Lichen Extracts Research Articles

Anti-Inflammatory Potential of Compounds Isolated from Tunisian Lichens Species.

The lichen's special symbiotic structure enables it to produce bioactive substances. They have historically been recognized for their aesthetic and medicinal benefits. Furthermore, in recent years, they have performed in various fields, including perfumery, dyeing, and pharmacology due to their rich secondary metabolites. From our study, four compounds were isolated from organic extracts of Parmotrema hypoleucinum, Roccella phycopsis, and Xanthoria parietina and identified by spectroscopic investigation as atranorin, (+)-iso-usnic acid, methyl orsellinate, and parietin, respectively. The anti-inflammatory effects of lichens extracts, and pure compounds were evaluated on RAW 264.7 macrophages cells at different concentrations. At 25 μg/mL all treated samples did not show any effect on cell viability. Atranorin and (+)-iso-usnic acid showed an inhibitory effect on nitric oxide (NO) levels in lipopolysaccharide (LPS)-stimulated macrophages. Nitric oxide (NO) production was measured using Griess reagent, atranorin and (+)-iso-usnic acid showed a high anti-inflammatory potential (75.99 % and 57.27 % at 25 μg/mL). On the other hand, methyl orsellinate and the organic extracts of three lichens showed good anti-inflammatory activity ranging from 29.16 % at 25 μg/mL to 86.91 % at 100 μg/mL.

New insights into the Van Krevelen diagram: Automated molecular formula determination from HRMS for a large chemical profiling of lichen extracts.

In recent years, LC-MS has become the golden standard for metabolomic studies. Indeed, LC is relatively easy to couple with the soft electrospray ionization. As a consequence, many tools have been developed for the structural annotation of tandem mass spectra. However, it is sometimes difficult to do data-dependent acquisition (DDA), especially when developing new methods that stray from the classical LC-MS workflow. An old tool from petroleomics that has recently gained popularity in metabolomics, the Van Krevelen diagram, is adapted for an overview of the molecular diversity profile in lichens through high-resolution mass spectrometry (HRMS). A new method is benchmarked against the state-of-the-art classification tool ClassyFire using a database containing most known lichen metabolites (n ≈2,000). Four lichens known for their contrasted chemical composition were selected, and extractions with apolar, aprotic polar, and protic polar solvents were performed to cover a wide range of polarities. Extracts were analyzed with direct infusion electrospray ionization mass spectrometry (DI-ESI-MS) and atmospheric solids analysis probe mass spectrometry (ASAP-MS) techniques to be compared with the chemical composition described in the literature. The most common lichen metabolites were efficiently classified, with more than 90% of the molecules in some classes being matched with ClassyFire. Results from this method are consistent with the various extraction protocols in the present case study. This approach is a rapid and efficient tool to gain structural insight regarding lichen metabolites analyzed by HRMS without relying on DDA by LC-MS/MS analysis. It may notably be of use during the development phase of novel MS-based metabolomic approaches.

Phenolic Secondary Metabolites and Antiradical and Antibacterial Activities of Different Extracts of Usnea barbata (L.) Weber ex F.H.Wigg from Călimani Mountains, Romania.

Phenolic compounds represent an essential bioactive metabolites group with numerous pharmaceutical applications. Our study aims to identify and quantify phenolic constituents of various liquid and dry extracts of Usnea barbata (L.) Weber ex F.H. Wigg (U. barbata) from Calimani Mountains, Romania, and investigate their bioactivities. The extracts in acetone, 96% ethanol, and water with the same dried lichen/solvent ratio (w/v) were obtained through two conventional techniques: maceration (mUBA, mUBE, and mUBW) and Soxhlet extraction (dUBA, dUBE, and dUBW). High-performance liquid chromatography with diode-array detection (HPLC-DAD) was performed for usnic acid (UA) and different polyphenols quantification. Then, the total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity (AA) were determined through spectrophotometric methods. Using the disc diffusion method (DDM), the antibacterial activity was evaluated against Gram-positive and Gram-negative bacteria known for their pathogenicity: Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 13883). All extracts contain phenolic compounds expressed as TPC values. Five lichen extracts display various UA contents; this significant metabolite was not detected in dUBW. Six polyphenols from the standards mixture were quantified only in ethanol and water extracts; mUBE has all individual polyphenols, while dUBE shows only two. Three polyphenols were detected in mUBW, but none was found in dUBW. All U. barbata extracts had antiradical activity; however, only ethanol and acetone extracts proved inhibitory activity against P. aeruginosa, S. pneumoniae, and S. aureus. In contrast, K. pneumoniae was strongly resistant (IZD = 0). Data analysis evidenced a high positive correlation between the phenolic constituents and bioactivities of each U. barbata extract. Associating these extracts’ properties with both conventional techniques used for their preparation revealed the extraction conditions’ significant influence on lichen extracts metabolites profiling, with a powerful impact on their pharmacological potential.

