Qinzhi Zhudan formula improves memory and alleviates neuroinflammation in vascular dementia rats partly by inhibiting the TNFR1-mediated TNF pathway

Abstract

The Qinzhi Zhudan formula (QZZD) exhibits a prominent therapeutic effect in the treatment of vascular dementia (VaD). This study combined a network pharmacology approach and experimental validation to identify the underlying biological mechanism of QZZD against VaD. Male Wistar rats received bilateral common carotid artery occlusion (BCCAO) surgery, and after 4 weeks of intragastric administration of QZZD, the therapeutic effect was assessed using the Morris water maze test and cerebral blood flow (CBF) assessment. Hematoxylin and eosin staining, Nissl staining, and electron microscopy were used to measure the histopathological changes in the neurons of rats. The effect of QZZD treatment on hippocampal neurotransmitters was assessed by high-performance liquid chromatography with electrochemical detection and liquid chromatography mass spectrometry. Immunofluorescence was used to observe VaD-induced microglia activation. The inflammatory cytokine levels were assessed by enzyme linked immunosorbent assay. Western blot was used to examine the TNFR1-mediated TNF pathway, which was screened out by network pharmacology analysis. QZZD treatment alleviated pathological changes and neuronal damage in VaD rats and attenuated their cognitive impairment. In addition, QZZD increased CBF and the expression of acetylcholine and 5-hydroxytryptamine in the hippocampal region. Notably, QZZD inhibited microglial activation and the expression of IL-6 and TNF-α. Network pharmacology and western blot indicated that QZZD inhibited the levels of TNFR1, NF-κBp65, p-ERK, TNF-α, and IL-6, which are related to the TNFR1-mediated TNF signaling pathway. QZZD clearly improved learning and memory function, reduced brain pathological damage, elevated CBF and hippocampal neurotransmitter levels, and alleviated neuroinflammation of VaD rats partly by inhibiting the TNFR1-mediated TNF pathway, indicating its potential value in the clinical therapy of VaD.