Protective Effects of Astaxanthin on Thioacetamide-Induced Hepatopancreatic Damage in Procambarus clarkii: Insights from Biochemical, Histological, and Metabolomic Analyses

The hepatopancreas of <i>Procambarus clarkii</i> plays a crucial role in metabolism and immune response, encompassing vital physiological functions. In our study, we established a hepatopancreatic injury model using thioacetamide (TAA) and evaluated the therapeutic potential of a commercial astaxanthin-based product (AST-product) on hepatopancreatic health. The experimental framework included a control group (Con), an injury model group (M), and a treatment group (T), enabling a comprehensive analysis of the effects of treatments on hepatopancreatic biochemical markers, tissue architecture, gene expression, and metabolic pathways. The biochemical results indicated significant oxidative damage and fibrosis in the M group post-TAA treatment, evidenced by increased malondialdehyde (MDA) levels, decreased superoxide dismutase (SOD) activity, and the disruption of tubular structures. Conversely, treatment with the AST-product significantly reduced MDA levels and ameliorated oxidative stress. Histological evaluations using hematoxylin and eosin (HE) and Sirius Red staining confirmed that the AST-product preserved tubular integrity and inhibited fibrosis progression. Metabolomic profiling revealed that the AST-product modulated key metabolic pathways, including arginine and proline metabolism, porphyrin metabolism, and nucleotide metabolism, which are critical for maintaining energy supply and antioxidative capabilities. This modulation mitigated the TAA-induced oxidative damage. Moreover, qPCR analysis demonstrated that the AST-product downregulated the pro-apoptotic gene CASP2, upregulated the energy metabolism-related gene NDUFA7, and enhanced the expression of the immune-related gene lysozyme, thereby boosting pathogen resistance. These findings elucidate the robust protective effects of the AST-product on hepatopancreatic health in <i>P. clarkii</i>, highlighting its potential to reduce oxidative stress, inhibit fibrosis, and enhance immune responses. This study provides a novel strategy for improving <i>P. clarkii</i> health in aquaculture and contributes valuable insights into hepatopancreatic protection and disease prevention in shrimp farming.