基于TLR4/NF-κB/NLRP3信号通路探讨香附挥发油对产后抑郁小鼠的干预作用OA

Objective To evaluate the intervention effects of Xiangfu(Cyperi Rhizoma)volatile oil on postpartum depression(PPD)and to explore its relationship with hippocampal neuroinflammation and the Toll-like receptor 4/nuclear factor-κB/NOD-like receptor pyrin domain-containing protein 3(TLR4/NF-κB/NLRP3)signaling pathway.Methods Network pharmacology was used to predict the potential targets and enriched pathways of Xiangfu(Cyperi Rhizoma)volatile oil.Female C57BL/6 mice were randomly divided into normal control group,model group,Xiangfu(Cyperi Rhizoma)volatile oil group,and fluoxetine group,with six mice in each group.Except for the normal control group,PPD models were established in the other groups by abrupt withdrawal of hormones following hormone-simulated pregnancy.The normal control and model groups were given normal saline by gavage,the Xiangfu(Cyperi Rhizoma)volatile oil group received Xiangfu(Cyperi Rhizoma)volatile oil 50 mg/(kg·d)by gavage,and the fluoxetine group received fluoxetine 10 mg/(kg·d)intraperitoneally,for two consecutive weeks.Behavioral tests were performed to evaluate depressive-like behaviors and drug intervention effects.HE staining was used to observe hippocampal pathological changes.ELISA was used to determine the levels of inducible nitric oxide synthase(iNOS),cyclooxygenase-2(COX-2),tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and interferon-γ(IFN-γ)in serum and hippocampal tissue.Immunofluorescence staining was performed to measure the positive expression levels of NLRP3 and cysteinyl aspartate-specific protease-1(Caspase-1)in the hippocampal dentate gyrus.Western blot was used to determine the protein expression levels of TLR4,myeloid differentiation factor 88(MyD88),phosphorylated nuclear factor-κB p65/nuclear factor-κB p65(p-p65/p65),tumor necrosis factor receptor-associated factor 6(TRAF6),NLRP3,and Caspase-1 in hippocampal tissues.Results Network pharmacology analysis showed that the targets related to Xiangfu(Cyperi Rhizoma)volatile oil were mainly enriched in inflammation-related signaling pathways,including Toll-like receptor,TNF,NF-κB,and NOD-like receptor pathways.In the animal experiments,at week 0,there were no statistically significant differences among groups in sucrose preference rate,forced swimming immobility time,or tail suspension immobility time(P>0.05).At week 5,compared with the normal control group,the model group showed a decreased sucrose preference rate,prolonged forced swimming immobility time,and tail suspension immobility time(P<0.01),increased levels of iNOS,COX-2,TNF-α,IL-1β,and IFN-γ in serum and hippocampal tissues(P<0.01),elevated positive expression levels of NLRP3 and Caspase-1 in the hippocampal dentate gyrus(P<0.01),and upregulated protein expression levels of TLR4,MyD88,p-p65/p65,TRAF6,NLRP3,and Caspase-1 in hippocampal tissue(P<0.01).Compared with the model group,both the Xiangfu(Cyperi Rhizoma)volatile oil and fluoxetine groups exhibited increased sucrose preference rate,shortened forced swimming immobility tissues and tail suspension immobility time(P<0.01),reduced levels of iNOS,COX-2,TNF-α,IL-1β,and IFN-γ in serum and hippocampal tissues(P<0.01),decreased positive expression levels of NLRP3 and Caspase-1 in the hippocampal dentate gyrus(P<0.01),and downregulated protein expression levels of TLR4,MyD88,p-p65/p65,TRAF6,and NLRP3 in hippocampal tissues(P<0.01 or P<0.05).Additionally,the Xiangfu(Cyperi Rhizoma)volatile oil group showed decreased caspase-1 protein expression(P<0.05),while the fluoxetine group showed a decreasing trend in caspase-1 protein expression without statistical significance(P>0.05).Conclusion Xiangfu(Cyperi Rhizoma)volatile oil may exert antidepressant effects on PPD by inhibiting hippocampal neuroinflammation mediated by the TLR4/NF-κB/NLRP3 signaling pathway,providing experimental evidence for its potential as an intervention drug for PPD.