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Metabolism of jaceosidin in the rats
S92
Abstracts / Toxicology Letters 180S (2008) S32–S246
ways; carbofuran formation and benfuracarb sulfoxide formation. Intrinsic clearance (Clint ) of carbofuran from benfuracarb by rat liver microsomes was 2.2-fold and 1.5 higher than those of human and mouse liver microsomes, respectively. Clint of benfuracarb sulfoxide formation from benfuracarb by rat liver microsomes was 1.2-fold and 1.8 higher than those of human and mouse liver microsomes, respectively. Clint of benfuracarb sulfoxide formation was higher than that of carbofuran formation. Selective inhibitors of the P450 isoforms in human liver microsomes ((naphthoflavone for CYP1A2, coumarin for CYP2A6, Thio-TEPA for CYP2B6, quercetin and montelucast for CYP2C8, sulfaphenazole for CYP2C9, s-benzylnirvanol for CYP2C19, quinidine for CYP2D6, DETC for CYP2E and ketoconazole for CYP3A4 and CYP3A5) were used to characterize responsible isoforms for the metabolic reactions. And the incubation of benfuracarb with ten different cDNA-expressed human recombinant CYP450s, 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A5 were studied. The results from those experiments demonstrated that the sulfoxidation of benfuracarb was mediated by CYP1A2, 2C19, CYP3A4 and CYP3A5. Clint of the CYP3A5 was 36.3-fold, 7.3-fold and 2.4-fold higher than CYP1A2, 2C19 and 3A4, respectively. When total normalized rates (%) were calculated, CYP3A4 appears to be mainly involved in the formation of sulfoxide from benfuracarb.
K11 Metabolism of jaceosidin in the rats
doi:10.1016/j.toxlet.2008.06.484
doi:10.1016/j.toxlet.2008.06.486
K10 Evaluation of zearalenone metabolism and absorption in human intestinal Caco-2 cells
K12 Effect of treatment with different statins on malondialdehyde level in rat plasma and heart tissue
Bernadette Videmann 2 , Michele Mazallon 1 , Jonathan Tep 2 , Sylvaine Lecoeur 1,∗
Jasna Lovric 1,∗ , Marija Macan 2 , Marta Kelava 3 , Jadranka Sertic 1,4 , Vlasta Bradamante Bradamante 2
1
1 Department of Chemistry and Biochemistry, School of Medicine, University of Zagreb, Zagreb, Croatia, 2 Department of Pharmacology, School of Medicine, University of Zagreb, Zagreb, Croatia, 3 School of Medicine, University of Zagreb, Zagreb, Croatia, 4 Clinical Institute of Laboratory Diagnosis, Zagreb University Hospital Center, Zagreb, Croatia
2
National Institute of Agronomic Research, Marcy l’Etoile, France, University of Lyon 1, Lyon, France
The mycotoxin zearalenone (ZEA) is found worldwide as a contaminant in cereals and grains. It is implicated in reproductive disorders and hyperoestrogenic syndromes in animals and humans that are exposed by food. We investigated the metabolism and transfer of ZEA using the human Caco-2 cell line as a model of intestinal epithelial barrier. Cells exposed to 5–200 M ZEA showed efficacious metabolism of the toxin. ␣-Zearalenol and -zearalenol were the preponderant metabolites (respectively 40.7 ± 3.1% and 31.9 ± 4.9% of total metabolites, after a 3 h exposure to 10 M ZEA), whereas ZEA-glucuronide and ␣-zearalenol glucuronide were less produced (respectively 8.2 ± 0.9% and 19.1 ± 1.3% of total metabolites, after a 3 h exposure to 10 M ZEA). The cell production of reduced metabolites was strongly inhibited by ␣- and -hydrosysteroid dehydrogenase inhibitors, and Caco-2 cells exhibited ␣-hydrosysteroid dehydrogenase type II and hydrosysteroid dehydrogenase type I mRNA. After apical exposure of the cells to ZEA, ␣-zearalenol was the main metabolite found at the basal side of the cells, whereas -zearalenol and both glucuronides were preferentially excreted at the apical side. As ␣-zearalenol shows the strongest oestrogenic activity, the preferential production and basal transfer of this metabolite suggests that intestinal cells may contribute to the manifestation of zearalenone adverse effects. doi:10.1016/j.toxlet.2008.06.485
Won Young Song, Nam Jin Kim, Hye Young Ji, Sung Yeon Kim ∗ , Hye Suk Lee Wonkwang University, Iksan, Republic of Korea Jaceosidin [5,7-dihydroxy-2-(4-hydroxy-3-methoxy-phenyl)-6methoxy-chromen-4-one] is an active ingredient of Artemisia argyi with anti-inflammatory activity. In vitro and in vivo metabolism of jaceosidin in the rats has been studied by LC-electrospray mass spectrometry. Rat liver microsomal incubation of jaceosidin in the presence of NADPH and UDPGA resulted in the formation of six metabolites (M1–M6). M4, M5 and M6 were identified as 6-O-demethyljaceosidin, 3-O-demethyljaceosidin and hydroxyl-jaceosidin, respectively. M1, M2 and M3 were 6-Odemethyljaceosidin glucuronide, hydroxyl-jaceosidin glucuronide and jaceosidin glucuronide, respectively. After incubation of jaceosidin with rat hepatocytes, M3, M5 and unchanged jaceosidin were detected. M1, M3, M4 and M5 were also characterized in urine or feces samples after an intravenous administration of jaceosidin to rats. Jaceosidin was metabolized via glucuronidation and demethylation in the rats.
