Antiviral Activity of Baicalin Against PRRSV In Vitro and in Infected Piglets

Abstract

Simple Summary Porcine reproductive and respiratory syndrome is a major infectious disease that causes breathing problems, poor growth, reproductive losses, and death in pigs. Current vaccines do not always provide complete protection against the many virus strains circulating on farms, creating a need for additional control measures. Baicalin is a natural plant compound found in Chinese skullcap and has reported antiviral and anti-inflammatory properties. This study examined whether baicalin could inhibit the virus in porcine alveolar macrophages and protect infected piglets. Baicalin showed its greatest detectable antiviral activity when it was present during the stage in which the virus attaches to the cell surface. In piglets, dietary baicalin reduced the virus copies in the blood and decreased virus release in nasal and throat secretions. Compared with the PRRSV group, piglets receiving prophylactic dietary baicalin supplementation had less pronounced fever and clinical signs, better growth performance, less severe pulmonary and lymphoid lesions, and a numerically higher survival proportion. Baicalin also reduced several inflammatory substances associated with tissue injury. Overall, these results show that baicalin can interfere with an early stage of viral infection and reduce the severity of disease in piglets, supporting its further evaluation as a feed additive for porcine reproductive and respiratory syndrome control.