Aqueous Ajwa dates seeds extract improves memory impairment in type-2 diabetes mellitus rats by reducing blood glucose levels and enhancing brain cholinergic transmission

Diabetes is a metabolic disorder prevalent across the globe and is known to cause brain dysfunction, especially memory and cognitive decline. The current study investigates the effect of aqueous Ajwa seeds extract (AASE) on type-2 diabetes mellitus (T2DM)-induced memory deficits using a rat model. T2DM was induced by an administration of nicotinamide (120 mg/kg, i.p.) and streptozotocin (STZ) (60 mg/kg, i.p.). AASE (200 and 400 mg/kg, p.o.) were treated to T2DM rats for 30 days and the results were compared with the metformin (200 mg/kg). Elevated plus maze (EPM), Y-maze, and novel object recognition (NOR) tests were performed to assess the memory functions. The blood glucose and plasma insulin levels were estimated to assess the anti-diabetic effects of AASE. Acetylcholine (ACh) and acetylcholinesterase (AChE) levels were estimated from brain homogenates to assess cholinergic transmission. Treatment with AASE resulted in the reversal of behavioral deficits. EPM showed, a significant reduction in transfer latency (TL) among T2DM rats. High exploration time with a novel object and improvement in discrimination index were observed among treated groups during the NOR test. The Y-Maze test improved the entries and also time spent in the novel arm. Moreover, treatment of AASE reversed hyperglycemic and enhanced plasma insulin levels (200 mg/kg: 3.81 ± 0.08 ng/ml and 400 mg/kg: 4.09 ± 0.10 ng/ml) among T2DM rats (2.81 ± 0.15 ng/ml). Improved ACh levels (200 mg/kg: 186.6 ± 9.51 pg/mg protein and 400 mg/kg: 165.5 ± 9.25 pg/mg protein) and reduced AChE levels (200 mg/kg: 0.29 ± 0.02 ng/mg protein and 400 mg/kg: 0.32 ± 0.03 ng/mg protein) were also noted in the brain of AASE treated groups as referred to diabetic group (ACh: 107.1 ± 7.16 pg/mg protein and AChE: 0.51 ± 0.03 ng/mg protein). The above results were found to be comparable with the metformin-treated groups. From the results, it can be concluded that AASE has the potential to improve T2DM associated cognitive deficits.