Biotechnology-based Profiling of Lichens and Their Metabolites for Therapeutic Applications

Main Article Content

Priyansh Srivastava
Indira Partha Sarethy

Abstract

Lichens have been inadequately studied for their medicinal value though recent studies have established them as potential sources of bioactive compounds that show antimicrobial, anticancer, antioxidant and neuroprotective properties. Ethnobotanical studies have shown that Pseudocyphellaria aurata, Usnea bismolliuscula, Usnea longissimi, Xanthoparmelia conspersa, Sulcaria sulcate and Solorina crocea have been used by humans since ancient times as a part of their folk wisdom. Recent studies have shown that metabolites from lichens show promising bioactive properties. This review focuses on the necessity for utilizing a modern biotechnology-based approach for elucidating the role and unrealized potential of lichens. Technologies such as genomics, metagenomics, and proteomics have been applied to a far lesser extent in lichens, but the limited studies have revealed the unrealized potential of lichens in modern therapeutics. We attempt to provide a broad overview of the known and unknown in lichen research – ranging from the metabolite production pathways to the genomics and metagenomics, and further to the proteomics and transcriptomics of lichens, the threads of which need to be pieced together to provide a roadmap for further studies.

Article Details

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Review Ariticle

References

Bajpai, R. and Upreti, D.K., 2014. Lichens on Indian Monuments Biodeterioration and Biomonitoring. New Delhi: Bishen Singh Publishers.

El-Garawani, I., Emam, M., Elkhateeb, W., El-Seedi, H., Khalifa, S., Oshiba, S., Abou-Ghanima, S. and Daba, G., 2020. In vitro antigenotoxic, antihelminthic and antioxidant potentials based on the extracted metabolites from lichen, Candelariella vitellina. Pharmaceutics, 12(5), https://doi.org/10.3390/pharmaceutics12050477.

Nugraha, A.S., Pratoko, D.K., Damayanti, Y.D., Lestari, N.D., Laksono, T.A., Addy, H.S., Untari, L.F., Kusumawardani, B. and Wangchuk, P., 2019. Antibacterial and anticancer activities of nine lichens of Indonesian Java Island. Journal of Biologically Active Products from Nature, 9(1), 39-46.

Parreira, P., Brás, T., Ramos, P.A. and Duarte, M.F., 2015. Bioactives against superbugs: using phytotherapy to counteract the drug-resistance burden in the 21st century. In: A. Mendez-Vilas, ed. The Battle against Microbial Pathogens: Basic Science, Technological Advances and Educational Programs. Badajoz: Formatex Research Center, pp. 109-116.

Zopf, W., 1896. Uebersicht der auf Flech-ten schmarotzenden Pilze. Hedwigia, 35, 312-366.

Crawford, S.D., 2019. Lichens used in traditional medicines. In: B. Rankovic, ed. Lichen Secondary Metabolites. Cham: Springer, pp. 31-97.

O’Neill, A.R., Badola, H.K., Dhyani, P.P. and Rana, S.K., 2017. Integrating ethnobiological knowledge into biodiversity conservation in the Eastern Himalayas. Journal of Ethnobiology and Ethnomedicine, 13, https://doi.org/10.1186/s13002-017-0148-9.

Rout, J., Kar, A. and Upreti, D.K., 2005. Traditional remedy for kidney stones from high altitude lichen: Cladonia rangiferina L. Wigg (reindeer moss) of Eastern Himalaya. Ethnobotany, 17(1-2), 164-166.

Ranković, B. and Mišić, M., 2008. The antimicrobial activity of the lichen substances of the lichens Cladonia furcata, Ochrolechia androgyna, Parmelia caperata and Parmelia conspresa. Biotechnology and Biotechnological Equipment, 22(4), 1013-1016.

Ranković, B., Mišić, M. and Sukdolak, S., 2008. The antimicrobial activity of substances derived from the lichens Physcia aipolia, Umbilicaria polyphylla, Parmelia caperata and Hypogymnia physodes. World Journal of Microbiology and Biotechnology, 24(7), 1239-1242.

