In vitro and in vivo antiviral effects of myrcene on MSRV infection in largemouth bass (Micropterus salmoides).

Abstract

The Micropterus salmoides rhabdovirus (MSRV), a highly pathogenic agent affecting largemouth bass, has been recognized as a primary causative pathogen responsible for substantial economic losses in aquaculture operations. Myrcene, a natural monoterpene organic compound predominantly isolated from Lindera aggregata (Sims) Kosterm, a plant species extensively utilized in traditional Chinese medicine. In this investigation, the therapeutic effects of myrcene against MSRV infection were systematically evaluated both in vitro and in vivo. Furthermore, the mechanistic pathways which myrcene exerted its anti-MSRV activity were comprehensively explored. The results demonstrated that myrcene had significant antiviral activity against MSRV in a concentration-dependent manner. Myrcene could improve the survival rate of largemouth bass infected with MSRV and reduce the viral load in tissues. The antiviral effect of myrcene might be attributed to its ability to significantly reduce viral infectivity, achieved through destruction of the MSRV envelope, interference with the stages of adsorption, invasion and replication in MSRV infection, and regulation of immune factors CAT, Nrf2, SOD, IL-1β, IL-8, and TNF - α. The above results indicated that myrcene had the potential to become an effective candidate drug against MSRV, providing a theoretical basis for the development of efficient and safe anti-MSRV fishing drugs.