Integrated Ecotoxicological Assessment of Hematological, Oxidative Stress, Genotoxic, and Histopathological Biomarkers in Bighead Carp (Aristichthys nobilis) Exposed to Bisphenol A

Background

Bisphenol A (BPA) is a pervasive endocrine-disrupting chemical frequently detected in aquatic ecosystems due to extensive industrial and domestic applications. Continuous discharge of BPA into freshwater environments poses serious ecological risks to aquatic organisms, particularly fish species used as environmental sentinels. This study aimed to evaluate the ecotoxicological effects of BPA in bighead carp (Aristichthys nobilis) using an integrated biomarker approach.

Methods

Bighead carp were exposed under controlled laboratory conditions to different concentrations of BPA for 60 days alongside an untreated control group. Multiple biomarkers were assessed, including hematological indices, serum biochemical parameters, oxidative stress markers, antioxidant enzyme activities, genotoxic responses, and histopathological alterations in liver, kidney, brain, and heart tissues.

Results

BPA exposure caused significant physiological and biochemical disturbances in exposed fish. Hematological analysis revealed decreased erythrocyte count, hemoglobin concentration, lymphocytes, and monocytes, whereas leukocyte and neutrophil counts increased significantly. Serum biochemical profiling demonstrated elevated ALT, AST, ALP, urea, creatinine, glucose, cholesterol, and LDH levels, accompanied by reduced total protein and albumin. Oxidative stress biomarkers, including ROS and TBARS, were significantly increased, while antioxidant enzymes such as catalase, superoxide dismutase, and peroxidase were markedly reduced. Genotoxic effects were evidenced by increased nuclear abnormalities and DNA damage. Histopathological observations revealed necrosis, hemorrhage, inflammatory infiltration, and cellular degeneration in multiple organs.

Conclusion

The findings demonstrate that chronic BPA exposure induces multi-organ toxicity and oxidative stress–mediated damage in A. nobilis. Integrated biomarker responses highlight the ecological threat of BPA contamination and support the utility of freshwater fish as sentinel species for aquatic ecosystem health assessment.