Piovano, M., Garbarino, J.A., Giannini, F.A., Correche, E.R., Feresin, G., Tapia, A., Zacchino, S. and Enriz, R.D., 2002. Evaluation of antifungal and antibacterial activities of aromatic metabolites from lichens. Boletín de la SociedD Chilena de Química, 47, 235-240.

Manojlović, N., Solujić, S. and Sukdolak, S., 2002. Antimicrobial activity of an extract and anthraquinones from Caloplaca schaereri. The Lichenologist, 34(1), 83-85.

Nugraha, A.S., Untari, L.F., Laub, A., Porzel, A., Franke, K. and Wessjohann, L.A., 2021. Anthelmintic and antimicrobial activities of three new depsides and ten known depsides and phenols from Indonesian lichen: Parmelia cetrata Ach. Natural Product Research, 35(23), 5001-5010.

Yadav, H., Nayaka, S. and Dwivedi, M., 2021. Analytics on antimicrobial activity of lichen extract. Journal of Pure and Applied Microbiology, 15(2), 701-708.

Fukuoka, F., Nakanishi, M., Shibata, S., Nishikawa, Y., Takeda, T. and Tanaka, M., 1968. Polysaccharides in lichens and fungi. II. Anti-tumor activities on sarcoma-180 of the polysaccharide preparations from Gyrophora esculenta Miyoshi, Cetraria islandica (L.) Ach. var. orientalis Asahina and some other lichens. GANN Japanese Journal of Cancer Research, 59(5), 421-432.

Shibata, S., Nishikawa, Y., Tanaka, M., Fukuoka, F. and Nakanishi, M., 1968. Antitumour activities of lichen polysaccharides. Zeitschrift fur Krebsforschung, 71, 102-104.

Kupchan, S.M. and Kopperman, H.L., 1975. l-Usnic acid: Tumor inhibitor isolated from lichens. Experientia, 31(6), https://doi.org/10.10007/BF01944592.

Suh, S.-S., Kim, T.K., Kim, J.E., Hong, J.-M., Nguyen, T.T.T., Han, S.J., Youn, U.J., Yim, J.H. and Kim, I.-C., 2017. Anticancer activity of Ramalin, a secondary metabolite from the Antarctic lichen Ramalina terebrata against colorectal cancer cells. Molecules, 22(8), https://doi.org/10.3390/molecules22081361.

Hong, J.-M., Suh, S.-S., Kim, T.K., Kim, J.E., Han, S.J., Youn, U.J., Yim, J.H. and Kim, I.-C.,2018. Anti-cancer activity of lobaric acid and lobarstin extracted from the Antarctic lichen Stereocaulon alpnum. Molecules, 23(3), https://doi.org/10.3390/molecules23030658.

Emsen, B., Aslan, A., Togar, B. and Turkez, H., 2016. In vitro antitumor activities of the lichen compounds olivetoric, physodic and psoromic acid in rat neuron and glioblastoma cells. Pharmaceutical Biology, 54(9), 1748-1762.

Cardile, V., Graziano, A.C.E., Avola, R., Piovano, M. and Russo, A., 2017. Potential anticancer activity of lichen secondary metabolite physodic acid. Chemico Biological Interaction, 263, 36-45.

Zhou, R., Yang, Y., Park, S.-Y., Nguyen, T.T., Seo, Y.-W., Lee, K.H., Lee, J.H., Kim, K.K., Hur, J.-S. and Kim, H., 2017. The lichen secondary metabolite atranorin suppresses lung cancer cell motility and tumorigenesis. Scientific Reports, 7(1), https://doi.org/10.1038/s41598-017-08225-1.

Kilic, N., Derici, M.K., Büyuk, I., Aydin, S.S., Aras, S. and Cansaran-Duman, D., 2018. Evaluation of in vitro anticancer activity of vulpinic acid and its apoptotic potential using gene expression and protein analysis. Indian Journal of Pharmaceutical Education and Research, 52(4), 626-634.

Liu, H., Liu, Y.-Q., Liu, Y.-Q., Xu, A.-H., Young, C.Y.F., Yuan, H.-Q. and Lou, H.-X., 2010. A novel anticancer agent, retigeric acid B, displays proliferation inhibition, S phase arrest and apoptosis activation in human prostate cancer cells. Chemico-Biological Interactions, 188(3), 598-606.

