Carboxymethyl chitosan modulates the genotoxic risk and oxidative stress of perfluorooctanoic acid in Nile tilapia (Oreochromis niloticus)

Abstract Perfluorooctanoic acid (PFOA) is one of the most commonly used perfluorinated compounds. Being a persistent environmental pollutant, it can accumulate in human tissues via various exposure routes. The aim of the current study was to evaluate the protective role of carboxymethyl chitosan (CMC) against PFOA-induced toxicity at the genetic and protein levels in Nile tilapia using the biochemistry analysis, SDS–PAGE electrophoresis, comet assay and RFLP–PCR methods. The results indicated that exposure to PFOA in water (30 mg/L) for 30 days resulted in a significant increase in ALT, AST, BUN, creatinine accompanied with a significant decrease in total protein and albumin. PFOA also increased DNA damage in electrophoresis condition and induced DNA and protein polymorphic band in comparison to control fish. CMC alone at 1% and 2% (W/W) in fish diets did not induce any alterations in the biochemical parameters, DNA or protein levels compared to the control group. Furthermore, CMC succeeded to decrease the toxicity of PFOA in a dose dependent manner. It could be concluded that PFOA induced genotoxicity and oxidative stress in fish similar to those reported in mammals. CMC is a promising candidate and has a protective effect against-PFOA induced in vivo DNA damage and protein alteration in Nile tilapia. This effect might be attributable to its ability to decrease intracellular ROS and its antioxidant properties.