Effects of a Combined Mitochondria-Targeted Treatment on the State of Mitochondria and Synaptic Membranes from the Brains of Diabetic Rats

Abstract

On samples of the mitochondria and synaptic membranes isolated from rat brains using differential centrifugation, we tried to evaluate the neuroprotective efficacy of a combination of mitochondriaspecific antioxidants, acetyl-L-carnitine (ALC) and α-lipoic acid (LA), with nicotinamide (NAm), against diabetes-induced disorders in the CNS. Three groups of adult male Wistar rats were examined; these were control intact rats (group C), animals with experimental streptozotocin (STZ)-induced diabetes (group D; 6 weeks after STZ injections), and diabetic rats treated during the two final weeks of the above period by a combination of ALC, LA, and NAm (separate daily injections; doses 100, 50, and 100 mg/kg body mass, respectively; group D+T). At the day of preparation of the organelle samples, the mean blood glucose levels in groups C, D, and D+T were 4.8, 20.3, and 15.4 mM, respectively. The intensity of reactive oxygen species (ROS) production in the brain mitochondria from rats of group D measured by fluorescent analyses using 2’,7’-dichlorofluorescein diacetate was, on average, 37.2% greater than that in group C. Co-treatment provided a significant decrease in the above index in group D+T (27.8% in comparison with group D). Diabetes led to dramatic intensification of the CYP2E1 protein level in the liver of group D animals (242% vs. group C). In group D+T, this index was 33.1% lower than that in group D.