Antiviral effects of Psidium guajava Linn. (guava) tea on the growth of clinical isolated H1N1 viruses: Its role in viral hemagglutination and neuraminidase inhibition

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• 作者：Nongluk Sriwilaijaroen^a ; ^c ; Syuichi Fukumoto^b ; Kenji Kumagai^b ; Hiroaki Hiramatsu^c ; Takato Odagiri^d ; Masato Tashiro^d ; Yasuo Suzuki^c ; ^e ; ^{suzukiy@isc.chubu.ac.jp}
• 关键词：Psidium guajava Linn. ; Influenza ; Oseltamivir resistance ; Pandemic ; Neuraminidase ; Hemagglutination
• 刊名：Antiviral Research
• 出版年：2012
• 期刊代码：7_01663542
• 类别：imm
• 出版时间：May, 2012
• 卷：94
• 期：2
• 页码：139-146
• 文件大小：582 K

摘要

Rapid evolution of influenza RNA virus has resulted in limitation of vaccine effectiveness, increased emergence of drug-resistant viruses and occurrence of pandemics. A new effective antiviral is therefore needed for control of the highly mutative influenza virus. Teas prepared by the infusion method were tested for their anti-influenza activity against clinical influenza A (H1N1) isolates by a 19-h influenza growth inhibition assay with ST6Gal I-expressing MDCK cells (AX4 cells) using fluorogenic quantification and chromogenic visualization. Guava tea markedly inhibited the growth of A/Narita/1/2009 (amantadine-resistant pandemic 2009 strain) at an IC₅₀ of 0.05%and the growth of A/Yamaguchi/20/06 (sensitive strain) and A/Kitakyushu/10/06 (oseltamivir-resistant strain) at similar IC₅₀ values ranging from 0.24%to 0.42%in AX4 cells, being 3.4- to 5.4-fold more potent than green tea (IC₅₀ values: 0.27%for the 2009 pandemic strain and 0.91%to 1.44%for the seasonal strains). In contrast to both teas, oseltamivir carboxylate (OC) demonstrated high potency against the growth of A/Narita/1/09 (IC₅₀ of 3.83 nM) and A/Yamaguchi/20/06 (IC₅₀ of 11.57 nM) but not against that of A/Kitakyushu/10/06 bearing a His274-to-Tyr substitution (IC₅₀ of 15.97 渭M). Immunofluorescence analysis under a confocal microscope indicated that both teas inhibited the most susceptible A/Narita/1/2009 virus at the initial stage of virus infection. This is consistent with results of direct inhibition assays showing that both teas inhibited viral hemagglutination at concentrations comparable to their growth inhibition concentrations but inhibited sialidase activity at about 8-times higher concentrations. Guava tea shows promise to be efficacious for control of epidemic and pandemic influenza viruses including oseltamivir-resistant strains, and its broad target blockage makes it less likely to lead to emergence of viral resistance.