title: [The effects of a hot water soluble extract (S-03) isolated from Isatis indigotica root on influenza A and B viruses in vitro].
abstract: This study was to investigate the antiviral effects of a hot water soluble extract S-03 isolated from Isatis indigotica root on different subtypes of influenza A and B viruses in MDCK cell cultures, using plaque reduction, immunofluorescence and hemo-agglutination inhibition (HAD) assays. Chemical analysis of the extract S-03 showed that it contained high proportion of polysaccharides. The antiviral effects in vitro showed that the S-03 had no effect on different influenza viruses if the drug was used before virus adsorption, but S-03 showed obvious activities against influenza viruses if treatment after virus adsorption or direct reaction of drug and virus before virus adsorption. Hemagglutination inhibition assay showed that S-03 inhibited HA activities of different human influenza viruses (inhibition concentration ranged from 3.12 to 25 mg/mL), avain influenza viruses (inhibition concentration ranged from 25 to 50 mg/mL). The antiviral effects of S-03 on different influenza A and B viruses in vitro might be through the inhibition of the HA to prevent infection.
authors.affiliation: Clinical Virology Division, State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, The First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510120, China. jeffyah@163.com
authors.forename: Zi-Feng
authors.initials: ZF
authors.lastname: Yang
authors.forename: Yu-Tao
authors.initials: YT
authors.lastname: Wang
authors.forename: Sheng
authors.initials: S
authors.lastname: Qin
authors.forename: Sui-Shan
authors.initials: SS
authors.lastname: Zhao
authors.forename: Yun-Shi
authors.initials: YS
authors.lastname: Zhao
authors.forename: Qin
authors.initials: Q
authors.lastname: Lin
authors.forename: Wen-Da
authors.initials: WD
authors.lastname: Guan
authors.forename: Qun-Di
authors.initials: QD
authors.lastname: Huang
authors.forename: Zi-Yao
authors.initials: ZY
authors.lastname: Mo
authors.forename: Chu-Yuan
authors.initials: CY
authors.lastname: Li
authors.forename: Nan-Shan
authors.initials: NS
authors.lastname: Zhong
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004285:Dogs; D005455:Fluorescent Antibody Technique; D006385:Hemagglutination Inhibition Tests; D009980:Influenza A virus / Q000187:drug effects*; D009981:Influenza B virus / Q000187:drug effects*; D031219:Isatis / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots
chemical_list: D010936:Plant Extracts