Antiviral innovations in largemouth bass aquaculture: Unveiling the potential of arctigenin derivatives against Micropterus Salmoides rhabdovirus

Abstract

Aquaculture confronts an escalating threat from viral infections, necessitating effective strategies to ensure fish health. This study investigated the comprehensive antiviral properties of compound A28 against Micropterus Salmoides Rhabdovirus (MSRV) in largemouth bass. Synthesized as a derivative of arctigenin, A28 was characterized for its inhibitory effects on MSRV at both cellular and organismal levels. To elucidate A28's impact on MSRV, cytotoxicity was gauged using the CCK-8 assay, revealing a safe concentration of 2.5 mg/L for A28 on GCO cell viability. At this concentration, A28 treatment resulted in remarkable inhibition rates, notably 99.14% for the MSRV nucleoprotein (N) gene and 99.46% for the glycoprotein (G) gene expression in GCO cells. Additionally, RT-qPCR analysis demonstrated a dose-dependent inhibition of MSRV genes (N and G) with increasing A28 concentrations. Morphological assessment revealed a reduction in MSRV-induced cytopathic effects in the presence of 2.5 mg/L A28 after 48 h. Intriguingly, preventive and therapeutic experiments underscored A28's dual role against MSRV infection. Water stability assessment indicated a sustained inhibitory effect of A28 on MSRV for approximately 2 days. Notably, A28 demonstrated the capacity to alleviate MSRV-induced nuclear and mitochondrial damage, underscoring its cytoprotective effects. In vivo experiments on largemouth bass revealed that A28 significantly enhanced fish survival rates upon MSRV challenge, with a notable 38% increase following A28 treatment. Concurrently, A28 upregulated fish immune-related genes, furnishing molecular evidence of its immunomodulatory effects. Furthermore, A28 exhibited efficacy in suppressing the horizontal transmission of MSRV in fish, suggesting its potential as a therapeutic agent in aquaculture settings. In conclusion, compound A28 emerges as a promising antiviral agent against MSRV in largemouth bass, offering insights into its potential application in managing aquaculture diseases. The findings provide a foundation for further research on A28's pharmacokinetics, environmental impact, and scalability for practical aquaculture applications.