Serratiopeptidase is a proteolytic enzyme originally derived from bacteria found in silkworms. Its primary traditional and clinical use has been as an anti-inflammatory agent, particularly for conditions involving pain and swelling. In the context of the bronchial system, serratiopeptidase has been studied for its potential to reduce the viscosity of sputum and promote its clearance, thereby helping to alleviate symptoms in respiratory conditions such as chronic bronchitis and sinusitis. Some small clinical trials and observational studies, primarily from India and Japan, suggest that serratiopeptidase may be helpful as a mucolytic agent, reducing sputum thickness and improving expectoration in patients with respiratory tract infections.

However, the overall scientific evidence is limited. Most studies are small, not always placebo-controlled, and sometimes lack rigorous methodology. Systematic reviews note a need for more robust, larger-scale clinical trials to clearly establish its efficacy and safety for bronchial conditions. There is biological plausibility for its use, given its enzymatic action on protein-based secretions, but this has not yet translated into high-quality evidence or guideline-based recommendations. Thus, while there is some scientific basis for its use in the bronchial system, the strength of the evidence is modest at present.