Inhibition of endosomal fusion activity of influenza virus by Rheum tanguticum (da-huang).
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. 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. 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.
Department of Biochemistry and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa First Road, Kweishan, Taoyuan 333, Taiwan, R.O.C.
Ta-Jen
TJ
Lin
Department of Cosmetic Science, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan, R.O.C.|Research Center for Industry of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan, R.O.C.
Chwan-Fwu
CF
Lin
Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Kweishan, Taoyuan 333, Taiwan, R.O.C.
Cheng-Hsun
CH
Chiu
Brion Research Institute of Taiwan, New Taipei City 231, Taiwan, R.O.C.
Ming-Chung
MC
Lee
Department of Biochemistry and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa First Road, Kweishan, Taoyuan 333, Taiwan, R.O.C.|Research Center for Industry of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan, R.O.C.|Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Kweishan, Taoyuan 333, Taiwan, R.O.C.|Research Center for Emerging Viral Infections, Chang Gung University, Kweishan, Taoyuan 333, Taiwan, R.O.C.
Jim-Tong
JT
Horng
D000327:Adsorption; D000818:Animals; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D004285:Dogs; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D011992:Endosomes / Q000187:drug effects / Q000821:virology*; D000431:Ethanol; D006388:Hemagglutinins / Q000378:metabolism; D061985:Madin Darby Canine Kidney Cells; D009975:Orthomyxoviridae / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000187:drug effects; D012367:RNA, Viral / Q000378:metabolism; D012250:Rheum / Q000737:chemistry*; D053585:Virus Attachment / Q000187:drug effects; D053586:Virus Internalization / Q000187:drug effects*; D014779:Virus Replication / Q000187:drug effects
D004365:Drugs, Chinese Herbal; D006388:Hemagglutinins; D010936:Plant Extracts; D012367:RNA, Viral; D000431:Ethanol