Inhibitory effects of berberine hydrochloride on porcine epidemic diarrhea virus in vitro and in vivo

Abstract

Porcine epidemic diarrhea virus (PEDV) causes severe economic losses in swine, necessitating the development of novel antiviral strategies. In this study, we evaluated the inhibitory effects of berberine hydrochloride (BBH) on PEDV in vitro and in vivo. PEDV-infected Vero-E6 cells were treated with BBH, followed by assays for cell viability, viral RNA levels, and protein expression. PEDV-infected piglets were administered BBH, and clinical signs, intestinal morphology, and viral load were assessed. In vitro, BBH (≤120 μM) exhibited low cytotoxicity and inhibited PEDV replication in a dose-dependent manner, markedly reducing viral titers and nucleocapsid (N) protein expression. Time-of-addition assays showed inhibition across multiple stages of the viral life cycle, with pronounced effects on viral attachment and internalization. Mechanistically, BBH suppressed the autophagy marker LC3-II in a dose- and time-dependent manner, and its antiviral activity was partially reversed by the autophagy activator rapamycin, indicating that autophagy suppression contributes to its effect. In PEDV-challenged suckling piglets, oral BBH (40 mg/kg/day) notably improved survival (66.7 % vs. 0 % in controls), alleviated diarrhea, reduced viral shedding in anal swabs, lowered viral load in intestinal tissues (duodenum, jejunum, ileum), and mitigated histopathological damage. Collectively, these results demonstrate that BBH exerts potent anti-PEDV activity through inhibition of viral entry/replication and modulation of autophagy modulation, supporting its potential as an adjunctive therapy against PEDV.