Russo, A., Caggia, S., Piovano, M., Garbarino, J. and Cardile, V., 2012. Effect of vicanicin and protolichesterinic acid on human prostate cancer cells: role of Hsp70 protein. Chemico-Biological Interactions, 195(1), 1-10.

Brisdelli, F., Perilli, M., Sellitri, D., Piovano, M., Garbarino, J.A., Nicoletti, M., Bozzi, A., Amicosante, G. and Celenza, G., 2013. Cytotoxic activity and antioxidant capacity of purified lichen metabolites: an in vitro study. Phytotherapy Research, 27(3),431-437.

Bačkorová, M., Jendželovský, R., Kello, M., Bačkor, M., Mikeš, J. and Fedoročko, P., 2012. Lichen secondary metabolites are responsible for induction of apoptosis in HT-29 and A2780 human cancer cell lines. Toxicology in Vitro, 26(3), 462-468.

Chae, H.-J., Kim, G.-J., Deshar, B., Kim, H.-J., Shin, M.-J., Kwo, H., Youn, U.-J., Nam, J.-W., Kim, S.-H., Choi, H. and Suh, S.-S., 2021. Anticancer activity of 2-O-caffeoyl alphitolic acid extracted from the lichen, Usnea barbata 2017-KL-10. Molecules, 26(13), https://doi.org/10.3390/molecules26133937.

Studzińska-Sroka, E., Majchrzak-Celińska, A., Zalewski, P., Szwajgier, D., Baranowska-Wójcik, E., Żarowski, M., Plech, T. and Cielecka-Piontek, J., 2021. Permeability of Hypogymnia physodes extract component-Physodic acid through the blood-brain barrier as an important argument for its anticancer and neuroprotective activity within the central nervous system. Cancers (Basel), 13(7), https://doi.org/10.3390/cancers13071717.

Jayaprakasha, G.K. and Rao, L.J., 2000. Phenolic constituents from the lichen Parmotremastuppeum (Nyl.) Hale and their antioxidant activity. Zeitschrift für Naturforschung C, 55(11-12), 1018-1022.

Michalak, A., 2006. Phenolic compounds and their antioxidant activity in plants growing under heavy metal stress. Polish Journal of Environmental Studies, 15(4), 523-530.

Odabasoglu, F., Aslan, A., Cakir, A., Suleyman, H., Karagoz, Y., Bayir, Y. and Halici, M. 2005. Antioxidant activity, reducing power and total phenolic content of some lichen species. Fitoterapia, 76(2), 216-219.

Stanly, C., Ali, D.M.H., Keng, C.L., Boey, P.-L. and Bhatt, A., 2011. Comparative evaluation of antioxidant activity and total phenolic content of selected lichen species from Malaysia. Journal of Pharmacy Research, 8, 2824-2827.

Shendge, A.K., Panja, S. and Mandal, N.,2021. Tropical lichen, Dirinaria consimilis, induces ROS-mediated activation of MAPKs and triggers caspase cascade mediated apoptosis in brain and cervical cancer cells. Molecular and Cellular Biochemistry, 476(5), 2181-2192.

Behera, B.C., Adawadkar, B. and Makhija, U., 2004. Capacity of some Graphidaceous lichens to scavenge superoxide and inhibition of tyrosinase and xanthine oxidase activities. Current Science, 87(1), 83-87.

Verma, N., Behera, B.C., Sonone, A. and Makhija, U., 2008. Lipid peroxidation and tyrosinase inhibition by lichen symbionts grown in vitro. African Journal of Biochemistry Research, 12(12), 225-230.

Zlatanović, I., Stanković, M., Jovanović, V.S., Mitić, V., Zrnzevic, I., Đorđević, A. and Stojanović, G., 2017. Biological activities of Umbilicaria crustulosa (Ach.) Frey acetone extract. Journal of the Serbian Chemical Society, 82(2), 141-150.

Stocker-Wörgötter, E. and Elix, J., 2009. Experimental studies of lichen-forming fungi: formation of depsidones and shikimic-acid derivatives by the cultured mycobionts of three selected species of Rhizocarpon (Lecideaceae, lichenized Ascomycota). Bibliotheca Lichenologica. 100, 495-512.

