Curcumin (Cur), a polyphenolic compound extracted from spice and common food colourant turmeric, contains versatile bio-activities. Monoacetylcurcumin (MAC), a structural analogue of Cur, differs from Cur by acetyl modification, but retains enone groups. Comparative analysis revealed MAC effectively inhibited influenza virus infection (IAV) to a similar extent as, if not superior to, curcumin. Both compounds mildly reduced viral NA activity. Surprisingly, unlike Cur, the MAC inhibition of IAV did not occur through the blocking of HA activity. However, MAC strongly dampened Akt phosphorylation, the prerequisite signalling for efficient IAV propagation. A much stronger inhibition effect on IAV infection was observed when MAC treatment was in combination with Cur. Collectively, MAC demonstrated clear antiviral activity, and likely inhibited IAV via multiple mechanisms that were not identical to Cur. Importantly, Cur and MAC in combination synergistically inhibited IAV infection.

中文翻译：

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姜黄素及其结构类似物（单乙酰姜黄素）抗流感病毒感染的协同作用

姜黄素 (Cur) 是一种从香料和常见食用色素姜黄中提取的多酚化合物，具有多种生物活性。单乙酰姜黄素 (MAC) 是 Cur 的结构类似物，与 Cur 的不同之处在于乙酰基修饰，但保留了烯酮基团。比较分析显示 MAC 有效抑制流感病毒感染 (IAV) 的程度与姜黄素相似，甚至优于姜黄素。两种化合物均轻度降低病毒 NA 活性。令人惊讶的是，与 Cur 不同，IAV 的 MAC 抑制不是通过阻断 HA 活性而发生的。然而，MAC 强烈抑制 Akt 磷酸化，这是有效 IAV 传播的先决条件。当 MAC 治疗与 Cur 联合使用时，观察到对 IAV 感染的抑制作用要强得多。总的来说，MAC 表现出明显的抗病毒活性，并且可能通过与 Cur 不同的多种机制抑制 IAV。重要的是，Cur 和 MAC 联合使用可协同抑制 IAV 感染。