Estrogenic potential of benzotriazole on marine medaka (Oryzias melastigma)

This study, for the first time, assessed the reproductive effects of benzotriazoles, widely used industrial chemicals, on marine fish. Marine medakas (Oryzias melastigma) were exposed to 0.01, 0.1, and 1 mg/L benzotriazole for periods of four and 35 days. The results that are obtained showed that the expression levels of CYP1A1 were down-regulated in the liver, gills and intestines of both males and females. Vitellogenin (VTG) was highly induced in the liver, gills and intestine of both male and female marine medaka, and CYP19a was up-regulated in the ovaries especially after being exposed for 35 days. Most importantly, the results of the present study suggest that even at environmentally relevant concentrations detected in the aquatic environment, 0.01 mg/L, benzotriazole also caused notable changes in expression levels of VTG, CYP1A1 and CYP19a. More concerns about the toxicity of benzotriazoles on marine animals should be raised.

► We examined the reproductive effects of benzotriazoles on marine medaka.
► Benzotriazole can inhibit CYP1A1 gene expression in liver and intestine.
► VTG genes can be induced in liver and intestines.
► CYP19a gene expression in ovary of female medaka increased at day 35.
► Benzotriazole is potentially estrogenic to marine fishes.