Quercetin Promotes M2 Polarization of Primary Microglia Induced by Lipopolysaccharide and Its Mechanism
10.16466/j.issn1005-5509.2025.03.001
- VernacularTitle:槲皮素促进脂多糖诱导的原代小胶质细胞M2型极化及机制研究
- Author:
Huiqin HU
1
;
Lin LI
1
;
Xiaowei HU
1
Author Information
1. 浙江中医药大学基础医学院 杭州 310053
- Publication Type:Journal Article
- Keywords:
quercetin;
microglia;
polarization;
neuroinflammation;
network pharmacology;
molecular docking;
PI3K/Akt
- From:
Journal of Zhejiang Chinese Medical University
2025;49(3):259-271
- CountryChina
- Language:Chinese
-
Abstract:
[Objective]To explore the effect and potential mechanism of quercetin on polarization of lipopolysaccharide(LPS)-induced primary microglia.[Methods]Primary rat microglia were isolated and cultured,and then randomly divided into control group,model group and quercetin low-dose,medium-dose,high-dose groups.In model group,microglial activation was induced with LPS.In the quercetin groups,microglia were pretreated with quercetin at concentrations of 20,40 and 80 μmol·L-1 for 1 hour,followed by the addition of LPS to the culture medium for an additional 24 hours.Cell viability was assessed by using the CCK-8 assay.The nitric oxide(NO)content in the supernatant was measured by the Griess assay.Microglia activation was detected by ionized calcium binding adapter molecule 1(Iba1)/CD68 immunofluorescence staining.The expression levels of CD86,inducible nitric oxide synthase(iNOS),tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),IL-6,CD206,arginase-1(Arg-1),chitinase like protein 1/2(Ym1/2),IL-10 and transforming growth factor-β(TGF-β)mRNA were determined by Real time-quantitative polymerase chain reaction(RT-qPCR).Network pharmacology and molecular docking methods were employed to predict the potential mechanisms of quercetin in regulating microglia polarization.The protein expression levels of CD86,iNOS,CD206,Arg-1,phosphophorylated-phosphatidylinositol 3-kinase(p-PI3K)/phosphatidylinositol 3-kinase(PI3K),phosphophorylated-protein kinase B(p-Akt)/protein kinase B(Akt),phosphophorylated-nuclear factor-κB(p-NF-κB)/nuclear factor-κB(NF-κB)and phosphophorylated-inhibitor of NF-κB α(p-IκB-α)/inhibitor of NF-κB α(IκB-α)were determined by Western blot.[Results]Compared with LPS group,the NO release and CD68 mean fluorescence intensity of microglia in quercetin groups were significantly reduced(P<0.01),indicating that quercetin inhibited LPS-induced activation of primary microglia.Quercetin inhibited the mRNA and protein expression of CD86 and iNOS(P<0.05,P<0.01),and decreased the mRNA expression of pro-inflammatory factors TNF-α,IL-1β and IL-6(P<0.05,P<0.01).Additionally,quercetin promoted the mRNA and protein expression of CD206 and Arg-1(P<0.05,P<0.01),and upregulated the mRNA expression of anti-inflammatory factors Ym1/2,IL-10 and TGF-β(P<0.05,P<0.01).These findings indicated that quercetin promoted the transformation of LPS-induced primary microglia from the M1 type to the M2 type,thereby inhibiting neuroinflammation.The results of network pharmacology and molecular docking indicated that the regulation of microglia polarization by quercetin may be through the PI3K/Akt/NF-κB signaling pathway.In vitro experimental results showed that compared with LPS group,the protein expression levels of p-NF-κB and p-IκB-α in quercetin medium and high dose groups were significantly reduced(P<0.01),and the protein expression of p-PI3K and p-Akt was significantly increased(P<0.05,P<0.01).[Conclusion]Quercetin inhibited LPS-induced microglia inflammatory response and promoted microglia polarization to the M2 type,and the mechanism may be related to its regulation of the PI3K/Akt/NF-κB signaling pathway.
