Bénéfices immunitaires de la glycine?

[Nutrimuscle-Conseils]

Glycine can prevent and fight virus invasiveness by reinforcing the extracellular matrix
Enrique Meléndez-Hevia Journal of Functional Foods Volume 76, January 2021,

Highlights
• The extracellular matrix is a physical barrier against infectious agents.
• Collagen (high glycine content) is the main protein of the extracellular matrix.
• Glycine is an essential amino acid as previously demonstrated.
• Glycine deficiency causes a weak mechanical system including the extracellular matrix.
• Glycine intake as nutritional supplement was very effective against virus infections.

The extracellular matrix, mainly composed of collagen, is a mechanical barrier against infective agents, including viruses. High glycine availability is needed for a healthy collagen turnover. Glycine produced by human metabolism is much lower than the cell’s needs giving a general glycine deficiency of 10 g/day in humans. This effect was tested for three years in 127 volunteers who had virus infections usually once or more times every year. 85 of them took glycine 10 g/day; 42 did not take glycine. Among those who took glycine, only 16 (12 of whom had infections two or more times each year) had the flu just in the first year –but much reduced in severity and duration– while those who did not take glycine, were infected as often and as severely as before. Glycine intake at the afore-mentioned dose prevents the spread of viruses by strengthening the extracellular matrix barriers against their advance.

[Nutrimuscle-Conseils]

[Nutrimuscle-Conseils]

The extracellular matrix, mainly composed of collagen, is not only the mechanical support of the tissues, but also a mechanical barrier that impedes or blocks the invasion of infective agents, such as bacteria.

Collagen constitutes approximately 25–33% of the total protein in mammalian organisms.

Glycine has been long been considered a non-essential amino acid, as it is synthesized by human metabolism.

glycine must be considered to be an essential or indispensable amino acid because, although it can be synthesized by human metabolism, the body’s capacity for its synthesis does not satisfy the needs of the cells, especially for collagen synthesis. Neither can glycine be considered “conditionally essential” as its need is a general requisite, independent of any particular circumstances.

In accordance with our results, glycine intake as nutritional supplement at the dose of 10 g/day (a dose of 5 g every 12 h) is highly recommended to block the spread of infectious agents –particularly viruses– thus preventing their invasion of the tissues.

[Nutrimuscle-Conseils]

High glycine concentration increases collagen synthesis by articular chondrocytes in vitro: acute glycine deficiency could be an important cause of osteoarthritis
Patricia de Paz-Lugo, Amino Acids volume 50, pages1357–1365(2018)

Collagen synthesis is severely diminished in osteoarthritis; thus, enhancing it may help the regeneration of cartilage. This requires large amounts of glycine, proline and lysine. Previous works of our group have shown that glycine is an essential amino acid, which must be present in the diet in large amounts to satisfy the demands for collagen synthesis. Other authors have shown that proline is conditionally essential.

In this work we studied the effect of these amino acids on type II collagen synthesis. Bovine articular chondrocytes were cultured under a wide range of different concentrations of glycine, proline and lysine. Chondrocytes were characterized by type II collagen immunocytochemistry of confluence monolayer cultures. Cell growth and viability were assayed by trypan blue dye exclusion method. Type II collagen was measured in the monolayer, every 48 h for 15 days by ELISA.

Increase in concentrations of proline and lysine in the culture medium enhances the synthesis of type II collagen at low concentrations, but these effects decay before 1.0 mM. Increase of glycine as of 1.0 mM exceeds these effects and this increase continues more persistently by 60–75%. Since the large effects produced by proline and lysine are within the physiological range, while the effect of glycine corresponds to a much higher range, these results demonstrated a severe glycine deficiency for collagen synthesis. Thus, increasing glycine in the diet may well be a strategy for helping cartilage regeneration by enhancing collagen synthesis, which could contribute to the treatment and prevention of osteoarthritis.

[Nutrimuscle-Diététique]

Traduction de l'étude

La glycine peut prévenir et combattre le caractère invasif du virus en renforçant la matrice extracellulaire
Enrique Meléndez-Hevia Journal of Functional Foods Volume 76, janvier 2021,

Points forts
• La matrice extracellulaire est une barrière physique contre les agents infectieux.
• Le collagène (teneur élevée en glycine) est la principale protéine de la matrice extracellulaire.
• La glycine est un acide aminé essentiel comme démontré précédemment.
• Une carence en glycine entraîne une faiblesse du système mécanique, y compris la matrice extracellulaire.
• L'apport en glycine en tant que complément nutritionnel s'est avéré très efficace contre les infections virales.

La matrice extracellulaire, principalement composée de collagène, est une barrière mécanique contre les agents infectieux, y compris les virus. Une disponibilité élevée de glycine est nécessaire pour un renouvellement sain du collagène. La glycine produite par le métabolisme humain est bien inférieure aux besoins de la cellule, ce qui donne une carence générale en glycine de 10 g / jour chez l’homme. Cet effet a été testé pendant trois ans chez 127 volontaires qui avaient généralement des infections virales une ou plusieurs fois par an. 85 d'entre eux ont pris 10 g de glycine / jour; 42 n'a pas pris de glycine. Parmi ceux qui prenaient de la glycine, seulement 16 (dont 12 avaient des infections deux fois ou plus par an) avaient la grippe juste au cours de la première année - mais beaucoup moins sévère et dure - tandis que ceux qui ne prenaient pas de glycine étaient infectés aussi souvent et aussi sévèrement qu'avant. L'apport en glycine à la dose précitée empêche la propagation des virus en renforçant les barrières de la matrice extracellulaire contre leur progression.