Murtagh, G.J., Dyer, P.S. and Crittenden, P.D., 2000. Sex and the single lichen. Nature, 404, https://doi.org/10.1038/35007142.

Armaleo, D. and Miao, V., 1999. Symbiosis and DNA methylation in the Cladonia lichen fungus. Symbiosis, 26(2), 143-163.

Scherrer, S., Haisch, A. and Honegger, R., 2002. Characterization and expression of XPH1, the hydrophobin gene of the lichen-forming ascomycete Xanthoria parietina. New Phytologist, 154(1), 175-184.

Scherrer, S., Zippler, U. and Honegger, R., 2005. Characterization of the mating-type locus in the genus Xanthoria (lichen-forming ascomyctes, lecanoromyctes). Fungal Genetics and Biology, 42(12), 976-988.

Armaleo, D. and Clerc, P., 1991. Lichen chimeras: DNA analysis suggests that one fungus forms two morphotypes. Experimental Mycology, 15(1), 1-10, https://doi.org/10.1016/0147-5975(91)90002-U.

Muggia, L., Schmitt, I. and Grue, M., 2008. Purifying selection is a prevailing motif in the evolution of ketoacyl synthase domains of polyketide synthases from lichenized fungi. Mycological Research, 112, 277-288.

Cubero, O.F., Crespo, A., Fatehi, J. and Bridge, P.D., 1999. DNA extraction and PCR amplification method suitable for fresh, herbarium-stored, lichenized, and other fungi. Plant Systematics and Evolution, 216(3-4), 243-249, https://doi.org/10.1007/BF01084401.

Grube, M., Depriest, P.T., Gargas, A. and Hafellner, J., 1995. DNA isolation from lichen ascomata. Mycological Research, 99(11), 1321-1324.

Landvik, S., Shailer, N.F.J. and Eriksson, O.E., 1996. SSU rDNA sequence support for a close relationship between the Elaphomycetales and the Eurotiales and Onygenales. Mycoscience, 37, 237-241.

Lee, S.B. and Taylor, J.W., 1990. Isolation of DNA from fungal mycelia and single spores. In: M.A. Innis, D.H. Gelfand, J.J. Sninsky and T.J. White, eds. PCR Protocols: A Guide to Methods and Applications. San Diego: Academic Press, pp. 282-287.

Martin, M.P. and Winka, K., 2000. Alternative methods of extracting and amplifying DNA from lichens. The Lichenologist, 32(2), 189-196.

Whiting., M.F., Carpenter, J.C., Wheeler, Q.D. and Wheeler, W.C., 1997. The Strepsiptera problem: Phylogeny of the holometabolous insect orders inferred from 18S and 28S ribosomal DNA sequences and morphology. Systematic Biology, 46(1), 1-68.

Keller, N.P. and Hohn, T.M., 1997. Metabolic pathway gene clusters in filamentous fungi. Fungal Genetics and Biology, 21(1), 17-29.

Keller, N.P., Turner, G. and Bennett, J.W., 2005. Fungal secondary metabolism-from biochemistry to genomics. Nature Reviews Microbiology, 3, 937-947.

Keller, N.P., 2019. Fungal secondary metabolism: regulation, function and drug discovery. Nature Reviews Microbiology, 17, 167-180.

Beck, J., Ripka, S., Siegner, A., Schiltz, E. and Schweizer, E., 1990. The multifunctional 6-methylsalicylic acid synthase gene of Penicillium patulum. Its gene structure relative to that of other polyketide synthases. European Journal of Biochemistry, 192(2), 487-498.

Kim, W., Liu, R., Woo, S., Kang, K.B., Park, H., Yu, Y.H., Ha, H.-H., Oh, S.-Y., Yang, J.H., Kim, H., Yun, S.-H. and Hur, J.-S., 2021. Linking a gene cluster to atranorin, a major cortical substance of lichens, through genetic dereplication and heterologous expression. mBio, 12(3), https://doi.org/10.1128/mBio.01111-21.

Rindi, F., Lam, D.W. and López-Bautista, J.M., 2009. Phylogenetic relationships and species circumscription in Trentepohlia and Printzina (Trentepohliales, Chlorophyta). Molecular Phylogenetics and Evolution, 52(2), 329-339.

