Harnessing the Potential of Enzymes as Inhaled Therapeutics in Respiratory Tract Diseases: A Review of the Literature

Respiratory tract diseases (RTDs) are a global cause of mortality and affect patient wellbeing and quality of life. Specifically, there is a high unmet need concerning respiratory tract infections (RTIs) due to limitations of vaccines and increased antibiotic resistance. Enzyme therapeutics, and in particular plant-based enzymes, represent an underutilised resource in drug development warranting further attention. This literature review aims to summarise the current state of enzyme therapeutics in medical applications, with a focus on their potential to improve outcomes in RTDs, including RTIs. We used a narrative review approach, searching PubMed and clinicaltrials.gov with search terms including: enzyme therapeutics, enzyme therapy, inhaled therapeutics, botanical enzyme therapeutics, plant enzymes, and herbal extracts. Here, we discuss the advantages and challenges of enzyme therapeutics in the setting of RTDs and identify and describe several enzyme therapeutics currently used in the respiratory field. In addition, the review includes recent developments concerning enzyme therapies and plant enzymes in (pre-)clinical stages. The global coronavirus disease 2019 (COVID-19) pandemic has sparked development of several promising new enzyme therapeutics for use in the respiratory setting, and therefore, it is timely to provide a summary of recent developments, particularly as these therapeutics may also prove beneficial in other RTDs.

Automated summary

This literature review provides an overview of the current state of enzyme therapeutics in medical applications, with a focus on their potential to improve outcomes in respiratory tract diseases, including infections. The advantages and challenges of enzyme therapeutics in the respiratory field are discussed, and several enzyme therapeutics currently used are identified and described. Recent developments in enzyme therapies and plant enzymes in (pre-)clinical stages are also included. The review highlights the potential benefits of enzyme therapeutics in respiratory diseases, including the ongoing COVID-19 pandemic.