Genotoxicity testing comet assay

DAB was genotoxic in the comet assay inducing DNA damage in the stomach, colon liver, bladder, lung, and bone marrow. It is also mutagenic to Salmonella in the Ames test. Because of its demonstrated carcinogenicity in animals, human exposure to DAB by any route should be avoided. In recent years, this compound has been used only in laboratories as a model of tumorigenic activity in animals. It is not produced commercially in the United States and is of little occupational health importance. 

Kammann, U., M. Bunke, H. Steinhart and N. Theobald. A permanent fish cell line (EPC) for genotoxicity testing of marine sediments with the comet assay. Mutat. Res. — Genet. Toxicol. Environ. Mutagen. 498 67-77, 2001. 

Speit, G., and Hartmann, A. (2005). The comet assay A sensitive genotoxicity test for the detection of DNA damage. Methods Mol Biol 291, 85-95. 

In mice administered an aqueous extract of chap u de couro in drinking water for 6 weeks with intake of 3,23, or 297 mg/kg of a lyophilized extract, or 2200 mg/kg of a crude extract daily, no genotoxic effects on liver or blood cells were observed in the comet assay. DNA analyses of the kidney cells detected some genotoxic activity for the highest dose tested but not at lower doses (da Costa Lopes etal.2000). 

No genotoxicity of an aqueous extract of Indian tinospora was observed in any of four different genotoxicity tests. Tests included the Ames test with Salmonella typhimurium strains TA97a, TA98, TAIOO, TA102, and TA1535 at concentrations of extract up to 5000 pg/plate, the chromosome aberration assay, the rodent bone marrow micronucleus assay, and the comet assay. For the bone marrow micronucleus and comet assays, mice were orally administered the extract for 7 days at doses of 150, 200, and 250 mg/kg (Chandrasekaran et al. 2009). 

A second genotoxicity test, the comet assay, detects a broad spectrum of DNA damage. A comet assay protocol developed and evaluated using the EpiDerm model demonstrated good interlaboratory reproducibility and concordance with in vivo data (Reus et al., 2013). Additional in vitro RhE comet assay development and evaluation of intra- and interlaboratory reproducibihty with EpiDerm, Realskin, and the Phenion model are currently ongoing. 

Boeira, J. M. Da Silva, J. Erdtmann, B. Henriques, J. A. P. Genotoxic effects of the alkaloids harman and harmine assessed by comet assay and chromosome aberration test in mammalian cells in vitro. Pharm. Toxicol. 2001, 89, 287-294. 

At present, several antigenotoxicity/genotoxicity assays which include the chromosome aberration (CA), micronucleus (MN), somatic mutation and recombination test (SMART), sister chromatid exchange (SCE) and the single-cell gel electrophoresis (SCGE) or COMET assays are available, and they are recommended to be used as a set for investigations. 

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