Ethnopharmacological relevance Peperomia sui Lin and Lu ( Peperomia sui ), a well-known Taiwanese folk medicine, has a broad range of biological effects, especially in treatment of upper respiratory tract diseases. However, no previous study has explored the activity of Peperomia sui against influenza virus infections. This study was carried out to evaluate the anti-influenza virus activity and the potential virucidal effect of the ethanolic extract of Peperomia sui (PSE). Methods The anti-H6N1 avian influenza viral activity of PSE against the influenza virus A/Chicken/TW/0518/2011 (H6N1) in chicken fibroblast DF-1 cells was evaluated by cell viability assay, hemagglutination assay, neuraminidase activity assay, indirect immunofluorescence assay and quantitative RT-PCR assay. Results PSE significantly increased the viability of cells that were infected by the H6N1 virus. PSE also suppressed the synthesis of viral nucleoprotein (NP), and inhibited the growth of the virus in DF-1 cells. Further, PSE inhibited the neuraminidase activity of H6N1 virus. Conclusions The findings of this study provide important information for the exploitation and utilization of Peperomia su i in treatment of influenza infection. Graphical abstract
【저자키워드】 Influenza virus, antiviral activity, HA, hemagglutinin, CPE, cytopathic effect, hemagglutination, NA, neuraminidase, PBS, phosphate-buffered saline, MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, CC50, 50% cytotoxic concentration, DAPI, (4′,6-diamidino-2-phenylindole), DMEM, Dulbecco׳s modified Eagle׳s medium, EC50, half maximal effective concentration, FITC, fluorescein isothiocyanate, IC50, half-maximum inhibitory concentration, IFA, indirect immunofluorescence assay, MEM, minimal essential medium, MU-NANA, 20-(4-Methylumbelliferyl)-a-D-N-acetylneuraminic acid, qRT–PCR, quantitative reverse transcription–PCR,