Usnea Acid-Incorporated Ca2+ /Mn2+ Ions Reservoirs for Elevated Ion-Interference Therapy through Synergetic Biocatalysis and Osmolarity Imbalance.

Ion-interference therapy (IIT) utilizes ions to disturb intracellular biological processes and has been received increasing attention in tumor treatments recently. However, the low therapeutic efficiency still hinders its further biological applications. Herein, via a simple and one-pot gas diffusion process, polyethylene glycol (PEG)-modified Mn2+ ions and usnic acid (UA)-incorporated CaCO3 nanomaterials (PEG CaMnUA) as Ca2+ /Mn2+ ions reservoirs are prepared for magnetic resonance imaging (MRI)-guided UA-elevated IIT. Among PEG CaMnUA, UA not only increases cytoplasmic Ca2+ ions to amplify Ca2+ overload caused by CaCO3 decomposition, but also enhances Mn2+ ions-participated Fenton-like biocatalysis by intracellular H2 O2 generation and glutathione consumption. Then increasing the intracellular oxidative stress and decreasing the triphosadenine supply induce apoptosis together, resulting in UA-boosted IIT. The simple and efficient design of the dual ions reservoirs will contribute to improve the antitumor activity of IIT and further development of calcium-based nanomaterials in the future.

Usnea aurantiaco-atra (Jacq) Bory: Metabolites and Biological Activities.

BACKGROUND: Lichens are complex symbiotic associations between a fungus and an alga or cyanobacterium. Due to their great adaptability to the environment, they have managed to colonize many terrestrial habitats, presenting a worldwide distribution from the poles to the tropical regions and from the plains to the highest mountains. In the flora of the Antarctic region, lichens stand out due to their variety and development and are a potential source of new bioactive compounds. METHODS: A phytochemical study of the Antarctic lichen Usnea aurantiaco-atra (Jacq) Bory was conducted with the intention of determining the most important metabolites. In addition, the cytotoxic and antioxidant activities of its extracts were determined. RESULTS: Cytotoxicity studies revealed that the hexane extract contains usnic acid as a majority metabolite, in addition to linoleic acid, ergosterols and terpenes, and demonstrates cytotoxic activity against an A375 melanoma cell line. On the other hand, the presence of total phenols in the extracts did not influence their antioxidant activity. CONCLUSIONS: U. aurantiaco-atra contains mainly usnic acid, although there are terpenes and ergosta compounds that could be responsible for its cytotoxic activity. The presence of phenols did not confer antioxidant properties.

ROS-Induced DNA-Damage and Autophagy in Oral Squamous Cell Carcinoma by Usnea barbata Oil Extract-An In Vitro Study.

Oxidative stress is associated with aging, cancers, and numerous metabolic and chronic disorders, and phenolic compounds are well known for their health-promoting role due to their free-radical scavenging activity. These phytochemicals could also exhibit pro-oxidant effects. Due to its bioactive phenolic secondary metabolites, Usnea barbata (L.) Weber ex. F.H. Wigg (U. barbata) displays anticancer and antioxidant activities and has been used as a phytomedicine for thousands of years. The present work aims to analyze the properties of U. barbata extract in canola oil (UBO). The UBO cytotoxicity on oral squamous cell carcinoma (OSCC) CLS-354 cell line and blood cell cultures was explored through complex flow cytometry analyses regarding apoptosis, reactive oxygen species (ROS) levels, the enzymatic activity of caspase 3/7, cell cycle, nuclear shrinkage (NS), autophagy (A), and synthesis of deoxyribonucleic acid (DNA). All these studies were concomitantly performed on canola oil (CNO) to evidence the interaction of lichen metabolites with the constituents of this green solvent used for extraction. The obtained data evidenced that UBO inhibited CLS-354 oral cancer cell proliferation through ROS generation (316.67 × 104), determining higher levels of nuclear shrinkage (40.12%), cell cycle arrest in G0/G1 (92.51%; G0 is the differentiation phase, while during G1 phase occurs preparation for cell division), DNA fragmentation (2.97%), and autophagy (62.98%) than in blood cells. At a substantially higher ROS level in blood cells (5250.00 × 104), the processes that lead to cell death-NS (30.05%), cell cycle arrest in G0/G1 (86.30%), DNA fragmentation (0.72%), and autophagy (39.37%)-are considerably lower than in CLS-354 oral cancer cells. Our work reveals the ROS-mediated anticancer potential of UBO through DNA damage and autophagy. Moreover, the present study suggests that UBO pharmacological potential could result from the synergism between lichen secondary metabolites and canola oil phytoconstituents.