ASAP-MS and DART-MS as ancillary tools for direct analysis of the lichen metabolome.

Lichens contain unique metabolites that most often need to be characterized from a limited amount of material. While thin layer chromatography is still the preferred analysis method for most lichenologists, liquid chromatography gives a deeper insight in the lichen metabolome, but an extractive step is needed before any analysis. Therefore, ambient ionization mass spectrometry (MS) analysis of lichen samples using Atmospheric Solid Analysis Probe (ASAP) and Direct Acquisition in Real Time (DART) techniques is evaluated. We looked for a faster method to screen the metabolome by disrupting the classical workflow of analysis. Four lichens selected for their metabolic diversity were analyzed with MS; namely Evernia prunastri, Lichina pygmaea, Parmelia saxatilis, and Roccella fuciformis. ASAP and DART analyses were compared against the reference electrospray ionization with a bioinformatic process including Van Krevelen diagrams as well as the multivariate comparison of the ionization methods in positive and negative modes. Metabolite profiles obtained from DART and ASAP analyses of lichen samples are consistent with classical analyses of lichen extracts. Through an easy and rapid experiment and without any extraction solvent, a large and informative profile of lichen metabolites is obtained when using complementary ionization modes of these high resolution mass spectrometry methods. ASAP-MS and DART-MS are two ancillary methods that provide a comprehensive evaluation of the lichen metabolome.

ISOLATION AND STRUCTURE ELUCIDATION OF ERYTHRIN AND BIOPROSPECTION STUDIES OF ROCCELLA MONTAGNEI EXTRACT

Objectives: Lichen is a stable mutually beneficial organism. Composed of fungi, a Mycobiont is united with algae, a phycobiont or cyanobacteria. Since the ancient period, the extract derived from Lichens is utilized in the medication of numerous diseases. An attempt was made to isolate and structure elucidation of the erythrin, a biologically active compound from corticolous lichen Roccella montagnei, and analyze the antimicrobial and antioxidant activities of lichen’s acetone extract under in vitro conditions. Methods: An attempt was made to isolate and characterized the erythrin, a biologically active compound from corticolous lichen R. montagnei using ultraviolet, Fourier transform infrared, High-performance liquid chromatography, nuclear magnetic resonance, and gas chromatography–mass spectrometry techniques. The antimicrobial activities of lichen extract were evaluated against six pathogenic microorganisms using the standard disc diffusion technique. For in vitro antioxidant activity, the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) scavenging method, hydrogen peroxide scavenging method, and phosphomolybdenum assay were done. Results: The outcomes show that the lichen extract has the maximum effective antibacterial activity compared to antifungal activity against pathogenic microorganisms. The maximum zone of inhibition was recorded in Escherichia coli (8.75±0.61 mm). Among fungal pathogens, the extract inhibited the growth of Candida albicans with a maximum inhibition zone of 7.50±0.52 mm. In vitro antioxidant activity, the DPPH scavenging method, IC50 value of lichen extract, and ascorbic acid were found to be 45.70 μg mL-1 and 39.74 μg mL-1, respectively. In the hydrogen peroxide scavenging method, it was observed that the IC50 value of lichen extract, ascorbic acid, and rutin were found to be 39.39 μg mL-1, 40.66 μg mL-1, and 45.58 μg mL-1, respectively. The maximum antioxidant content of 44.66 mg/g ascorbic acid equivalents was observed in the 100 μg mL-1 lichen extract in the phosphomolybdenum assay. Total phenolic content was higher in lichen extract with 214.84±14.84 mg gallic acid equivalent (GAE/g lichen extract). Conclusion: The present study did the isolation and structure elucidation of erythrin obtained from R. montagnei from Anaikatty and reveals that the lichen extract has the potential to control the human pathogenic microorganisms in the future and the study also suggested that the lichen extract possesses active antioxidant substances to scavenge free radicals.

