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).