat, however, could not be reduced by either a lower weight at slaughter or dietary manipulation.

High skatole and to a lesser degree indole levels in some entire male pigs result in occurrence of off-flavor in meat, called boar taint. In this study, plasma samples from 117 Yorkshire, 134 Landrace, 184 Hampshire and 75 Duroc entire male pigs collected at different ages were analyzed for skatole and slightly fewer samples for indole concentrations. For each breed, a distinct age-related distribution of plasma skatole levels was observed. Skatole levels were increased at approximately 180–200 days of age, reaching very high levels is some individuals. Afterwards, the levels decreased; in Yorkshire and Landrace at approximately 240–260 and in Hampshire and Duroc at 310–360 days of age. The decrease of skatole levels was also observed in samples collected from 15 Landrace boars at two different ages: 16.8 μg/L (SD=17.36) vs. 5.9 μg/L (SD=3.48, p =0.016) in samples taken at the mean age of 210 and 314 days, respectively. Indole levels showed similar age- and breed-related variations to skatole. At the time of increased skatole concentrations (age from 180 to 360 days, depending on breed) 25.5% of Yorkshire, 31.6% of Landrace, 20.3% of Hampshire and 61.1% of Duroc entire male pigs had skatole levels above 12.6 μg/L of plasma, which corresponds to the threshold level of 0.20 μg/g of fat that is used for selecting tainted carcasses. The results indicate that increased levels of skatole in entire male pigs are related to puberty and taking skatole measurements at that age could be advantageous when considering genetic selection to reduce boar taint level in entire male pigs. Breed differences should be also taken into account.

The objectives of the study were to investigate the age-associated variations of plasma skatole and androstenone levels and their relationship to testosterone, estrone sulphate and thyroxine in plasma from entire male pigs. Effect of photoperiod on boar taint compounds in plasma was also investigated. In total, 47 uncastrated crossbred male pigs, siblings from 13 litters, were divided into three groups: Control group (natural photoperiod), Spring/Summer group (artificial spring conditions) and Autumn/Winter group (artificial autumn conditions). Blood samples were collected every 2 weeks at the average age from 8 weeks until slaughter at the age of 20–24 weeks. Neither skatole nor androstenone levels in plasma were affected by photoperiod. Skatole concentrations in plasma varied with age and were high at the age of 8–10 weeks. The early increase of skatole levels related to no other investigated compounds. At the older age, skatole levels in plasma were positively correlated to androstenone ( r =0.30; 20 weeks of age), testosterone and estrone sulphate levels ( r =0.43 and 0.54, respectively; 22 weeks of age) and negatively to thyroxine levels ( r =−0.44; 22 weeks of age, and r =−0.72; 24 weeks of age). Plasma androstenone levels were positively correlated to levels of testosterone and estrone sulphate from approximately 14 to 24 weeks of age, not at younger age, with correlation coefficients ranging from 0.34 to 0.79. Negative correlations between androstenone and thyroxine levels in plasma were found at the ages of 16, 18 and 20 weeks ( r =−0.42, −0.35 and −0.30, respectively). Skatole and androstenone levels in fat at slaughter, 20–24 weeks of age, were highly correlated ( r =0.68; P