Chuanxiong Renshen Decoction Inhibits Alzheimer's Disease Neuroinflammation by Regulating PPARγ/NF-κB Pathway

Background and Aim: Previous studies of our research group have shown that Chuanxiong Renshen Decoction (CRD) has the effect of treating AD, but the exact mechanism of its effect is still not clarified. The aim of this study was to investigate the effect and mechanism of CRD on AD neuroinflammation. Materials and Methods: Morris Water Maze (MWM) tests were employed to assess the memory and learning capacity of AD mice. HE and Nissl staining were used to observe the neural cells of mice. The expression of Iba-1 and CD86 were detected by immunohistochemical staining. Utilize UHPLC-MS/MS metabolomics techniques and the KEGG to analyze the metabolic pathways of CRD against AD. Lipopolysaccharide (LPS) induced BV2 microglia cells to construct a neuroinflammatory model. The expression of Iba-1 and CD86 were detected by immunofluorescence and flow cytometry. The contents of TNF-alpha and IL-1(3 were detected by ELISA. Western blot assay was used to detect the expression of PPAR gamma, p-NF-kappa B p65, NF-kappa B p65 proteins and inflammatory cytokines iNOS and COX-2 in PPAR gamma/NF-kappa B pathway with and without PPAR gamma inhibitor GW9662. Results: CRD ameliorated the learning and memory ability of 3xTg-AD mice, repaired the damaged nerve cells in the hippocampus, reduced the area of Iba-1 and CD86 positive areas in both the hippocampus and cortex regions, as well as attenuated serum levels of IL-1(3 and TNF-alpha in mice. CRD-containing serum significantly decreased the expression level of Iba-1, significantly reduced the levels of TNF-alpha and IL-1(3, significantly increased the protein expression of PPAR gamma, and significantly decreased the proteins expression of iNOS, COX-2 and p-NF-kappa B p65 in BV2 microglia cells. After addition of PPAR gamma inhibitor GW9662, the inhibitory effect of CRDcontaining serum on NF-kappa B activation was significantly weakened. Conclusion: CRD can activate PPAR gamma, regulating PPAR gamma/NF-kappa B signaling pathway, inhibiting microglia over-activation and reducing AD neuroinflammation.