Robigenin in combating largemouth bass ranavirus: Investigating the antiviral potency and underlying mechanisms.

Abstract

The largemouth bass ranavirus (LMBV) represents a significant pathogen causing severe damage to the aquaculture industry, for which specific prevention and control measures are currently lacking. This study systematically evaluated the anti-LMBV activity of the natural flavonol compound robigenin and elucidated its underlying molecular mechanisms through both in vitro cell experiments and in vivo infection models. The results demonstrated that robigenin at concentrations ≤6.25 μg/mL exhibited no significant cytotoxicity to the fathead minnow cells (FHM). Within this concentration range, its anti-LMBV efficacy increased in a dose-dependent manner. Robigenin was found to inhibit LMBV infection by blocking viral entry and replication phases without interfering with virus-receptor binding. Additionally, the results revealed that robigenin upregulated the expression of interferon-related genes, including IRF3, IRF7, IFN, ISG15, and MAVS, thereby enhancing cellular immune responses. In vivo experiments further confirmed that robigenin significantly alleviated LMBV-induced symptoms in juvenile Micropterus salmoides and markedly improved survival rates. In conclusion, this study provides the first evidence that robigenin effectively suppresses LMBV infection, offering both a promising candidate compound and theoretical foundation for the eco-friendly control of aquatic viral diseases.