Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.99.3 (heme oxygenase)
 4,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carcinogen-resistant inbred DRH rats developed from the Donryu strain showed a remarkably low incidence of liver tumors when they were fed diets containing hepatocarcinogens such as 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). In this work, we examined various characteristics of male DRH and Donryu rats during 3'-Me-DAB administration for 8 weeks. 32P-Postlabeling analysis showed that essentially similar levels of DNA-adducts were generated by the metabolites of 3'-Me-DAB in the livers of these two strains of rats at several time points. However, both GADD45 (growth arrest and DNA damage-inducible) and O6-methylguanine methyltransferase (putatively DNA damage-inducible) mRNA levels were increased significantly in Donryu rat livers, but were increased to a lesser extent in DRH rats. [3H]Thymidine incorporation into hepatic DNA began to increase around 10 to 20 days after the start of 3'-Me-DAB administration in Donryu rats probably due to DNA repair, while no significant change occurred in DRH rats under the same conditions. Furthermore, inductions of heme oxygenase (due to degradation of heme-proteins) and hepatocyte growth factor (HGF; cell death and regeneration of hepatocytes) mRNAs were greater in Donryu rat livers than those of DRH, suggesting that the former were more sensitive to cytotoxic effects of 3'-Me-DAB than the latter. Another remarkable difference observed between these two strains was the significant induction of cytochrome P-450 2E1 mRNA in Donryu rat livers; this may contribute to the generation of reactive oxygen intermediates. Finally, increases of glutathione S-transferase (P-form) and gamma-glutamyltranspeptidase mRNAs as marker enzymes of preneoplastic changes of hepatocytes were clearly seen only in Donryu rat livers at 6 to 8 weeks after the start of 3'-Me-DAB administration. These results indicate that the different susceptibility to hepatocarcinogenesis between these two strains of rats may arise from events other than the DNA adduct formation.
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PMID:Different responses other than the formation of DNA-adducts between the livers of carcinogen-resistant rats (DRH) and carcinogen-sensitive rats (Donryu) to 3'-methyl-4-dimethylaminoazobenzene administration. 976 15

Moutan Cortex Radicis (MCR) is one of the most widely used Oriental medicines. In this study, we assessed the reducing effect of ethanol extract of MCR on hydrogen peroxide-induced reactive oxygen production, the main cause of cell damage or death in PC12 cells. The viability of cells treated with 1 mg/ml of MCR was significantly restored from that of oxidative-stressed PC12 cells. Measurement of intracellular reactive oxygen species (ROS) generation was determined using the H(2)DCFDA assay. MCR at 1-0.01 mg/ml concentration inhibited ROS production in oxidative-stressed cells. To identify candidate genes responsible for the anti-oxidative effects of MCR on PC12 cells, an oligonucleotide microarray analysis was performed. The result of gene expression profiles showed that 10 genes were up-regulated and 7 were down-regulated in MCR plus hydrogen peroxide treated cells compared with hydrogen peroxide treated cells. Among them, heme oxygenase (HO) and cathechol-O-methyltransferase (COMT) are related to regulation of ROS generation and the others are known to regulate cell survival and progression. Subsequently, we performed real-time RT-PCR to quantify the ROS related gene. MCR treatment increased the expression of HO by 370% and COMT by 280% at the concentration of 1 mg/ml. These findings suggest that MCR inhibits the production of ROS and cytotoxicity by oxidative-stressed PC12 cells through over-expression of HO and COMT.
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PMID:Inhibition of production of reactive oxygen species and gene expression profile by treatment of ethanol extract of Moutan Cortex Radicis in oxidative stressed PC12 cells. 1580 6