Exposure to bisphenol A alternatives bisphenol AF and fluorene-9-bisphenol induces gonadal injuries in male zebrafish

Bisphenol A (BPA), present in many household products, can damage the male reproductive system. Accordingly, we summarized urine samples from 6921 human in National Health and Nutrition Examination Survey and found urinary BPA levels were inversely linked with blood testosterone in the children group. Currently, BPA replacements, such as fluorene-9-bisphenol (BHPF) and Bisphenol AF (BPAF), have been introduced to produce "BPA-free" products. Here we demonstrated that BPAF and BHPF could induce delayed gonadal migration and reduce the number of progenitors of germ cell lineage in zebrafish larvae. A close receptor analysis study reveals that BHPF and BPAF can strongly bind to androgen receptors, leading to the downregulation of meiosis-related genes and the overexpression of inflammatory markers. Furthermore, BPAF and BPHF can induce activation of the gonadal axis via negative feedback, leading to the hypersecretion of some upstream hormones and an increase in the expression of upstream hormone receptors. Our findings call for further research on the toxicological effects of BHPF and BPAF on human health and recommend that BPA replacements be investigated for anti-estrogenic action.