Ames test for mutagenicity

Besides applications in studying the metabolism of compounds the S9 liver fractions of human or aroclor induced rat are in use as metabolic activation of the Ames Test for mutagenicity of chemicals, in most instances without addition of Phase II cofactors (Maron and Ames 1983). S9 fractions are also used for activation in reportergene assays (Sumida et al. 2001). 

As an alternative to the much-used Ames test for mutagenicity, forward mutation to 8-azaguanine resistance is being used as a more positive, and equally sensitive, alternative to the usual reverse mutation to histidine utili-zation. ... 

Perhaps the most reassuring part of Ikekawa s report was the toxicological data. The LD50 was 1 g/kg (oral) for the mouse, 2 g/kg (oral and dermal) for the rat, and the Ames test for mutagenicity was negative. 

We worry with some justification about chemical carcinogens in the workplace - blue asbestos and chromium salts being prime examples - but there is a high degree of over-reaction to things like pesticide residues and artificial flavours and colours in our diet. As the American biochemist Bruce Ames (inventor of the so-called Ames test for mutagenicity) has pointed out ... 

Ames Test for Mutagenicity of 13-Hydroperoxylinoleate (Methyl Ester)... 

Nicotine tested negative in the Neu-rospora crania-aneuploidy and histidine reversion-Ames tests for mutagenicity. 

The histidine reversion-Ames test for mutagenicity gave inconclusive results. 

F mice in humans, inhalation of 2% concentration for 1.5 h may impair liver, showing jaundice-like symptoms damaging effects on embryo were observed in animals from a short exposure to unusually high concentrations of 8% in air ingestion of 10-12 mL may be fatal to humans tested positive in histidine reversion-Ames test for mutagenicity ... 

No carcinogenic actions in animals or humans have been reported. The histidine reversion-Ames test for mutagenicity was inconclusive. 

Methyl chloride caused adverse reproductive effects in test animals. These include embryo toxicity, fetal death, developmental abnormalities, and paternal effects in rats and mice. It tested positive to the histidine reversion-Ames test for mutagenicity. The carcinogenic properties of this compound have not been established. The evidence in animals and humans is inadequate. 

Benzyl chloride tested positive to the histidine reversion-Ames test for mutagenicity. Subcutaneous administration of this compound in laboratory animals caused tumors at the site of application. 

The toxic properties of this compound are similar to those of quinoline. It is moderately toxic in rats and rabbits by oral route and skin absorption. The oral LD50 value in rats is 360 mg/kg. The irritation effects on skin and eyes in rabbits were moderate to severe. Carcinogenicity due to isoquinoline in animals or humans is not known. The histidine reversion-Ames test for mutagenicity was inconclusive. 

There is very little information published on the acute toxicity of chrysene. The oral toxicity is expected to be low. Animal studies show sufficient evidence of carcinogenicity. It produced skin cancer in animals. Subcutaneous administration of chrysene in mice caused tumors at the site of application. Cancer-causing evidence in humans is not known. A histidine reversion-Ames test for mutagenicity showed positive. 

Severe eye irritant can cause skin burns irritant action and toxicity lower than ethylenimine moderately toxic by all routes of exposure inhalation of 500 ppm for 4 hr was lethal to rats tested positive to histidine reversion — Ames test for mutagenicity produced tumors in blood, brain, and skin in animals A2 — suspected human carcinogen TLV-TWA sMn 2 ppm ( 5 mg/m ) (ACGIH, MSHA, and OSHA), IDLH 500 ppm (NIOSH) ... 

Microsomes contain membrane-bound DMEs and cytosol has soluble ones, but another available product, liver subcellular fraction S9, the supernatant obtained from centrifugation at 9000 g, contains both. When all of the necessary co-factors are added, a more complete representation of the hepatic metabolism of a compound can be obtained. However, an even better one could come from the use of whole cells, hepatocytes, as discussed below. Consequently, S9 most often finds its use in conjunction with the Ames test for mutagenicity (Chapter 10). A metabolite rather than the parent compound can often be the genotoxic species, and incorporating S9 incubation allows both to be evaluated. " ... 

In the Ames test for mutagenicity, horse chestnut extract was weakly mutagenic with metabolic activation by S9 but... 

In the Ames test for mutagenicity, no mutagenic effects were shown for garlic tincture. Garlic juice, however, in the absence of metabolic activation, induced significant levels of chromosomal damage (Schimmer et al. 1994). 

In the Ames test for mutagenicity, ethanol extracts of arnica produced a two- to fourfold increase in the number of rever-tants, as compared to controls with S. typhimurium TA98 with and without metabolic activation and with S. typhimurium TAIOO with metabolic activation an increase was not seen with TAIOO without metabolic activation (Goggelmann and Schimmer 1986). The authors indicated that the effect was likely due to the flavonol compounds in arnica, noting that "the origin of the plant is important for the presence of essential components" and that results can differ based on the district of growth and the preparation of the extract (Goggelmann and Schimmer 1986). 

In the Ames test for mutagenicity in Salmonella typhimurium, no mutagenic activity of a standardized extract of bacopa was observed at concentrations of up to 5000 pg/plate (Deb etal.2008). 

Aqueous extracts of cow s foot demonstrated mutagenic activity in the Ames test for mutagenicity in Salmonella typhimurium strains TA98 with or without metabolic activation, and in strain TAIOO without metabolic activation. No mutagenic activity was observed when the same extract was tested in TAIOO with metabolic activation, or in TA97a and TA104 with or without metabolic activation (Rivera et al. 1994). 

In Ames tests for mutagenicity, no mutagenic activity of water, methanol, or hexane extracts of caraway was observed in Salmonella typhimurium strains TA98 and TAIOO (Higashimoto et al. 1993), while an ethanol extract showed moderate mutagenic activity in strains TA98 and TA102 (Mahmoud et al. 1992). 

In the Ames test for mutagenicity, with Salmonella typhimurium strains TA98 and TAIOO, a methanol extract of Madagascar periwinkle exhibited some mutagenic activity in strain TA98 with but not without metabolic activation. No mutagenic activity was observed in strain TAIOO or in the VitoTOX assay (Elgorashi et al. 2003). 

Antimutagenic activity of flavonoid compounds from chrysanthemum has been observed in the Ames test for mutagenicity in Salmonella typhimurium strains treated with chemical mutagens (Miyazawa and Hisama 2003). 

In the Ames test for mutagenicity and the Escherichia coli WP2 uvrA reversion test, no mutagenic activity of cinnamon essential oil was observed. The essential oil exhibited mutagenic activity in the Bacillus subtilis rec assay without S9 (Sekizawa and Shibamoto 1982). 

No genotoxic activity of a polysaccharide fraction of zedoary was observed in the Ames test for mutagenicity with or without metabolic activation with S9. No clastogenic activity of the same polysaccharide fraction was observed in micro-nucleus or chromosomal aberration assays performed using Chinese hamster lung fibroblast cells with or without metabolic activation (Kim et al. 2000). 

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