Antiviral activities of Radix isatidis polysaccharide against pseudorabies virus in swine testicle cells

Background: Radix isatidis has been used in China and other Asian countries for its antiviral and anti-inflammatory effects for thousands of years. However, the antiviral effect of Radix isatidis polysaccharide against pseudorabies virus (PRV) is still unknown. Methods: The polysaccharide were isolated from extract of the roots of Radix isatidis. MTT assays were used to determine the preventive effect, inhibitory effect and antiviral effect of Radix isatidis polysaccharide on PRV in vitro. Results: This study found that different concentrations of polysaccharides from this plant can inhibit PRV replication by 14.674-30.840%, prevent infection at rates of 6.668-14.923%, and kill this virus at rates of 32.214-67.422%. Conclusion: These results broaden the understanding of this traditional Chinese herb and provide a theoretical basis for further research. Moreover, Radix isatidis polysaccharide could be used for antiviral therapy.