Showing papers in "Chemico-Biological Interactions in 2002"

TL;DR: Flavonoids show an estrogenic or anti-estrogenic activity owing to the structural similarity with the estrogen skeleton, and may reduce the risk of various cancers, especially hormone-dependent breast and prostate cancers, as well preventing menopausal symptoms.

TL;DR: In this paper, a review summarizes the current understanding of AHR diversity among animal species and the evolution of the AHR signaling pathway, as inferred from molecular studies in vertebrate and invertebrate animals.

TL;DR: The current state of knowledge with respect to naturally occurring AhR ligands is described and the first theoretical model of the AhR LBD based on crystal structures of homologous PAS family members is discussed.

TL;DR: The aryl hydrocarbon receptor exists in the absence of a ligand as a tetrameric complex composed of a 95-105 kDa ligand binding subunit, a dimer of hsp90, and the immunophilin-like X-associated protein 2 (XAP2).

TL;DR: Multiple regression analysis suggests that the change in the CL(R) of PFOA is, at least in part, due to altered expression of OAT2 and OAT3, which was significantly reduced by probenecid.

TL;DR: Aryl hydrocarbon receptor (AHR) degradation has been shown to be ubiquitin mediated and occurs via the 26S proteasome pathway following nuclear export of AHR as mentioned in this paper.

TL;DR: Data suggest that caspase inhibition plays an important role in the cell death pathway decision, particularly with treatments dependent on the caspases cascade to induce apoptosis.

TL;DR: The aspects of AHR biology relevant to its role in cell cycle regulation, from the activation of mitogen-activated protein kinases to the cross-talk between AHR and the RAS pathway and the functional significance of the interaction between A HR and the retinoblastoma protein are examined.

TL;DR: The diverse mechanisms by which AHR generates an oxidative stress response, including inflammation, antioxidant and prooxidant enzymes and cytochrome P450 are evaluated.

TL;DR: Hypochlorous acid proved to exert a rapid inhibitory effect on DNA synthesis, consistent with its primary role in bacterial killing by phagocytes, and Cytotoxicity produced by increasing NaOCl concentrations and assessed by measuring both mitochondrial function and cell DNA synthesis was reduced.

TL;DR: Common properties of drugs that cause idiosyncratic liver toxicity are reviewed and it is proposed that these common properties may be useful experimental endpoints for the prediction and therefore avoidance of the selection of drug candidates with idiosyncratic drug toxicity for further development.

TL;DR: The search continues for polymorphisms that alter AHR function because this receptor is a central factor in determining responses to important environmental contaminants and also plays a physiologic role in early development in mammals.

TL;DR: This review discusses Ah receptor–NF-κB interactions and examines potential mechanistic explanations for toxic responses as a result of TCDD exposure and the suppression of cytochrome P450 1A1/1A2 by stress stimuli such as inflammation and infection.

TL;DR: Studies of both the basic helix-loop-helix transcription factors and the nuclear hormone receptor family can provide significant insights into how this unique signaling pathway activates its target genes.

TL;DR: The results suggest that defective expression of CYP2E1 in some pigs is due to excessive concentrations of androstenone which prevent CYP 2E1 induction by its substrate skatole, and skatoles metabolism is reduced andSkatole is accumulated in adipose tissue.

TL;DR: Evidence is presented showing that idiosyncratic NSAID drugs form prooxidant radicals when metabolised by peroxidases known to be present in these tissues, and it is hypothesized that the NSAID radicals and/or the resulting oxidative stress initiates the cytotoxic processes leading to idiosyncratic toxicity.

TL;DR: The mechanism of covalent binding remains to be established, but significantly less abacvir-protein residue was detected with an analog of abacavir in which the double bond was removed, suggestive of a double bond migration and 1,4 addition process.

TL;DR: In vitro metabolic activities of human liver microsomes (HLM) and human cytochrome P450 (CYP) isoforms toward carbaryl were investigated and the production of carbaryl methylol was primarily the result of metabolism by CYP2B6.

TL;DR: Results indicate that some hydroxylated intermediates such as DHB rather than the parent compound act as a xenoestrogen via biotransformation.

TL;DR: A common practice is to assume that percutaneous absorption does not significantly contribute to total bioavailability and therefore, absorption through other routes is more important to human risk assessment, but the assessment of the potential contribution of total body burden from dermal exposures should be considered.

TL;DR: The results show that the antimicrobial effects of individual fatty acids released from hydrolysed milkfat were at least additive and suggest that hydrolysis of milkfat may be a significant factor in controlling growth of organisms imbibed with food in pre-weaned animals.

TL;DR: The data suggest that under normal physiological conditions glutathione plays a protective role in preventing IDR during felbamate therapy, further emphasizing a correlation between reactive metabolite formation and a toxic outcome.

TL;DR: The results indicate that 8-nitroguanosine in cellular RNA could be measured as a marker of damage caused by endogenous reactive nitrogen species in tissues and cells.

TL;DR: It is demonstrated that sanguinarine and chelerythrine are metabolized by hepatic microsomes to species, which generate DNA adducts, which are detectable by 32P-postlabeling.

TL;DR: Findings point to lipophilicity as a major characteristic determining polyphenol cytotoxicity, which could be explained if polyphenols involved the formation of radicals, which interacted with the mitochondrial inner membrane resulting in a disruption of the membrane potential.

TL;DR: Competitive interactions of ochratoxin A (OTA) and several other acidic compounds were utilized to gain insight into the localization of binding sites and the nature of binding interactions between anionic species and human serum albumin (HSA).

TL;DR: Significant differences in the shapes of the dose-response curves were generally nonlinear at doses above 200 mg naphthalene per kg body weight, and the nature of nonlinearity differed, showing evidence of supralinearity for NPO-Hb, NPQ-hb and NPQ -Alb and of sublinearity forNPO-Alb.

TL;DR: The results obtained suggest that reactive oxygen species, including free radicals, may be involved in the formation of DNA lesions induced by idarubicin and vitamin C can be considered as protective agents against DNA damage in normal cells in persons receiving idarubsicin-based chemotherapy, but the use of vitamin E cannot be recommended and at least needs further research.

TL;DR: The sensitive human donors were found to form significantly less troglitazone GSH conjugates and glucuronides than the resistant donors, suggesting that several P450s may play a role in the TGZ metabolic pathway.

TL;DR: The CL generation was suggested to be closely related with salicylic acid-induced lipid peroxidation, and to be coupled with the oxidative metabolism mediated by P450 in rat liver microsomes.