Kaw, Anne Bernadette S.3Bio4 The anti-cancer properties of foliose endolichensLichens, the symbiotic relationship of specialized fungi associated with algae, exist in a wide range of habitats throughout the world and dominating about 8% of terrestrial ecosystems (Nayaka, Upreti, & Khare, 2010). Lichens and their metabolites exhibit antifungal, antimicrobial, antitumor, antiproliferative, and antiviral properties (Huneck, 1999). Usnic acid and atranorin are just some of the components that exhibit anticancer properties, particularly on breast cancer cells. In a study conducted Bakorova, Bakorb, Mikea, Jendelovska, and Fedorokoa, (2011), the suppression of viability and cell proliferation by usnic acid or atranorin was found to be more efficient at equitoxic doses and correlated more strongly with an increased number of floating cells or a higher apoptotic index. Mitrovic, et al. (2011) investigated the anticancer properties, antitumor and antiproliferative properties of Hypogymnia physodes and Cladonia foliacea. Hypogymnia physodes was found to be abundant in phenolic compounds and its antioxidative power could be considered as a cotreatment with some stronger cytotoxic agents, chemotherapy agents. Another study investigating the genotoxic activity of Hypogymnia physodes was conducted by Ari, et al. (2014) and the results indicate that H. physodes has an anti-growth effect of cancer cells at relatively lower concentrations, while relatively higher concentrations are required for genotoxic activity. In addition, the amount of usnic acid present in various Hypogymnia species is also responsible for its antioxidant properties. Usnic acid, together with atranorin, produces the antioxidant properties of Cladonia foliacea (Yilmaz, Trk, Tay, & Kivan, 2004). Atranorin induced apoptosis in breast carcinomas (4T1) with the activation of effector caspase-3. atranorin has antiproliferative effects on cancer 4T1 cells at relatively low concentrations. (Koptaikov, et al., 2013).Usnic acid is an active compound mainly found in lichens. According to Song et al. (2012), tumor growth depends on angiogenesis and inducing angiogenesis is one of the hallmarks in cancer development. In a mouse xenograft tumor model, usnic acid was found to suppress Bcap-37 breast tumor growth and angiogenesis without affecting the body weight. In addition, usnic acid inhibited Bcap-37 tumor cell proliferation. Chitosan is a component found in the cell walls and mycelia, stalks, and spores of Basidiomycetes, Ascomycetes, and Phycomycetes (Logesh, Thillaimaharani, Sharmila, Kalaiselvam, & Raffi, 2012). Among the strains isolated from the lichen (R. montagnei), A. niger was considered as a potential candidate for the chitosan product. The study also showed that chitosan derivatives inhibit cell proliferation and induce apoptosis in breast cancer cells. (Jiang, et al., 2011).

ReferencesAri, F., Celikler, S., Oran, S., Balikci, N., Ozturk,S., Ozel, M.Z., Ulukaya, E. (2014). Genotoxic, cytotoxic, and apoptotic effects of Hypogymnia physodes (L.) Nyl. on breast cancer cells. Environ. Toxicol., 29, 804813. doi: 10.1002/tox.21809

Bakorova, M., Bakorb, M., Mikea, J., Jendelovska, R., & Fedorokoa, P. (2011). Variable responses of different human cancer cells to the lichen compounds parietin, atranorin, usnic acid and gyrophoric acid. Toxicology In vitro, 25(1), 37-44. doi:10.1016/j.tiv.2010.09.004

Huneck, S. (1999).The Significance of Lichens and their metabolites. Naturwissenschaften, 86(12), 559-570. Retrieved from http://link.springer.com/article/10.1007%2Fs001140050676?LI=true

Jiang, M., Handong, O., Ruan, P., Zhao, H., Zhenjun, P., Huang, S., Crepin, M. (2011). Chitosan derivatives inhibit cell proliferation and induce apoptosis in breast cancer cells. Anticancer Research, 31(4), 1321-1328. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/21508382

Koptaikov, L. Solar, P., Jendzelovsky, R., Uhrinova, M., Ferenc, P., Backor, M., Hrkova, G. (2013). Anticancer and antiproliferative effects of atranorin on mammary cancer 4T1 and normal NMuMG cells. Drug Discovery and World Therapy World Congress 2013. Retrieved from http://www.giievent.jp/eur279588-2014/Abstract-Book-DDTWC-(2013).pdf

Logesh, A.R., Thillaimaharani, K.A., Sharmila, K., Kalaiselvam, M., & Raffi, S.M. (2012). Production of chitosan from endolichenic fungi isolated from mangrove environment and its antagonistic activity. Asian Pacific Journal of Tropical Biomedicine, 140-143. doi:10.1016/S2221-1691(11)60208-6

Mitrovic, T., Stamenkovi , S., Cvetkovi, V., Toi, S., Stankovi , M., Radojevi, I Markovi, S. (2011). Antioxidant, antimicrobial and antiproliferative activities of five lichen species, International Journal of Molecular Sciences, 12, 5428-5448. doi:10.3390/ijms12085428

Nayaka, S., Upreti, D. K., & Khare, R. (2010). Medicinal lichens of India. Drugs from Plants, 1-6. Retrieved from http://www.researchgate.net/publication/259391362_MEDICINAL_LICHENS_OF_INDIA

Song, Y., Dai, F., Zhai, D., Dong, Y., Zhang, J., Lu, B., Yi, Z. (2012). Usnic acid inhibits breast tumor angiogenesis and growth by suppressing VEGFR2-mediated AKT and ERK1/2 signaling pathways. Angiogenesis, 15(3), 421-432. Doi 10.1007/s10456-012-9270-4

Yilmaz, M., Trk A.O., Tay, T., Kivan, M. (2004). The antimicrobial activity of extracts of the lichen Cladonia foliacea and its (-)-usnic acid, atranorin, and fumarprotocetraric acid constituents. Unbound Medline, 59, 249-254. Retrieved from http://www.unboundmedicine.com/medline/citation/15241936/The_antimicrobial_activity_of_extracts_of_the_lichen_Cladonia_foliacea_and_its_____usnic_acid_atranorin_and_fumarprotocetraric_acid_constituents_