*3.6. Rg1 Treatment Exhibits Antiviral Activity in Piglets*

Given the antiviral activity of Rg1 against type 2 PRRSV that we analyzed in vitro, we wondered whether Rg1 could be used in antiviral therapy in piglets. HP-PRRSV JXA1 (EF112445) strain is a prototypical HP-PRRSV strain, characterized by discontinuous deletion of 30 amino acids in nonstructural protein 2, causes typical clinical symptom and pathological changes with high morbidity and mortality in piglets [9]. Here, we have evaluated the antiviral activity of Rg1 against JXA1 strain in vitro and calculated the EC50 of it (Table 2). Therefore, HP-PRRSV JXA1 was used to evaluate the anti-PRRSV effect of Rg1 in piglets.
