An insight into the role of magnesium in the immunomodulatory properties of mesenchymal stem cells.

Magnesium (Mg2+) is a mineral with the ability to influence cell proliferation and to modulate inflammatory/immune responses, due to its anti-inflammatory properties. In addition, mesenchymal stem cells (MSCs) modulate the function of all major immune cell populations. Knowing that, the current work aimed to investigate the effects of Mg2+ enrichment, and its influence on the immunomodulatory capacity of MSCs. Murine C3H/10T1/2 MSCs were cultivated in media with different concentrations of Mg2+ (0, 1, 3 and 5 mM), in order to evaluate the effects of Mg2+ on MSC immunomodulatory properties, cell proliferation rates, expression of NFκB and STAT-3, production of IL-1ß, IL-6, TGF-ß, IL-10, PGE2 and NO, and TRPM7 expression. The results showed that TRPM7 is expressed in MSCs, but Mg2+, in the way that cells were cultivated, did not affect TRPM7 expression. Additionally, there was no difference in the intracellular concentration of Mg2+. Mg2+, especially at 5 mM, raised proliferation rates of MSCs, and modulated immune responses by decreasing levels of IL-1ß and IL-6, and by increasing levels of IL-10 and PGE2 in cells stimulated with LPS or TNF-α. In addition, MSCs cultured in 5 mM Mg2+ expressed lower levels of pNFκB/NFκB and higher levels of pSTAT-3/STAT-3. Furthermore, conditioned media from MSCs reduced lymphocyte and macrophage proliferation, but Mg2+ did not affect this parameter. In addition, conditioned media from MSCs cultured at 5 mM of Mg2+ modulated the production profile of cytokines, especially of IL-1ß and IL-6 in macrophages. In conclusion, Mg2+ is able to modulate some immunoregulatory properties of MSCs.

IN VITRO AND IN VIVO ANTIOXIDANT ACTIVITY OF BURITI FRUIT (MAURITIA FLEXUOSA L.F.).

INTRODUCTION: studies have shown high concentration of monounsaturated fatty acids, carotenoids, polyphenols and ascorbic acid in Buriti fruit (Mauritia flexuosa L.f.). This study evaluated the in vitro and in vivo antioxidant activities of buriti fruit (Mauritia flexuosa L.f.). METHODS: the chemical composition and total phenolic and carotenoid contents of the buriti pulp and the feed rations were determined, and the in vitro antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay. Wistar rats (21 days old) were randomly allocated (n=10) into a control groups and experimental groups (feed enriched with buriti pulp). After 60 days, the in vivo antioxidant activity was evaluated through the determination of the catalase activity and non-protein sulfhydryl (NPSH) groups in the liver and quantification of malondialdehyde (MDA) in the plasma and tissues. RESULTS: high contents of oleic fatty acids (73.3%), phenolic compounds (192 ± 0.3 mg/100 g) and carotenoids (23.9 ± 0.5 mg/100 g) as well as elevated in vitro antioxidant activity were found in the buriti pulp. The enriched diet had higher contents of phenols and carotenoids as well as higher antioxidant activity compared with the standard feed (p < 0.05). There were no differences between the groups regarding catalase activity in the liver and MDA concentrations in the plasma, liver and kidneys. The male rats of the experimental group had higher liver concentrations of NPSH compounds (p < 0.05). CONCLUSION: these results may corroborate the claim that buriti fruit is an antioxidant functional food and support its utilization in a nutritionally balanced diet.

Introducción: estudios previos han demostrado que la fruta Burití (Mauritia flexuosa L.f). posee una alta concentración de ácidos grasos monoinsaturados, carotenoides, polifenoles y ácido ascórbico. Este estudio evaluó la actividad antioxidante in vitro e in vivo del Burití. Métodos: fueron determinadas la composición química, el contenido de compuestos fenólicos y de carotenoides tanto de la pulpa del Burití como de las raciones de alimento. La actividad antioxidante in vitro fue analizada utilizando el ensayo del radical 2,2-difenil-1-picrilhidrazil (DPPH). Ratas Wistar (21 días de edad) fueron asignadas al azar (n = 10) en grupos controles y grupos experimentales (alimentación enriquecida con pulpa de Burití). Después de 60 días, la actividad antioxidante in vivo se evaluó mediante la actividad enzimática de la catalasa y grupos sulfhidrílo no proteico (NPSH) en el hígado, y se cuantificó el malondialdehído (MDA) en plasma y tejidos. Resultados: la pulpa del Burití presentó alto contenido de ácido graso oleico (73,3%), compuestos fenólicos (192 ± 0,3 mg/100 g) y carotenoides (23,9 ± 0,5 mg/100 g), así como una elevada actividad antioxidante in vitro. La dieta enriquecida tenía mayor contenido de fenoles y carotenoides, y una mayor actividad antioxidante en comparación con la alimentación estándar (p < 0,05). No se observaron diferencias entre los grupos con respecto a la actividad de la catalasa en el hígado y las concentraciones de MDA en plasma, hígado y riñones. Las ratas macho del grupo experimental tuvieron concentraciones hepáticas más altas de NPSH (p < 0,05). Conclusión: estos resultados pueden corroborar la hipótesis de que la fruta Burití es un alimento funcional antioxidante y su consumo es conveniente en una dieta nutricionalmente equilibrada.

Magnesium Status and Its Relationship with C-Reactive Protein in Obese Women.

This study assessed the relationship between magnesium status and C-reactive protein concentration in obese and nonobese women. This cross-sectional study included 131 women, aged between 20 and 50 years, who were divided into two groups: obese (n=65) and control (n=66) groups. Magnesium intake was monitored using 3-day food records and NutWin software version 1.5. The plasma, erythrocyte, and urinary magnesium concentrations were determined by flame atomic absorption spectrophotometry. C-reactive protein concentration in serum was measured by immunoturbidimetric assay. The mean values of the magnesium content in the diet were lower than those recommended, though there was no significant difference between groups (p>0.05). The mean concentrations of plasma and erythrocyte magnesium were within the normal range, with no significant difference between groups (p>0.05). Urinary excretion of this mineral was less than the reference values in both groups, with no significant difference (p>0.05). The mean concentration of serum C-reactive protein was within the normal range in both groups, with no significant difference (p>0.05). There was a positive correlation between urinary magnesium and serum C-reactive protein (p=0.015). Obese patients ingest low dietary magnesium content, which seems to induce hypomagnesuria as a compensatory mechanism to keep plasma concentrations of the mineral at adequate levels. The study shows a positive correlation between urinary magnesium concentrations and serum C-reactive protein, suggesting the influence of hypomagnesuria on this inflammatory protein in obese women.