February 25, 2013

expert reaction to BPA and isolated neurons

Exposure to bisphenol A (BPA), a chemical used widely in plastics, may suppress a gene involved in the development of the central nervous system, according to a study of cortical neurons in mice, rats and humans, published in the journal Proceedings of the National Academy of Sciences.

Prof Richard Sharpe, Research Group Leader/Professor, MRC Centre For Reproductive Health, Edinburgh University said:

“This is an interesting and well-conducted study that has explored the potential effects of bisphenol-A on human and rodent neuronal development in vitro.  Clear effects of exposing the neuronal cells to 100nM bisphenol A are shown.  Interesting though the effects are from a mechanistic point of view, they have no relevance to human health because the concentration of bisphenol A used, exceeds human exposure by ~100,000 times (and this is probably a conservative estimate).  As the motivation for the studies was publications suggesting an association between bisphenol A exposure and later behavioural problems in children, this would not provide any linking/supporting evidence because of lack of credibility with the doses used.

“This study is reminiscent of many similar studies with bisphenol A in vitro or in animal studies – many show convincing effects on various biological processes relevant to human health, but they always involve doses that are in a different ballpark to human exposure.  When realistic doses are applied (i.e. those to which humans are internally exposed), no effects are found – although I hasten to add that most such studies never explore human-relevant doses.”

‘Bisphenol A delays the perinatal chloride shift in cortical neurons by epigenetic effects on the Kcc2 promoter’ by Yeo, M. et al., published in PNAS on 25 February 2013.