Effects of chronic bisphenol A exposure on hepatic antioxidant parameters in medaka (Oryzias latipes)

Bisphenol A (BPA), the plastic monomer and plasticizer with well-known endocrine-disrupting chemical properties, is widely present in the aquatic environment, but little is known regarding hepatic toxicity in fish. This study assessed the effects of chronic exposure to BPA on the antioxidant defense system of Japanese medaka liver. Fish were exposed to sub-lethal concentrations of BPA (0.1, 1, 10, 100, or 1000?µg?L^?1) for 60 days. Antioxidant parameters were determined and compared with controls. The results showed that the activities of catalase (CAT), superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and the content of reduced glutathione were all induced at 10?µg?L^?1 BPA after 60 days. Further, hepatic CAT was sensitive to BPA at 1?µg?L^?1 concentration. In conclusion, CAT may serve as a potential early biomarker of BPA exposure in aquatic environment.