Phytochemical Characterization and Pharmacological Properties of Lichen Extracts from Cetrarioid Clade by Multivariate Analysis and Molecular Docking.

Introduction Lichens, due to the presence of own secondary metabolites such as depsidones and depsides, became a promising source of health-promoting organisms with pharmacological activities. However, lichens and their active compounds have been much less studied. Therefore, the present study aims to evaluate for the first time the antioxidant capacity and enzyme inhibitory activities of 14 lichen extracts belonging to cetrarioid clade in order to identify new natural products with potential pharmacological activity. Materials and Methods In this study, an integrated strategy was applied combining multivariate statistical analysis (principal component analysis and hierarchical cluster analysis), phytochemical identification, activity evaluation (in vitro battery of antioxidant assays FRAP, DPPH, and ORAC), and enzyme inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and molecular profiling with in silico docking studies of the most promising secondary metabolites. Results. Among fourteen lichen samples, Dactylina arctica stands out for its higher antioxidant capacities, followed by Nephromopsis stracheyi, Tuckermannopsis americana, Vulpicida pinastri, and Asahinea scholanderi. Moreover, Asahinea scholanderi and Cetraria cucullata extracts were the best inhibitors of AChE and BuChE. The major secondary metabolites identified by HPLC were alectoronic acid and α-collatolic acid for Asahinea scholanderi and usnic acid and protolichesterinic acid for Cetraria cucullata. Molecular docking studies revealed that alectoronic acid exhibited the strongest binding affinity with both AChE and BuChE with and without water molecules. Conclusions Our results concluded that these species could be effective in the treatment of neurodegenerative diseases, being mandatory further investigation in cell culture and in vivo models.

Green synthesis of Ag-ZnO nanocomposites by using Usnea florida and Pseudevernia furfuracea lichen extracts and evaluation of their neurotoxic effects

First time in this study, neuroprotective or neurotoxic effects of Pseudevernia furfuracea and Usnea florida lichen extracts based silver decorated zinc oxide nanocomposites (Ag-ZnO NCs) were evaluated. The characteristic light absorption point of P. furfuracea and U. florida based Ag-ZnO NCs were observed at 339 nm and 361 nm; effective diameter was detected at 342 nm and 495 nm. According to SEM analysis, the diameter of P. furfuracea and U. florida extract based NCs were approximately 35 nm and 85 nm, respectively. When we examined the toxicity of SH-SY5Y against human neuroblastoma cells, it was observed that NCs have neurotoxic effects on a concentration of 100 μg/ml. In this study, it was predicted that P. furfuracea and U. florida extract based Ag-ZnO NCs could be used in cytotoxic studies by synthesizing them in a cheap, short time and with eco-friendly method.

Xanthoparmelia somloensis (Gyelnik) Hale likeninin liyofilize etanol ekstraktının domates bitkisi üzerindeki allelopatik etkilerinin araştırılması

All organisms in nature interact and compete with each other. Various groups of organisms such as algae, lichens, crops and weeds have been found as allelopathic interaction and it is known that lichens have many potent secondary metabolites. The aim of this study was to determine the allelopathic effects of lyophilized ethanolic extract of Xanthoparmelia somloensis (Gyelnik) Hale lichen (XS) on tomato (Lycopersicum esculentum L.) germination and early development stage. Obtained lyophilized ethanolic extracts of XS lichen at concentrations of 50 ppm (XS-50), 100 ppm (XS-100), 200 ppm (XS-200) and 400 ppm (XS-400) were applied to tomato seeds and seedlings. In order to determine the effects caused by the extracts, germination rate and seedling growth parameters (vigor index, length, fresh weight, relative water content and pigment contents) were analyzed. According to the obtained data, there were significant decreases in germination rate and vigor index values depending on the increase in lichen extract concentration. Similar effects were also observed in root and shoot length and pigment contents. However, results of the lowest application (XS-50) were similar to control except root length and carotenoid content. The data obtained from this study exhibited that the lichen Xanthoparmelia somloensis has allelopathic effects and has the potential to be used for agricultural purposes.

