Trichloroethylene (TCE) has previously been shown to be carcinogenic in mouse liver when administered by daily gavage in corn oil. The metabolism of TCE results, in part, in the formation of trichloroacetic acid (TCA) as a major metabolite and dichloroacetic acid (DCA) as a minor metabolite. These chlorinated acetic acids ...

The metabolism of the mercapturic acids S-pentachlorobutadienyl-N-acetylcysteine (N-Ac-PCBC), S-trichlorovinyl-N-acetylcysteine (N-Ac-TCVC) and S-dichlorovinyl-N-acetylcysteine (N-Ac-DCVC) by subcellular fractions from male rat liver and kidney homogenates was studied. As a model compound, N-Ac-PCBC, 14C labelled, was synthesised. It was intensively metabolised by cytosolic but not by microsomal enzymes from rat liver and kidney. ...

The mutagenicities of 12 conjugated non-fused nitroaromatic compounds and 1 amino analogue were determined in strains TA100 and TA98 of Salmonella typhimurium. Reversions by p-nitroaromatics increased in the order of the acetophenone, benzaldehyde, styrene, chalcone, cinnamic acid and stilbene indicating the importance for mutagenic potency of extended conjugation to the ...

Chlorine dioxide (ClO2) is currently being considered as an alternate to chlorine as a disinfectant for water treatment. Many organic compounds present in water and food treated with ClO2 are subject to oxidation. 21 amino acids and 3 peptides (L-aspartyl-L-phenylalanine methyl ester (aspartame), L-glycyl-L-tryptophan and L-tryptophylglycine) were studied for their ...

The nature of the adducts formed between benzo[a]pyrene (BP) and globin were investigated in animals treated with [3H]BP. Modification levels on globin were determined by radioactivity measurements. Since BP tetraols can be released from benzo[a]pyrene diol epoxide modified protein and DNA by acid treatment, globin samples were treated with acid, ...

Aqueous extracts of smokeless tobacco products (snuff, chewing tobacco, smokeless tobacco) sold in the USA are mutagenic in the base-pair substitution mutant, Salmonella typhimurium TA100, with potencies of 8000-16,000 revertants/g tobacco. Most of the activity failed to extract into organic solvents at neutral pH and a portion of the activity ...

Polar solvent extracts of tobacco snuff under acidic conditions were mutagenic in Salmonella typhimurium. Using the Griess reagent test, nitrite ranging from approximately 1.8 to 5.4 mg/g of snuff was found in the polar fraction of extracts. After acid treatment, nitroso compounds in the amount corresponding to the nitrite concentration ...

Humic acid inhibited the mutagenicity of various mutagens. The inhibitory effect was desmutagenic, heat-resistant and increased with an increase of the humic acid molecular weight. Typical monomeric components of humic acids had no desmutagenic effect. The desmutagenic effect of humic acid was caused by adsorption of mutagen, not by decomposition ...

Azide is metabolized to the proximate mutagen, L-azidoalanine in bacterial systems. While this novel mutagenic metabolite plays a key role in azide mutagenesis, the biochemistry of this role is unknown. The chemical synthesis of authentic racemic azidoalanine and several derivatives thereof allowed the exploration of structure-activity relationships with this unique ...

3 bile acids (cholic acid, chenodeoxycholic acid and deoxycholic acid) were assayed for mutagenicity in Salmonella typhimurium TA98 and TA100 in fluctuation tests in the absence of an external source of metabolic activation. At the doses tested, there were no dose-related statistically significant increases in mutagenicity compared with appropriate controls. ...

The detoxification of penicillic acid by reaction with ammonia was examined by means of a polymerase assay using two strains of Escherichia coli (pol A+ and pol A-1) and a recombination assay using two strains of Bacillus subtilis (rec+ and rec-). A 100-fold surplus of ammonia added to penicillic acid ...

Nitrosation of dietary components has been combined with the 4-(para-nitrobenzyl)pyridine (NBP) colorimetric test for screening alkylating agents and with the Ames test for the detection of mutagenic activity. This allowed the investigation of short-lived nitrosation products of dietary components which generate electrophilic degradation products requiring no metabolic activation (natural amino ...

An organic extract of airborne particles collected in Tokyo and its fractions (neutral, acidic, and basic) were investigated in Ames Salmonella assays for mutagenicity and in newborn mice for carcinogenicity. Mutagenicity to TA100 and TA98 strains was detected in the whole extract, the neutral, the acidic and the basic fractions ...

