Evaluation of androgen receptor transcriptional activities of bisphenol A, octylphenol and nonylphenol in vitro

In this study, we have developed a human androgen receptor (hAR) reporter gene assay using African monkey kidney cell line CV-1 transiently transfected with the constructed reporter gene plasmid pMMTV-CAT and the hAR expression plasmid AR/pcDNA3.1. The assay displayed appropriate response to the known AR agonist 5α-dihydrotestosterone (DHT) and AR antagonist flutamide. DHT induced AR-mediated transcriptional activity in a concentration-dependent manner with median effective concentration (EC50) value of (3.90 ± 1.43) × 10−10 M. Flutamide exhibited potent antiandrogenic activity with median inhibitory concentration (IC50) value of (1.02 ± 0.35) × 10−7 M. Bisphenol A (BPA) and alkylphenols (APs) belong to the industrial chemicals that have received considerable attention due to high production and widespread usage. We investigated BPA, 4-octylphenol (OP) and 4-nonylphenol (NP) for their agonistic and antagonistic activities by the AR reporter gene assay. BPA showed significant inhibitory effects on the transcriptional activity induced by DHT with IC50 value of (7.46 ± 1.23) × 10−7 M. OP and NP exhibited lower antiandrogenic activities than BPA with IC50 of (9.71 ± 3.82) × 10−5 M and (2.02 ± 0.90) × 10−5 M, respectively. On the other hand, we failed to find AR-mediated androgenic activities of the three tested chemicals. In conclusion, BPA, OP and NP all act as AR antagonists, and BPA possesses the highest activity.