Comparative study of cholinergic and oxidative stress biomarkers in brains of diabetic and hypercholesterolemic rats

Diabetes mellitus (DM) and hypercholesterolemia (HC) when poorly controlled lead to debilitating central nervous system complications including cognitive deficits and memory impairment. In the present study, we investigated the mechanisms that may be responsible for such deficits.

Both diabetes and HC were induced in two groups of rats independently using alloxan and high cholesterol diet, respectively.

Acetyl cholinesterase was significantly increased in brain of diabetic rats. Also, brain malondialdehyde level was extremely elevated in both diabetic and hypercholesterolemic groups. Meanwhile, brain albumin was markedly decreased in both of them. However, the brain iron level was significantly increased in DM with concomitant increase in total antioxidant capacity in the same group as compared to the normal control. The concentration of brain calcium was noticeably increased in HC group. Our results were confirmed by the increased activity of lactate dehydrogenase in both DM and HC groups, indicating major brain cytotoxicity.

Overall, our results suggested that both DM and HC have deleterious effects on the brain which may be attributed to oxidative stress and dysregulation of both cholinergic function and calcium level. Administration of antioxidant is recommended in both cases.