In vivo estrogenicity of p-phenoxyphenol and p-pentyloxyphenol

p -Alkoxyphenols (AOPs) are a class of ethers that are widely used in industrial and agricultural productions and daily necessities. p -Phenoxyphenol (PhOP) and p -pentyloxyphenol (PeOP) belong to this class and have been reported to be estrogenic in vitro. However, their in vivo estrogenic activities have rarely been of concern. In this study, we performed an immature mouse uterotrophic assay and studied the estrogenic effects of these two compounds in mice. The results revealed that the uterine weights of the animals treated with PhOP significantly increased at doses of 30 and 300 mg kg -1 bw day -1 for 3 days ( P  < 0.05), while no significant uterotrophic effects were observed in the mice treated with PeOP. Using next-generation transcriptome sequencing (RNA-seq), we also analyzed the gene expression in the uterine tissue of mice treated with PhOP and PeOP. The observed gene regulation patterns of the PhOP- and PeOP-treated specimens were similar to those of the 17 β -estradiol (E 2 )-treated specimens. In particular, some estrogen-responsive genes, such as the Sprr2 gene family, Apoa1 , Prap1 , and Ahsg , displayed a regulation trend similar to that of E 2 . In addition, molecule docking analysis revealed that both PhOP and PeOP could be well docked into the active site of hERα, with potential of mean force (PMF) values of − 58.68 and − 52.67 kcal mol -1 for PhOP and PeOP, respectively. The results of this study indicate that PhOP exhibits relatively strong in vivo estrogenic activity, which could be of future concern.