Alzheimer's disease (AD) is a common and debilitating neurodegenerative disease characterized by progressive cognitive impairment, and oxidative stress is a recognized contributor. Despite numerous studies, effective treatments remain scarce. This study synthesized and assessed the neuroprotective effects of a Schiff base complex, Copper(II) 4-(benzylideneamino)-3-hydroxynaphthalene-1-sulfonic acid [Cu(BAHN)], against scopolamine-induced (SCOP) cognitive and synaptic deficits in adult albino mice. Eight-week-old male BALB/c mice were randomly split into 4 groups: (1) controls (normal saline, 0.9%), (2) SCOP (1 mg/kg), (3) SCOP and Schiff base complex (30 mg/kg) and (4) Schiff base complex alone (30 mg/kg). Cognitive function was assessed using the Morris Water Maze (MWM) and Y-maze test. To assess the biochemical effects of the complex, antioxidant enzyme activities, and western blot analyses were performed. Treatment with the Schiff base complex significantly restored the activity of important antioxidant enzymes-catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and reduced glutathione (GSH) which were decreased by SCOP exposure. In addition, lipid peroxidation (LPO) rates were decreased. The complex also counteracted SCOP-induced decreases in both pre- and post-synaptic proteins, in line with improved behavioral performance in both cognitive challenges. Mechanistically, the compound activated phosphorylated Akt (p-Akt) and upregulated Nrf2 signaling, as well as downregulating nuclear factor kappa B (NF-kB) and interleukin-1β (IL-1β), show a decrease in neuroinflammation. In summary, these data suggest that the Schiff base complex reduces the oxidative, inflammatory, and synaptic deleterious effects of SCOP, probably, by regulating the p-Akt/Nrf2 pathway. Additional mechanistic studies are needed to understand its potential therapeutic implications in dementia. 2
