Detection of Genotoxicity of Phenolic Antioxidants, Butylated hydroxyanisole and tert-Butylhydroquinone in Multiple Mouse Organs by the Alkaline Comet Assay

In this study we tested the genotoxicity of two widely used phenolic antioxidants, butylated hydroxyanisole (BHA) and tert-butylhydroquinone (TBHQ) in multiple mouse organs using the alkaline comet assay. Tissue samples from four organs (stomach, liver, kidney and bone marrow) were collected from male mice at 3 and 24 h post treatment with BHA (800 mg/kg) or TBHQ (400 mg/kg) and examined for genotoxicity. The two compounds induced significant increase in DNA migration in a time dependant manner in specific organs. Extensive DNA damage was observed in stomach cells at 24 h post treatment in treatment groups. In addition to stomach, TBHQ treatment induced significant increase in DNA migration in liver and kidney cells. Although increased DNA damage was found in kidney cells of treatment groups at 3 h time point, at later time point it was persistent only in mice treated with TBHQ and in other treatment group (BHA) it appeared to be recovered with time. Evidently, bone marrow cells did not show genotoxicity in response to treatment with TBHQ and BHA. Considering these findings, although TBHQ and BHA are generally considered non-genotoxic, the DNA damage observed in this experiment may be related to their indirect action on DNA via ROS mechanism. Since toxicity of these compounds are often ascribed to their metabolic products such as quinone thioethers and hence differences in the metabolism of these compounds may play an important role in determining the target organ of toxicity. The present work draws our attention to revising the genotoxicity of the widely used antioxidants and accepted as safe artificial antioxidants. [Ramadan, A.M. Ali and Takayoshi Suzuki. Detection of Genotoxicity of Phenolic Antioxidants, Butylated hydroxyanisole and tert-butylhydroquinone in Multiple Mouse Organs by the Alkaline Comet Assay. Journal of American Science 2012;8(1):722-727 ] (ISSN: 1545-1003). http://www.americanscience.org. 98 Key wards: BHA; TBHQ; comet assay; mice; bone marrow; liver; kidney; stomach; ENU.