木犀草素及其黄酮苷的抗炎、抗氧化作用

Anti-inflammatory and Antioxidant Effects of Luteolin and Its Flavone Glycosides

目的:以木犀草素及其3种黄酮苷(木犀草苷、荭草素、异荭草素)为研究对象,基于HTP-1细胞探究其抗炎与抗氧化活性。方法:采用荧光定量聚合酶链式反应法和Western Blot法分析4种黄酮类化合物预处理后细胞因子表达情况,核转录因子κB(nuclear factorκB,NF-κB)信号通路调控蛋白κB抑制因子α亚基(αinhibitor ofκB,IκBα)、IκB激酶β亚基(IκB kinaseβ,IKKβ)、P65的表达情况,以及抗氧化相关核因子E2相关性因子2(nuclear factor erythroid 2 related factor 2,Nrf2)及血红素氧合酶1(heme oxygenase 1,HO-1)的表达情况。结果:4种黄酮类化合物对肿瘤坏死因子(tumor necrosis factor-α,TNF-α)、促炎因子白细胞介素(interleukin,IL)-6均具有极显著抑制作用(P<0.01),荭草素可以进一步抑制促炎因子IL-1β的表达(P<0.01);木犀草素及3种黄酮苷均可以显著抑制炎性细胞中IKKβ、IκBα的磷酸化,3种黄酮苷还可减少细胞核中P65的表达量,进而较好地抑制NF-κB信号通路发挥抗炎活性;荭草素可极显著促进炎性细胞中Nrf2的表达(P<0.01),促进Nrf2发生核移位(P<0.01),使HO-1的表达量处于较低水平(P<0.01),保持较低的氧化应激水平。结论:木犀草素及3种黄酮苷具有较好的抗炎作用,其中荭草素可通过抑制NF-κB信号通路调控蛋白IKKβ、IκBα、P65的表达发挥较强的抗炎活性,显著降低细胞中TNF-α、IL-6、IL-1β的表达,同时通过促进核转录因子Nrf2的表达与核移位,激活Nrf2发挥较好的抗氧化作用,使细胞中HO-1酶表达量处于较低水平。

The anti-inflammatory and antioxidant activities of luteolin,cynaroside,orientin and homoorientin were explored on THP-1 cells.The expression of cytokines in the cells pretreated with each of the four flavonoids were analyzed by fluorescence quantitative polymerase chain reaction(PCR)and Western Blot,and the expression of IκB kinaseβ(IKKβ),αinhibitor ofκB(IκBα),NF-κB P65,nuclear factor erythroid 2 related factor 2(Nrf2)and heme oxygenase 1(HO-1)enzyme were also analyzed.It was found that the expression of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)were extremely significantly inhibited by each of the four flavonoids(P<0.01).Orientin also inhibited the expression of IL-1β(P<0.01).These four flavonoids significantly inhibited the phosphorylation of IKKβand IκBαin inflammatory cells,and the three luteolin glycosides also reduced the content of P65 in the nuclei,thereby exerting their anti-inflammatory effects through the NF-κB signaling pathway.Moreover,orientin extremely significantly promoted the expression and nuclear translocation of Nrf2 in inflammatory cells(P<0.01),which resulted in a lower expression of HO-1(P<0.01)and a lower level of oxidative stress.In conclusion,luteolin and its three derivatives are effective against inflammation.In particular,orientin can down-regulate the expression of the NF-κB signaling pathway-related proteins IKKβ,IκBαand P65,thereby exerting its strong anti-inflammatory activity by significantly reducing the expression of TNF-α,IL-6 and IL-1β.Furthermore,by promoting Nrf2 expression and nuclear translocation,orientin can exert a good antioxidant effect,leading to a low level of HO-1 expression.