Anti-yeast potential of lichen-extracted substances- An analytical review

A meta-analysis of literature data with statistical analysis concerning the effect of lichen substances on the inhibition of 10 yeast species (Candida albicans, C. dubliniensis, C. glabrata, C. parapsilosis, C. sake, C. tropicalis, Colacogloea diffluens, Cryptococcus neoformans, Issatchenkia orientalis and Saccharomyces cerevisiae) is pro-vided. Lichen extracts were obtained using 16 solvents from 100 epiphytic, 51 epigeic and 37 epilithic lichen species. The most studied lichen taxa at the generic level belonged to the family Parmeliaceae. 67 individual secondary metabolites belonging to 12 biochemical classes were subjected to experiments. The MIC was used most frequently. Candida albicans was the most commonly tested species; other fungal species remain relatively less or very poorly tested. Against C. albicans, a stronger antifungal potential is demonstrated by extracts from numerous lichen species, including Evernia prunastri, Hypotrachyna vexans, Pseudevernia furfuracea, Ramalina pollinaria, R. polymorpha, Cladonia foliacea, C. pocillum, C. rangiformis and Umbilicaria cylin-drica, which generated secondary compounds such as atranorin, acollatolic acid, ethyl everninate, lecanoric acid, methyl 2,6-dihydroxy-4-methylbenzoate, protolichesterinic acid, retigeric acid A and B, scrobiculin and usnic acid. The potential of the extracts and secondary metabolites makes it possible to replace several commercial antibiotics in the future, in particular clotrimazole and fenticonazole. For the purpose of future experiments, this review stresses the need to standardizse research methodology, especially for the simultaneous determination of MIC and IZ and, if possible, MFC. There is a need for greater use of water as a solvent to extract lichen substances as a safe and feasible method for phytopharmaceutical and cosmetic purposes. The conclusions drawn highlight the prospective use of lichen extracts and secondary metabolites against yeast in the medical, phytopharmaceutical and cosmetic fields and as preservatives.& COPY; 2023 SAAB. Published by Elsevier B.V. All rights reserved.