The frequency of his+ revertants induced by N-methyl-N-nitrosourea (MNU) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the strain TA100 of Salmonella typhimurium was decreased by gallic and tannic acid. In weak buffer solutions, the inhibition effects of gallic acid towards MNU and MNNG mutagenicity was caused primarily by a decrease of pH in ...

The effect of lettuce cultivars on the nitrosation rate of proline was investigated. The lettuce was analysed for the presence of phenolic compounds. Lettuce and/or fish was incubated with nitrite under acidic conditions, and the incubation mixtures were investigated for the presence of N-nitroso compounds and mutagenic activity. Both volatile ...

Toxic properties of the mycotoxins cyclopiazonic acid and aflatoxin B1 have been analyzed separately and in combination by monitoring their effects on luminescence in the marine bacterium Photobacterium phosphoreum, Strain NCMB 844. Genotoxicity was analyzed with a dark mutant of this organism whose reversion to the bioluminescent condition is stimulated ...

This study has confirmed that the direct mutagenicity previously observed when S. typhimurium TA100 was treated with (Z)-1,3-dichloropropene (DCP) was in fact due to trace impurities. These impurities result from autoxidation of (Z)-1,3-DCP and have now been identified. Both (Z)- and (E)-2-chloro-3-(chloromethyl)oxiranes (DCP oxides) were identified as significant products during ...

Benzidine and several derivatives are activated to mutagenic species in an H2O2-dependent Ames test system. Optical and electron paramagnetic resonance (EPR) spectroscopy are employed in studies of the H2O2-dependent oxidation of benzidine and 3,5,3',5'-tetramethylbenzidine (TMB) catalyzed by intact bacteria, and provide direct evidence for peroxidase activity in Salmonella typhimurium. The ...

The ability of 3 plant flavonoids (morin, myricetin and quercetin) and 4 polyphenolic acids (caffeic acid, chlorogenic acid, ellagic acid and ferulic acid) to inhibit the genotoxic effects of a number of cooked-food mutagens (IQ, MeIQ, MeIQx, Trp-P-1 and Trp-P-2), was investigated in a bacterial mutation assay using Salmonella typhimurium ...

The mutagenicity of 2-hydroxylamino-4-nitrotoluene (2HA4NT), 4-hydroxylamino-2-nitrotoluene (4HA2NT), 2-hydroxylamino-6-nitrotoluene (2HA6NT) or 4-acetylamino-2-hydroxylaminotoluene (4AA2HAT) towards Salmonella typhimurium strains TA98 and TA100 was investigated in the absence and presence of uridine-5'-diphosphoglucuronic acid (UDPGA), acetyl CoA or 3'-phosphoadenosine-5'-phosphosulfate (PAPS) systems, or S9 mix. None of the hydroxylaminonitrotoluenes (2HA4NT, 4HA2NT or 2HA6NT) were mutagenic in ...

Chlorination of humic and fulvic acid results in the formation of direct-acting mutagenicity, detectable in the Salmonella/microsome assay (Ames test). This mutagenicity is being characterized as part of an overall effort aimed at evaluating potential health risks associated with the presence of mutagenic chemicals in drinking water. A number of ...

The effect of ellagic acid and some of its more lipophilic derivatives on the mutagenicity of (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenz[a]pyrene was examined in Salmonella typhimurium TA100. Ellagic acid, 3,3'-di-O-methylellagic acid, 4,4'-di-O-methylellagic acid and 3-O-decylellagic acid were found to have approximately equal antimutagenic activity. The tissue distribution and elimination of ...

The effect of ellagic acid and its more lipophilic derivative, 3-O-decylellagic acid, on the amount of DNA-bound adducts in the epidermis or lung of CD-1 mice treated with [3H]benzo-[a]pyrene ([3H]B[a]P) was evaluated using several different treatment protocols. The i.v. administration of 50 mumol/kg of ellagic acid or 3-O-decylellagic acid either ...

In the present study, humic acid was not found to be mutagenic and did not inhibit spontaneous mutation. It did, however, inhibit the mutagenicities of benzo[a]pyrene and 3-aminoanthracene (+S9 mix), but not the mutagenicities of 4NQO, AF-2 and MNNG (-S9 mix). 2-Nitrofluorene and 1-nitropyrene do not need S9 mix for ...

