ABSTRACT
There are strong correlations between diabetes mellitus and cognitive dysfunction. This study sought to investigate the modulatory effects of Moringa oleifera leaf (ML) and seed (MS) inclusive diets on biomolecules [acetylcholinesterase (AChE), butyrylcholinesterase (BChE)] angiotensin-I converting enzyme (ACE), arginase, catalase, glutathione transferase (GST) and glutathione peroxidase (GSH-Px) activities, glutathione (GSH) and nitric oxide (NO) levels] associated with cognitive function in the brain of streptozotocin (STZ)-induced diabetic rats treated with acarbose (ACA). The rats were made diabetic by intraperitoneal administration of 0.1 M sodium-citrate buffer (pH 4.5) containing STZ [60 mg/kg b.w (BW)] and fed with diets containing 2 and 4% ML/MS. Acarbose (25 mg/kg BW) was administered by gavage daily for 14 days. The animals were distributed in eleven groups of eight animals as follows: control, STZ-induced, STZ + ACA, STZ + 2% ML, STZ + ACA + 2% ML, STZ + 4% ML, STZ + ACA + 4% ML, STZ + 2% MS, STZ + ACA + 2% MS, STZ + 4% MS, STZ + ACA + 4% MS. There were marked increase in AChE, BChE, arginase, ACE and concomitant decrease in catalase, GST, GSH-Px, activities and NO levels in STZ-diabetic group compared with the control. However, there was a decrease in AChE, BChE and ACE activities and concomitant increase in the antioxidant molecules in the groups fed with supplemented diets treated with/without ACA compared with the STZ-diabetic group. These findings suggest that ML/MS supplemented diet could prevent cognitive dysfunction-induced by chronic hyperglycemia.