Fractionated Lichen Parmelia vagansExtract Exhibits Two distinct Antiproliferative Activities Against Human Cancer Cells

IntroductionApproximately one quarter of all prescription drugs contain active ingredients of plant origins. Lichens have been historically used to treat a multitude of ailments, ranging from headaches during the Middle Ages to dressing wounds before colonial times and much of the potency of lichen relies on the secondary metabolites they produce. The purpose of this project is to analyze antiproliferative properties of the secondary metabolites of lichen Parmelia vagans.MethodsLichen extracts were prepared using different organic solvents and further fractionated either by preparative TLC or by reverse‐phase chromatography. We assessed the antiproliferative activity of the fraction using human cancer cell lines. The same number of cells of different cell lines were plated into a 96‐well plate and allowed to adhere overnight. Next day, different dilutions of the enriched fractions were added to the adhered cells and the plate was placed in CO2 incubator for 24 hours. By the end of the incubation time a picture of each well was taken to assess cell confluency and morphology followed by Resazurin assay to analyze the effect of the lichen extract on cell growth and proliferation. After Resazurin assay, the cells in each well were treated with trypsin, suspended in growth medium and counted using Bio‐Rad cell counter to evaluate a percent of live cells.ResultsAssessment of antiproliferative activity of the TLC and reverse‐phase chromatography fractions revealed two separate peaks of inhibitory activity against cancer cell. The fraction obtained from P.vagans extract significantly suppress (30% ‐ 80%) the growth of human lung carcinoma A549. We also found that cancer cells treated by the lichen extracts results in their morphological changes that resemble an activation of apoptosis.DiscussionOur findings indicate that from P.vagans produces secondary metabolites that slow cancer cells growth and proliferation. Future experiments will be focused on isolation and identification of the compounds from P.vagans that are responsible for the inhibition of cancer cells growth. Another important aspect of the future research is to identify the cellular target(s) of the antiproliferative compound(s) and its molecular mechanism of action. I summary, the lichen’s secondary metabolites may hold a vast medicinal potential and could be a viable source of a novel of anticancer drugs.

Antibacterial Properties of Several Lichen Extracts against Two Moderately Halophilic Bacteria from Salted Sheepskins

It is well known that possible undesirable defects in finished leathers can result from microbial activities on the salted raw hides/skins during storage. The traditionally used salt curing method can control bacterial activities on the raw stock, but it does not seem possible to completely eliminate microbial attacks. Moderately halophilic bacteria can cause serious damage to hides/skins. From this point of view, potential procedures such as applying new antibacterialagents in the leather industry should be considered. Since some lichen species have been indicated for their promising biological efficacies in the literature; most researchers have focused on their potencies in various fields including leather industry from ancient times. In this study, the bacterial growth of proteolytic and lipolytic Gram-negative moderately halophilic bacteria, Chromohalobacter canadensis (YN6) and Halomonas eurihalina (BL5), from saltedsheepskin samples were tested with the extracts of Usnea sp., Plastismatia glauca, Ramalina farinacea, Evernia divaricata, Bryoria capillaris, Hypogymnia tubulosa, Pseudevernia furfuracea and Lobaria pulmonaria. Some of these lichen species were found to be successful to inhibit the bacterial growth of C. canadensis (YN6) and H. eurihalina (BL5). In conclusion, lichen extracts may be utilized in stacked raw hides/skins in tanneries or warehouses to control moderately halophilic bacteria which causes several defects on leather.

