Magnesium augments immunosuppressive effects of a corticosteroid in obese mice with airway inflammation

Magnesium deficiency common in obesity is known to promote chronic low-grade inflammation and aggravate asthma symptoms; however, the effects of magnesium supplementation in obese asthmatic patients have not been investigated. To examine the effects of magnesium co-administration with dexamethasone on airway inflammation in obese mice. Female C57BL/6 mice were fed a high-fat diet, sensitized with ovalbumin (OVA) to induce allergic reactions, challenged with aerosolized OVA, and administered dexamethasone (3 mg/kg) with or without magnesium. Bronchial inflammation was analyzed based on the presence of inflammatory cells and cytokines in bronchoalveolar lavage fluid, total and OVA-specific IgE in serum, goblet cells ratios, bronchial wall thickness, and expression of α-smooth muscle actin. In obese mice, co-administration of magnesium and dexamethasone decreased IL-13 in bronchoalveolar lavage fluid and total and OVA-specific IgE in serum, and reduced α-smooth muscle actin-positive areas in the bronchi compared with mice treated with dexamethasone alone. However, no differences were observed in dexamethasone-treated normal-weight mice depending on magnesium supplementation. These results suggest that magnesium increases immunosuppressive effects of dexamethasone in airway inflammation aggravated by obesity, suggesting that magnesium supplementation may have a potential in alleviating asthma symptoms in obese patients with reduced responses to corticosteroids.