Antiviral Activity against Respiratory Syncytial Virus of Polysaccharide from Jerusalem Artichoke ( Helianthus tuberosus L.).

Jerusalem artichoke ( Helianthus tuberosus L.) polysaccharide (JAP) is a chain polysaccharide composed of D-fructose connected by β (1-2) glycosidic bonds, which is a kind of inulin. This study evaluated the anti-respiratory syncytial virus (RSV) activity of JAP in vivo and in vitro . To investigate its antiviral activity, an MTT assay, q-PCR, enzyme-linked immunosorbent assay (ELISA), and lung histological observation were performed. The results showed that JAP showed anti-RSV activity in vitro with a half maximal inhibitory concentration (IC 50 ) of approximately 29.15  μ g/mL. In vivo results suggested that JAP could effectively inhibit RSV proliferation in the lungs and improve lung tissue lesions in RSV-infected mice. Additionally, JAP could also reduce the expression of TLR3 and TLR4 in the lungs, increase serum anti-inflammatory factors IL-4 levels, and reduce pro-inflammatory factors TNF- α and TNF- β levels, which may be related to its anti-RSV activity. This study provides a new approach to anti-RSV therapy and enriches the potential applications of JAP.