Vanadyl sulfate restores memory impairment in streptozotocin-induced rat model of sporadic alzheimer’s disease by repressing FoxO1 gene expression

Impaired brain insulin signaling is a risk factor for the pathogenesis of Alzheimer's disease (AD). FoxO1 and HMGA1 transcription factors are involved in the pathogenesis of both type 2 diabetes (T2D) and Alzheimer's disease (AD). This study aimed to assess the effect of vanadyl sulfate (VS) on impaired memory and hippocampal FoxO1 and HMGA1 RNA expression in sporadic AD (sAD) model in rats. Thirty-two male Wistar rats (250 ± 10 g) were divided into sham, AD, and VS 0.5 and 0.75 treated groups. The animals were subjected to two bilateral intracerebroventricular (icv) injections of either citrate buffer or streptozotocin (STZ) at 72-hour intervals. The VS-treated groups were treated with either 0.5 or 0.75 mg/ml oral VS for 3 weeks. The target quadrant entry latency, path length, and time and distance traveled in the target quadrants were assessed with the Morris water maze (MWM). Hippocampal tissues were analyzed for FoxO1 and HMGA1 RNA expressions. Group differences and group‒time interactions were analyzed via mixed two-way repeated-measures ANOVA. VS treatment in icv STZ rats restored impaired spatial memory. Hippocampal FOXO1 and HMGA1 RNA expressions were significantly lower in VS-treated and sham groups compared to AD control. VS can restore impaired spatial memory in sAD rats, possibly via the repression of FoxO1 and HMGA1 RNA expression in hippocampus.