The impact of melatonin on antioxidant defense mechanisms in Alzheimer’s disease
Daria Malicka 1 , Dominika Markowska 1 , Jarosław Nuszkiewicz 2 , Karolina Szewczyk-Golec 2Abstract
During aging, the increased risk of neurodegenerative disease development is observed. One of the most common and most serious disorders is Alzheimer’s disease manifested by the loss of nerve cell functions. In the course of the disease, extracellular senile plaques consisting of beta-amyloid and intracellular neurofibrillary tangles of hyper-phosphorylated tau protein are formed. As a result of aging, the repair potential of damaged nerve cells is reduced. Free radicals formed in excess generate augmented oxidative stress, which contributes to the damaging of biomolecules and the development of pathological changes. This mechanism is favored by a decrease in the efficiency of antioxidant enzymes and the deficiency of antioxidants, observed in aging organism. With age, the secretion of the pineal hormone melatonin, functioning as a biochemical biological clock, is significantly reduced. This compound has been proved to be a very effective antioxidant that plays a key role in protecting cells against excessive damage, especially in nervous tissue. Studies have shown that supplementation with exogenous melatonin can prevent oxidative stress-induced degeneration of neurons. Considering the action of melatonin and the pathogenesis of Alzheimer’s disease, the idea of using the hormone supplementation in the prevention and alleviation of the effects of the disease seems to be extremely interesting.