Medema, M.H., Blin, K., Cimermancic, P., de Jager, V., Zakrzewski, P., Fischbach, M.A., Weber, T., Takano, E. and Breitling, R., 2011. AntiSMASH: Rapid identification, annotation and analysis of secondary metabolite biosynthesis gene clusters in bacterial and fungal genome sequences. Nucleic Acids Research, 39, W339-W346.

Terlouw, B.R., Blin, K., Navarro-Muñoz, J.C., Avalon, N.E., Chevrette, M.G., Egbert, S., Lee, S., Meijer, D., Recchia, M.J.J., Reitz, Z.L., van Santen, J.A., Selem-Mojica, N., Tørring, T., Zaroubi, L., Alanjary, M., Aleti, G., Aguilar, C., Al-Salihi, S.A.A., Augustijn, H.E., Avelar-Rivas, J.A., Avitia-Domínguez, L.A., Barona-Gómez, F., Bernaldo-Agüero, J., Bielinski, V.A., Biermann, F., Booth, T.J., Carrion Bravo, V.J., Castelo-Branco, R., Chagas, F.O., Cruz-Morales, P., Du, C., Duncan, K.R., Gavriilidou, A., Gayrard, D., Gutiérrez-García, K., Haslinger, K., Helfrich, E.J.N., van der Hooft, J.J.J., Jati, A.P., Kalkreuter, E., Kalyvas, N., Kang, K.B., Kautsar, S., Kim, W., Kunjapur, A.M., Li, Y.X., Lin, G.M., Loureiro, C., Louwen, J.J.R., Louwen, N.L.L., Lund, G., Parra, J., Philmus, B., Pourmohsenin, B., Pronk, L.J.U., Rego, A., Rex, D.A.B., Robinson, S., Rosas-Becerra, L.R., Roxborough, E.T., Schorn, M.A., Scobie, D.J., Singh, K.S., Sokolova, N., Tang, X., Udwary, D., Vigneshwari, A., Vind, K., Vromans, S.P.J.M., Waschulin, V., Williams, S.E., Winter, J.M., Witte, T.E., Xie, H., Yang D., Yu, J., Zdouc, M., Zhong, Z., Collemare, J., Linington, R.G., Weber, T., Medema, M.H., 2022. MIBiG 3.0: A community-driven effort to annotate experimentally validated biosynthetic gene clusters. Nucleic Acids Research, 51(D1), D603-D610.

Kautsar, S.A., Blin, K., Shaw, S., Weber, T. and Medema, M.H., 2021. BiG-FAM: The biosynthetic gene cluster families database. Nucleic Acids Research, 49(D1), D490-D497.

Singh, G., 2023. Linking lichen metabolites to genes: Emerging concepts and lessons from molecular biology and metagenomics. Journal of Fungi, 9(2), https://doi.org/10.3390/jof9020160.

Grube, M., Berg, G., Andrésson, Ó.S. and Dyer, P.S., 2013. Lichen genomics: Prospects and progress. In: F. Martin, ed. The Ecological Genomics of Fungi. Paris: John Wiley and Sons, pp. 191-212.

Xavier, B.B., Miao, V.P.W., Jónsson, Z.O. and Andrésson, Ó.S., 2012. Mitochondrial genomes from the lichenized fungi Peltigera membranacea and Peltigera malacea: Features and phylogeny. Fungal Biology, 116(7), 802-814.

Miao, V.P.W., Manoharan, S.S., Snæbjarnarsonn, V. and Andrésson, Ó.S., 2012. Expression of lec-1, a mycobiont gene encoding a galectin-like protein in the lichen Peltigera membranacea. Symbiosis, 57(1), 23-31.

Blaha, J., Baloch, E. and Grube, M., 2006. High photobiont diversity associated with the euryoecious lichen-forming ascomycete Lecanora rupicola (Lecanoraceae, Ascomycota). Biological Journal of the Linnean Society, 88(2), 283-293.

Fernández-Mendoza, F., Domaschke, S, García, M.A., Jordan, P., Martín, M.P. and Printzen, C., 2011. Population structure of mycobionts and photobionts of the widespread lichen Cetraria aculeata. Molecular Ecology, 20(6), 1208-1232.

