An extract from the culture of a thermophilic <i>Staphylococcus aureus</i> strain suppresses allergic inflammation in the airways <i>in vivo</i> and degranulation of mast cells and basophils <i>in vitro</i>

Abstract

Aim. To study the anti-allergic effects of ruzam, an extract from the culture of a thermophilic Staphylococcus aureus strain, in an in vivo model of asthma and its influence on degranulation of mast cells and basophils in vitro.Materials and methods. Allergic asthma in guinea pigs was reproduced by two intraperitoneal injections of ovalbumin followed by a series of inhalations of this antigen for 1.5 months. Ruzam (6 μg / kg) or a reference drug (sodium cromoglycate, 3 mg / kg) was administered daily via a nebulizer during the last 6 days of immunization. One day after completion of inhalations with ovalbumin and compared drugs, changes in the airways were assessed using cytological, morphometric, and histologic methods. Rabbit blood basophils and rat peritoneal mast cells were used to determine the effect of ruzam on IgE-independent degranulation induced by the compound 48 / 80 in vitro. The effect of ruzam was compared with that of hydrocortisone hemisuccinate. Basophils from the blood of ovalbumin-sensitized guinea pigs were used to evaluate the effect of the drug on IgE-dependent degranulation induced by ovalbumin. Granules of mast cells and basophils were detected by alcian blue staining to calculate the degranulation index.Results. In the asthma model, ruzam reduced the degree of airway obstruction by increasing the bronchoalveolar lavage volume returned and suppressed neutrophilic and eosinophilic inflammation, while mobilizing other effector cells of the anti-pathogen immunity (lymphocytes and macrophages). Ruzam has proven to have a stronger anti-allergic effect than sodium cromoglycate by several parameters. At concentrations of 8.4–840 μg / ml, ruzam inhibited degranulation of mast cells and basophils, induced by the compound 48 / 80, equally to hydrocortisone hemisuccinate (10–3 M). At concentrations of 280 and 420 μg / ml, ruzam dose-dependently inhibited ovalbumin-induced degranulation of basophils in sensitized guinea pigs.Conclusion. The anti-allergic effect of ruzam was confirmed in test systems in vivo and in vitro. We speculate here that the TLR2 signaling pathway may be involved in biological and pharmacological effects of this drug.