The Infection Properties of ITrionyx sinensis/I Hemorrhagic Syndrome Virus and the Antiviral Effect of Curcumin In Vivo

Trionyx sinensis (Chinese soft-shelled turtle) is one of the main economic animals in the aquaculture industry due to its nutritional value and medicinal value. However, the farming industry is facing various challenges, including water quality, stocking density, and viral disease outbreaks. Trionyx sinensis hemorrhagic syndrome virus has high lethality to Trionyx sinensis, but the detailed pathogenic characteristics of the virus are unclear, and there is no available treatment for the virus. After experiments, we revealed the pathogenic characteristics of the virus at the cellular and tissue levels and found a material for the culture of the virus. Curcumin is a natural herbal extract that has antiviral, antifungal, and antibacterial properties and acts as an immunomodulator. In vivo tests have shown that curcumin is effective in preventing viral infection and improving the immune response. These results demonstrate that curcumin is a promising strategy for preventing viral disease. Trionyx sinensis hemorrhagic syndrome virus (TSHSV) is an aquatic arterivirus causing a high mortality rate for T. sinensis (Chinese soft-shelled turtle), but the detailed infection properties of TSHSV are unclear, and no effective treatment is available. In this study, cell culture and histopathology were performed to elucidate the infection properties of TSHSV. Furthermore, the anti-TSHSV and immune-enhancing effects of curcumin were evaluated using survival statistics, qPCR, and tissue immunofluorescence. The results demonstrated that TSHSV could proliferate in the spleen cell line of T. sinensis, leading to cytopathic effects. TSHSV damaged the livers, kidneys, and lungs, characterized by cell disintegration and hyperemia. Curcumin at 250 mg/kg improved the survival of T. sinensis, and significantly reduced the viral load in the spleens, kidneys, and lungs. Moreover, curcumin inhibited the mRNA expression of immune-related genes, RSAD2, IFN-γ, and TNF-α (p < 0.05). In conclusion, these results imply that TSHSV is pathogenic to the spleen cell line, liver, spleen, kidney, and lung of T. sinensis. Curcumin effectively inhibits TSHSV and modulates the immune function of T. sinensis, so it holds promise as a means to prevent TSHSV.