Effect of Metformin on Some Cognitive Functions in Old Rats

Introduction: Aging is a complex process and is considered as a risk factor for many diseases such as hypertension, Alzheimer, cancer, depression and anxiety. Recently, it has been shown that metformin, an anti-diabetic drug, has important neurological effects such as preventing memory loss, stroke, anxiety, inflammation and seizures. Therefore, the aim of this study was investigating the effects of metformin on some cognitive factors in elderly male rats. Methods: 24 rats (22 months) were randomly divided into 3 groups (n=8). The first group was the control group that received water orally, the second group received metformin 1 mg/kg orally and the third group received metformin 10 mg/kg orally. After treatment for 40 days (once daily), behavioral tests, including Y-maze, elevated plus maze and depression test were performed on animals. Results were analyzed using GraphPad Prism version 6 and One-way ANOVA followed by Tukey-post hoc test. Results: The results of this study showed that metformin at a dose of 10 mg/kg significantly reduced anxiety (P<0.001) and depression (P<0.001) in older animals. Metformin at a dose of 1 mg/kg failed to improve aging-related disorders in this model. Conclusion: Metformin at a dose of 10 mg/kg can reduce the quality of life by reducing anxiety and depression.