Anticancer Activity of 2-O-caffeoyl Alphitolic Acid Extracted from the Lichen, Usnea barbata 2017-KL-10.

Colorectal cancer is one of the life-threatening ailments causing high mortality and morbidity worldwide. Despite the innovation in medical genetics, the prognosis for metastatic colorectal cancer in patients remains unsatisfactory. Recently, lichens have attracted the attention of researchers in the search for targets to fight against cancer. Lichens are considered mines of thousands of metabolites. Researchers have reported that lichen-derived metabolites demonstrated biological effects, such as anticancer, antiviral, anti-inflammatory, antibacterial, analgesic, antipyretic, antiproliferative, and cytotoxic, on various cell lines. However, the exploration of the biological activities of lichens' metabolites is limited. Thus, the main objective of our study was to evaluate the anticancer effect of secondary metabolites isolated from lichen (Usnea barbata 2017-KL-10) on the human colorectal cancer cell line HCT116. In this study, 2OCAA exhibited concentration-dependent anticancer activities by suppressing antiapoptotic genes, such as MCL-1, and inducing apoptotic genes, such as BAX, TP53, and CDKN1A(p21). Moreover, 2OCAA inhibited the migration and invasion of colorectal cancer cells in a concentration-dependent manner. Taken together, these data suggest that 2OCAA is a better therapeutic candidate for colorectal cancer.

Antioxidant enzyme activities and immune responses in rainbow trout (Onchorhynchus mykiss) juveniles fed diets supplemented with dandelion (Taraxacum officinalis) and lichen (Usnea barbata) extracts.

In the present study, antioxidant activity, immune responses, and growth performance of rainbow trout (Onchorhynchus mykiss) juveniles fed with diets supplemented with dandelion (Taraxacum officinalis) and lichen (Usnea barbata) extracts were assessed. Four different concentrations of aqueous methanolic extract of the plants (0% (control), 0.1%, 0.5%, and 1% (D, dandelion; L, lichen) were added to the diets, and fish were fed for 75 days. On the 15th, 45th, and 75th day of the study, liver antioxidant enzyme activities were determined, and immune responses were determined every 15th day. The results showed that SOD activity increased in the fish group of 0.1% D on the 15th and 45th day compared to control; however, it was lower in all the lichen extract-treated groups than in control at almost all sampling times, except on the 15th day in the 0.1% L group. CAT activity showed an increased value (P < 0.05) in 0.5% L and 1% L treated fish groups on the 15th day, in fish of 1% D and 1% L groups on 45th and on 75th day in 0.1% D group. GPX activity increased on the 15th day of the study in fish of 0.1% D group, on the 45th day in 1% D and 1% L groups and on the 75th day in fish of 0.5% D, 0.1% D, and 0.5% L groups (P < 0.05). G6PDH enhanced in all treatment groups compared to control on the 15th day, except in 0.1% L and 0.5% L groups. An elevated G6PDH activity was also observed on the 75th day of the study in 0.5% D, 1% D, and 0.5% L fish groups. An increase on lipid peroxidation (LP) was observed in all L groups on the 45th day of the study. Lysozyme activity was determined to be the highest in 0.5% and 1% L on the 45th day, in 0.1% L on the 60th day and in the 0.5% L fish group on the 75th day compared to control (P < 0.05). Myeloperoxidase was found to be the highest at the end of the study in 1% L fish group compared to the control (P < 0.05). In conclusion, we suggest the use of dandelion to combat oxidative stress and to lower FCR and the use of lichen to modulate the immune response in rainbow trout. The use of such products will be economical for aquaculture and harmless for the environment.

