title: Comparison of in vitro antiviral activity of tea polyphenols against influenza A and B viruses and structure-activity relationship analysis.
abstract: Influenza poses a particular risk of severe outcomes in the elderly, the very young and those with underlying diseases. Tea polyphenols are the natural phenolic compounds in teas, and principally consist of catechins, proanthocyanidins, flavonols, and theaflavins, which antiviral activities have been reported recently. This study is to gain a further insight into potential of various tea polyphenols for inhibiting influenza virus infection. Five tea polyphenols exhibited inhibitory activity against influenza A virus in the trend of theaflavin>procyanidin B-2>procyanidin B-2 digallate>(-)-epigallocatechin(EGC)>(-)-epigallocatechingallate(EGCG) with IC50 values in the range of 16.2-56.5 μg/ml. Six of the tested compounds showed anti-influenza B virus activity in the order of kaempferol>EGCG>procyanidin B-2>(-)-EGC~methylated EGC>theaflavin with IC50 values in the range of 9.0-49.7 μg/ml. Based on these results, the structure-activity relationship (SAR) was explained as follows. First, the dimeric molecules, such as theaflavin and procyanidin B-2, generally displayed more potent antiviral activity against both influenza A and B viruses than the catechin monomers. Second, the kaempferol for inhibition of influenza B virus indicated that the more planar flavonol structure with only one C-4' phenolic hydroxyl group in the B ring is necessary for the anti-influenza B virus activity. A similar SAR can be drawn from the assays of another enveloped RNA virus, such as respiratory syncytial virus. These results are expected to provide guides for rational design of antiviral drugs based on polyphenols.
authors.affiliation: State Key Laboratory of Respiratory Disease (Guangzhou Medical University), The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Road, Guangzhou, China; National Clinical Research Center, Guangzhou, China.
authors.forename: Zi-Feng
authors.initials: ZF
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau SAR, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Bai
authors.affiliation: State Key Laboratory of Respiratory Disease (Guangzhou Medical University), The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Road, Guangzhou, China.
authors.forename: Wen-bo
authors.initials: WB
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Respiratory Disease (Guangzhou Medical University), The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Road, Guangzhou, China.
authors.forename: Xu-Zhao
authors.initials: XZ
authors.lastname: Li
authors.affiliation: State Key Laboratory of Respiratory Disease (Guangzhou Medical University), The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Road, Guangzhou, China.
authors.forename: Sui-Shan
authors.initials: SS
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Respiratory Disease (Guangzhou Medical University), The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Road, Guangzhou, China; National Clinical Research Center, Guangzhou, China. Electronic address: nanshan@vip.163.com.
authors.forename: Nan-Shan
authors.initials: NS
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau SAR, China. Electronic address: zhjiang@must.edu.mo.
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Jiang
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000032:analysis* / Q000494:pharmacology; D028241:Camellia sinensis / Q000737:chemistry*; D003588:Cytopathogenic Effect, Viral; D004285:Dogs; D009980:Influenza A virus / Q000187:drug effects*; D009981:Influenza B virus / Q000187:drug effects*; D061985:Madin Darby Canine Kidney Cells; D008826:Microbial Sensitivity Tests; D059808:Polyphenols / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013662:Tea / Q000737:chemistry
chemical_list: D000998:Antiviral Agents; D059808:Polyphenols; D013662:Tea
keywords: (−)-Epicatechin (PubChem CID: 72276); (−)-Epicatechingallate (PubChem CID: 107905); (−)-Epigallocatechin (PubChem CID: 72277); (−)-Epigallocatechingallate (PubChem CID: 65064); Antiviral; Influenza virus; Kaempferol (PubChem CID: 5280863); Myricetin (PubChem CID: 5281672); Procyanidin B2 (PubChem CID: 122738); Quercetin (PubChem CID: 5280343); Structure–activity relationship; Tea polyphenols; Theaflavin(PubChem CID: 114777); Theaflavindigallate (PubChem CID: 44448535)