Shi Ya, Zhang Bing, Lu Yiyu, Qian Chaodong, Feng Yan, Fang Liwei, Ding Zhishan, Cheng Dongqing
College of Medical Technology, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, 310053, China.
Zhejiang Provice Center For Disease Control and Prevention, Hangzhou, Zhejiang, 310051, China.
BMC Complement Altern Med. 2017 May 22;17(1):273. doi: 10.1186/s12906-017-1780-6.
Influenza represents a serious public health concern. The emergence of resistance to anti-influenza drugs underlines the need to develop new drugs. This study aimed to evaluate the anti-influenza viral activity and possible mechanisms of 12 phenanthrenes from the medicinal plant Bletilla striata (Orchidaceae family).
Twelve phenanthrenes were isolated and identified from B. striata. Influenza virus A/Sydney/5/97 (H3N2) propagated in embryonated chicken eggs was used. Phenanthrenes mixed with the virus were incubated at 37 °C for 1 h and then inoculated into 9-day-old embryonated chicken eggs via the allantoic route to survey the antiviral activity in vivo. A (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS)-based assay was performed to evaluate the reduction of cytopathic effect induced by H3N2 on Madin-Darby canine kidney (MDCK) cells. The hemagglutination inhibition assay was used to study the blockage of virus receptors by the phenanthrenes, and the neuraminidase (NA) inhibition assay to evaluate the effects of the release of virus. The synthesis of influenza viral matrix protein mRNA in response to compound treatment was measured by real-time polymerase chain reaction.
This study showed that phenanthrenes 1, 2, 3, 4, 6, 9, 10, 11, and 12 significantly inhibited the viruses in vivo, with inhibition rates of 20.7, 79.3, 17.2, 34.5, 34.5, 34.5, 44.8, 75.9, and 34.5%, respectively. In MDCK models, the phenanthrenes did not show significant antiviral activity when administered as pretreatment, while phenanthrenes 2, 3, 4, 6, 7 10, and 11 exhibited inhibitory activities as simultaneous treatment with 50% inhibition concentration (IC) ranging from 14.6 ± 2.4 to 43.3 ± 5.3 μM. The IC ranged from 18.4 ± 3.1 to 42.3 ± 3.9 μM in the post-treatment assays. Compounds 1, 3, 4, 6, 10, and 11 exhibited an inhibitory effect on NA; and compounds 2, 3, 4 6, 7, 10, and 11 resulted in the reduced transcription of virus matrix protein mRNA. However, no compound could inhibit hemagglutination by the influenza virus.
Phenanthrenes from B. striata had strong anti-influenza viral activity in both embryonated eggs and MDCK models, and diphenanthrenes seemed to have stronger inhibition activity compared with monophenanthrenes.
流感是一个严重的公共卫生问题。抗流感药物耐药性的出现凸显了开发新药的必要性。本研究旨在评估来自药用植物白及（兰科）的12种菲类化合物的抗流感病毒活性及可能机制。
从白及中分离并鉴定出12种菲类化合物。使用在鸡胚中增殖的甲型流感病毒A/悉尼/5/97（H3N2）。将菲类化合物与病毒混合，在37℃孵育1小时，然后通过尿囊途径接种到9日龄鸡胚中，以检测体内抗病毒活性。进行基于（3-(4,5-二甲基噻唑-2-基)-5-(3-羧甲氧基苯基)-2-(4-磺基苯基)-2H-四唑）（MTS）的试验，以评估H3N2对犬肾传代细胞（MDCK）细胞诱导的细胞病变效应的降低情况。采用血凝抑制试验研究菲类化合物对病毒受体的阻断作用，采用神经氨酸酶（NA）抑制试验评估病毒释放的影响。通过实时聚合酶链反应测定化合物处理后流感病毒基质蛋白mRNA的合成。
本研究表明，菲类化合物1、2、3、4、6、9、10、11和12在体内显著抑制病毒，抑制率分别为20.7%、79.3%、17.2%、34.5%、34.5%、34.5%、44.8%、75.9%和34.5%。在MDCK模型中，作为预处理给药时，菲类化合物未显示出显著的抗病毒活性，而菲类化合物2、3、4、6、7、10和11作为同时处理时表现出抑制活性，50%抑制浓度（IC）范围为14.6±2.4至43.3±5.3μM。在处理后试验中，IC范围为18.4±3.1至42.3±3.9μM。化合物1、3、4、6、10和11对NA有抑制作用；化合物2、3、4、6、7、10和11导致病毒基质蛋白mRNA转录减少。然而，没有化合物能抑制流感病毒的血凝作用。
白及中的菲类化合物在鸡胚和MDCK模型中均具有较强的抗流感病毒活性，与单菲类化合物相比，双菲类化合物似乎具有更强的抑制活性。
