鼠尾草酸对甲型流感病毒的体外抑制作用研究

In vitro inhibition of carnosic acid against influenza A virus infections

鼠尾草酸(carnosic acid,CA)是迷迭香与鼠尾草等植物中主要的酚二萜类活性成分,具有抗氧化、抗炎等作用,但目前未见CA抗流感病毒的相关报道。本研究通过病毒滴度测定方法评价了迷迭香中主要活性成分迷迭香酸、CA和熊果酸的抗流感病毒活性,发现CA在A549细胞中显著抑制流感病毒H5N1增殖,进一步通过间接免疫荧光、Western blot和实时荧光定量PCR等方法对CA的体外抗流感病毒作用进行了系统评价并初步探讨其作用机制。结果表明,CA在A549和MDCK细胞中可显著抑制流感病毒H5N1复制,半数有效浓度(EC_(50))分别为4.30和3.64μmol·L^(-1)。同时,CA也抑制流感病毒2009panH1N1(EC_(50):10.1μmol·L^(-1))和H3N2(EC_(50):12.8μmol·L^(-1))在A549细胞中的复制。机制研究发现,CA对H5N1复制的抑制作用与其诱导A549细胞血红素加氧酶-1(HO-1)的表达并减少H5N1感染细胞中活性氧的水平有关。

Carnosic acid(CA)is the main phenolic diterpenoid active ingredient in plants such as rosemary and sage,and has antiviral,antioxidant,anti-inflammatory effects and so on,however,its antiviral activity against influenza virus infections was not reported.In this study,antiviral activities against influenza A virus infections of three main bioactive ingredients from rosemary,including rosmarinic acid,CA and ursolic acid,were evaluated using virus titer titration assay,and CA showed remarkable inhibition on influenza H5N1 replication in A549 cells.The antiviral activity of CA was further confirmed and its mechanism of action was investigated using the indirect immunofluorescence assay(IFA),Western blot and real-time fluorescence quantification polymerase chain reaction(qRT-PCR).The results showed that the 50%effective concentration(EC_(50))of CA against influenza H5N1 in A549 cells and MDCK cells were 4.30 and 3.64μmol·L^(-1),respectively.Meanwhile,CA also showed inhibition on influenza virus 2009panH1N1(EC_(50):10.1μmol·L^(-1))and H3N2(EC_(50):12.8μmol·L^(-1))replications in A549 cells.Mechanistic studies showed that antiviral activity of CA is related to its induction of heme oxygenase-1(HO-1)in A549 cells and suppression on production of reactive oxygen in H5N1-infected cells.