Lysozyme – An Underexploited Molecule with High Therapeutic Potential but of Little Interest to the Pharmaceutical Industry.

ABSTRACT

The discovery of lysozyme has accomplished its hundredth anniversary. Lysozyme is mainly known for its bactericidal, bacteriostatic, and antiviral properties, but has also antifungal, anti-inflammatory, immunostimulant, and anti-cancer functions. Lysozyme-based medical applications could be developed not only for infectious but also for a variety of chronic diseases, including cancer, hypertension, and diseases related to insulin resistance with the advantage of having no adverse effects. Also, lysozyme has been associated with the prevention of infections and has anti-inflammatory properties. Therefore, it could be also considered as a functional food and for clinical nutrition. Despite its affirmed and promising medical applications, the need for developing new treatments against antibiotic-resistant strains, and affordable treatments especially for diseases with high social, societal, and economic impact, today, surprisingly, lysozyme-based approved drugs and treatments for humans are still almost not existing. The development or re-profiling of lysozyme-based drugs appears to be unattractive for the industry. One probable reason for that is, that already well-known sources, such as egg-white lysozyme, are unlikely to be patentable due to a lack of innovation. In the current system, the development of unpatentable drugs can only be attractive with a sufficiently long market exclusivity granted. Today, drug development depends exclusively on the economic interests of the industry. However, for more sustainable drug development and full exploitation of available resources, a more public interest-driven system may be needed. Also, for the targeted use of lysozyme as a functional food and for clinical nutrition public resources for research and clinical trials are necessary.