Abstract
Due to wide range of secondary metabolites, lichens were used from antiquity as sources of colorants, perfumes and medicaments. This research focuses on exploring the antioxidant, antimicrobial and cytotoxic activities of methanol, ethanol, acetone extracts and aqueous infusions of corticolous lichens sampled from Armenia. Methanol, ethanol and acetone extracts from all tested lichens were active against Gram-positive bacterial strains. The most effective solvent to retrieve antimicrobial compounds was methanol. Aqueous infusions of tested lichens didn’t show any significant antibacterial and antifungal activity. The highest antimicrobial activity was observed for methanol extract of Ramalina sinensis. The minimum inhibitory concentration of methanol extract of Ramalina sinensis were 0.9–1.8 mg mL− 1. Pseudevernia furfuracea demonstrated antifungal activity (Ø 12 mm). Methanol extract of Parmelia sulcata demonstrated largest 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity (71 %). The cytotoxicity was measured on human HeLa (cervical carcinoma) cell lines using microculture tetrazolium test assay. The IC50 values estimated for methanol extracts of Peltigera praetextata, Evernia prunastri, Ramalina sinensis and Ramalina farinacea species in HeLa cell line were within 1.8–2.8 mg mL− 1 and considered as non-cytotoxic. Obtained results suggest that studied lichens can be prospective in biotechnologies as alternative sources of antimicrobial and antioxidant substances.
Highlights
About 20,000 species of lichens growing on wide variety of substrates like rocks, walls, exposed soil surfaces and as epiphytes on the bark of trees and leaves have been recorded worldwide (Ellis 2012)
Since biotechnological potential of lichens distributed on the territory of Armenia still remains unexplored, we aimed to study of bioactivity of the aqueous and different alcoholic extracts of the corticolous lichens sampled from Armenia
Antibacterial activity Results of antimicrobial activity of alcoholic extracts and aqueous infusions of tested lichens against tested bacteria and yeast are summarized in the Table 1
Summary
About 20,000 species of lichens growing on wide variety of substrates like rocks, walls, exposed soil surfaces and as epiphytes on the bark of trees and leaves have been recorded worldwide (Ellis 2012) They are well adapted to survive in various geographical zones, from sea level to high elevations and from equator to polar regions. It was shown that besides cyanobacteria other bacteria exist in lichen thalli and take part in mutualistic relationship (Bates et al 2011; Aschenbrenner et al 2016; Pankratov et al 2017) Due to this multiparty mutualism they adapted to survive even in extreme environments characterized by high or low temperatures, periodic desiccation, high levels of UV radiation and salinity. Parmelia sulcata have been used to treat diseases of respiratory system, while Xanthoria parietina and Letharia vulpina were used against to cure jaundice and gastrointestinal disorders, respectively (Ranković et al 2011; Crawford 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
