Neurobehavioral and neurobiochemical effect of atomoxetine and N-acetylcysteine in streptozotocin diabetes induced endothelial dysfunction and related dementia

Metabolic conditions like diabetes, is a major risk factor for the development of dementia of vascular origin. This study investigates the efficacy of atomoxetine (ATX) and N-acetylcysteine (NAC) in streptozotocin (STZ) diabetes induced vascular endothelium dysfunction and related dementia. Single dose STZ (50 mg/kg i.p) was administered to Albino Wistar rats (male, 200-250 g) by dissolving in citrate buffer. Morris water maze (MWM) and attentional set shifting tests (ASST) were used to assess the spatial learning, memory, reversal learning, and executive functioning in animals. Body weight, serum glucose, serum nitrite/nitrate, vascular endothelial function, aortic superoxide anion, brains' oxidative markers (thiobarbituric acid reactive species-TBARS, reduced glutathione-GSH, superoxide dismutase-SOD, and catalase-CAT), inflammatory markers (IL-6, IL-10, TNF-α, and myeloperoxidase-MPO), acetylcholinesterase activity-AChE and histopathological changes were also assessed. Atomoxetine - ATX (2 mg kg-1/ 4 mg kg-1) and N-acetylcysteine- NAC (250 mg kg-1/ 500 mg kg-1) were used alone as well as in combination, as the treatment drugs. Donepezil (0.5 mg kg-1) was used as a positive control. STZ administered rats showed increase in serum glucose levels and decrease in body weight. Rats administered with STZ also showed reduction in learning, memory, reversal learning, executive functioning, impairment in endothelial function, increase in brains' oxidative stress, inflammation, AChE activity and histopathological changes. Administration of ATX and NAC in two different doses as well as in combination, significantly attenuated the STZ induced diabetes induced impairments in the behavioral, endothelial, biochemical parameters and histopathological changes. Co-treatment of ATX and NAC was better in comparison to the doses when given alone. Hence, STZ administration caused diabetes induced dementia of vascular origin which was attenuated by the administration of ATX and NAC. Therefore, these agents may be studied further for the assessment of their full potential in diabetes induced dementia of vascular origin conditions.