Anti-viral activity of rhubarb extract and emodin in rotavirus-infected cells

Objective To evaluate the antiviral effect of rhubarb extract and emodin on human rotavirus(RV)R709-infected cells.Methods Cytopathic effect(CPE)of human RV R709 was examined by infection of monkey African green kidney MA-104 cell line.Viral inhibition rate was detected by MTT colorimetric assay and the anti-rotavirus effect of rhubarb extract and emodin was evaluated by therapeutic index(TI).Preventive effects were evaluated through analysis of virucidal effect and the anti-viral biosynthesis effect.Ribavirin was used as the anti-viral positive control.Results The extract from rhubarb showed significant and dose-dependent inhibitory activity against rotavirus in MA-104 cells when the extract was added at different stages of viral replication cycles.The 50% inhibitory concentrations(IC50)were(101.08±1.57)mg/L,(111.27±4.94)mg/L and(46.88±3.50)mg/L for rhubarb extract and(35.94±6.80)mg/L,(12.25±0.93)mg/L and(13.65±1.08)mg/L for emodin when the addition of the extract or emodin was before,during and after the viral infection,respectively;and the therapeutic index(TI)were(3.13±0.13),(3.45±0.06)and(7.45±0.56)for rhubarb extract and(0.37±0.07),(1.07±0.08),(0.95±0.08)for emodin,respectively.Conclusions Rhubarb extract is highly effective inhibiting RV in virus infected MA-104 cells,while emodin only showed mild antivirus activity.