Nutraceutical management of stress-induced redox imbalance and mitochondrial damage

We propose that stress may contribute to aging acceleration and age-associated degenerative disease by generating oxidants in the mitochondria, causing oxidative damage to lipids, proteins, and nucleic acids, weakening antioxidant defense systems, and further affecting the homeostasis of numerous mediators of defense reactions including hormones, neurotransmitters, and immune cytokines, all of which, like oxidants, are dangerous in excess. Because mitochondria are the source and also the targets of oxidants and play a key role in stress response, protecting mitochondrial from stress-induced dysfunction should be an effective strategy to fight against stress and stress-associated aging acceleration and degenerative diseases. We have identified a group of mitochondrial protective nutrients which can enhance antioxidant defense system, scavenge oxidants, improve mitochondrial function, inhibit oxidative damage, and consequently, regulate the balances of all stress mediators. We reviewed the recent evidence of stress-induced oxidative damage by different stress models in different organs, especially in the brain, and also summarized the neuroprotective effects of mitochondrial targeting nutrients, including vitamins A, C, E, estrogen, dehydroepiandrosterone, glutathione, acetylcarnitine, and some herbal extracts.Stress can affect many aspects of physiology, and has an important influence on health and disease. In the cardiovascular system, stress stimulates the release of catecholamines, which excite β-receptors, thus increasing heart rate, myocardial contraction, cardiac output and blood pressure. In the digestive system, stress induces either stimulation of chewing and eating, which is the inducing factor of obesity, inhibition of appetite, or neuro-anorexia. In the blood system, stress causes an increase in white blood cell numbers, platelet numbers, viscosity, fibrinogen, as well as anticoagulating factors V and VIII. In the reproductive system, stress generally disrupts reproductive function. The central nervous system is the regulating center of stress, but at the same time its function is affected by stress. The hypothalamus-pituitary-adrenal (HPA) system, which releases glucocorticoids, and the sympathetic adrenomedullary system which releases catecholamines, acts as integrating units controlling the physiological and behavioral responses. At the same time, stress causes serious psychological changes, associated with response of the brain limbic system, including the hippocampus and olfactory bulb, which are closely associated with hypothalamus. Different stressors cause different emotional reactions; strong and persistent emotional reactions may induce disorders of the central nervous systems, including psychological disorders and psychosis.