1,2-Dibromopropane was administered orally in doses of 50-350 mg/kg to male Wistar rats. Four mercapturic acids were identified in urine by GC/MS, viz. N-acetyl-S-(2-oxopropyl)-L-cysteine (I), N-acetyl-S-(2-hydroxypropyl)-L-cysteine (II), N-acetyl-S-(1-carboxyethyl)-L-cysteine (III), and N-acetyl-S-(2-bromo-2-propenyl)-L-cysteine (IV). Mercapturic acid IV was a minor metabolite which could only be measured at doses of 200 mg/kg or ...

Methapyrilene, four structurally related antihistamines, three metabolites of methapyrilene and two products of the reaction of methapyrilene with nitrite were all tested for mutagenicity to Salmonella typhimurium. The two products of the methapyrilene-nitrite reaction have also been identified as metabolites of methapyrilene. None was mutagenic alone, either with or without ...

Methylisocyanate (MIC) induced mutagenic responses in the absence of exogenous activation in the mouse lymphoma cell forward mutation assay at concentrations as low as 8-24 microM. MIC produced predominantly small mutant colonies, suggesting the possibility of clastogenic activity. The intermediate hydrolysis product, methylamine, was also mutagenic without exogenous activation but ...

Preliminary screening of polycyclic mutagens is achieved within 20 min by using a biomimetic electrode composed of an oxygen electrode and a copper-phthalocyanine membrane. When benzo[alpha]pyrene (0.05 mM) was added to the buffer solution in the presence of 0.98 M hydrogen peroxide, the current of the phthalocyanine electrode decreased. A ...

We have demonstrated that the pyrolysis products of amino acids and proteins in model systems are mutagenic. The mutagenic principles in the pyrolyzates of amino acids have been isolated and identified by Sugimura et al. We have isolated and identified amino-alpha-carbolines from pyrolyzed soybean globulin as mutagens. The yield of ...

A mutation assay system with Chinese hamster lung cells (CHL) using diphtheria toxin resistance as a selective marker has been established. The mutagenic activities of heterocyclic amines, originally isolated from pyrolyzates of amino acids and proteins, broiled fish and fried beef were assayed in cultured CHL cells in the absence ...

The mutagenic activity of N-arylacetohydroxamic acids, their O-acetates, their O-glucosides, and N-arylhydroxylamines, derived from chlorinated 4-nitrobiphenyl ethers (CNBs), was tested in the Salmonella reversion assay. N-Arylhydroxylamines were mutagenic by themselves; however, other compounds containing an N-acetyl group showed mutagenic activity in the presence of guinea pig liver S9. The mutagenic ...

The effect of sorbic acid alone and in combination with sodium nitrite has been studied on bone marrow chromosomes of mice following 30 days oral treatment. Bone marrow of mice exposed to sorbic acid (15 mg/kg) and sorbic acid nitrite (7.5-1 mg/kg) showed an increase in mitotic index indicating that ...

The two secondary biliary acids (lithocholic and deoxycholic acids) were co-mutagenic when they were each co-incubated with dimethylhydrazine in the presence of Salmonella typhimurium TA 100. These observations were extended to other toxic chemicals, acting as direct (N-methyl-N'nitro-N-nitrosoguanidine and 2-nitrofluorene) or indirect (2-acetylaminofluorene) mutagens. Lithocholic and deoxycholic acids show a ...

Chronic p.o. feeding of small amounts of ellagic acid, a naturally occurring dietary plant phenol, to BALB/c mice in drinking water afforded significant protection against skin tumorigenesis induced by 3-methylcholanthrene, a polycyclic aromatic hydrocarbon carcinogen. A significant increase in the latent period for the development of skin tumors by 3-methylcholanthrene ...

As a result of frequent phencyclidine (PCP) abuse, pyrolysis studies were conducted to further investigate its fate during smoking. Marijuana placebo cigarettes were impregnated with 3H-PCP X HCI and burned under conditions simulating smoking. Mainstream smoke was passed through glass wool filters as well as acidic and basic traps. Approximately ...

14C-hexachlorobutadiene (HCBD), a mutagenic and nephrocarcinogenic pollutant, was administered by oral gavage of 100 mg/kg to female rats, and the radioactivity in 24 hr urine pooled. The average amount of radioactivity recovered in urine was 5.4% of the total 14C-activity ingested. Solvent extraction, high performance liquid chromatography (HPLC), radio gas ...

Plant components with bio-antimutagenic activity were screened on UVC (254 nm)-induced mutagenesis using E. coli B/r WP2. The components with a pyrogallol moiety including gallic acid, (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) reduced the mutation induction, but other components such as caffeic acid, chlorogenic acid and quercetin ...

