This study presents the biopharmaceutical potential and bioactive composition of Xanthoria lichens (X. candelaria, X. elegans, X. parietina) that wildly grown and traditionally utilized as medicine in North Eastern Anatolia, Turkey, which has specific microclimatic and ecological zones.
Chromatographic findings revealed significant levels of parietin compound (35 to 49 mg/g extract), low levels of various fatty acids and a volatile compound; α-terpinene in the extracts. The extracts exhibited pronounced antioxidant potential through reducing and scavenging mechanisms; FCR: 33-38 mg gallic acid equivalent, FRAP: 511-815 µ mol Fe2+, ORAC: 1032-1355 µ mol Trolox equivalent per gram extract, respectively and DPPH: IC50: 1.1-2.7, ABTS: IC50: 2-2.3, CUPRAC: IC50: 0.7-1.2, phosphomolybdenum: IC50: 2-2.9, metal chelation: IC50: 1.3-2.3 mg extract/ml, respectively. Concerning enzyme inhibitory activities, the extracts effectively suppressed the activity of acetylcholinesterase (IC50: 0.5-0.75 mg/ml), butyrylcholinesterase (IC50: 0.7-1.1 mg/ml), tyrosinase (IC50: 0.6-0.7 mg/ml), amylase (IC50: 1.7-2 mg/ml), glucosidase (IC50: 0.6-3 mg/ml) and lipase (IC50: 55-79 µg/ml) enzymes.
These findings showed that Xanthoria lichens are dominated by parietin as the major key compound and high-tolerated lichen taxa towards to different ecological and climatic conditions. These lichens might be promising sources of novel antioxidant and enzyme inhibitory activities such as Xanthoria candelaria as antioxidant and antilipase, Xanthoria elegans as anticholinesterase, and Xanthoria parietina as antiamylase and antiglucosidase.