There is a growing need for short-term assays which can assess the mechanisms and efficacy of cancer chemopreventive agents. In the present study we have employed a microsome-mediated test system concomitantly with DNA adduct detection to assess the efficacy of five chemopreventive agents, N-acetylcysteine, butylated hydroxytoluene (BHT), curcumin, oltipraz, and ellagic acid. 32P-Postlabeling a...

Suspensions of Salmonella typhimurium TA100 or TA1535 cells were exposed to pure enantiomeric forms or racemic mixtures of 3H-labeled benzo(a)pyrene anti- or syn-7,8-dihydrodiol-9,10-epoxide. Diol-epoxide-induced cytotoxicity and mutation frequencies at the hisG and gpt loci were determined. Hydrolysates of diol-epoxide-modified bacterial DNA were also examined by high-performance liquid chroma...

Aflatoxins are mycotoxins produced by Aspergillus spp. Although AFB1 is implicated as a carcinogen in hepatocellular carcinoma, brain autopsies in affected areas have revealed its presence in 81% of cases. Given its haematogenous spread, here we determined the cytotoxic effects of AFB1 on primary human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier, huma...

BACKGROUND Metabolism of benzene produces reactive electrophiles, including benzene oxide (BO), 1,4-benzoquinone (1,4-BQ), and 1,2-benzoquinone (1,2-BQ), that are capable of reacting with blood proteins to produce adducts. OBJECTIVES The main purpose of this study was to characterize relationships between levels of albumin adducts of these electrophiles in blood and the corresponding benzene ...

17α-estradiol (αE2), an endogenous stereoisomer of the hormone 17β-estradiol (E2), is capable binding to estrogen receptors (ER). We aimed mathematically describe, using experimental data, possible interactions between αE2 and sperm ER during process capacitation develop a kinetic model. The goal was compare suggested model with previously published results E2 17α-ethynylestradiol (EE2). HPLC-M...

Highly reactive glycosyl chlorides and bromides have been analysed by a routine mass spectrometric method using electrospray ionization and lithium salt adduct-forming agents in anhydrous acetonitrile solution, providing salient lithiated molecular ions [M+Li]⁺, [2M+Li]⁺ etc. The role of other adduct-forming salts has also been evaluated. The lithium salt method is useful for accurate mass dete...

The crystal structure of the nitrosomethane adduct of human Hb shows N-binding of the MeNO ligands to heme Fe. The structure of the EtNO adduct reveals a surprising 4.9 Å heme slippage in the β subunit, and explains the ability of C-nitroso compounds to degrade Hb removing it from circulation.

biotransformation of benzo[a]pyrene (bap) in the presence of microsomal fractions derived from liver and epiderm of adult and weanling rats was examined. the aim of this study was to evaluate the effect of age on the capacity of two organs in transformation of bap. subcellular fractions were prepared from skin and liver by ultracentrifugation and were used as the source of bap metabolizing enzy...

3-Nitrobenzanthrone (3-NBA), a suspected human carcinogen occurring in diesel exhaust and air pollution, and its human metabolite 3-aminobenzanthrone (3-ABA) were investigated for their ability to induce biotransformation enzymes in rat liver and the influence of such induction on DNA adduct formation by the compounds. Rats were treated (i.p.) with 0.4, 4, or 40 mg/kg body weight 3-NBA or 3-ABA...

Smokers with a low body mass index (BMI; weight/height) have a higher risk for developing lung malignancies as compared with smokers of average weight, but there is no mechanistic explanation for this observation. Carcinogens in cigarette smoke are thought to elicit cancer by the formation of DNA adducts, which give the opportunity to additionally investigate the biological link between BMI and...