title: Antiviral activity of Rheum palmatum methanol extract and chrysophanol against Japanese encephalitis virus.
abstract: Rheum palmatum, Chinese traditional herb, exhibits a great variety of anti-cancer and anti-viruses properties. This study rates antiviral activity of R. palmatum extracts and its components against Japanese encephalitis virus (JEV) in vitro. Methanol extract of R. palmatum contained higher levels of aloe emodin, chrysophanol, rhein, emodin and physcion than water extract. Methanol extract (IC₅₀ = 15.04 μg/ml) exhibited more potent inhibitory effects on JEV plaque reduction than water extract (IC₅₀ = 51.41 μg/ml). Meanwhile, IC₅₀ values determined by plaque reduction assay were 15.82 μg/ml for chrysophanol and 17.39 μg/ml for aloe-emodin, respectively. Virucidal activity of agents correlated with anti-JEV activity, while virucidal IC₅₀ values were 7.58 μg/ml for methanol extract, 17.36 μg/ml for water extract, 0.75 μg/ml for chrysophanol and 0.46 μg/ml for aloe-emodin, respectively. In addition, 10 μg/ml of extract, chrysophanol or aloe emodin caused 90 % inhibition of JEV yields in cells and significantly activated gamma activated sequence-driven promoters. Hence, methanol extract of R. palmatum and chrysophanol with high therapeutic index might be useful for development of antiviral agents against JEV.
authors.affiliation: School of Pharmacy, China Medical University, Taichung, Taiwan.
authors.forename: Shu-Jen
authors.initials: SJ
authors.lastname: Chang
authors.forename: Su-Hua
authors.initials: SH
authors.lastname: Huang
authors.forename: Ying-Ju
authors.initials: YJ
authors.lastname: Lin
authors.forename: Yi-Yun
authors.initials: YY
authors.lastname: Tsou
authors.forename: Cheng-Wen
authors.initials: CW
authors.lastname: Lin
mesh_terms: D000818:Animals; D000880:Anthraquinones / Q000494:pharmacology*; D000998:Antiviral Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification / Q000494:pharmacology*; D004664:Encephalitis Virus, Japanese / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D020834:Ethnopharmacology; D017930:Genes, Reporter / Q000187:drug effects; D020128:Inhibitory Concentration 50; D050832:Interferon-Stimulated Gene Factor 3 / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D049409:Luciferases, Firefly / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008647:Mesocricetus; D000432:Methanol / Q000737:chemistry; D011401:Promoter Regions, Genetic / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012250:Rheum / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D000880:Anthraquinones; D000998:Antiviral Agents; D004365:Drugs, Chinese Herbal; D050832:Interferon-Stimulated Gene Factor 3; D011993:Recombinant Fusion Proteins; D012997:Solvents; C079868:gamma interferon activation factor; C518327:aloe emodin; D049409:Luciferases, Firefly; C027113:chrysophanic acid; D000432:Methanol