The metabolic syndrome is a constellation of coronary risk factors. Statins, inhibitors of hydroxy-methylglutaryl coenzyme A reductase, are considered the first-line therapy for treatment of hypercholesterolemia. There is extensive evidence that links hypercholesterolemia with increased lipid peroxidation and increased oxidative stress. Since the beneficial effects of statin treatment on cardiovascular morbidity and mortality have not been entirely explained by reduction in LDL, we have decided to investigate the effect of treatment with Simvastatine, Atorvastatine and Pravastatine on rat MDA plasma and heart tissue level. Three groups, with forty-six male Wistar rats each, were in treatment. Each group of rats was divided in two control groups (n = 7) and four experimental groups (n = 8). Experimental groups were on SIMV, ATOR or PRA treatment which was given orally in 10 and 50 mg/kg/day doses for 3 weeks. After the drug treatment, one control and two experimental groups (one taking 10 mg/kg/day and the other 50 mg/kg/day) were sacrificed and blood samples were taken. The remaining groups were left additional 9 days and then sacrificed. The level of MDA in plasma was measured by standard analytical methods (HPLC, UV), and the level of MDA in tissue was measured spectrophotometrically and by GC–MS method of phenylhidrazone derivative of MDA. Data were analyzed by Kruskal–Wallis test.
Abstracts / Toxicology Letters 180S (2008) S32–S246
ways; carbofuran formation and benfuracarb sulfoxide formation. Intrinsic clearance (Clint ) of carbofuran from benfuracarb by rat liver microsomes was 2.2-fold and 1.5 higher than those of human and mouse liver microsomes, respectively. Clint of benfuracarb sulfoxide formation from benfuracarb by rat liver microsomes was 1.2-fold and 1.8 higher than those of human and mouse liver microsomes, respectively. Clint of benfuracarb sulfoxide formation was higher than that of carbofuran formation. Selective inhibitors of the P450 isoforms in human liver microsomes ((naphthoflavone for CYP1A2, coumarin for CYP2A6, Thio-TEPA for CYP2B6, quercetin and montelucast for CYP2C8, sulfaphenazole for CYP2C9, s-benzylnirvanol for CYP2C19, quinidine for CYP2D6, DETC for CYP2E and ketoconazole for CYP3A4 and CYP3A5) were used to characterize responsible isoforms for the metabolic reactions. And the incubation of benfuracarb with ten different cDNA-expressed human recombinant CYP450s, 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A5 were studied. The results from those experiments demonstrated that the sulfoxidation of benfuracarb was mediated by CYP1A2, 2C19, CYP3A4 and CYP3A5. Clint of the CYP3A5 was 36.3-fold, 7.3-fold and 2.4-fold higher than CYP1A2, 2C19 and 3A4, respectively. When total normalized rates (%) were calculated, CYP3A4 appears to be mainly involved in the formation of sulfoxide from benfuracarb.