Formation of triazene derivatives from sodium nitrite and sulphanilamide, sulphamethizole or sulphamethoxazole in acidic solution containing saliva or canned vegetable juice was studied using reverse-phase high-performance liquid chromatography with ultraviolet light detection at 365 nm. At the optimal pH of 3.2-3.7, the mean yield of the triazene formed by reaction ...

Rats treated orally with direct brown 95, a benzidine-based dye, widely used in dyeing of textiles, plastics, paper and other materials, showed 2 peaks of excretion of mutagenic products in urine, one between 6 h and 18 h after administration and one about 30 h later. Prevention of coprophagy by ...

135 patients wearing hydrogel lenses were prescribed a care system of sorbic acid preserved surfactant, Lensept and Bausch and Lomb Sensitive Eyes Saline (sorbic acid 0.10%). Fifteen percent of patients presented with an adverse ocular response to their care system. The etiology was attributed to sorbic acid as the use ...

The main metabolic pathway of the genotoxic environmental contaminant hexachloro-1,3-butadiene (HCBD) is the direct conjugation reaction with glutathione. To establish structure-effect relationships we studied the mutagenic activity of four S-containing HCBD conjugates with and without metabolic activating enzymes (S9 mix) in Salmonella typhimurium. The N-acetyl-S-pentachlorobutadienyl-L-cysteine (mercapturic acid) was clearly mutagenic ...

Ellagic acid, a plant phenol present in various foods consumed by humans, has been reported to have both anti-mutagenic and anti-carcinogenic potential. To evaluate the potential anti-carcinogenic property of ellagic acid, we tested its effects on the toxicity of benzo[a]pyrene and benzo[a]pyrene, 7,8-dihydrodiol and binding of benzo[a]pyrene to DNA in ...

Cigarette smoke condensate is known to enhance the frequency of sister-chromatid exchanges (SCE) in human lymphocytes in vitro and some of the activity has been found in the most volatile part of the particulate phase, the semivolatile fraction. In this study we have investigated the chemical composition and the SCE-inducing ...

Migration of melamine and formaldehyde into food-simulating solvents from cups made of melamine resin was studied under various conditions. Little migration of melamine was observed in any unused cups kept at 60 degrees C for 30 min, room temperature (26 degrees C) for 1 h or cooled at -20 degrees ...

Mutagenicity inhibition of MNNG*, NFAA* as well as of nitrovin by ascorbic acid was observed. The influence of ascorbic acid on these compounds was parallelly studied also by spectroscopy. Mutagenicity inhibition was characterized by SOS chromotest. Inhibition degree was evaluated quantitatively introducing the coefficient of inhibition. The influence of ascorbic ...

The effects of 3 different retinoids (all-trans-retinol, all-trans-retinoic acid, and all-trans-retinyl acetate) on the mutagenic activity of cigarette-smoke condensate were investigated in Salmonella typhimurium TA98. Neither an enhancing nor an inhibitory effect of the retinoids on the mutagnicity of cigarette-smoke condensate was observed.

The rat liver 9000 g supernatant mediated metabolism of the carcinogenic aristolochic acid, which consists of aristolochic acid I (AAI) and aristolochic acid II (AAII), was investigated. Under anaerobic conditions the major metabolites were the corresponding aristolactams for both AAI and AAII. In contrast under aerobic conditions AAII was not ...

Five unusual amino acids were identified as antimutagens against spontaneous mutation of Salmonella typhimurium TA100: L-azetidine-2-carboxylic acid (1) from Liliaceae plants, alpha-(methylenecyclopropyl)glycine (2) from Litchi chinensis seeds, and 2-amino-4-methylhex-5-ynoic acid (3), hypoglycin A (4), and (2S,4R)-2-amino-4-hydroxyhept-6-ynoic acid (5) from Euphoria longana seeds. The absolute stereochemistry of 5 was determined by ...

The mutagenic heterocyclic amines Glu-P-2, MeA alpha C and Phe-P-1, which possess a 2-aminopyridine structure in their molecule (non-IQ-type mutagens), were found to be inactivated by nitrite treatment under acidic conditions, as observed previously with Trp-P-1, Trp-P-2, Glu-P-1 and A alpha C. In contrast, MeIQx, 4,8- and 7,8-DiMeIQx, which were ...

The possibility that ascorbic acid, as a nucleophile, may inhibit mutagenicity induced by electrophilic metabolites of N-nitroso compounds was examined. In vitro data are presented to show that ascorbic acid does not decrease the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in a modified Ames bacterial mutagenicity system if deionized water is used ...