No Overgeneralization in Mesnage et al. Regarding Bisphenol A Alternatives: Response Free

To the Editor,

We thank Prof. Ana Soto and colleagues for their interest in our paper published in Toxicological Sciences showing clear estrogenic activity of a range of bisphenol A (BPA) alternative compounds (Mesnage R etal. Toxicol Sci. 158, 431–443).

However, the assertion they make in their letter that we claim “all” BPA alternative compounds are estrogenic is misplaced. They support the concern they raise by quoting the following from the abstract of our paper: “all BPA alternatives act as ERα agonists in MCF-7 cells.” This quote is taken out of context to arrive at an inaccurate conclusion regarding the interpretation and intention we wish to impart based on our results. First, the quote from our abstract these commentators use is only a part of the sentence within which it occurs. The full sentence reads as follows: “The comparison of transcriptome profile alterations resulting from BPA alternatives with an ERα gene expression biomarker further indicates that all BPA alternatives act as ERα agonists in MCF-7 cells.” Second, when looked at in the context of the abstract as well as paper as a whole, we feel it is clear that when we use the term “all BPA alternative(s)” we are referring only to those tested in our study. When all this is taken together we believe that no ambiguity exists in our phraseology that could lead the reader to conclude that we are implying that “all” BPA alternative compounds are estrogenic, which is not the case.

We also wish to point out that we posted our manuscript on the bioRχiv website (see http://www.biorxiv.org/content/early/2017/03/02/112862) for individuals to pass comment prior to our submission to Toxicological Sciences. This allowed a period of several weeks for comments to be posted; we received none highlighting the apparent ambiguity, which Soto and colleagues imply in their letter.

Thus, there is no overgeneralization regarding the estrogenic potential of BPA alternative compounds in our paper.

Finally, we would like to thank these commentators for bringing to our attention papers reviewed and published concurrently to ours, which show that some BPA alternative compounds do not show estrogenic activity in similar assays to those we employed.

We hope the combination of our results will be taken on board by industry and regulators alike to ensure safer BPA alternative substances are used.