The effects of endurance exercise and metformin on memory impairment caused by diabetes

Abstract

Objectives Diabetes has a negative effect on learning and memory performance, and it is a risk factor for Alzheimer’s disease and dementia development. The present study aims to investigate the effects of two kinds of endurance exercise including high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) as well as metformin on impaired memory and learning related to streptozotocin (STZ) induced diabetes in rats. Methods Forty adult male rats (250 ± 20 g weight) were divided into five groups (n=8), including control, diabetic, as well as diabetic rats treated with metformin (300 mg/kg), and HIIT (20 m/min), and MICT (15 m/min) exercises. Diabetes was induced by STZ (60 mg/kg, i.p.). Serum glucose concentration and oxidative stress markers (SOD, CAT, thiol, and MDA) in the cortex and hippocampus were determined by colorimetric assay. Behavioral tests were performed with a passive avoidance test. Results The diabetic groups treated with metformin and both HIIT, and MICT exercises improved the latency and the staying time in the darkroom and lightroom. The entrance frequency into the darkroom also was restored (p<0.01–p<0.001). In both HIIT and MICT exercises as well as metformin groups the oxidative stress induced by diabetes has been reversed and attenuation of the serum glucose level has been observed compared to non-treated diabetic ones (p<0.05–p<0.001). Conclusions The results of the present study revealed both HIIT and MICT exercises had protective effects against oxidative stress and behavioral impairments induced by diabetes and these effects were comparable to the effects of metformin.

Endurance Exercise Prevented Diabetic Cardiomyopathy through the Inhibition of Fibrosis and Hypertrophy in Rats

“…As in previous similar experimental and clinical investigations, FBS levels in diabetic rats were significantly reduced following exercise training, although this reduction was more pronounced in the Met-HIIT group [ 23 , 26 , 27 , 28 , 29 ]. However, another study indicated the beneficial effect of MICT in lowering blood sugar in diabetic rats [ 13 ].…”

“…The protocol MICT was defined at a continuous speed of 15 meters per minute. The first and last 3 minutes of the training duration were dedicated to warming and cooling the rats, respectively, at a speed of 12 m/min [ 13 , 16 , 21 , 22 , 23 ]. At the end of the experiments, after performing echocardiography, deep anesthesia with xylazine and ketamine (8 mg/kg and 60 mg/kg, respectively, i.p.)…”