Inhibition of endosomal fusion activity of influenza virus by Rheum tanguticum (Da-Huang)

• Main Authors: Ta Jen Lin, 林大任
• Other Authors: J. T. Horng
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/rby3sb

博士 === 長庚大學 === 生物醫學研究所 === 104 === Rhubarb (Rheum tanguticum; da-huang in Chinese medicine) is a herbal medicine that has been used widely for managing fever and removing toxicity. In this study, we investigated how rhubarb inhibits influenza virus during the early stage of the infectious cycle using different functional assays. A non-toxic ethanolic extract of rhubarb (Rex) inhibited several H1N1 subtypes of influenza A viruses in Madin–Darby canine kidney cells, including strains that are clinically resistant to oseltamivir. Time course analysis of Rex addition showed that viral entry was one of the steps that was inhibited by Rex. We also confirmed that Rex effectively inhibited viral attachment and penetration into the host cells. Although Rex could not inhibit haemagglutination, the inhibition of red blood cell haemolysis and cell–cell fusion by Rex suggests that Rex may block haemagglutinin-mediated fusion (virus–endosome fusion) during the fusion/uncoating step. We found Rex effectively inhibited NA activity against H1N1 than H3N2. It seems that Rex could also affect HA glycosylation. Rex has the capacity to inhibit influenza viruses by blocking viral endocytosis. Thus, rhubarb might provide an alternative therapeutic approach when resistant viruses become more prevalent.