Sepsis, systemic inflammatory response, and acute respiratory distress syndrome are common and very dangerous complications in clinical intensive care (ICU); the mortality rate in critically ill patients is 10%-50%.
These conditions are currently believed to be due to severe oxidative stress.
Oxidative stress refers to the imbalance between oxidation and anti-oxidation in the body, which tends to oxidize, leading to inflammatory infiltration of neutrophils, increased secretion of proteases, and production of a large number of oxidized intermediates.
The main consequence of oxidative stress is the damage to the oxidation of biological macromolecules such as protein, fat, nucleic acid, etc. Diseases such as Alzheimer's disease and an important cause of human aging.
There is a double close relationship between nutrition and oxidative stress. On the one hand, nutrients can generate reactive oxygen species and intermediate product free radicals in the process of metabolism in the body; transition metal trace elements, such as iron ions and copper ions, can promote the generation of reactive oxygen species. On the other hand, a balanced diet and reasonable nutrition can enhance the body's antioxidant defense function; some nutrients and food components can directly or indirectly exert antioxidant effects.
Certain peptides have antioxidant effects:
Among them, the most familiar ones are glutathione, which is widely present in animals and plants, and Carnosine, a natural 2-peptide present in animal muscle.
At present, the research on the antioxidant mechanism of carnosine and glutathione is relatively clear. Carnosine mainly shows that the histidine residue on its side chain can be used as a hydrogen acceptor to scavenge free radicals.
Glutathione mainly acts as a reversible hydrogen donor through the conversion of its sulfhydryl oxidation-reduction state, and plays an anti-oxidative protection role in the aqueous phase of the cell.
Appropriate supplementation of bioactive peptides through nutritional support means to reduce peroxidative damage during critical stress and reduce harmful or excessive inflammatory responses has become an important means of critical illness treatment.