Casano, L.M., del Campo, E.M., García-Breijo, F.J, Reig-Armiñana, J., Gasulla, F., Del Hoyo, A., Guéra, A. and Barreno, E., 2011. Two Trebouxia algae with different physiological performances are ever-present in lichen thalli of Ramalina farinacea. Coexistence versus competition? Environmental Microbiology, 13(3), 806-818.

Pogoda, C.S., Keepers, K.G., Nadiadi, A.Y., Bailey, D.W., Lendemer, J.C., Tripp, E.A. and Kane, N.C., 2019. Genome streamlining via complete loss of introns has occurred multiple times in lichenized fungal mitochondria. Ecology and Evolution, 9(7), 4245-4263.

Schoch, C.L., Seifert, K.A., Huhndorf, S., Robert, V., Spouge, J.L., Levesque, C.A. and Chen, W., 2012. Nuclear ribosomal internal transcribed spacer (ITS) region as a universal DNA barcode marker for fungi. Proceedings of the National Academy of Sciences of the United State of America, 109(16), 6241-6246.

Lofgren, L.A., Uehling, J.K., Branco, S., Bruns, T.D., Martin, F. and Kennedy, P.G., 2019. Genome‐based estimates of fungal rDNA copy number variation across phylogenetic scales and ecological lifestyles. Molecular Ecolog, 28(4), 721-730.

Bradshaw, M., Grewe, F., Thomas, A., Harrison, C.H., Lindgren, H., Muggia, L., Clair, L.L.S., Lumbsch, H.T. and Leavitt, S.D., 2020. Characterizing the ribosomal tandem repeat and its utility as a DNA barcode in lichen-forming fungi. BMC Evolutionary Biology, 20(1), https://doi.org/10.1186/s12862-019-1571-4.

Hodkinson, B.P. and Lutzoni, F., 2009. A microbiotic survey of lichen-associated bacteria reveals a new lineage from the Rhizobiales. Symbiosis, 49, 163-180.

Tuovinen, V., Ekman, S., Thor, G., Vanderpool, D., Spribille, T. and Johannesson, H., 2019. Two basidiomycete fungi in the cortex of wolf lichens. Current Biology, 29(3), 476-483.

Pogoda, C.S, Keepers, K.G., Lendemer, J.C., Kane, N.C. and Tripp, E.A., 2018. Reductions in complexity of mitochondrial genomes in lichen-forming fungi shed light on genome architecture of obligate symbioses. Molecular Ecology, 27(5), 1155-1169.

Schneider, T. and Riedel, K., 2010. Environmental proteomics: Analysis of structure and function of microbial communities. Proteomics, 10(4), 785-798.

Schneider, T., Schmid, E., de Castro, J.V., Cardinale, M., Eberl, L., Grube, M., Berg, G. and Riedel, K., 2011. Structure and function of the symbiosis partners of the lung lichen (Lobaria pulmonaria L. Hoffm.) analyzed by metaproteomics. Proteomics, 11(13), 2752-2756.

Özenoğlu-Aydınoğlu, S., Yıldızhan, H. and Cansaran-Duman, D., 2021. A proteomic analysis of Pseudevernia furfuracea after exposure to Cr+6 by MALDI-TOF mass spectrometry. 3 Biotech, 11(10), https://doi.org/10.1007/s13205-021-02986-3.

Eymann, C., Lassek, C., Wegner, U., Bernhardt, J., Fritsch, O.A., Fuchs, S., Otto, A., Albrecht, D., Schiefelbein, U., Cernava, T., Aschenbrenner, I., Berg, G., Grube, M. and Riedel, K., 2017. Symbiotic interplay of fungi, algae, and bacteria within the lung lichen Lobaria pulmonaria L. Hoffm. as assessed by state-of-the-art metaproteomics. Journal of Proteome Research, 16(6), 2160-2173.

Joneson, S., Armaleo, D. and Lutzoni, F., 2011. Fungal and algal gene expression in early developmental stages of lichen-symbiosis. Mycologia, 103(2), 291-306.

