Nanotherapeutic potential of Baicalein-encapsulated hUC-MSC exosomes in Alzheimer's disease: Modulating oxidative stress and neuroinflammation

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by excessive amyloid-β (Aβ) accumulation, neuroinflammation, and oxidative stress. Exosomes derived from human umbilical cord mesenchymal stem cells (hUC-MSC@Exo) represent promising nanoscale carriers for targeted drug delivery. In this study, Baicalein (Bac), a potent antioxidant and anti-inflammatory flavonoid, was encapsulated into hUC-MSC-derived exosomes (Exo@Bac) to enhance its therapeutic efficacy. The neuroprotective potential of Exo@Bac was evaluated in a rat model of Aβ1–42-induced AD. Rats received intraperitoneal injections of Bac, hUC-MSC@Exo, or Exo@Bac, and cognitive performance was assessed using the passive avoidance test and Morris water maze. Exo@Bac treatment significantly improved memory deficits and elevated brain-derived neurotrophic factor (BDNF) expression compared to controls. Histopathological analyses revealed reduced neuronal damage and apoptosis, alongside decreased Aβ1–42 deposition in Exo@Bac-treated rats. Furthermore, Exo@Bac enhanced antioxidant defense (increased SOD), attenuated pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), and lowered lipid peroxidation (MDA). Mechanistically, Exo@Bac promoted AMPK phosphorylation while suppressing NF-κB p65 signaling, indicating modulation of both oxidative stress and neuroinflammatory pathways. These findings demonstrate that Exo@Bac acts as a nanotherapeutic agent capable of mitigating AD pathology, highlighting its potential as a novel strategy for Alzheimer's disease therapy.