Chestnut inner shell extract inhibits viral entry of porcine epidemic diarrhea virus and other coronaviruses .

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes acute diarrhea in suckling piglets. Although vaccines are able to reduce the incidence of PEDV infection, outbreaks of PEDV continue to be reported worldwide and cause serious economic losses in the swine industry. To identify novel antiviral sources, we identified the chestnut () inner shell (CIS) as a natural material with activity against PEDV infection . The ethanol fractions of CIS extracts potently inhibited PEDV infection with an IC90 of 30 μg/ml. Further investigation of the virus lifecycle demonstrated that CIS extract particularly targeted the early stages of PEDV infection by blocking viral attachment and membrane fusion at rates of 80~90%. In addition, CIS extract addition reduced the viral entry of other members of the family. Our data demonstrated that CIS extract inhibited PEDV infection by blocking cell entry and suggest that CIS extract is a new prophylactic and therapeutic agent against PEDV and other coronavirus infections.