Nebulization of S-Carboxymethylcysteine Does Not Adversely Affect the Mucociliary System in the Paranasal Sinus and Trachea of the Healthy Rabbit

Abstract

Chronic sinusitis is a persistent inflammatory impairment of the paranasal sinus. Disturbance of the mucociliary function in the paranasal sinus is the most common finding in chronic sinusitis. S-carboxymethylcysteine (S-CMC) has been shown to directly enhance the ciliary activity of the chronic sinusitis mucosa. Direct contact of the disturbed cilia with S-CMC may recover the reduced beating activity of cilia in chronic sinusitis and the mucosal pathology of the disease can thus be improved. Before S-CMC as a medicine for nebulization in the treatment of chronic sinusitis can be clinically applied, however, it should be experimentally established whether nebulization of S-CMC has any adverse effects on the mucociliary system of the respiratory mucosa. The present study was designed to experimentally examine the safety of nebulization of S-CMC especially with regard to the respiratory mucosa. Rabbits were treated with nebulization of three different concentrations of S-CMC solution for 20 min a day for 14 successive days, and their mucosal pathology of the sinus and trachea was examined and compared with that of healthy animals. Nebulization of concentrations of 0.5–10% of S-CMC solution did not affect the ciliary activity in the sinus and tracheal mucosa, nor did this treatment induce pathological changes such as epithelial injury and inflammatory cell accumulation. It is therefore concluded that concentrations of 0.5–10% S-CMC solution are quite safe for the use of nebulization in the treatment of chronic sinusitis.