¹Department of Biochemistry, Faculty of Farmacy, Erciyes University, Kayseri, Türkiye
²Department of Biology, Faculty of Science, Erciyes University, Kayseri, Türkiye In this study, we investigated the anti-microbial and anti-inflammatory activities of the cosmopolite macrolichens Usnea articulata (L.) Hoffm., Umbilicaria crustulosa (Ach.) Lamy and Bryoria fuscescens (Gyeln.) Brodo & D.Hawksw hydroalcoholic extracts to contribute the potential pharmacological uses of lichens. In vitro antimicrobial activities of ethanol extracts against Gram-negative bacteria Escherichia coli, Gram-positive bacteria Staphylococcus aureus, and the yeast Candida albicans were presented using the Broth microdilution method. The most effective lichen extract against gram-positive bacteria S. aureus was U. articulata ethanol extract with a MIC value of 0.125 mg/ml. U. articulata and B. fuscences extracts have similar anti-fungal activities despite having MIC values of 0.5 mg/ml. The antiinflammatory effects of the extracts on Lipopolysaccharide/Interferon-gamma (LPS/IF-γ) induced macrophage-like cellular systems (BV-2 microglia and RAW 264,7 macrophages) were evaluated by measuring P38 mitogen-activated protein kinase phosphorylation (P38MAPK), cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase 2 (NOS2) mRNA and protein expression. Especially, Usnea and Umbilicaria extracts also attenuated the LPS/IF-γ induced increase in P38MAPK phosphorylation, COX-2, and NOS2 expression in both macrophage-like cells without any cytotoxicity. According to the results of our study, we suggest that the anti-inflammatory mechanism of lichen extracts might result from the inhibition of P38MAPK phosphorylation through a reduction in COX-2 and NOS2 expressions. Keywords : Inflammation; Lichens; Microglia; Lipopolysaccharide; Interferon-gamma