Rubiadin Alleviates Alzheimer's Disease Pathology via NF-κB Pathway Regulation

Alzheimer's disease (AD) is a severe neurodegenerative disorder that impacts the global impact on the population. Nevertheless, the intricate nature of its pathogenesis has posed significant challenges to drug discovery in this field. This study aimed to verify the therapeutic potential of rubiadin (RB) on AD through both in vivo and in vitro experiments, thereby facilitating translational research for the advancement of AD treatment.

We investigated the neuroprotective effects of RB on AD using both in vivo and in vitro models. Immunohistochemistry and western blot analysis were employed to evaluate inflammatory factors and the Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway in Mo/HuAPP695swe (APP)/PS1-dE9 (PS1) mice and N2a cells.

RB enhanced the memory performance of APP/PS1 mice in various tests, including the Morris water maze, step-down and step-through passive avoidance tasks, and novel object recognition. RB reduced the accumulation of Amyloid-beta (Aβ) plaques, as shown by immunohistochemical analysis. It also decreased the expression levels of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α), while increasing the release of IL-4. Additionally, RB inhibited the NF-κB pathway, as demonstrated by western blot. Moreover, a cell viability test showed that RB protected N2a cells against toxicity caused by Aβ_1-42 through a cell viability test. Western blot analysis revealed that neuroinflammation and the NF-κB pathway were inhibited by RB treatment in Aβ_1-42-induced N2a cells. Accordingly, RB suppressed the nuclear translocation of NF-κB in Aβ_1-42-induced N2a cells.

Our results provide experimental evidence supporting the preclinical research and future clinical applications of RB, thereby facilitating the development of new drugs for AD clinical therapy.