Supplementation of amino acids in the hyperinflammatory state
Inflammation and changes in amino acid metabolism are related to Covid e affect the skeletal muscles, therefore probably rehabilitation requires personalized approaches. In addition amino acids they are essential nutrients for infectious microorganisms and the levels of some amino acids such as tryptophan decrease in response to infection and / or inflammation and for this reason they should be restored so as not to experience severe malnutrition.
Some nutrients, including amino acids, have been shown to have a remarkable amountinfluence on immune function (immunonutrients) and improvement of metabolic and nutritional indices, such as nitrogen balance and serum proteins. Immunonutrients can promote patient recovery by inhibiting inflammatory responses and regulating immune function. Glutamine which can modulate and preserve intestinal and lung function, compromised in conditions of severe stress, reducing the production of pro-inflammatory cytokines. Cytokine mediated effects are an essential part response to infection but excessive production of pro-inflammatory cytokines increases the risk of pneumonia and death in Covid-19. The production of pro-inflammatory cytokines (TH1 cytokines: eg tumor necrosis factor-α [TNF-α], IL-1, IL-6, interferon-γ [IFN-γ]) in coronavirus pneumonia are overexpressed in a storm. Chronic inflammation occurs when the triggering factors persist or there is some sort of resolution failure processes. Inflammation plays a fundamental role in the pathogenesis of COVID-19: an imbalance between pro-inflammatory and anti-inflammatory cytokines, leading to the cytokine storm is currently considered to contribute to the development and progression of COVID-19.
Many authors have shown that amino acids have anti-inflammatory effects and the integration of arginine, glutamine or glycine improves lung damage induced by infections or any other inflammatory event thus contributing to alveolar improvement in its integrity and function. In particular, the administration of glutamine has been shown to significantly reduce inflammatory cytokines without affecting other parameters. Arginine or glycine supplementation may be a new nutritional strategy for reduce the deleterious effects of bacterial infection on alveolar function.
The proinflammatory cytokines (TNFα, IL-1β and IL-6) and chemotactic cytokines (CXCL-1, MCP-1 and ICAM-1) produced by immune cells are powerful inducers of apoptosis in alveolar epithelial cells and cause a severe inflammatory state and the use of amino acids has reduced mRNA levels for TNFα, IL-1β and IL-6 indicating a reduction inflammatory response. Importantly, IL-6 promotes expression of CXCL-1, which in turn regulates neutrophils accumulation and contributes to lung injury. The administration of arginine or glycine is associated with reduced expression of IL-6, CXCL-1 and decrease in the accumulation of neutrophils in the alveolar epithelium, indicating a regulatory effect of chemokine secretion in lung tissues. Whereas the inhibition of CXCL-1 reduces the accumulation of neutrophils in the lungs tissues and protects against lung injury in clinical patients, arginine or glycine can be used as a new adjuvant nutrient in clinical therapy. Further studies are needed to clarify molecular mechanisms underlying this important modulatory effect of arginine, glycine and glutamine.
Glutamine inhibits the accumulation of white blood cells and Arginine, glycine or glutamine have been reported to inhibit cell death in various studies but the metabolism of amino acids and the production of their metabolites differ from each other in alveolar epithelial cells, thus leading to different responses.
Furthermore, it should be added that malnutrition easily leads to a decrease in the lean body mass and can cause sarcopenia, a frequently encountered disease in the elderly with aggravation of geriatric pathologies. Current opinions consider malnutrition and possible sarcopenia as a consequence of multiple medical, behavioral and environmental factors involving the nervous, hormonal, nutritional system, substitution of muscle proteins, proinflammatory conditions and the load of reactive oxygen species inside of mitochondria.With the intake of amino acids there is a better functional recovery of the muscles and a significant reduction in serum cancer necrosis factor– (TNF-) and a significant increase in both insulin-like growth factor without having significant adverse effects. These preliminary data indicate that dietary supplements with the oral amino acid mixture have significantly increased lean body mass in elderly subjects with and without sarcopenia (10-15).