Diabetes mellitus (DM) is a prevalent metabolic disorder attributed to resistance to insulin or inadequate insulin production, resulting in hyperglycemia [1]. Hyperglycemia in diabetes mellitus results in oxidative stress, which results in peroxidation of lipids and reactive oxygen species (ROS) creation. This causes brain cell death, protein oxidation, DNA and plasma membrane damage [2]. Alzheimer's disease, known as "type 3 diabetes", is linked to diabetes. The mechanisms involve vascular damage, Insulin resistance, impaired insulin signaling in the brain may contribute to the amyloid-beta protein accumulation and tau protein phosphorylation, characteristic of Alzheimer's pathology. [3]., Additionally, diabetes-related oxidative stress, and inflammation further promote neurodegenerative processes in the cerebral cortex, exacerbating the risk of Alzheimer's disorder [4]. Thioctic acid, or alpha-lipoic acid (ALA), is an endogenously formed compound in trace quantities from fatty acids and cysteine and has potent antioxidant properties. Food supplements and dietary sources such organ meats, spinach, broccoli, and potatoes are good sources of it [5]. Strong antioxidants like ALA scavenge free radicals, which are unstable molecules that can damage tissues and cells. Oxidative stress can be decreased by ALA through direct scavenging of free radicals. Additionally, it regenerates various antioxidants like coenzyme Q10, glutathione, and vitamins C and E. Moreover, ALA serves a distinct antioxidant function in the CNS because it can cross the blood-brain barrier. Its ability to be equally absorbed by both the CNS and the peripheral nervous system is attributed to its hydrophilic and lipophilic characteristics, allowing for easy absorption and distribution throughout all body tissues [72]. Thus, this trial examined STZ-induced diabetes mellitus effects on cerebral cortex structure and ALA's protective effects.