Cladonia uncialis as a valuable raw material of biosynthetic compounds against clinical strains of bacteria and fungi

Elżbieta Studzińska-Sroka; Hanna Tomczak; Natalia Malińska; Marta Wrońska; Robert Kleszcz; Agnieszka Galanty; Judyta Cielecka-Piontek; Dorota Latek; Jarosław Paluszczak

doi:10.18388/abp.2019_2891

Elżbieta Studzińska-Sroka 1Department of Pharmacognosy, Poznan University of Medical Sciences, Poznań, Poland
Hanna Tomczak Central Microbiological Laboratory, Święcicki University Hospital, Poznań, Poland; Department of Dermatology and Venereology, Poznan University of Medical Sciences, Poznań, Poland
Natalia Malińska Central Microbiological Laboratory, Święcicki University Hospital, Poznań, Poland https://orcid.org/0000-0001-5401-2363
Marta Wrońska Central Microbiological Laboratory, Święcicki University Hospital, Poznań, Poland https://orcid.org/0000-0001-7817-9790
Robert Kleszcz Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, Poznań, Poland https://orcid.org/0000-0002-6607-7436
Agnieszka Galanty Department of Pharmacognosy, Jagiellonian University Medical College, Kraków, Poland
Judyta Cielecka-Piontek Department of Pharmacognosy, Poznan University of Medical Sciences, Poznań, Poland
Dorota Latek Faculty of Chemistry, University of Warsaw, Warsaw, Poland https://orcid.org/0000-0002-0429-0637
Jarosław Paluszczak Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, Poznań, Poland https://orcid.org/0000-0002-6187-7549

DOI: https://doi.org/10.18388/abp.2019_2891

Abstract

Cladonia uncialis is a lichen species with confirmed antibacterial activity and whose genome has been recently sequenced, enabling first attempts in its functional characterization. In this work, we investigated activity of the C. uncialis acetone extract (CUE) and usnic acid (UA) enantiomers against ten clinical microbial strains causing skin infections. The results showed that CUE, containing (–)-UA and squamatic acid, assayed at the same concentrations as UA, was noticeably more active than (–)-UA alone, in its pure form. The studied CUE displayed an activity that was comparable to that of (+)-UA observed for Staphylococcus epidermidis and Enterococcus faecium (18-24 mm zone of growth inhibition), but did not display any activity against fungal strains. The CUE demonstrated low cytotoxicity against HaCaT cells, in comparison to UA enantiomers, which is important for its therapeutic use. Results of the antioxidant assay (DPPH) indicated low antioxidant activity (IC50>200 µg/mL) of CUE, while the total phenolic content was 70.36 mg Gallic Acid Equivalent/g of the dry extract.