The role of the cholinergic system in the memory-protecting effects of metformin in a model of scopolamine-induced memory impairment in aged rats
Özet
Purpose: As the elderly population grows, the prevalence of dementia is also rapidly increasing worldwide.
Metformin, an antidiabetic drug, has been shown to have ameliorative effects on impaired cognitive functions in
experimental models. However, studies have generally used young animals. Additionally, although it has a major
role in Alzheimer’s disease (AD) and memory, literature information about the effects of metformin on the
cholinergic system is limited. In this study, we investigated the effects of metformin on memory in a model of
scopolamine-induced memory impairment in aged rats. We also examined the effects of metformin on the
cholinergic system, which is very important in cognitive functions.
Methods: Metformin was administered orally to male Wistar rats (20–22 months old) at 100 mg/kg/day for three
weeks. Morris water maze (MWM) tests were performed to assess spatial memory. Before the probe test of the
MWM test, scopolamine was injected intraperitoneally at a dose of 1 mg/kg. After testing, animals were sacri
ficed, whole brains were removed, and hippocampus samples were separated for biochemical analysis.
Results: Impaired memory associated with scopolamine administration was reversed by metformin. In addition,
metformin administration ameliorated scopolamine-induced changes in acetylcholine (ACh) levels, acetylcho
linesterase (AChE), butyrylcholinesterase (BuChE), and choline acetyltransferase (ChAT) activity.
Conclusion: Our results show that metformin may have protective effects in a scopolamine-induced memory
impairment model in aged animals by improving cholinergic function. Metformin shows promise in preventing
dementia with its dual cholinesterase inhibition and ChAT activation effect.
