Abstract

With the acceleration of global aging, Alzheimer’s disease (AD) poses a significant public health challenge, and effective treatments are still lacking. Neuroinflammation, particularly microglia-mediated inflammation, plays a central role in AD pathogenesis, with the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway being a key regulator. The histone deacetylase inhibitor (HDACi) Vorinostat (SAHA) has shown anti-inflammatory and neuroprotective potential in preclinical studies. Given the significant sex differences in AD incidence, pathology, and treatment response, this study aimed to systematically investigate the effects of SAHA on lipopolysaccharide (LPS)-induced neuroinflammation and cognitive dysfunction, analyzing its sex-specific effects and underlying mechanisms. An LPS-induced neuroinflammation model was established in male and female C57BL/6 mice via intraperitoneal injection (1 mg/kg) for 7 consecutive days, followed by SAHA (50 mg/kg) gavage intervention for 23 days. Cognitive function was assessed using Y-maze, novel object recognition, and passive avoidance tests. Hippocampal pathology was analyzed via hematoxylin-eosin (HE) staining and Nissl staining. Western blot and quantitative PCR (qPCR) were used to detect hippocampal expression of the TLR4/TRAF6/IKKα/NF-κB pathway, inflammatory factors (IL-6, IL-1β, TNF-α, iNOS), and neuroplasticity-related proteins (BDNF, p-CREB). In vitro experiments using LPS-stimulated BV2 microglia validated SAHA’s anti-inflammatory mechanisms via CCK-8, Griess assay, qPCR, and Western blot. Results showed that LPS treatment significantly activated the TLR4/TRAF6/IKKα/NF-κB pathway, upregulated hippocampal pro-inflammatory factors, caused neuronal damage, and impaired learning and memory; these effects appeared more pronounced in female mice, though this observation is exploratory and requires cautious interpretation. SAHA treatment markedly alleviated LPS-induced inflammation, neuropathology, and c