RESUMEN
Exercise can induce a pro-inflammatory response in aged subjects with metabolic disorders and nitrate supplementation has shown anti-inflammatory effects. We evaluated the influence of dietary nitrate on the response of the antioxidant and mitochondrial dynamics genes to acute exercise in peripheral blood mononuclear cells (PBMCs), as well as the antioxidant and the inflammatory response of PBMCs against immune stimulation. Metabolic syndrome patients participated in a crossover study in which they consumed a beverage containing 16 mM sodium nitrate or a placebo with the same composition without nitrate before performing a submaximal test at 60%-70% of their maximal heart rate for 30 min. The intake of nitrate increased the nitrate plus nitrite plasma levels about 8-fold and induced the upregulation of catalase, superoxide dismutase, glutathione peroxidase, mitofusin 2 and PGC1α in PBMCs after exercise. The gene expression of catalase and TNFα was enhanced by phorbol myristate acetate (PMA) only in the placebo group, while the glutathione peroxidase expression was enhanced by PMA only after nitrate intake. The intake of nitrate by metabolic syndrome patients induces an antioxidant and mitochondrial response to exercise at the same time that it attenuates the pro-inflammatory response to immune stimulation.
RESUMEN
The beneficial effects of exercise for the treatment and prevention of metabolic syndrome pathologies have been related to its anti-inflammatory and antioxidant effects. Dietary nitrate supplementation is an emerging treatment strategy to alleviate the symptoms of metabolic syndrome affections and to improve vascular function. In this double-blind crossover trial, metabolic syndrome patients performed two exercise tests for 30 min at 60-70% maximal heart rate after the intake of a placebo or a nitrate-enriched beverage. Acute exercise increased the plasma concentration of TNFα, intercellular adhesion molecule ICAM1, PGE1, PGE2 and the newly detected 16-hydroxypalmitic acid (16-HPAL) in metabolic syndrome patients. The cytokine and oxylipin production by peripheral blood mononuclear cells (PBMCs) and neutrophils could be responsible for the plasma concentrations of TNFα and IL6, but not for the plasma concentration of oxylipins nor its post-exercise increase. The intake of sodium nitrate 30 min before exercise increased the concentration of nitrate and nitrite in the oral cavity and plasma and reduced the oxygen cost of exercise. Additionally, nitrate intake prevented the enhancing effects of acute exercise on the plasma concentration of TNFα, ICAM1, PGE1, PGE2 and 16-HPAL, while reducing the capabilities of PBMCs and neutrophils to produce oxylipins.