Endolichenic fungus, Aspergillus quandricinctus of Usnea longissima inhibits quorum sensing and biofilm formation of Pseudomonas aeruginosa PAO1.

Lichens are composite organisms, comprising of a fungus (mycobiont) and a blue-green alga (photobiont). Along with the mycobiont, numerous non-obligate microfungi live in lichen thalli. These microfungi are called endolichenic fungi (ELF). In recent years, the ELF are emerging as promising natural sources because of their capability to exert unique drug molecules. The current study aimed to isolate the ELF from the lichen, Usnea longissima Ach., to control of biofilm formation and quorum sensing phenomenon in Pseudomonas aeruginosa PAO1, an opportunistic multidrug resistance pathogen that uses quorum sensing network to produce an array of pathogenic agents. Therefore, inhibiting quorum sensing to manage the infection caused by PAO1 could be the paramount alternative approach to conventional antibiotics. The isolated ELF was identified by amplifying the long subunit region of the fungal genome. The extracted metabolites of ELF (MELE) using the acetone solvent was further investigated for anti-quorum sensing activity using the biomarker strain Chromobacterium violaceum 12472 which exerts violacein pigment via the AHL mediated quorum sensing signalling. Moreover, the effect of MELE was also evaluated on the production of virulence factors and biofilm formation of P. aeruginosa PAO1. The molecular identification revealed that ELF (accession number MN171299) exhibited 100% similarity with Aspergillus quandricinctus strain CBS 135.52. The MELE showed significant anti-quorum sensing activity at the concentration of 4 mg/mL without affecting the bacterial cell viability of P. aeruginosa PAO1. The MELE diminished the production of virulence factors, including pyocyanin, protease, elastase, rhamnolipids, and extracellular polysaccharides of P. aeruginosa PAO1 in a concentration-dependent manner. The MELE also disturbed biofilm formation of P. aeruginosa PAO1. The 3-D analysis of biofilm architecture showed that the thickness and surface area covered by microcolonies was decreased as the concentration of MELE was increased. The GC-MS analysis of MELE exhibited that organic acids and fatty acids are major constituents of the MELE. The present study reports first time that the ELF, A. quandricinctus possesses potential to inhibit quorum sensing and biofilm formation of P. aeruginosa and can be further exploited for hospital and healthcare facilities.

Evaluation of the Cytotoxic Activity of the Usnea barbata (L.) F. H. Wigg Dry Extract.

The secondary metabolites of lichens have proven to be promising sources of anticancer drugs; one of the most important of these is usnic acid, which is a phenolic compound with dibenzofuran structure that is responsible for the numerous biological actions of lichens of genus Usnea. As a result, in this study, we related to this phenolic secondary metabolite. The aim of the present study is the evaluation of the cytotoxic activity of Usnea barbata (L.) F. H. Wigg dry acetone extract (UBE). In advance, the usnic acid content was determined in various extracts of Usnea barbata (L.) F. H. Wigg: the liquid extracts were found in water, ethanol, acetone, and the dry acetone extract; the highest usnic acid quantity was found in the dry acetone extract. First, the cytotoxic action of UBE was assessed using Brine Shrimp Lethality (BSL) test; a significant lethal effect was obtained after 24 h of treatment at high used concentrations of UBE, and it was quantified by the high mortality rate of the Artemia salina (L.) larvae. Secondly, in vitro cytotoxicity of UBE was evaluated on human tongue squamous cells carcinoma, using CAL 27 (ATCC® CRL-2095™) cell line. The most intense cytotoxic effect of UBE on CAL 27 cells was registered after 24 h; this response is directly proportional with the tested UBE concentrations. The obtained results have been reported regarding usnic acid content of UBE, and the data show that CAL 27 cells death was induced by apoptosis and high oxidative stress.

Trace elements baseline levels in Usnea antarctica from Clearwater Mesa, James Ross Island, Antarctica.

