School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T, Hong Kong, China.
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T, Hong Kong, China.
J Ethnopharmacol. 2020 May 10;253:112671. doi: 10.1016/j.jep.2020.112671. Epub 2020 Feb 17.
Bai Shao (Radix Paeoniae Alba, BS), the root of Paeonia lactiflora Pall., in ancient China was used for Wen Bing (Warm Disease) treatment. Wen Bing has the symptoms of influenza. Ethanol extract of the root has recently been shown to possess anti-influenza activity. However, the active compounds have not yet been identified.
We showed that BS aqueous extract was potent in inhibiting influenza A virus in infected cells. We aimed to isolate the bioactive compounds and characterize the anti-influenza mechanism.
Plaque reduction assay was performed for fractions isolated from BS. Hemagglutination inhibition assay and neuraminidase inhibition assay were performed to find the target protein. Molecular docking and reverse genetics were used to confirm the action site of gallic acid on the neuraminidase protein.
We identified three tannin compounds gallic acid (GA), methyl gallate (MG) and pentagalloylglucose (PGG) in BS aqueous extract that could inhibit the replication of influenza A virus in MDCK cells. While only PGG was found to inhibit the influenza virus-induced hemagglutination of chicken erythrocytes, all three compounds significantly reduced the activity of the neuraminidase. The results from molecular docking and reverse genetics showed that GA interacted with Arg152 of neuraminidase protein.
Three compounds GA, MG and PGG isolated from BS were found to inhibit influenza A virus in MDCK cells. GA interacts with amino acid Arg152 of the viral neuraminidase. Our study identified anti-influenza compounds of BS and demonstrated their antiviral mechanism, thus providing scientific evidence for using this herb for clinical treatment.
白芍（芍药根，BS），是中国古代用于治疗温病（流感症状）的白芍根。最近研究表明，BS 的乙醇提取物具有抗流感活性。然而，其活性化合物尚未确定。
我们发现 BS 水提取物在感染细胞中能有效抑制甲型流感病毒。我们旨在分离生物活性化合物并阐明其抗流感机制。
通过噬斑减少试验对 BS 中分离的各馏分进行分析。通过血凝抑制试验和神经氨酸酶抑制试验确定靶蛋白。分子对接和反向遗传学用于证实没食子酸在神经氨酸酶蛋白上的作用位点。
我们在 BS 水提物中鉴定出三种单宁化合物，即没食子酸（GA）、甲基没食子酸（MG）和五没食子酰葡萄糖（PGG），它们能够抑制 MDCK 细胞中甲型流感病毒的复制。虽然只有 PGG 被发现能够抑制流感病毒诱导的鸡红细胞血凝作用，但这三种化合物均能显著降低神经氨酸酶的活性。分子对接和反向遗传学的结果表明，GA 与神经氨酸酶蛋白的 Arg152 相互作用。
从 BS 中分离出的三种化合物 GA、MG 和 PGG 被发现能抑制 MDCK 细胞中的甲型流感病毒。GA 与病毒神经氨酸酶的氨基酸 Arg152 相互作用。本研究鉴定了 BS 中的抗流感化合物，并阐明了其抗病毒机制，为临床应用该草药提供了科学依据。
