Department of Biochemistry and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Sci Rep. 2016 Oct 31;6:36015. doi: 10.1038/srep36015.
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 EC 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 ECs 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.
流感病毒仍然是一种新兴病毒，会引起高死亡率的大流行。在筛选具有潜在抗流感活性的不同植物提取物后，发现落羽杉茎的水提取物（TDSWex）对流感病毒具有优异的活性。TDSWex 对流感病毒 A/WSN/33 的 EC 为 0.051±0.024mg/mL。TDSWex 对各种人源甲型和乙型流感病毒具有出色的抗病毒功效，特别是对奥司他韦耐药的临床分离株和猪源流感株。我们观察到在 TDSWex 存在的情况下，病毒 RNA 和蛋白质的合成受到抑制。时效实验结果表明，TDSWex 抑制病毒进入和出芽。在血凝抑制实验中，TDSWex 抑制了红细胞的凝集，表明该提取物靶向与血凝相关的功能，如病毒进入。在附着和渗透实验中，TDSWex 的 EC 值分别为 0.045±0.026 和 0.012±0.003mg/mL，表现出抗病毒活性。此外，TDSWex 还能阻断神经氨酸酶的活性。我们得出结论，TDSWex 在病毒复制过程中对血凝素和神经氨酸酶具有双重作用。
