An extract from Taxodium distichum targets hemagglutinin- and neuraminidase-related activities of influenza virus in vitro.

Abstract

Influenza virus remains an emerging virus and causes pandemics with high levels of fatality. After screening different plant extracts with potential anti-influenza activity, a water extract of Taxodium distichum stems (TDSWex) showed excellent activity against influenza viruses. The EC50 of TDSWex was 0.051 ± 0.024 mg/mL against influenza virus A/WSN/33. TDSWex had excellent antiviral efficacy against various strains of human influenza A and B viruses, particularly oseltamivir-resistant clinical isolates and a swine-origin influenza strain. We observed that the synthesis of viral RNA and protein were inhibited in the presence of TDSWex. The results of the time-of-addition assay suggested that TDSWex inhibited viral entry and budding. In the hemagglutination inhibition assay, TDSWex inhibited the hemagglutination of red blood cells, implying that the extract targeted hemagglutin-related functions such as viral entry. In the attachment and penetration assay, TDSWex showed antiviral activity with EC50s of 0.045 ± 0.026 and 0.012 ± 0.003 mg/mL, respectively. In addition, TDSWex blocked neuraminidase activity. We conclude that TDSWex has bimodal activities against both hemagglutinin and neuraminidase during viral replication.

• Authors: Chung-Fan Hsieh, Yu-Li Chen, Chwan-Fwu Lin, Jin-Yuan Ho, Chun-Hsun Huang, Cheng-Hsun Chiu, Pei-Wen Hsieh, Jim-Tong Horng
• Journal: Scientific reports (Sci Rep) Vol. 6 Pg. 36015 (10 31 2016) ISSN: 2045-2322 [Electronic] England
• PMID: 27796330 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hemagglutinins
• Plant Extracts
• RNA, Viral
• Viral Proteins
• Neuraminidase

Topics

• Animals
• Cell Line
• Cell Survival (drug effects)
• Dogs
• Hemagglutinins (chemistry, metabolism)
• Humans
• Madin Darby Canine Kidney Cells
• Microscopy, Fluorescence
• Neuraminidase (antagonists & inhibitors, metabolism)
• Orthomyxoviridae (enzymology, metabolism)
• Plant Extracts (chemistry, metabolism, toxicity)
• RNA, Viral (chemistry, metabolism)
• Taxodium (chemistry, metabolism)
• Viral Proteins (metabolism)
• Virus Internalization (drug effects)
• Virus Release (drug effects)