Lecanoric acid mediates anti-proliferative effects by an M phase arrest in colon cancer cells

Lichen extracts containing, among other compounds, depsides such as evernic acid, atranorin, and lecanoric acid possess anti-proliferative effects. We aimed to identify lichen metabolites that are responsible for the observed anti-proliferative effects. We performed cytotoxicity, cell colony, cell cycle and apoptosis assays in various cell lines or primary immune cells. We analyzed several cell cycle proteins and apoptosis-related proteins to gain insights into the underlying mechanism. All depsides reduced the viability of the tested cell lines (HCT-116, HEK293T, HeLa, NIH3T3, RAW246.7) in a cell line-dependent manner with lecanoric acid being the most effective. Atranorin did not influence the cell cycle or colony formation in HCT-116 cells, but induced apoptosis in HCT-116 cells. Evernic acid showed no anti-proliferative effects. Lecanoric acid inhibited cell colony formation already at 0.03 µg/ml in HCT-116 cells and induced a G2 cell cycle block in several cell lines. Moreover, lecanoric acid arrested the cell cycle, presumably in the M phase, since expression of cyclin B1 and phosphorylated histone H3 was upregulated, whereas the inactive cyclin-dependent kinase 1 (CDK1) was reduced in HCT-116 cells. Most importantly, cell death induced by lecanoric acid was more prominent in cancer cells than in primary human immune and endothelial cells. In conclusion, lecanoric acid seems to mediate its anti-proliferative effects via arrest of cells in the M phase. Our data suggest lecanoric acid may be a potential new candidate for anti-cancer therapy, because it has anti-proliferative effects on cancer cell lines, and does not affect primary immune cells.

Extracts from lichenLobaria retigeradecrease the stemness potential of colorectal cancer cells

Lichens are symbiotic organisms with the potential to be used in the pharmaceutical industry. To identify novel lichen extracts that inhibit the stemness potential of colorectal cancer cells, we tested acetone extracts ofLobaria retigeracollected in Vietnam. Crude acetone extracts ofL. retigeradecreased spheroid formation in CSC221, DLD1, and HT29 cells. In addition, mRNA levels of genes encoding cancer stem markers aldehyde dehydrogenase-1, CD44, CD133, Lgr5, and Musashi-1 were significantly downregulated in a dose-dependent manner after treatment withL. retigeraextract. Moreover,L. retigeraextract decreased the transcriptional activities of Gli and the Notch-relatedHes1promoter in reporter assays. Together, these results demonstrate thatL. retigeraextract is a potent inhibitor of colorectal cancer cell stemness.

Antimicrobial Activity of Some Lichen Extracts

Antimicrobial Activity of Some Lichen Extracts

Antibacterial activity of <i>Leptogium cochleatum</i> and <i>Leptogium moluccanum</i>

There is an increase in the emergence and re-emergence of bacterial infections nowadays, and lichens are potential sources of pharmaceutically important secondary metabolites to halt this problem. Lichens are unique plant-like organisms which are relatively less explored in the Philippines. Here, lichen extracts of<italic> Leptogium cochleatum</italic> and <italic>Leptogium moluccanum</italic> were tested against <italic>Escherichia coli</italic>, <italic>Enterobacter agglomerans</italic>,<italic> Klebsiella pneumoniae,</italic> <italic>Pseudomonas aeruginosa</italic>, and <italic>Staphylococcus aureus</italic> using paper disk diffusion assay. Hexane extract of <italic>L. moluccanum</italic> led to a 17.14 mm zone of inhibition (ZOI) against <italic>K. pneumoniae,</italic> while hexane extract of <italic>L. cochleatum</italic> led to a 15.28 mm ZOI against <italic>E. agglomerans</italic>. Dichloromethane extracts of <italic>L. cochleatum</italic> exhibited a ZOI of 15.86 mm against <italic>E. agglomerans</italic> and 14.84 mm ZOI against <italic>E. coli</italic>. The bioactivities exhibited by the lichen extracts may be due to the secondary metabolites detected using thin layer chromatography. Indeed, lichen-derived bioactive compounds hold great promise for pharmaceutical applications for the benefit of human life.

Dye yielding potential and antibacterial properties of lichens from Kerala, India

