Toxicity studies of nonylphenol on rosy barb (Puntius conchonious): a biochemical and histopathological evaluation

Acute and subacute toxicity of the nonylphenol (NP) on fish was investigated in laboratory toxicity tests with rosy barb (Puntius conchonious). The acute toxicity of NP to rosy barb was determined in semi-static bioassays. Median lethal concentration (LC50) for 96 h was 1.72 microM. The effects of sublethal concentrations of NP (0.17, 0.34 and 0.68 microM) on the structures and biochemical parameters [alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanin aminotransferase (ALT)] in gills, liver and kidney of rosy barb were studied after 14 days. The results showed that NP caused alteration of the structure in organs, as evidenced by the hyperplasia of epithelium and the fusion of secondary lamellae in the gills, the disappearance of the cell membrane and the cell necrosis in the liver as well as haemorrhages in the kidney. In addition, the functional enzyme activities were also changed. The increase trend in ALP activity in organs of fish treated with NP was recorded. The levels of AST and ALT in gills, liver and kidney were stimulated to rise at the lower concentration and fall at the higher concentration NP treatment compared to controls. This study suggests that NP can alter of the structures and biochemical parameters within non-endocrine tissue of fish and these changes may be mediated via destroying membrane structure and inducing cell necrosis.