Lichen: A comprehensive review on Lichens as a natural sources exploring nutritional and biopharmaceutical benefits

Lichens are used as traditional medicines, rich in nutritional values, and have been described as potent medicines in various pharmacopoeias world-wide. Lichens are environmental biological indicators for human operations to change the ecosystem and also generate a range of unique secondary metabolites with varying biological potential. In addition to their prospective biological role as photoprotection, anticancer, anti-hepatotoxic, antidiabetic, allelopathic, and immunornodulatory, etc. Over the past few decades, the interest in lichens as a source of novel bioactive molecules has been renewed and increasing. Research on lichens secondary metabolites and nutritional value even at the international level has been scanty. This review summarizes the present status of characterization, nutritional values, and pharmaceutical properties of lichens and their applications. This study provides a baseline for future studies, particularly those dealing with nutritional and medicinal aspects of lichens.