Real-time cell analysis of the inhibitory effect of Xalocoa ocellata (Fr.) Kraichak, Lücking & Lumbsch on breast cancer cells

Background: Xalocoa ocellata is a mild-temperature to Mediterranean lichen found on limestone, dolomite and calciferous sandstone. It contains depsidones, namely norstictic acid and connorstictic acid [1].

Methos: Dried lichen samples were extracted by ethanol at a ratio of 1:20 (w/v) with the help of soxhlet extractor (26°C, 2 hr). Then, solvent was removed from samples by rotary extractor (250 Rpm, 50°C, 1 hr.) and lyophilization for 12 hours. Human Breast Cancer MCF-7 cell line was maintained in RPMI supplemented with a 10% fetal calf serum, L-glutamine, penicillin, streptomycin and non-essential amino acids. Extracts were added to the culture medium to achieve the final concentration of 25-250 μg/ml. Growth of MCF-7 cells was continuously monitored for at least 120 h using the xCELLigence RTCA MP instrument (Roche).

Results: Our research directs that X. ocellata extracts shows effective preferential cytotoxicity at a concentration range of 25 to 250 μg/mL at the MCF-7 breast cancer cells. We examined the dose- and time- dependent inhibition of the human breast cell lines after X. ocellata extracts treatment.

Conclusion: In this report, for the first time in literature, it was shown that X. ocellata extracts provide a preferential cytotoxicity in breast cancer cells in-vitro.

Keywords: Cytotoxicity, MCF-7, RTCA, Xalocoa ocellata.

References: [1] H. Thorstenlumbsch and John A. Elix,1989, Taxonomy of Some Diploschistes spp. (Lichenized Asco-Mycetes, Thelotremataceae) Containing Gyrophoric Acid. Pl. Syst. Evol. 167,195-199.