Protective effects of Cuscuta chinensis Lam. extract against learning and memory dysfunction induced by streptozotocin and amyloid β 25-35 in vivo model

Alzheimer's disease (AD) is associated with hyperglycaemia and amyloid beta (Aβ) accumulation. In the present study, we investigated whether an aqueous extract of Cuscuta chinensis Lam. (CCWE) improved cognitive disorder in a hyperglycaemic and cognitive-impaired mouse model. Hyperglycaemia was induced by streptozotocin (STZ, 50 mg/kg) and a single intracerebroventricular injection of Aβ_25-35 (25 nM) was performed. The Aβ_25-35-injected hyperglycaemic mice were then administered CCWE (100 or 200 mg/kg/day) for 14-d. The protective effects of the CCWE were evaluated by behavioural tests and western blot analysis. The bioactive compounds in CCWE were isolated by UPLC-QTOF/MS analysis. The administration of CCWE improved the learning and memory function in STZ/Aβ_25-35-injected mice. Moreover, CCWE positively regulated the amyloidogenic pathway-related proteins and insulin signalling-related proteins. The bioactive components in CCWE were also identified. These findings suggest the possibility of CCWE as a potential candidate for the dual-targeting treatment of hyperglycaemia and AD.