Showing papers in "Chemico-Biological Interactions in 2000"

TL;DR: This review focuses on detoxification reactions catalyzed by NQO1 and its role in antioxidant defense via the generation of antioxidant forms of ubiquinone and vitamin E.

TL;DR: This review summarizes the rat and human UDP-glucuronosyltransferases that may be involved in the formation of bioactive glucuronides, including their substrate- and tissue-specificity and genetic and environmental influences on their activity.

TL;DR: This review summarizes the ALDHs with an emphasis on catalytic properties and xenobiotic substrates of these enzymes.

TL;DR: Xenobiotic-metabolizing sulfotransferases are cytosolic enzymes, which form a superfamily (SULT), which may be involved in the individual genetic disposition, species differences, and organotropisms for toxicological effects of chemicals.

TL;DR: Epoxides are organic three-membered oxygen compounds that arise from oxidative metabolism of endogenous, as well as xenobiotic compounds via chemical and enzymatic oxidation processes, including the cytochrome P450 monooxygenase system.

TL;DR: The interaction of a potent carcinogen, aflatoxin B(1) (AFB(1), with a probiotic strain of lactic acid bacteria, Lactobacillus rhamnosus strain GG (GG), has been investigated and the effect of urea suggested hydrophobic interactions play a major role in binding.

TL;DR: The results suggest that the structural features of tannic acid that are important for its anti-oxidant action are also those that contribute to the generation of hydroxyl radicals in the presence of Cu(II).

TL;DR: Individual susceptibility for each of these agents is determined by individual transferase subunit composition and methods are becoming available to assess this susceptibility.

TL;DR: Some of the more recent work characterizing the interactions and the factors that influence the interactions of XOR with various physiological and xenobiotic compounds are reviewed.

TL;DR: The time-dependent pattern of serum lipid peroxidation and the level of erythrocyte antioxidant enzymes were shown to be related to the concentrations of the BaP-quinone metabolites, suggesting that BaP treatment, probably via the formation of Ba P-quinones, oxidatively altered lipids and antioxidant enzymes in the blood, and might be associated with Bap-related vascular toxicity including carcinogenesis.

TL;DR: The presence of recombinant human glutathione S-transferase(GST)P1-1 significantly accelerated the initial rate of GSH-mediated consumption of curcumin in 10 mM potassium phosphate, pH 7.0, and 1 mM GSH and was shown to catalyze the reverse reaction leading to the formation ofCurcumin from GSH adducts of FMK and FAL.

TL;DR: Two quantitative structure-activity relationship (QSAR) regression equations were developed which showed that separate mechanisms of phenolic cytotoxicity are important - nonspecific toxicity due to hydrophobicity and formation of phenoxyl radicals.

TL;DR: Although ITCs have been repeatedly advocated as very promising anticancer agents, the data presented here indicate that the compounds are genotoxic, and probably carcinogenic in their own right.

TL;DR: Some aspects of the formation and properties of DNA adducts, induced by some industrially important alkenes and mono-substituted epoxides are discussed.

TL;DR: CYP2E1 is the major human enzyme responsible for CCl(4) bioactivation at lower, environmentally relevant levels and CYP3A and possibly other CYP450 forms may contribute to CCl (4) metabolism.

TL;DR: The in vivo role of NQO2 and its role in quinone detoxification remains unknown and significant differences exist in relative affinities for the various substrates.

TL;DR: The results obtained in this study suggest that flavonols whose genotoxicity in eukaryotic cells depends on their autooxidation can autooxidize when the pH value is slightly alkaline, such as in the intestine, and therefore can induce genot toxicity in humans.

TL;DR: Modulation of human CYP1A expression by green tea extracts can not be attributed to the action of a single tea catechin, but rather is due to the effects of a complex mixture.

TL;DR: A novel post-addition method, based on the trapping of ABTS-radicals, is applied, in which seminal plasma quenches radicals in a continuous, relatively slow fashion, and quantification of the total antioxidant capacity strongly depends on the chosen time point after onset of radical trapping.

TL;DR: The data show that cytochrome P450 activities can clearly be induced in co-cultures of cryopreserved hepatocytes, in a fashion which for the investigated inducers, is similar to that in cultures from freshly isolated hepatocytes and similar to the in vivo situation.

TL;DR: It is reported here a novel observation that 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD) induced predominantly cytochrome P4501A1 (CYP1A1) in rat hepatocytes and predominantly CYP1A2 in human hepatocytes.

TL;DR: It is suggested that intracellular Zn(2+) interfere with the apoptosis process, possibly through the regulation of cellular redox potential involving GSH.

TL;DR: Different potency of the induction of peroxisomal beta-oxidation was compared between perfluorinated fatty acids (PFCAs) with different carbon chain lengths in the liver of male and female rats to indicate that difference in accumulation between PFCAs in the Liver was responsible for the different potency.

TL;DR: A study of the inhibition of the purified recombinant human and rat dihydroorotate dehydrogenase by ten compounds, which confirmed the slow binding features of this potent inhibitor were verified and seen to be one of the reasons for the narrow therapeutic window reported from clinical trials on its antiproliferative and immunosuppressive action.

TL;DR: The results show that OTA is metabolized to genotoxic metabolite(s) which interact with the guanine residues of DNA, and lend support to the hypothesis of the preferential activation of OTA by the peroxidase activity of prostaglandin synthases and/or lipoxygenases to direct genot toxic metabolites.

TL;DR: The results indicate that DEM and EMS induce cell death by a similar mechanism, which is dependent on the induction of ROS production and lipid peroxidation, and mitochondria are the major source for this toxic ROS generation.

TL;DR: The inhibition by azole antifungals of human cytochrome CYP3A4, the major form of drug metabolising enzyme within the liver, was compared with their inhibitory activity against their target enzyme, Candida albicans sterol 14alpha-demethylase (CYP51), following heterologous expression in Saccharomyces cerevisiae.

TL;DR: Circular dichroism (CD) spectra, atomic absorption measurements and DNA melting profiles suggest that GHAu in vitro is able to bind DNA, the presumed target for several antitumor metal complexes, and to modify its conformation, even if the observed changes are generally small.

TL;DR: It is suggested that aspirin can prevent some of the late complications of diabetes, lowering glucose concentration and probably inhibiting glycation by acetylation of protein amino groups and oxidative stress might play an important role in streptozotocin induced diabetes.

TL;DR: The antidepressants caused increases in intracellular GSH in the C6 cells at subcytotoxic concentrations, with decreases in GSH occurring at higher concentrations, and Pretreatment with BSO enhanced toxicity with the exception of fluoxetine.