Usnea barbata (L.)F.H.Wigg. - known as “old man’s beard”, “tree moss”, “songluo” is a lichen in the family Parmeliaceae, genus Usnea. Usnea species have recorded history of therapeutic use dating back over three thousand years in Chinese medicine. The lichen secondary metabolites have shown an impressive range of biological proprieties, including antibiotic, antifungal, antiviral, anti-inflammatory, or anticancer activities.
In this study, the antitumor activity of Usnea barbata extract was evaluated by observing the morphological changes on squamous cells carcinoma cell-line CAL 27 (ATCC® CRL-2095 ™) in contact with different concentrations of extract, ranged between 12.5–400 μg/mL. The results obtained were quantified by the intensity of morphological changes of the tumor cells after 24 hours of contact. The most significant activity were recorded for 400 μg/mL extract.
This study shows that Usnea barbata (L.)F.H.Wigg. extract has antitumor activity. The analysis of the obtained results showed that the cytotoxicity of lichen extract on CAL 27 tumor cells is directly related to the concentration of the applied solution.