RESUMEN
The anti-aging effects of alpha-lipoic acid (αLA), a natural antioxidant synthesized in human tissues, have attracted a growing interest in recent years. αLA is a short- -chain sulfur-containing fatty acid occurring in the mitochondria of all kinds of eukaryotic cells. Both the oxidized disulfide of αLA and its reduced form (dihydrolipoic acid, DHLA) exhibit prominent antioxidant function. The amount of αLA inside the human body gradually decreases with age resulting in various health disorders. Its lack can be compensated by supplying from external sources such as dietary supplements or medicinal dosage forms. The primary objectives of this study were the analysis of updated information on the latest two-decade research regarding the use of αLA from an anti-aging perspective. The information was collected from PubMed, Wiley Online Library, Scopus, ScienceDirect, SpringerLink, Google Scholar, and clinicaltrials.gov. Numerous in silico, in vitro, in vivo, and clinical studies revealed that αLA shows a protective role in biological systems by direct or indirect reactive oxygen/nitrogen species quenching. αLA demonstrated beneficial properties in the prevention and treatment of many age-related disorders such as neurodegeneration, metabolic disorders, different cancers, nephropathy, infertility, and skin senescence. Its preventive effects in case of Alzheimer's and Parkinson's diseases are of particular interest. Further mechanistic and clinical studies are highly recommended to evaluate the wide spectrum of αLA therapeutic potential that could optimize its dietary intake for prevention and alleviation disorders related to aging.
RESUMEN
The immune system protects the body from infectious agents such as bacteria, viruses, or fungi. Once encountered with pathogens or antigens, the innate and adaptive arms of the immune system trigger a strong immune response to eliminate them from the system and protect the body. Thus, well-balanced immunity is pivotal for maintaining human health, as an insufficient level of immune defense leads to infections and tumors. In contrast, the excessive functioning of the immune system causes the development of autoimmune diseases and allergies. Strong immunity requires adequate nutrition, dietary interventions, and sufficient intake of certain vitamins (vitamin C, vitamin D, and folic acid) and minerals (magnesium, zinc, and selenium). Therefore, nutritional and micronutrient deficiencies lead to compromised immunity. Several natural ingredients have shown potent immunomodulatory properties. The immune-enhancing properties of many plants and fungi are due to containing bioactive phytoconstituents such as polyphenols, terpenoids, ß-glucans, vitamins, etc. Probiotics and prebiotics can be used as innovative tools to reduce intestinal inflammation and downregulate hypersensitivity reactions. Plant sources of melatonin, a multifunctional molecule with proven anti-inflammatory and immunomodulatory properties, have been discovered relatively recently. The bioactive compounds augment the immune response by directly increasing the cytotoxic activity of natural killer cells, macrophages, and neutrophils. Many phytoconstituents prevent cell damage due to their powerful antimicrobial, antioxidant, and anti-inflammatory properties. The present review attempts to understand the molecular mechanisms underlying the immune-enhancing properties of some bioactive compounds from plants, fungi, animals, microorganisms, and other natural sources.