Metformin and donepezil, when administered at 300mg/kg and 10mg/kg, respectively, were shown lower most plasma and brain biomarkers, including glucose, triglycerides, tumour necrosis factor a, amyloid β 42, nitric oxide, acetylcholinesterase, malondialdehyde, and β secretase in rats suffering from diabetes mellitus. Here, ACHE is linked to diabetes mellitus.