化瘀通络灸通过调节TLR4/NF-κB通路与小胶质细胞极化改善血管性痴呆大鼠认知障碍OA

Objective To investigate the role and mechanism of stasis-resolving and collateral-dredging moxibustion in impro-ving cognitive impairment in a rat model of vascular dementia(VD).Methods Among the 60 rats selected by the Morris water maze test,12 were randomly selected as sham-operation group,and the remaining 48 rats were used to establish a model of VD by modified permanent ligation of both common carotid arteries.After successful modeling,the rats were randomly divided into model group,stasis-resolving and collateral-dredging moxibustion group,and donepezil group,with 12 rats in each group.The rats in the stasis-resolving and collateral-dredging moxibustion group were given moxibustion at Baihui,Dazhui,and Shenting points for 20 minutes each time,once a day,and those in the donepezil group were given donepezil(0.5 mg/kg)by gavage,twice a day;each course of treatment included 7 consecutive days of intervention and 1 day of rest,and both groups were trea-ted for 3 courses.The Morris water maze test was used to observe behavioral changes;HE staining was used to observe patho-logical morphology of hippocampal tissue;Western blot was used to measure the protein expression levels of Toll-like receptor 4(TLR4)and nuclear factor-kappa B p65(NF-κB p65);immunofluorescence assay was used to measure the expression levels of M1-type microglial cell markers[inducible nitric oxide synthase(iNOS)and ionized calcium-binding adapter molecule 1(Iba1)]and M2-type microglial cell markers[arginase 1(Arg)]and Iba1 in hippocampal CA1 region;ELISA was used to measure the serum levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and interleukin-4(IL-4).Results Stasis-resolving and collateral-dredging moxibustion could significantly shorten escape latency(P＜0.05),increase the number of platform crossings(P＜0.05),and improve the disordered arrangement and karyopyknosis of neurons in hippocampal tissue(P＜0.05).In addition,it could also significantly reduce the protein expression levels of TLR4 and NF-κB p65(P＜0.05)and iNOS/Iba1 fluorescence intensity ratio in hippocampal tissue(P＜0.05),increase Arg1/Iba1 fluorescence intensity ratio(P＜0.05),reduce the serum levels of TNF-α and IL-6(P＜0.05),and increase the level of IL-4(P＜0.05).Conclusion Stasis-resolving and collateral-dredging moxibustion may exert a protective effect on hippocampal neurons and improve VD in rats by inhibiting the TLR4/NF-κB signaling pathway and regulating the transformation of microglial cells from the pro-inflammatory type(M1 type)to the anti-inflammatory type(M2 type).