板蓝根水提物S-03体外抑制甲、乙型流感病毒感染的实验研究

The Effects of a Hot Water Soluble Extract (S-03) Isolated from Isatis Indigotica Root on Influenza A and B Viruses in vitro

以水提法分离制备板蓝根水提物S-03分析其基本化学成分,并在狗肾细胞（MDCK）上分别接种人甲1、3型和乙型流感病毒标准株、临床分离株以及禽流感病毒,采用空斑减少和免疫荧光及血凝抑制实验方法,在预防、治疗和直接作用三种试验模式下探讨S-03体外对流感病毒的抑制作用。研究结果表明S-03的主要化学成分为糖类,多糖所占总重的比例最高。S-03体外抗病毒药效显示：①预防模式：对各型流感病毒均无抑制作用;②治疗和直接作用模式：对不同亚型流感病毒均有一定程度的抑制作用,且直接作用（SI=2.5~16）效果优于治疗模式（SI=2.2~5.8）;③血凝抑制试验：对不同亚型的人流感病毒血凝素有不同程度抑制作用（最低抑制浓度为3.12~25 mg/mL）,并且对禽流感病毒（H6N2、H7N3、H9N2）的血凝素也有一定的抑制作用（最低抑制浓度25~50 mg/mL）,其作用机制可能为抑制流感病毒表面的血凝素（HA）,从而阻止病毒感染。

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（HAI） 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.