title: Antiviral effect of epigallocatechin gallate on enterovirus 71.
abstract: Oxidative stress is known to be a determinant of a host's susceptibility to pathogens. Natural compounds with antioxidant activity may provide a preventive measure against infection. Tea polyphenols were evaluated for their ability to inhibit enterovirus 71 (EV71) replication in Vero cell culture. Among the polyphenolic compounds tested, epigallocatechin gallate (EGCG) and gallocatechin gallate (GCG) potently inhibited replication of EV71. EGCG and GCG reduced the titer of infectious progeny virus by 95%. Quantitative RT-PCR analysis also revealed that EGCG suppressed replication of genomic RNA. It was accompanied by an increased cytoprotective effect. EGCG and GCG caused 5-fold increase in the viability of EV71-infected cells. The viral inhibitory effect correlated well with the antioxidant capacity of polyphenol. Mechanistically, EV71 infection led to increased oxidative stress, as shown by increased dichlorofluorescein and MitoSOX Red fluorescence. Upon EGCG treatment, reactive oxygen species (ROS) generation was significantly reduced. Consistent with this, EV71 replication was enhanced in glucose-6-phosphate dehydrogenase deficient cells, and such enhancement was largely reversed by EGCG. These findings suggest that EGCG may suppress viral replication via modulation of cellular redox milieu.
authors.affiliation: Graduate Institute of Medical Biotechnology and Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Kwei-san, Taoyuan, Taiwan. hoh01@mail.cgu.edu.tw
authors.forename: Hung-Yao
authors.initials: HY
authors.lastname: Ho
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Cheng
authors.forename: Shiue-Fen
authors.initials: SF
authors.lastname: Weng
authors.forename: Yann-Lii
authors.initials: YL
authors.lastname: Leu
authors.forename: Daniel Tsun-Yee
authors.initials: DT
authors.lastname: Chiu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D000998:Antiviral Agents / Q000494:pharmacology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002460:Cell Line; D002522:Chlorocebus aethiops; D029821:Enterovirus A, Human / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D005347:Fibroblasts / Q000821:virology; D005953:Glycogen Storage Disease Type I; D006801:Humans; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D012367:RNA, Viral / Q000096:biosynthesis; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014709:Vero Cells; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000975:Antioxidants; D000998:Antiviral Agents; D012367:RNA, Viral; D017382:Reactive Oxygen Species; D002392:Catechin; C045651:epigallocatechin gallate