原文：Proanthocyanidins (PC), a natural flavonoid compound, was reported to possess a variety of pharmacological activities such as anti-tumor and anti-viral effects. In this study, the anti-Enterovirus 71 (EV71) activities and mechanisms of PC were investigated both in vitro and in vivo. The results showed that PC possessed anti-EV71 activities in different cell lines with low toxicity. PC can block both the adsorption and entry processes of EV71 via directly binding to virus VP1 protein. PC may competitively interfere with the binding of VP1 to its receptor SCARB2. PC can also regulate three different MAPK signaling pathways to reduce EV71 infection and attenuate virus induced inflammatory responses. Importantly, intramuscular therapy of EV71-infected mice with PC markedly improved their survival and attenuated the severe clinical symptoms. Therefore, the natural compound PC has potential to be developed into a novel anti-EV71 agent targeting viral VP1 protein and MAPK pathways. 简化版：天然黄酮类化合物原花青素（Proanthocyanidins，简称PC）具有多种药理作用，如抗肿瘤和抗病毒作用。本研究在体外和体内探讨了PC对肠道病毒71型（Enterovirus 71，EV71）的抑制作用和机制。结果表明，PC对多种细胞系有良好的低毒抗EV71活性，可通过直接结合病毒VP1蛋白而阻止EV71的吸附和入侵过程；可能并可竞争性干扰VP1与其受体SCARB2的结合；还可调节三种MAPK信号通路以减少EV71感染并减轻病毒诱导的炎症反应。重要的是，肌肉注射PC治疗EV71感染的小鼠，显著提高了其生存率并减轻了严重的临床症状。因此，PC这种天然化合物具有开发成为靶向病毒VP1蛋白和MAPK通路新型抗EV71剂的潜力。

Proanthocyanidins (PC), a natural flavonoid compound, was reported to possess a variety of pharmacological activities such as anti-tumor and anti-viral effects. In this study, the anti-Enterovirus 71 (EV71) activities and mechanisms of PC were investigated both in vitro and in vivo. The results showed that PC possessed anti-EV71 activities in different cell lines with low toxicity. PC can block both the adsorption and entry processes of EV71 via directly binding to virus VP1 protein. PC may competitively interfere with the binding of VP1 to its receptor SCARB2. PC can also regulate three different MAPK signaling pathways to reduce EV71 infection and attenuate virus induced inflammatory responses. Importantly, intramuscular therapy of EV71-infected mice with PC markedly improved their survival and attenuated the severe clinical symptoms. Therefore, the natural compound PC has potential to be developed into a novel anti-EV71 agent targeting viral VP1 protein and MAPK pathways.Copyright © 2023. Published by Elsevier B.V.