K11 Metabolism of jaceosidin in the rats
doi:10.1016/j.toxlet.2008.06.484
doi:10.1016/j.toxlet.2008.06.486
K10 Evaluation of zearalenone metabolism and absorption in human intestinal Caco-2 cells
K12 Effect of treatment with different statins on malondialdehyde level in rat plasma and heart tissue
Bernadette Videmann 2 , Michele Mazallon 1 , Jonathan Tep 2 , Sylvaine Lecoeur 1,∗
Jasna Lovric 1,∗ , Marija Macan 2 , Marta Kelava 3 , Jadranka Sertic 1,4 , Vlasta Bradamante Bradamante 2
1
1 Department of Chemistry and Biochemistry, School of Medicine, University of Zagreb, Zagreb, Croatia, 2 Department of Pharmacology, School of Medicine, University of Zagreb, Zagreb, Croatia, 3 School of Medicine, University of Zagreb, Zagreb, Croatia, 4 Clinical Institute of Laboratory Diagnosis, Zagreb University Hospital Center, Zagreb, Croatia
2
National Institute of Agronomic Research, Marcy l’Etoile, France, University of Lyon 1, Lyon, France
The mycotoxin zearalenone (ZEA) is found worldwide as a contaminant in cereals and grains. It is implicated in reproductive disorders and hyperoestrogenic syndromes in animals and humans that are exposed by food. We investigated the metabolism and transfer of ZEA using the human Caco-2 cell line as a model of intestinal epithelial barrier. Cells exposed to 5–200 M ZEA showed efficacious metabolism of the toxin. ␣-Zearalenol and -zearalenol were the preponderant metabolites (respectively 40.7 ± 3.1% and 31.9 ± 4.9% of total metabolites, after a 3 h exposure to 10 M ZEA), whereas ZEA-glucuronide and ␣-zearalenol glucuronide were less produced (respectively 8.2 ± 0.9% and 19.1 ± 1.3% of total metabolites, after a 3 h exposure to 10 M ZEA). The cell production of reduced metabolites was strongly inhibited by ␣- and -hydrosysteroid dehydrogenase inhibitors, and Caco-2 cells exhibited ␣-hydrosysteroid dehydrogenase type II and hydrosysteroid dehydrogenase type I mRNA. After apical exposure of the cells to ZEA, ␣-zearalenol was the main metabolite found at the basal side of the cells, whereas -zearalenol and both glucuronides were preferentially excreted at the apical side. As ␣-zearalenol shows the strongest oestrogenic activity, the preferential production and basal transfer of this metabolite suggests that intestinal cells may contribute to the manifestation of zearalenone adverse effects. doi:10.1016/j.toxlet.2008.06.485
Won Young Song, Nam Jin Kim, Hye Young Ji, Sung Yeon Kim ∗ , Hye Suk Lee Wonkwang University, Iksan, Republic of Korea Jaceosidin [5,7-dihydroxy-2-(4-hydroxy-3-methoxy-phenyl)-6methoxy-chromen-4-one] is an active ingredient of Artemisia argyi with anti-inflammatory activity. In vitro and in vivo metabolism of jaceosidin in the rats has been studied by LC-electrospray mass spectrometry. Rat liver microsomal incubation of jaceosidin in the presence of NADPH and UDPGA resulted in the formation of six metabolites (M1–M6). M4, M5 and M6 were identified as 6-O-demethyljaceosidin, 3-O-demethyljaceosidin and hydroxyl-jaceosidin, respectively. M1, M2 and M3 were 6-Odemethyljaceosidin glucuronide, hydroxyl-jaceosidin glucuronide and jaceosidin glucuronide, respectively. After incubation of jaceosidin with rat hepatocytes, M3, M5 and unchanged jaceosidin were detected. M1, M3, M4 and M5 were also characterized in urine or feces samples after an intravenous administration of jaceosidin to rats. Jaceosidin was metabolized via glucuronidation and demethylation in the rats.
The metabolic syndrome is a constellation of coronary risk factors. Statins, inhibitors of hydroxy-methylglutaryl coenzyme A reductase, are considered the first-line therapy for treatment of hypercholesterolemia. There is extensive evidence that links hypercholesterolemia with increased lipid peroxidation and increased oxidative stress. Since the beneficial effects of statin treatment on cardiovascular morbidity and mortality have not been entirely explained by reduction in LDL, we have decided to investigate the effect of treatment with Simvastatine, Atorvastatine and Pravastatine on rat MDA plasma and heart tissue level. Three groups, with forty-six male Wistar rats each, were in treatment. Each group of rats was divided in two control groups (n = 7) and four experimental groups (n = 8). Experimental groups were on SIMV, ATOR or PRA treatment which was given orally in 10 and 50 mg/kg/day doses for 3 weeks. After the drug treatment, one control and two experimental groups (one taking 10 mg/kg/day and the other 50 mg/kg/day) were sacrificed and blood samples were taken. The remaining groups were left additional 9 days and then sacrificed. The level of MDA in plasma was measured by standard analytical methods (HPLC, UV), and the level of MDA in tissue was measured spectrophotometrically and by GC–MS method of phenylhidrazone derivative of MDA. Data were analyzed by Kruskal–Wallis test.