Alpha lipoic acid improved spatial working memory and reduced acetylcholinesterase levels in type-2 diabetic Wistar rats

Diabetes mellitus is one of the most common metabolic disorders that is associated with many complications such as memory impairment and dementia.Alpha lipoic acid (ALA) has been shown to have antihyperglycaemic and antioxidant effects.This study aimed to evaluate the effects of ALA on spatial working memory, and acetylcholinesterase level in type-2 diabetic Wistar rats.Thirty rats were divided into six groups of five each (n=5).Diabetes mellitus was induced using a high-fat diet for six weeks followed by a single low dose of streptozotocin (40 mg/kg) intraperitoneally and followed by a high-fat diet for another two weeks.Group I served as normoglycemic control and received 1 ml/kg normal saline, group II, III, IV, V, and VI were diabetic and received 1 ml/kg normal saline, glibenclamide 1 mg/kg, ALA 100 mg/kg, ALA 200 mg/kg and ALA 400 mg/kg respectively.All administrations were done orally for 21 days.Blood glucose level was determined before and after administrations, spatial working memory was determined using spontaneous alternation in the Y-maze, and the serum was used for the determination of acetylcholinesterase level.The results showed that ALA at 200 mg/kg significantly increased percentage alternation on day 21 with values of 69.73 ± 2.67% compared to the untreated group (57.97 ± 2.27%).Serum acetylcholinesterase level was significantly (p < 0.05) reduced (78.62 ± 1.66 U/ml) in the rats that received 400 mg/kg ALA compared to the untreated group (88.28 ± 1.82 U/ml).The findings of this study suggest that ALA improved spatial working memory and acetylcholine activity in Wistar rats.