In a study published online February 21, 2013, French and American scientists report a dose-dependent change in male mice’s global metabolism in response to the chemical bisphenol A (BPA). The research was published in the peer-reviewed journal Environmental Health Perspectives (Cabaton et al. 2013). Cabaton and his colleagues carried out a comprehensive analysis of the total biochemical response to BPA, also called metabolomics. Usually in metabolomics, hundreds of different biochemical substances are assessed, generating large amounts of data and requiring specialized statistical tools for analysis. These tools allow characterization of the metabolome, meaning the global biochemical response to nutrients, chemicals and other factors. The metabolome of exposed animals is then compared to the metabolome of the untreated control animals.
In the present study, metabolomics was used to investigate how different concentrations of BPA affected cellular response to the chemical in different tissues and the overall organism. Dosing with BPA was performed by injection into pregnant mice during critical windows of fetal development, or directly in postnatal mice. Significant changes were observed following exposure to low doses of BPA, between 2’000 and 2 million times below the no observed effect level of previous oral dosing studies.
One aim of the study was to identify early biomarkers for BPA low dose exposures that are stable over time. In all treatment groups many different changes were observed. Among these observations most notable effect was increased glucose levels in all BPA treatment groups compared to the unexposed control. Changes in the global metabolic response following chemical exposures offer important insights into the toxic potential of a compound. As such, these changes are observed early, before effects on the level of organs or even the whole organism can be detected. Therefore such methods are interesting to reduce testing duration and associated costs. Findings from this study are consistent with earlier results from other groups where effects of low dose BPA exposure on energy metabolism and brain development were observed. Further studies are necessary to identify biomarkers that can also be used to analyze human samples.
Cabaton, N. J., et al. (2013). “Effects of Low Doses of Bisphenol A on the Metabolome of Perinatally Exposed CD-1 Mice.” Environmental Health Perspectives (published online February 21,2013).