title: Water extract of Glycyrrhiza uralensis inhibited enterovirus 71 in a human foreskin fibroblast cell line.
abstract: Human infection by enterovirus type 71 (EV71) can cause life-threatening meningo-encephalitis. Currently, there is no effective anti-EV71 therapy available. Since EV71 infection commonly involves skin lesions, we tested our hypothesis that water extract of Glycyrrhiza uralensis (G. uralensis) could inhibit the cytopathic effects of EV71 in a human foreskin cell line by using an XTT-based method. Our results showed that the water extract of G. uralensis at 3,000 microg/ml has only 30% cytotoxicity on host cells, and furthermore, that the water extract of G. uralensis at 0.1 microg/ml could effectively protect host cells against EV71 infection (p < 0.0001). The half maximal inhibitory concentration (IC(50)) was 0.056 microg/ml with a selective index greater than 50,000. The water extract of G. uralensis exerted its effects not only by preventing viral attachment (p < 0.0001), but also by inhibiting the penetration of the virus (p < 0.0001). EV71 infection caused cells to produce significant amounts of IFN-beta (p = 0.0003). However, the anti-EV71 activity of the water extract of G. uralensis was not mediated by IFN. In conclusion, the water extract of G. uralensis possesses potent anti-EV71 effects with less cytotoxicity. Its low IC(50) and high 50% cytotoxic concentration (CC(50)) values suggest that it is a promising anti-EV71 agent.
authors.affiliation: Division of Hepatobiliary Pancreatic Surgery, Department of Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Kung-Kai
authors.initials: KK
authors.lastname: Kuo
authors.forename: Jung-San
authors.initials: JS
authors.lastname: Chang
authors.forename: Kuo-Chih
authors.initials: KC
authors.lastname: Wang
authors.forename: Lien-Chai
authors.initials: LC
authors.lastname: Chiang
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D029821:Enterovirus A, Human / Q000187:drug effects* / Q000472:pathogenicity; D005347:Fibroblasts / Q000821:virology; D029882:Glycyrrhiza uralensis / Q000737:chemistry*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D014867:Water
chemical_list: D000998:Antiviral Agents; D010936:Plant Extracts; D014867:Water