Lichens are a group of lower plants that adapt to extreme environmental conditions. The utility of lichens is due to the wide range of secondary metabolites produced by them. The present study is to analyse the dye yielding potential and anti-bacterial properties of lichen species Heterodermia boryi , Hypotrachyna cirrhata , and Cladonia fruticulosa collected from different parts of Kerala. Dyes were extracted using methods such as Ammonia fermentation method (AFM), Di-methyl sulphoxide extraction method (DEM) and the boiling water method (BWM). The dye extracts were experimented on mulberry silk and banana fibre. The fibre stability was tested by exposure to sunlight and action with detergent and shampoo. Most of the dyed colours appeared to be stable. The colours were detected using COSMIN software. The colours that appeared were mainly shades of brown, khaki, tan and gold. AFM and DEM are better extraction methods than BWM. To investigate the antibacterial activity, methanol, ethanol, acetone, chloroform and distilled water extracts of lichens were tested against Gram-positive and negative bacteria along with positive control. Chloroform and acetone extracts showed exceptional inhibition activity followed by methanol and ethanol and the least activity by distilled water extracts. Extracts of H. cirrhata and C. fruticulosa showed better antibacterial activity than H. boryi . These results indicate the presence of different secondary metabolites.

Evaluating Search Methods for Identifying Candidates for Novel Biologically Inspired Sunscreens

As the Earth's ozone layer, which blocks harmful UV radiation from reaching Earth's surface, becomes thinner, sunscreens have become one the most used and most important cosmetic products in recent decades. However, UV filters (both organic and inorganic) in the current synthetic sunscreen are found to affect the marine ecosystem negatively. They pollute the marine environment and cause damage to organisms’ reproductive and digestive systems (from microorganisms to mammals). Here, we use biologically inspired design with a problem and sustainability-driven approach to identify a possible plant or animal-inspired ingredients that could be extracted and used to obtain high protection from the sun while minimizing toxicity to human skin and pollution of the marine environment. We used Google, Google Scholar, and AskNature to identify solutions and evaluate their effectiveness. While the three search methods did not differ statistically in the number of initial solutions found, Google was perhaps surprisingly the one that generated the most hits. However, in terms of the most promising solutions, AskNature generated the most. We identified nine solutions with a particularly high potential based on their UV absorption and potential for mass production for further development: raspberry seed oil, nanoparticles of ivy rootlets, cuticular wax of dwarf mountain pine, lichen extract, MAAs from cyanobacteria, MAAs from dinoflagellates, red sweat of hippopotamus, mucus from mushroom coral, and gadusol compound from marine organisms of which we found that nanoparticles of ivy rootlets, lichen extracts, and gadusol to be especially promising.

Biogenic fabrication and characterization of Silver nanoparticles using high altitude lichen Heteroderimia leucomela extract and its potential applications

Lichens are symbionts formed from the intimate union of fungi and algae and are enriched with distinct phytocompounds. Plants, bacteria, fungi and algae have been extensively explored for metallic nanoparticle synthesis but the use of lichens in the field of nanotechnology remains less explored. In the present study, Silver nanoparticles (Ag NPs) were synthesized using Heteroderimia leucomela lichen extract and characterized using different techniques. GC–MS analysis was performed to identify the phytocompounds supporting the synthesis of Ag NPs as capping and reducing agents. The antioxidant and antimicrobial activities were evaluated by in-vitro assays. Results showed that the synthesized Ag NPs had an average particle size of 20 ± 0.2 nm and were predominantly spherical in shape. The synthesized Ag NPs exhibited significant free radical scavenging activity for 2,2-diphenyl-1-picrylhydrzyl (DPPH) radicals with an IC50 value of 7.5 ± 0.1 μg/ml. The antibacterial activity of the synthesized Ag NPs against the test organisms were observed as follows: E. coli ≥ B. subtilis ≥ V. cholera ≥ S. pneumonia ≥ P. aeruginosa and the results of anticandida activity revealed that the candida strains were susceptible in the following order: C. albicans ≥ C. glabrata ≥ C. parapsilosis ≥ C. krusei ≥ C. tropicalis. Thus Ag NPs synthesized from high altitude lichen extract demonstrated that it has potent antioxidant and antimicrobial activities with greater importance to the field of nanomedicine.

