ゼブラフィッシュを用いたインビボ・インシリコ解析による環境化学物質の抗アンドロゲン作用評価法の開発

抄録

The present study aimed to establish in vivo and in silico assay systems to evaluate anti-androgenic potentials of environmental chemicals using zebrafish. We assessed transcript expression of sulfotransferase 2st3 (sult2st3) in embryos exposed to androgen 17α-methyltestosterone (TES) alone or in combination with anti-androgens, such as flutamide (FLU), p,p’-DDE (DDE), vinclozolin (VIN), linuron (LIN), and fenitrothion (FEN). Developmental toxicity of these anti-androgens was also monitored to see if the toxicity is associated with anti-androgenic potency. The expression of sult2st3 was significantly induced by TES at later stages of embryonic development. The TES-induced expression of sult2st3 was inhibited by FLU to the level of DMSO control (IC₅₀ = 5.7 μM), suggesting the role of androgen receptor (AR) in the sult2st3 induction. Similarly, DDE, VIN and LIN repressed the TES-induced expression of sult2st3 in a concentration dependent manner (IC₅₀ = 0.35, 3.9, and 52 μM, respectively). FEN suppressed sult2st3 expression almost completely at the highest concentration tested. FEN and LIN induced broader toxicities to zebrafish embryos, suggesting no clear relationship between developmental toxicities and anti-androgenic potency. In silico docking simulation also showed that all five chemicals were interacted with zebrafish AR, being Arg702 as a key amino acid for the ligand binding. Our findings suggest that the combination of in vivo and in silico assessments using zebrafish becomes a promising tool to predict anti-androgenic potentials of environmental chemicals.