Piceatannol as an Antiviral Inhibitor of PRV Infection In Vitro and In Vivo

SIMPLE SUMMARY: PRV can infect most mammals, mainly affecting the nervous and reproductive systems of infected animals, and can cause the death of piglets and other susceptible animals. Identifying effective antiviral agents against PRV to prevent a latent infection is essential. Piceatannol is a bioactive polyphenol substance. It is mainly found in grapes, mushrooms, blueberries, passion fruit and other edible fruits and vegetables. In this study, we evaluated the inhibitory effect of piceatannol on PRV replication in vivo and in vitro and investigated the mechanism of action of piceatannol against PRV. Piceatannol could exert an anti-PRV effect by reducing the transcription level of viral genes, reducing PRV-induced apoptosis and elevating the levels of IL-4, TNF-α and IFN-γ in the serum of mice. Animal experiments showed that piceatannol could delay the onset of disease, reduce the viral load in the brain and kidney and reduce the pathological changes in the tissues and organs of the mice to improve the survival rate of the mice (14.3%). Therefore, the anti-PRV activity of piceatannol in vivo and in vitro was systematically evaluated in this study to provide scientific data for developing a new alternative measure for controlling PRV infection. ABSTRACT: Pseudorabies virus (PRV) belongs to the family Herpesviridae. PRV has a wide host range and can cause cytopathic effects (CPEs) in PK-15 cells. Therefore, PRV was used as a model to study the antiviral activity of piceatannol. The results showed that piceatannol could restrain PRV multiplication in PK-15 cells in a dose-dependent manner. The 50% inhibitory concentration (IC(50)) was 0.0307 mg/mL, and the selectivity index (SI, CC(50)/IC(50)) was 3.68. Piceatannol could exert an anti-PRV effect by reducing the transcription level of viral genes, inhibiting PRV-induced apoptosis and elevating the levels of IL-4, TNF-α and IFN-γ in the serum of mice. Animal experiments showed that piceatannol could delay the onset of disease, reduce the viral load in the brain and kidney and reduce the pathological changes in the tissues and organs of the mice to improve the survival rate of the mice (14.3%). Therefore, the anti-PRV activity of piceatannol in vivo and in vitro was systematically evaluated in this study to provide scientific data for developing a new alternative measure for controlling PRV infection.