Aubert, S., Juge, C., Boisson, A.-M., Gout, E. and Bligny, R., 2007. Metabolic processes sustaining the reviviscence of lichen Xanthoria elegans (link) in high mountain environments. Planta, 226(5), 1287-1297.

Crowe, J.H., Hoekstra, F.A. and Crowe, L.M., 1992. Anhydrobiosis. Annual Review of Physiology, 54, 579-599.

Lines, C.E.M., Ratcliffe, R.G., Rees, T.A.V and Southon, T.E., 1989. A 13C NMR study of photosynthate transport and metabolism in the lichen Xanthoria calcicole Oxner. The New Phytologist, 111(3), 447-456.

Eisenreich, W., Knispel, N. and Beck, A., 2011. Advanced methods for the study of the chemistry and the metabolism of lichens. Phytochemistry Reviews, 10, 445-456.

Jóhannsson, F., Cherek, P., Xu, M., Rolfsson, Ó. and Ögmundsdóttir, H., 2021. The anti-proliferative lichen-compound protolichesterinic acid inhibits oxidative phosphorylation and is processed via the Mercapturic pathway in cancer cells. Planta Medica, 88(11), 891-898.

Singh, N., Nambiar, D., Kale, R.K. and Singh, R.P., 2013. Usnic acid inhibits growth and induces cell cycle arrest and apoptosis in human lung carcinoma A549 cells. Nutrition and Cancer, 65(Suppl 1), 36-43.

Kohlhardt-Floehr, C., Boehm, F., Troppens, S., Lademann, J. and Truscott, T.G., 2010. Prooxidant and antioxidant behaviour of usnic acid from lichens under UVB-light irradiation–Studies on human cells. Journal of Photochemistry and Photobiology B: Biology, 101(1), 97-102.

Bačkorová, M., Bačkor, M., Mikeš, J., Jendželovský, R. and Fedoročko, 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.

Lohézic-Le Dévéhat, F., Legouin, B., Couteau, C., Boustie, J. and Coiffard, L., 2013. Lichenic extracts and metabolites as UV filters. Journal of Photochemistry and Photobiology B: Biology, 120, 17-28.

Mohammadi, M., Bagheri, L., Badreldin, A., Fatehi, P., Pakzad, L., Suntres, Z. and van Wijnen, A.J., 2022. Biological effects of gyrophoric acid and other lichen derived metabolites, on cell proliferation, apoptosis and cell signaling pathways. Chemico-Biological Interactions, 351, https://doi.org/10.1016/j.cbi.2021.109768.

Russo, A., Caggia, S., Piovano, M., Garbarino, J. and Cardile, V., 2012. Effect of vicanicin and protolichesterinic acid on human prostate cancer cells: role of Hsp70 protein. Chemico-Biological interactions, 195, 1-10.

Luo, H., Yamamoto, Y., Kim, J.A., Jung, J.S., Koh, Y.J. and Hur, J.-S., 2009. Lecanoric acid, a secondary lichen substance with antioxidant properties from Umbilicaria antarctica in maritime Antarctica (King George Island). Polar Biology, 32(7), 1033-1040.

Xiao, D., Zhang, Y., Wang, R., Fu, Y., Zhou, T., Diao, H., Wang, Z., Lin, Y., Li, Z., Wen, L., Kang, X., Kopylov, P., Shchekochikhin, D., Zhang, Y. and Yang, B., 2019. Emodin alleviates cardiac fibrosis by suppressing activation of cardiac fibroblasts via upregulating metastasis associated protein 3. Acta Pharmaceutica Sinica B, 9(4), 724-733.

Hsu, S.-C. and Chung, J.-G., 2012. Anticancer potential of emodin. BioMedicine, 2, 108-116.

Liu, H., Liu, Y.Q., Liu, Y.Q., Xu, A.H., Young, C.Y.F., Yuan, H.Q. and Lou, H.X., 2010. A novel anticancer agent, retigeric acid B, displays proliferation inhibition, S phase arrest and apoptosis activation in human prostate cancer cells. Chemico-Biological Interactions, 188(3), 598-606.

Choudhary, M.I., Azizuddin, Jalil, S. and Atta-ur-Rahman, 2005. Bioactive phenolic compounds from a medicinal lichen, Usnea longissima. Phytochemistry, 66(19), 2346-2350.