Potential of heat shock protein inducers in mitigating benzo[α]pyrene toxicity in stellate sturgeon fingerlings (Acipenser stellatus): Assessing the effects on CYP450 and AChE activity, HSP70 expression, antioxidant levels, cortisol, and immunological responses

Benzo[α]pyrene (BαP), a polycyclic aromatic hydrocarbon (PAH), is a significant contaminant in the environment, which accumulates and is toxic to invertebrates and fish. The present study aimed to determine the acute toxicity of sublethal concentrations of BαP in the presence of the heat shock protein (HSP) inducer (HSPi) on CYP450 activity, HSP70 gene expression, antioxidant levels, immunological alterations, and AChE activity in stellate sturgeon fingerlings. Two‐hundred and forty fish were exposed to 100 mg L−1 of Nopal endurance (HSPi) for 4 h. In the next step, the fish were exposed to BαP concentrations equivalent to 25%, 50%, and 75% of the 96‐h LC50 values. Sampling was carried out on the first, third, and sixth days of the experiment, and the samples were analyzed using two‐way analysis of variance (ANOVA), cluster analysis (CA), and principal component analysis (PCA). The CYP450 activity significantly increased under BαP treatments. Higher expression of the HSP70 gene was observed in the higher concentration of HSPi + BαP treatments. The lowest AChE activity was observed in BαP treatments. However, the activity of superoxide dismutase, catalase, and total antioxidant activity enzymes and immunological responses (lysozyme, IgM, and C3) increased by using HSPi. It can be concluded that the HSP inducer significantly decreased BαP toxicity and resulted in more resistance to stress situations in sturgeon fingerlings.