Host cdc2-like kinase 1 (CLK1) is responsible for the alternative splicing of the influenza virus M2 gene during influenza virus infection and replication that has been recognized as a potential anti-influenza virus target. In this study, we showed that gallocatechin-7-gallate (J10688), a novel CLK1 inhibitor isolated from Pithecellobium clypearia Benth, exerted potent anti-influenza virus activity in vivo and in vitro. ICR mice were intranasally infected with a lethal dose of H1N1. Administration of J10688 (30 mg·kg^-1·d^-1, iv, for 5 days) significantly increased the survival rate of the H1N1-infected mice to 91.67% and prolong their mean survival time from 5.83 ± 1.74 days to 13.66 ± 1.15 days. J10688 administration also slowed down body weight loss, significantly alleviated influenza-induced acute lung injury, reduced lung virus titer, elevated the spleen and thymus indexes, and enhanced the immunological function. We further explored its anti-influenza mechanisms in the H1N1-infected A549 cells: as a novel CLK1 inhibitor, J10688 (3, 10, 30 μmol/L) dose-dependently impaired synthesis of the viral proteins NP and M2, and significantly downregulated the phosphorylation of splicing factors SF2/ASF and SC35, which regulate virus M2 gene alternative splicing. As a novel CLK1 inhibitor with potent anti-influenza activity in vitro and in vivo, J10688 could be a promising antiviral drug for the therapy of influenza A virus infection.

中文翻译：

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皮氏疟原虫Bethth的化学成分gallocatechin-7-gallate的抗流感作用及其作用机理。

宿主cdc2样激酶1（CLK1）负责流感病毒感染和复制期间的流感病毒M2基因的选择性剪接，该过程已被认为是潜在的抗流感病毒靶标。在这项研究中，我们显示了从谷胱甘肽比索氏分离的一种新型CLK1抑制剂gallocatechin-7-gallate（J10688）在体内和体外均具有有效的抗流感病毒活性。致死剂量的H1N1鼻内感染ICR小鼠。施用J10688（30 mg·kg ^{- 1} ·d ^-1静脉注射5天）可将感染H1N1的小鼠的存活率显着提高至91.67％，并将其平均存活时间从5.83±1.74天延长至13.66±1.15天。J10688的给药还可以减缓体重减轻，显着减轻流感引起的急性肺损伤，降低肺病毒滴度，提高脾脏和胸腺指数，并增强免疫功能。我们进一步探讨了其在H1N1感染的A549细胞中的抗流感机制：作为一种新型CLK1抑制剂，J10688（3、10、30μmol/ L）剂量依赖性地削弱了病毒蛋白NP和M2的合成，并显着下调了剪接因子SF2 / ASF和SC35的磷酸化，它们调节病毒M2基因的选择性剪接。作为一种新型的CLK1抑制剂，在体内外均具有强​​大的抗流感活性，