title: Antiviral activity of polymethoxylated flavones from "Guangchenpi", the edible and medicinal pericarps of citrus reticulata 'Chachi'.
abstract: The present study found that the supercritical fluid extract of "Guangchenpi" possessed in vitro antiviral activity against respiratory syncytial virus (RSV). Bioassay-guided isolation and identification of this extract led to obtain five active polymethoxylated flavones (1-5). Cytopathic effect (CPE) reduction assay exhibited that tangeretin (2) and nobiletin (3), two major polymethoxylated flavones in the extract, possessed better anti-RSV effect comparable to the positive control ribavirin. Plaque reduction assay revealed that tangeretin dose-dependently inhibited RSV-induced plaque formation on the HEp-2 cells. This polymethoxylated flavone mainly affected the intracellular replication of RSV, and it also could inhibit RSV entry into the HEp-2 cells. Further investigations with quantitative real-time PCR and confocal and Western blot assays indicated that tangeretin downregulated the expression of RSV phosphoprotein (P protein). Results suggest the potential application of the supercritical fluid extract of "Guangchenpi" and tangeretin in the treatment and the prevention of RSV infection.
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University , Guangzhou 510632, People's Republic of China.
authors.forename: Jiao-Jiao
authors.initials: JJ
authors.lastname: Xu
authors.forename: Xia
authors.initials: X
authors.lastname: Wu
authors.forename: Man-Mei
authors.initials: MM
authors.lastname: Li
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Li
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Yang
authors.forename: Hu-Jie
authors.initials: HJ
authors.lastname: Luo
authors.forename: Wei-Huang
authors.initials: WH
authors.lastname: Huang
authors.forename: Hau Yin
authors.initials: HY
authors.lastname: Chung
authors.forename: Wen-Cai
authors.initials: WC
authors.lastname: Ye
authors.forename: Guo-Cai
authors.initials: GC
authors.lastname: Wang
authors.forename: Yao-Lan
authors.initials: YL
authors.lastname: Li
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line / Q000187:drug effects / Q000821:virology; D002957:Citrus / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D047309:Flavones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D010936:Plant Extracts / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012136:Respiratory Syncytial Viruses / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D015678:Viral Structural Proteins / Q000378:metabolism; D053585:Virus Attachment / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D047309:Flavones; C529603:P protein, human respiratory syncytial virus; D010936:Plant Extracts; D015678:Viral Structural Proteins; C008661:nobiletin; C059006:tangeretin