Effects of bisphenol A and bisphenol S on human fallopian tube contractions: An in vitro and in silico study

Bisphenol A (BPA), a widely used industrial compound, and its structural analogue Bisphenol S (BPS) are known to exert reproductive toxicity. However, their direct impact on human fallopian tube contractility remains unexplored. This study aimed to investigate the effects of BPA and BPS on spontaneous smooth muscle contractions of the human fallopian tube. Fallopian tube samples from the proliferative phase were used for in vitro contractility assays. The effects of BPA and BPS (1-20 µM) on maximum contractile strength (MCS), basal tone (BT), and contraction frequency (CF) were recorded and analyzed using ANOVA. Cytotoxicity of both compounds was assessed in MCF-7 cells using the MTT assay. Molecular docking examined BPA and BPS binding affinities to key receptors. Both BPA and BPS significantly reduced contractile activity in a concentration-dependent manner (p < 0.001), with BPA exhibiting a stronger inhibitory effect than BPS. MTT assays demonstrated a significant dose- and time-dependent decrease in cell viability for both compounds. Molecular docking indicated comparable binding affinities of BPA and BPS toward estrogen, progesterone, oxytocin, prostaglandin, and calcium channel receptors. BPA and BPS impair human fallopian tube contractility and exhibit cytotoxicity. These findings highlight potential reproductive risks associated with exposure to bisphenol compounds and underscore the need for subsequent extensive studies.