Chapter 8: Cosmetic Applications of Lichens

Lichens are symbiotic complexes of fungi and algae (or cyanobacteria), whose special symbiotic structure allows them to produce unique and abundant metabolites. The variety of biological activities of lichen substances has been proven, but research on lichen substances in the field of modern cosmetics is still scattered and lacking. In this chapter, lichens and their metabolites are introduced, and their applications in cosmetics and potential health benefits are reviewed. The antibacterial, antifungal, antioxidant, photoprotective, anti-inflammatory, enzyme-inhibiting and moisturizing activities of lichen substances may offer new options for the development of and research into cosmetic and natural ingredients. However, the mechanism of action, skin permeability and skin safety of lichen bioactive substances are still unclear, and this may be a direction for future research.