Metformin attenuates behavioral impairment in a rat model of dementia induced by high fat diet

Objective To investigate the effect of metformin( MET) on learning and memory behavior in HFD-induced insulin-resistant rats. Methods Thirty male Sprague-Dawley( SD) rats were divided into three groups to receive either a normal diet( Control group) or a high-fat diet( two HFD groups) for four weeks( HFD + MET). From two HFD groups,one received vehicle( HFD group) alone and other MET administration( HFD + MET group). MET was dissolved in drinking water at a concentration of 2 mg / ml. All rats were subjected to the glucose tolerance test( GTT) and behavioral tests using the elevated plus maze( EPM),open field test( OFT),Morris water maze( MWM) test and the step-through passive avoidance test( PA) after four-week consecutive MET treatment. Blood samples were collected for determination of glucose.Results MET attenuated the glucose resistant condition and improved cognitive behavior in MWM and PA,vs the HFD group.Conclusion MET can improve the impaired learning and memory behavior in HFD-induced insulin-resistant rats.