Hibiscus sabdariffa synthesized gold nanoparticles ameliorate aluminum chloride induced memory deficits through inhibition of COX-2/BACE-1 mRNA expression in rats

Alzheimer’s disease (AD) is a major health challenge worldwide, especially among the elderly. The disease is associated with cognitive and memory deficits. This study investigated the effect of Hibiscus sabdariffa synthesized-gold nanoparticles (HS-AuNPs) on AlCl₃-induced memory deficits in rats. Forty-two male Wistar rats were divided into six groups (n = 7). Group I served as control. Rats in group II - V were exposed to AlCl₃ (100 mg/kg) to induce AD. Group III - V rats were treated with 5 mg/kg donepezil, 5 and 10 mg/kg HS-AuNPs, respectively, for 14 days. Behavioral tests were carried out on the rats on day 28 and 42. At the end of animal experiment, rats were sacrificed and used for various biochemical assays and gene expression. The AD rats showed memory and learning impairment, and these conditions were ameliorated by HS-AuNPs. Significant (p < 0.05) elevation in the activities of acetylcholinesterase, monoamine oxidase and adenosine deaminase, as well as malondialdehyde levels was noted. A significant reduction in the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) noted in AlCl₃-induced rats were ameliorated by the 5 and 10 mg/kg b.w. doses of HS-AuNPs. In addition, the increased mRNA expression of cyclooxygenase-2 (COX-2) and beta-secretase 1 (BACE-1) caused by AlCl₃ were assuaged by the HS-AuNPs treatment. Based on the activities of HS-AuNPs against AlCl₃-induced AD, HS-AuNPs could be considered a potential therapeutic agent for managing AD.