Effects of LH crude oil and No.0 diesel oil emulsion on hepatopancreatic antioxidant enzyme activity and related functional gene expression in Litopenaeus vannamei

Marine oil spills cause multiple threats to the growth and development of marine organisms in coastal areas. To investigate the toxic effects of LH crude oil and No.0 diesel emulsion on the hepatopancreas of Litopenaeus vannamei, we divided LH crude oil and No.0 diesel into a dispersant control group (Group D, 0 μg·L⁻¹), a low concentration group (Group A, 25 μg·L⁻¹), a medium concentration group (Group B, 50 μg·L⁻¹), and a high concentration group (Group C, 250 μg·L⁻¹). Then we measured the changes of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione (GSH), as well as the expression of related functional genes SOD, CAT, GPx, lysozyme (LZM), apoptosis factor (caspase2), peroxiredoxin (Prx), elongation factor (EF) and prophenoloxidase (proPO) on the 15^th day. The results show that: 1) Both LH crude oil and No.0 diesel oil emulsions stress caused changes in the antioxidant system and related functional genes in the hepatopancreas of L. vannamei, and the effects of No.0 diesel oil were more significant than that of LH crude oil. 2) The integrated biomarker response (IBR) index showed a dose-effect and time- effect pattern, rising with increasing stress concentration and prolonged time. 3) The results of principal component analysis (PCA) show that LH crude oil and No.0 diesel oil significantly affected the antioxidant enzyme activities and the relative expression of caspase2. However, there was a difference in the biomarkers sensitivity to crude oil and diesel oil. The study reveals that LH crude oil and No.0 diesel oil emulsion significantly affect the hepatopancreatic antioxidant enzyme activities and the expression of related functional genes in L. vannamei, affecting its normal physiological functions, which provides fundamental data support for assessing the toxic effects of petroleum pollution on L. vannamei.