Antioxidant Mechanisms in Myocardial Ischemia: Narrative Review

Ischemia is a common condition in the population and has become one of the leading causes of mortality in recent years. It occurs due to a shortage of oxygen in the cell caused by inadequate blood flow, leading to the formation of free radicals. These free radicals can bind to the phospholipids in the cell membrane, resulting in proxy radicals and lipid hydroperoxidation. Malondialdehyde (MDA) is a cytotoxic byproduct of lipid peroxidation that causes cell damage and necrosis by rupturing the cell membrane. Subsequently, mitochondrial dysfunction related to fatty acid oxidation can develop, further exacerbating the damage caused by ischemia. Reactive oxygen species (ROS) produced in mitochondria have been shown to elevate oxidative phosphorylation disorder and disrupt the functioning of complexes I and IV. These enzyme activities can be restored to normal levels by activating antioxidant enzymes such as superoxide dismutase (Mn-SOD) and catalase, thereby strengthening the antioxidant defense system. Various antioxidants have been found to have protective effects. In this review, we compare the antioxidant effects of various plants and tannins that have been studied up to this point on myocardial ischemia. We also explain some of the cellular and molecular pathways that have been investigated to protect the myocardium against ischemia-reperfusion injury.