Clearwater Mesa is a pristine area located SE of Croft Bay in James Ross Island, at the northeast of the Antarctic Peninsula. The closest anthropic construction is the summer Mendel station located 25 km to the NE. Clearwater is a remote basalt volcanic mesa, (64° 01' S, 57° 42' W) located at ~ 250 m a.s.l., with around 50 small shallow lakes, a well-developed lichens flora and scarce fauna. The mesa offers a good opportunity to use lichens, like Usnea antarctica, as a biomonitor species. The aim of this study was to determine the baseline levels of trace elements in Usnea antarctica and their relationships with geographical parameters and climatological aspects, to use them as reference levels in futures studies. Usnea antarctica was collected in 23 sites in two transects: perpendicular and parallel to the shore. We found high contents of the elements associated with long-distance transport like Sm, La, Sc, Fe, Co, Hg, and Ca. The elements linked to the marine biogenic cycle as Sr, Rb, Cs, K, Na, Sb, As, Se, and Br were less significant. The distance to the sea was the factor that related the element contents. Hg, Se, As, and Br content in Usnea antarctica increased from the inland towards the sea coast.

A facile in vivo procedure to analyze metabolic pathways in intact lichens.

Lichen secondary metabolites show important biological activities as well as pharmaceutical and chemotaxonomic potential. In order to utilize such substances of interest, detailed knowledge of their biosynthetic pathways is essential. 13 CO2 -pulse/chase experiments using intact thalli of the lichen Usnea dasopoga resulted in multiple 13 C-labeled isotopologs in amino acids, but not in the dibenzofuran derivative usnic acid - one of the best-studied lichen metabolites, with considerable and renewed interest for pharmaceutical and lifestyle applications. Spraying an aqueous solution of [U-13 C6 ]glucose onto the thalli of U. dasopoga afforded a specific mixture of multiple 13 C-labeled isotopologs in usnic acid. One- and two-dimensional NMR analysis of the crude lichen extract corroborated the polyketide biosynthetic pathway via methylphloroacetophenone but not via phloroacetophenone. With usnic acid as an exemplar, we provide proof-of-principle experiments that can be used in general to study metabolic pathways and fluxes in intact lichens.

New insights into the Usnea cornuta aggregate (Parmeliaceae, lichenized Ascomycota): Molecular analysis reveals high genetic diversity correlated with chemistry.

Biological processes such as hybridization, incomplete lineage sorting and gene flow can obscure the recognition of distinct evolutionary lineages, particularly in groups of organisms that have recently diverged. Therefore, compiling pieces of evidence from diverse data sources is critical to accurately assess species boundaries in such groups. The increasing availability of DNA sequence data allows for a much deeper understanding of diversification and speciation processes and their consequences on biodiversity. In this study, we applied an integrative approach based on DNA sequence, chemical, geographic and morphological data to attempt to define species boundaries in the lichen-forming genus Usnea (Parmeliaceae), particularly the U. cornuta aggregate, a cosmopolitan species group. We provide the first species delimitation for this group in the neotropics based on the multispecies coalescent (MSC) model. Using ITS rDNA and two protein-coding genes, Mcm7 and RPB1, we estimated the species tree under the MSC model in a Bayesian framework using STACEY. Our results indicate that at least nine strongly supported distinct lineages coexist in the U. cornuta aggregate, which are well chemically characterized. Additionally, we found evidence for the polyphyly of three morphospecies, Usnea brasiliensis, U. cornuta and U. dasaea.

Therapeutic effects of beard lichen, Usnea barbata extract against Lactococcus garvieae infection in rainbow trout (Oncorhynchus mykiss).

