Luteoloside Acts as 3C Protease Inhibitor of Enterovirus 71 In Vitro.
Luteoloside Acts as 3C Protease Inhibitor of Enterovirus 71 In Vitro.
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DOI：
10.1371/journal.pone.0148693
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Xiao W
中科院分区：
文献类型：
--
作者：
Cao Z;Ding Y;Ke Z;Cao L;Li N;Ding G;Wang Z;Xiao W
木犀草苷是黄酮类化合物家族的一员，具有多种生物活性，包括抗微生物和抗癌活性。然而，木犀草苷对肠道病毒71（EV71）的抗病毒活性和负责这种作用的潜在机制仍然未知。本研究主要研究木犀草苷对肠道病毒71型的抗病毒作用及其对3C蛋白酶活性的抑制作用。首先，我们研究了木犀草苷对横纹肌肉瘤（RD）细胞的细胞毒性，该细胞系被选择用于体外感染模型。在随后的抗病毒测定中，通过施用木犀草苷（EC 50 = 0.43 mM，选择指数= 5.3），EV71的细胞病变效应显著且剂量依赖性地减轻。使用空斑减少测定，我们在不同时间点施用木犀草苷，发现该化合物降低RD细胞中的EV71活力，而不是增加防御动员或病毒吸收。此外，生化研究集中在VP1（EV71的关键结构蛋白）的mRNA转录和蛋白水平也揭示了木犀草苷对EV71病毒产量的抑制作用。最后，我们使用木犀草苷进行抑制试验，以评估其对重组3C蛋白酶活性的影响。我们的研究结果表明，木犀草苷阻断3C蛋白酶的酶活性的剂量依赖性的方式（IC50 = 0.36 mM），这是类似的效果芦丁，这是一个众所周知的C3蛋白酶抑制剂。总的来说，本研究的结果表明，木犀草苷可以阻断3C蛋白酶活性，随后在体外抑制EV71的产生。
Luteoloside is a member of the flavonoids family that exhibits several bioactivities including anti-microbial and anti-cancer activities. However, the antiviral activity of luteoloside against enterovirus 71 (EV71) and the potential mechanism(s) responsible for this effect remain unknown. In this study, the antiviral potency of luteoloside against EV71 and its inhibitory effects on 3C protease activity were evaluated. First, we investigated the cytotoxicity of luteoloside against rhabdomyosarcoma (RD) cells, which was the cell line selected for an in vitro infection model. In a subsequent antiviral assay, the cytopathic effect of EV71 was significantly and dose-dependently relieved by the administration of luteoloside (EC50 = 0.43 mM, selection index = 5.3). Using a plaque reduction assay, we administered luteoloside at various time points and found that the compound reduced EV71 viability in RD cells rather than increasing defensive mobilization or viral absorption. Moreover, biochemical studies focused on VP1 (a key structural protein of EV71) mRNA transcript and protein levels also revealed the inhibitory effects of luteoloside on the EV71 viral yield. Finally, we performed inhibition assays using luteoloside to evaluate its effect on recombinant 3C protease activity. Our results demonstrated that luteoloside blocked 3C protease enzymatic activity in a dose-dependent manner (IC50 = 0.36 mM) that was similar to the effect of rutin, which is a well-known C3 protease inhibitor. Collectively, the results from this study indicate that luteoloside can block 3C protease activity and subsequently inhibit EV71 production in vitro.