Ethylbenzene Induces Microsomal Oxygen Free Radical Generation: Antibody-Directed Characterization of the Responsible Cytochrome P450 Enzymes

Serron, Sonia C.; Dwivedi, Neelam; Backes, Wayne L.

doi:10.1006/taap.2000.8910

Cited by 56 publications

(22 citation statements)

References 49 publications

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“…16,17) This assay has been shown to detect the fluorescence associated with the oxidation of DCFH by several reactive intermediates, including superoxide anions, H 2 O 2 , and hydroxyl radicals in microsomes. 16) Microsomes (rate, 0.5 mg/ml) were preincubated for 15 min with 4 mM of DCFH-DA for deesterification by endogenous esterase in phosphate buffer 50 mM, pH 7.4, at 37°C.…”

Section: Consumptionmentioning

confidence: 99%

Synthesis and in Vitro Antioxidant Activity of Glycyrrhetinic Acid Derivatives Tested with the Cytochrome P450/NADPH System

et al. 2004

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Section: Consumptionmentioning

confidence: 99%

Synthesis and in Vitro Antioxidant Activity of Glycyrrhetinic Acid Derivatives Tested with the Cytochrome P450/NADPH System

et al. 2004

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“…The concentration of microsomal protein was determined using BCA Protein Assay Kits (Pierce, IL, USA). ROS were measured by the partially modified method of Serron et al (2000). Microsomes (final concentration 0.2 mg/ml) were incubated in the dark at 37°C in 40 mM Tris buffer (pH 7.4) and 5 μM 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCFDA, Life Technologies).…”

Section: Microsomal Ros Productionmentioning

confidence: 99%

Modifying effects of liver tumor promotion in rats subjected to co-administration of indole-3-carbinol and phenobarbital

et al. 2014

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-Indole-3-carbinol (I3C) and phenobarbital (PB) are cytochrome P450 (CYP) 1A and CYP2B inducers, respectively, and have liver tumor-promoting effects in rats. In this study, we investigated the modifying effects on tumor promotion by I3C and PB co-administration. Six-week-old male F344 rats received a single intraperitoneal injection of N-diethylnitrosamine for initiation treatment. Two weeks after the initiation, rats were given no tumor-promoting agents (DEN alone), I3C (2,500 or 5,000 ppm in diet), PB (60 or 120 ppm in drinking water), or 2,500 ppm I3C + 60 ppm PB for 6 weeks. One week after the I3C/PB treatments, all animals underwent a two-thirds partial hepatectomy. The number and area of liver cell foci positive for glutathione S-transferase placental form (GST-P + foci) were not significantly fluctuated in the PB+I3C group in the isoadditive statistical model. On the contrary, the mRNA levels of Cyp2b1/2 and Nqo1 were suppressed and enhanced, respectively, in the PB+I3C group in the isoadditive model, but there was no enhancement in the microsomal reactive oxygen species (ROS) production, thiobarbituric acid-reactive substance levels, and Ki-67 + cell ratio in this group. The results suggest that the co-administration of I3C and PB causes no modifying effects in liver tumor promotion in rats.

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“…ROS was measured by the partially modified method of Serron et al (2000). Microsomes (final concentration 0.2 mg/ml) were incubated in the dark at 37°C in 40 mM Tris buffer (pH 7.4) and 5 μM 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCFHDA, Invitrogen).…”

Section: Microsomal Reactive Oxygen Species (Ros) Productionmentioning

confidence: 99%

Enhanced liver tumor promotion activity in rats subjected to combined administration of phenobarbital and orphenadrine

et al. 2013

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-Phenobarbital (PB) and orphenadrine (ORPH) are cytochrome P450 (CYP) 2B inducers and have liver tumor-promoting effects in rats. In this study, we performed a rat two-stage liver carcinogenesis bioassay to examine the tumor-promoting effect of PB and ORPH co-administration. Twelve male rats per group were given an intraperitoneal injection of N-diethylnitrosamine (DEN) for initiation. Twoweek after DEN administration, rats were given PB (60 or 120 ppm in drinking water), ORPH (750 or 1,500 ppm in diet) or 60 ppm PB+750 ppm ORPH for 6-week. One-week after the PB/ORPH treatment, all rats were subjected to two-thirds partial hepatectomy. To evaluate the effect of the combined administration, we used two statistical models: a heteroadditive model and an isoadditive model. In the heteroadditive model, the net values of the number and area of glutathione S-transferase placental form (GST-P) positive foci, Cyp2b1/2, Gstm3 and Gpx2 mRNA levels, microsomal reactive oxygen species (ROS) production and thiobarbituric acid-reactive substances level in the PB+ORPH group were significantly higher than the sum of the net values of those in the Low PB and Low ORPH groups. In the isoadditive model, the average values of the area of GST-P positive foci and PCNA positive hepatocyte ratio and Gstm3 mRNA level in the PB+ORPH group were significantly higher than the average values of those in the High PB and High ORPH groups. These results suggest that PB and ORPH co-administration causes synergistic effects in liver tumor-promoting activity in rats resulting from oxidative stress due to enhanced microsomal ROS production.

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Ethylbenzene Induces Microsomal Oxygen Free Radical Generation: Antibody-Directed Characterization of the Responsible Cytochrome P450 Enzymes

Cited by 56 publications

References 49 publications

Synthesis and in Vitro Antioxidant Activity of Glycyrrhetinic Acid Derivatives Tested with the Cytochrome P450/NADPH System

Synthesis and in Vitro Antioxidant Activity of Glycyrrhetinic Acid Derivatives Tested with the Cytochrome P450/NADPH System

Modifying effects of liver tumor promotion in rats subjected to co-administration of indole-3-carbinol and phenobarbital

Enhanced liver tumor promotion activity in rats subjected to combined administration of phenobarbital and orphenadrine

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