Acacetin improves cognitive function of APP/PS1 Alzheimer's disease model mice via the NLRP3 inflammasome signaling pathway.

Abstract

Background: Acacetin (5,7-dihydroxy-4'-methoxyflavone), one of the main extractions from Saussurea involucrata, has anti-inflammatory effects. Our previous study found that acacetin inhibited the Nod-like receptor pyrin domain containing 3 (NLRP3) signaling pathway after cerebral ischemia-reperfusion injury. NLRP3 inflammasome plays a role in Alzheimer's disease (AD) process. However, few studies have examined the effects of acacetin in AD.

Methods: We randomly divided APP swe/PS1dE9 double transgenic mice into acacetin group (intraperitoneal injection of 25 mg/kg acacetin) and AD model group (intraperitoneal injection of same volume of saline). C57BL/6 mice were selected as control group (same treatment with AD model group). After treating for 30 days, a Morris water maze test was conducted to evaluate spatial learning and memory of the mice. Senile plaque (SP) formation was evaluated by immunohistochemistry. NLRP3 inflammasome-related inflammatory factors and amyloid-β-42 were detected by Western blot or enzyme-linked immunosorbent assay.

Results: Acacetin improved spatial learning and memory of AD mice and reduced APP/β expression, thereby decreasing SP formation in the brain. Acacetin also reduced the expression of NLRP3, cysteinyl aspartate-specific proteinase 1 (caspase-1), and interleukin-1β (IL-1β) and the release of inflammatory factors, tumor necrosis factor-α (TNF-α) and IL-1β.

Conclusions: Acacetin improved the learning and memory abilities of AD mice and exerted a protective effect on AD by inhibiting the NLRP3 signaling pathway and reducing SP formation.