Antioxidant capacity and cholinesterase inhibitory activity of Vulpicida pinastri lichen and its chemical composition

This study reports for first time the antioxidant capacity and cholinesterase inhibitory activity of the methanol extract of the lichen Vulpicida pinastri (Scop.) J.E. Mattsson & M.J. Lai and its chemical composition. This lichen specie with a greenish yellow foliose thallus was collected in Puerto Alto del Peñon, Zamora (Spain). Antioxidant capacity was assessed by in vitro tests (DPPH, ORAC and FRAP), total phenolic content by Folin-Ciocalteu method, cholinesterase inhibitory activity by Ellman’s colorimetric method and chemical composition by HPLC-UV method. The results showed that the values for antioxidant capacity were IC₅₀ 283.7 ± 31.7 microg/ml for DPPH, 1.5 ± 0.1 micromol TE/mg dry extract for ORAC and 25.4 ± 2.3 micromol of Fe²⁺ eq/g sample for FRAP. Moreover, total phenolic content had a value of 48, 9 ±4.8 microg GA/mg. Furthermore, IC₅₀ values were 0.19 ± 0.003 mg/mL for acetylcholinesterase inhibitory activity and 0.89 ± 0.018 mg/mL for butyrylcholinesterase inhibitory activity. Finally, the analysis of chemical composition revealed that the major secondary metabolites were vulpinic acid (9.3 ± 0.8), pinastric acid (41.9 ± 1.07) and usnic acid (36.5 ± 3.62). In conclusion, Vulpicida pinastri is a promising agent to further study for the prevention and treatment of Alzheimer’s disease based on its antioxidant and cholinesterase inhibitory activities.