Oxidative Stress as a Contributing Factor and Potential Target in Diabetic Complications

Diabetes mellitus (DM) is one of the biggest concerns for public health, which gives rise to an elevated risk of mortality. Oxidative stress is a key driver in the onset of hyperglycemia-induced diabetic vascular damage, including both microvascular and cardiovascular complications. Mitochondrial superoxide overproduction in endothelial cells is a consequent cause of diabetes-related metabolic abnormalities. This in turn leads to the activation of 5 main pathways involved in the pathogenesis: (1) polyol pathway flux, (2) increased advanced glycation end-products (AGEs) formation, (3) enhanced expression of AGE receptors, (4) activation of protein kinase C isoforms, and (5) hyperactive hexosamine pathway ^{[1] [2]}. 

Beyond metabolic disruption, oxidative stress strongly engages inflammatory signaling. ROS promote activation of NF-κB, NLRP3 inflammasomes, iNOS, and COX-2, leading to sustained cytokine production and endothelial dysfunction. Persistent oxidative stress drives the phenomenon of metabolic memory, in which vascular injury continues even after glycemic control is achieved. Impaired mitochondrial biogenesis, reduced NAD⁺/SIRT signaling, and mtDNA damage further propagate this chronic inflammatory state ^{[1] [3]}.

Antioxidant treatment using vitamin E or other antioxidants is considered a symptomatic therapy against vascular oxidative stress. Lipoic acid is another substance with self-regenerating capacity as a mitochondrial antioxidant, which can restore endothelial dysfunction in vivo. Ruboxistaurin, a protein kinase β isoform inhibitor, has been shown to lower retinal oxidative stress. PJ34 blocks poly(ADP-ribose) polymerase and regulates mitochondrial function in oxidatively challenged cells. These two compounds also ameliorate hyperglycemia-induced endothelial dysfunction. In addition, thiazolinediones, statins, ACE inhibitors, and ATI inhibitors have strong antioxidant activity that may have potential benefits against diabetic complications ^[4]. 

In conclusion, extensive evidence highlights oxidative stress as a central mechanism in diabetic complications. Antioxidant therapy and approaches targeting redox imbalance, mitochondrial dysfunction, and ROS-driven inflammatory signaling offer significant therapeutic potential and remain a growing focus of diabetes research.