Protective effect of sodium cromoglycate on lipopolysaccharide-induced bronchial obstruction in asthmatics

Lipopolysaccharides (LPS, the major part of endotoxins) are bacterial proinflammatory substances which can induce in asthmatic patients after inhalation a bronchial obstruction with an increase in both histamine bronchial hyperresponsiveness and blood inflammatory markers. The aim of the present study was to evaluate whether an acute inhalation of sodium cromoglycate, an anti-inflammatory and membrane-stabilizating agent, can block the LPS-induced lung function response. Using a double-blind placebo-controlled crossover method, 7 asthmatic subjects were submitted, at 4 days' interval, to a bronchial challenge test with either solvent solution or LPS (20 micrograms) preceded by inhalation of sodium cromoglycate (10 mg) or placebo. Compared to the solvent reaction, LPS induced a significant bronchial obstruction [measured by both the forced expiratory volume in 1 s (FEV1) and the airway resistances] beginning at the 60th minute and lasting more than 300 min (p < 0.01, 2-way ANOVA). On the other hand, acute pretreatment with sodium cromoglycate significantly inhibited the LPS-induced bronchial obstruction. The total lung capacity did not change significantly after LPS inhalation. Thus, this study showed that in asthmatics the LPS-induced FEV1 response is blocked by acute treatment with sodium cromoglycate. Sodium cromoglycate could be an active treatment in asthmatics exposed to house dust containing endotoxin.