Abstract

Simple SummaryMarine diesel oil pollution poses a serious threat to sea cucumber aquaculture by causing skin ulceration and physical damage. This study investigated the protective effects and mechanisms of an inhibitor composition under diesel stress. The results showed that the inhibitor significantly reduced ulceration area, suppressed the overactivation of autolytic enzymes (cathepsin L and B), and enhanced antioxidant and neural function-related enzymes. Transcriptomic analysis revealed that the protective mechanism involves coordinated regulation of tissue repair, detoxification, and antioxidant pathways. This research offers a potential strategy to mitigate diesel pollution impacts in aquaculture, supporting marine environmental protection and sustainable fishery development.No. 0 diesel oil may pose a serious threat to sea cucumber (Apostichopus japonicus) aquaculture by inducing skin ulceration. This study aimed to evaluate the protective efficacy and mechanism of a previously developed inhibitor composition against diesel-induced injury. The inhibitor composition significantly alleviated skin ulceration in the experimental group (Eg), reducing the lesion area to 14.44 ± 1.79% after 96 h, compared to 33.19 ± 2.94% in the diesel-exposed control group (Cg) (p< 0.05). It effectively suppressed the overactivation of autolytic enzymes (cathepsin L and B) while enhancing the activities of acetylcholinesterase, superoxide dismutase, and catalase. Transcriptomic profiling revealed 3137 differentially expressed genes, with functional enrichment in pathways related to Notch signaling, ECM–receptor interaction, glycosaminoglycan biosynthesis, and detoxification. The upregulation of genes such asHES-C,CYP1A1,GST, andUGTmay be linked to the regulation of apoptosis inhibition, xenobiotic metabolism, and antioxidant defense. Furthermore, enhanced expression of NAD kinase and PNLIPRP may indicate a potential strengthening of energy metabolism and lipid utilization during s