The majority of diabetes types across the world may be correlated to modern diets, sedentary lifestyles, and obesity. The mortality associated with diabetes is mainly a result of the augmented danger of several complications of this disease. Even though diabetes is primarily defined by chronic hyperglycemia, many diabetic patients, particularly those with type 2, have elevated blood pressure (hypertension), chronic high levels of insulin (hyperinsulinemia), and abnormal levels of cholesterol, triglycerides, and/or other blood lipids (hyperlipidemia). In addition, lipoprotein abnormalities are some of the most prevalent problems associated with type 2 diabetes [11]. These complications are strictly related to the disease disorders, as well as to the procedures used to diagnose and treat them (Figure 2).

Biochemical processes in the body may produce intermediate products called reactive oxygen species (ROS). Among ROS, harmful free radicals have one or more unpaired electrons that make them very reactive with other molecules. Excess ROS may lead to an imbalance in its metabolism and in the body’s ability to detoxify or counteract the harmful oxidant effects of the free radicals [12,13]. This condition is known as oxidative stress, which depends on the balance between ROS production and antioxidant defenses [14]. Oxidative stress is thus the result of the imbalance between the formation and neutralization of reactive oxygen and nitrogen species [15,16]. Electron transfers to O₂ are catalyzed by oxidase enzymes to produce chemical energy or oxidation of substrates. These enzymes are potential sources of reduced Cu₂⁺ derivatives in biological settings; they also produce O₂^•− during catalysis [17,18,19]. The mitochondrial electron transport chain reduces O₂ to O₂^•− [20,21]. Dismutase enzymes reduce O₂^•− radicals to form hydrogen peroxide (H₂O₂) and/or further react to form the hydroxyl secondary radical (^•−OH) as another type of the ROS [17,19]. Although the cause-effect relationship remains unsure, there appears to be a strong correlation between mitochondrial dysfunction and chronic metabolic diseases, such as obesity [17] and diabetes mellitus (Figure 3) [22]. This relationship results in oxidative damage to cellular components in the form of lipid peroxidation, protein denaturation or DNA conjugation, and finally, cell death [23]. As a result of the aforementioned reasons, oxidative stress has been related to many diseases, such as cancer, post-ischemic and neural degradation, Parkinson’s and Alzheimer’s diseases, acquired immune deficiency syndrome (AIDS), aging, and cardiovascular diseases [24].