TOXICOLOGICAL AND BEHAVIOR ANALYSES OF A FOLIOSE LICHEN PARMOTREMA TINCTORUM (DELISE EX NYL.) HALE EXTRACT USING ZEBRAFISH (DANIO RERIO) MODEL

Objective: The objective of the study was to evaluate the toxicity and behavior analysis with the extract of foliose lichen Parmotrema tinctorum against the adult zebrafish. Methods: The zebrafishes were exposed to different concentrations of P. tinctorum extract such as 50, 100, and 200 mg/ml for 7 days of exposure, in which the mortality and behavioral responses of zebrafishes were recorded. The standard histopathological examination was conducted with the lichen extracts of P. tinctorum. Results: The results revealed that P. tinctorum extract did not show any prominent behavior abnormalities in zebrafishes even at a high concentration of 200 mg/ml. The extract was found to have dose-dependent toxic to zebrafish and the number of neutrophil cells in the muscle bundles reduced at a high concentration. The results of the inflammatory marker gene expression using polymerase chain reaction results suggested that the dose-dependent suppression of tumor necrosis factor gene by the P. tinctorum lichen extract. Conclusion: Overall, concluded that the extract might contain anti-inflammatory induction properties and further tests are required to prove apoptosis and anticancer activity using other in vivo or in vitro techniques.

Modifying the tumor effects in the lungs of laboratory mice with lichen extracts

The anti-tumor properties of common lichens of Belarus: Hypogymnia physodes, Ramalina pollinaria, Cladonia arbuscula, Evernia prunastri were studied using the models of spontaneous and induced carcinogenesis in mice Af lungs. Without exposing to a carcinogen in 20 weeks after taking aqueous lichen extracts (1 g/l) of 4 species for 28 days, only C. arbuscula showed the pro-carcinogenic properties almost doubling the average number of pulmonary adenomas per mouse. R. pollinaria and E. prunastri did not provoke spontaneous carcinogenesis and had a corrective effect significantly reducing the number of adenomas per mouse by 21 and 45 %, respectively. To carry out induced carcinogenesis, after 2 weeks of taking aqueous extracts, mice were injected intraperitoneally with urethane (1 g/kg). The analysis of the total number of adenomas per mouse showed a pro-tumor tendency for C. arbuscula, and the analysis of the number of adenomas of 1 mm and more showed that for H. physodes. The extracts do not affect the proportion of urethane adenomas of various sizes in their total number, but increase the incidence of high-yield adenomas of various sizes; at the same time, H. physodes has a much greater pro-carcinogenic activity according to the incidence of high-yield adenomas of 1 mm or more. The analysis of the total number of urethane adenomas per mouse, as well as adenomas of 1 mm showed an anti-tumor tendency for R. pollinaria and a pro-tumor tendency for E. prunastri. Taking E. prunastri increased the incidence of high-yield adenomas of various sizes, along with a notable increase in the incidence of low-yield adenomas. In the case of R. pollinaria, the increase in the incidence of low-yield adenomas was supplemented by a sharp decrease in the incidence of high-yield adenomas. As a result of the experiment, E. prunastri has exhibited both the pro-carcinogenic activity and the anti-tumor properties, but R. pollinaria has revealed a pronounced anti-tumor potential.

Antimicrobial and antioxidant potentials of non-cytotoxic extracts of corticolous lichens sampled in Armenia

Due to wide range of secondary metabolites, lichens were used from antiquity as sources of colorants, perfumes and medicaments. This research focuses on exploring the antioxidant, antimicrobial and cytotoxic activities of methanol, ethanol, acetone extracts and aqueous infusions of corticolous lichens sampled from Armenia. Methanol, ethanol and acetone extracts from all tested lichens were active against Gram-positive bacterial strains. The most effective solvent to retrieve antimicrobial compounds was methanol. Aqueous infusions of tested lichens didn’t show any significant antibacterial and antifungal activity. The highest antimicrobial activity was observed for methanol extract of Ramalina sinensis. The minimum inhibitory concentration of methanol extract of Ramalina sinensis were 0.9–1.8 mg mL− 1. Pseudevernia furfuracea demonstrated antifungal activity (Ø 12 mm). Methanol extract of Parmelia sulcata demonstrated largest 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity (71 %). The cytotoxicity was measured on human HeLa (cervical carcinoma) cell lines using microculture tetrazolium test assay. The IC50 values estimated for methanol extracts of Peltigera praetextata, Evernia prunastri, Ramalina sinensis and Ramalina farinacea species in HeLa cell line were within 1.8–2.8 mg mL− 1 and considered as non-cytotoxic. Obtained results suggest that studied lichens can be prospective in biotechnologies as alternative sources of antimicrobial and antioxidant substances.