Asthma is a global health problem. Asthma attacks are becoming more severe and more resistant to usual treatment by β2 agonists nebulisation. The search for a new product that could reduce the morbidity of asthmatic disease seems necessary. The objective of this study was to compare the effectiveness of inhaled magnesium fluoride (MgF2) with that of magnesium sulphate (MgSO4) 15% alone and sodium fluoride (NaF) 0.5 M alone in rats precontracted by methacholine (MeCh). Fifty six adult male Wistar rats of medium weight 259 ± 15 g were divided randomly into five groups. They inhaled respectively: MeCh, MgF2 + NaCl 0.9%, MgF2 + acetic acid, MgSO4 15% single and NaF (0.5 M) single. Airway resistances were measured after each dose of MeCh by pneumomultitest equipment. Results indicated that (1) MgF2 + NaCl 0.9%, MgF2 + acetic acid and MgSO4 reversed significantly the methacholine-induced bronchial constriction in rats and had a bronchodilating effect at the moment of its administration (2) MgF2 + acetic acid led to a greater decrease (P<0.05) of bronchial resistances when compared to that obtained from MgF2 + NaCl 0.9%, NaF exclusively and MgSO4 alone (3) inhaled NaF alone led to a significant bronchorelaxing effect (P<0.05) that starts at the sixth dose of MeCh (17 mg/L). As a matter of fact, MgF2 dissolved in acetic acid and delivered in aerosol form reduces significantly bronchial spasm. In conclusion, MgF2 can be used as a bronchodilator for diseases with bronchospasma such as asthma and chronic obstructive pulmonary disease (COPD).
