Procarcinogenic polycyclic aromatic hydrocarbons (PAHs) induce their own metabolism and activation by binding to the cytosolic aryl hydrocarbon receptor (AhR), which then translocates to the nucleus and activates CYP1A1 gene transcription via xenobiotic response elements (XREs). Although the AhR demonstrates a strict specificity for planar aromatics, nonplanar (+/-)-trans-7,8-dihydroxy-7,8-dihy...

We investigated CYP1A1*2A, CYP1A1*2C, CYP1A2*1C, CYP1A2*1F, GSTM1 and NAT2 gene polymorphisms, involving enzymes which metabolize many carcinogens, with reference to colorectal cancer risk. The distribution of these genotypes was not associated with risk overall. However, the CYP1A1*2A T/C genotype showed a significant association with colorectal cancer risk in never-smokers (odds ratio [OR], 3...

The mechanisms involving the inhibitory effects of ascorbic acid (AA) on carcinogenesis have not fully defined, except for its free-radical scavenging activity against oxidative DNA damage. In this study, we examined the effects of AA on the expression of the aryl hydrocarbon receptor (AhR)-regulated gene cytochrome P4501A1 (CYP1A1), which catalyzes the activation of genotoxic metabolites that ...

The purpose of the present experiments was to examine dose-response relationships for induction of hepatic mRNA following a single administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to rats. The induction of cytochrome P450-1A1 (CYP1A1) mRNA is compared to other "dioxin-responsive" genes including UDP-glucuronosyltransferase I, plasminogen activator inhibitor 2, and transforming growt...

Indoxyl sulfate (IS) induces fibrosis and inflammation in kidneys via oxidative stress through the induction of transforming growth factor-β1 (TGF-β1) and monocyte chemotactic protein-1 (MCP-1). Furthermore, IS is a potent endogenous agonist for aryl hydrocarbon receptor (AHR), which regulates the transcription of genes such as cytochrome P450 (CYP) 1A1. Indole-3-propionic acid (IPA) is an anti...

Polycyclic aromatic hydrocarbons (PAHs) and metals are often environmental cocontaminants, yet there have been relatively few studies of combined effects of PAHs and metals on cytochrome P450 (P450)-catalyzed metabolism. We examined the effects of NaAsO(2) in combination with benzo[a]pyrene (BAP) on CYP1A1 and CYP1B1 in T-47D human breast cancer cells by using estrogen metabolism as a probe of ...

Quaternary benzo[c]phenanthridine alkaloids (QBA) sanguinarine and chelerythrine exhibit a wide spectrum of biological activities whence they are used in dental care products. Recent studies indicated that cytochrome P450 CYP1A attenuates sanguinarine toxicity both in vivo [Williams, M.K., Dalvi, S., Dalvi, R.R., 2000. Influence of 3-methylcholanthrene pretreatment on sanguinarine toxicity in m...

Metabolik işleyiş, etkileri ve neden olduğu hastalıklar açısından daha multidisipliner bir bakış açısıyla anlaşılması gereken obezite, son yıllarda prevalansı insidansı artan hastalıklardan biri olarak görülmektedir. Bu hastalığın metabolik yolunda önemli enzim gruplarından olan sitokrom p450 (CYP1A1 CYP1B1) izozimlerinin rolünün ortaya konulması amaçlanmıştır. 2017-2019 yılları arasında Ankara...

The aryl hydrocarbon receptor (AhR) mediates a wide variety of toxic effects due to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The human hepatoma cell line SK-HEP-1 expresses AhR and ARNT. However, TCDD failed to induce CYP1A1 and XRE-dependent reporter genes in these cells. Although CYP1A1 was not induced by TCDD exposure, both CYP1B1 and AhR repressor (AhRR) were constitutively expressed. Th...

We explored the correlation between smoking, polymorphisms of extracellular superoxide dismutase (ECSOD) and cytochrome P450 (CYP) 1A1-Msp I and the prevalence of oral cancer. The genetic polymorphisms of EC SOD and CYP1A1-Msp I were detected by polymerase chain reaction (PCR) technique in peripheral blood leukocytes of 874 oral cancer patients and 874 non-cancer controls, and the correlations ...