In this study, therapeutic effects of aqueous methanolic extracts of beard lichen (Usnea barbata) against Lactococcus garvieae (ATCC 43921) in rainbow trout (Onchorhynchus mykiss) were investigated. Six different experimental groups [0 mg/100 µL (Control), 4 mg/100 µL, 8 mg/100 µL, 12 mg/100 µL, 6 mg/100 µL florfenicol (positive control), 6 mg/100 µL erythromycin (positive control)] were set up to determine effects of lichen extract on immune responses and survival rate. In the study, superoxide radical production was increased in fish treated with 12 mg beard lichen extract, florfenicol and erythromycin compared to that of control (P < 0.05). Lysozyme activity was generally decreased (P < 0.05) or no differences were observed in all experimental groups compared to that of control (P > 0.05). Myeloperoxidase was significantly increased in all antibiotic treated groups. No differences were observed in liver histology of experimental groups compared to control. Cytokine gene expressions were elevated in all experimental groups compared to that of control (P < 0.05), except IL-1ß expression at 10th day sampling time. Other immune related genes (IL-8, TGF- ß, IL-12 Beta, TNFα1, IL-10, COX-2, IL-6, TLR5, C3, IGM, MHC-II, iNOS, IgT, IFN1, IFN2, IFN reg) were also elevated in all experimental groups compared to that of control group. The survival rates obtained in 4 mg beard lichen treated group, 8 mg beard lichen treated group and erythromycin treated group were 73.08, 65.38 and 80.77% respectively. Our results suggest that beard lichen methanolic extract could be an effective therapeutic agent to be used against L. garvieae infection in rainbow trout at the dose of 4 mg/17.41 ±â€¯0.3 g body weight/day.

C18H17NO6 Inhibits Invasion and Migration of Human MNNG Osteosarcoma Cells via the PI3K/AKT Signaling Pathway.

BACKGROUND Osteosarcoma (OS) is a highly aggressive, metastatic bone tumor with a poor prognosis, and occurs more commonly in children and adolescents. Therefore, new drugs and treatments are urgently needed. In this study, we investigated the effect and potential mechanisms of C18H17NO6 on osteosarcoma cells. MATERIAL AND METHODS Human MNNG osteosarcoma cells were treated with different concentrations of C18H17NO6. The proliferation of the MNNG cells was examined via CCK-8 assay. Cell migration and invasion were tested via wound-healing assay and Transwell migration and invasion assays. ELISA was used to detect MMP-2, MMP-9, and VEGF secretion. Finally, Western blotting and qRT-PCR were used to detect protein and mRNA expressions, respectively. RESULTS C18H17NO6 inhibited MNNG proliferation in a dose- and time-dependent manner and inhibited MMP-2, MMP-9, and VEGF secretion. C18H17NO6 treatment significantly downregulated N-cadherin and Vimentin expression levels and upregulated E-cadherin expression levels in vitro and in vivo. C18H17NO6 inhibited tumor growth in a MNNG xenograft. We also found that C18H17NO6 can significantly reduce the phosphorylation of the PI3K/AKT signaling pathway in vivo and in vitro. However, 740Y-P (a PI3K agonist) had the opposite effect on proliferation, migration and invasion of MNNG cells treated with C18H17NO6. LY294002 (a PI3K inhibitor) downregulated p-PI3K and p-AKT could mimic the inhibitory effect of C18H17NO6. CONCLUSIONS Our results suggest that C18H17NO6 can inhibit human MNNG osteosarcoma cell invasion and migration via the PI3K/AKT signaling pathway both in vivo and in vitro. C18H17NO6 may be a highly effective and low-toxicity natural drug for the prevention or treatment of OS.

Inhibition of growth of U87MG human glioblastoma cells by Usnea longissima Ach.

Herbal medicines are efficient to reduce side effects in the fight against glioblastoma, which plays a critical role within brain cancer species. The recent studies designated for testing the effects of lichens that have shown numerous anticancer activities on glioblastoma so far. In the present study, different concentrations of water extract obtained from Usnea longissima Ach. were used in order to determine cytotoxic (via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase tests), antioxidant (via total antioxidant capacity test), pro-oxidant (via total oxidant status test) and genotoxic (via 8-hydroxy-2'-deoxyguanosine test) effects of them on human U87MG-glioblastoma cancer cell lines. Primary mixed glial-neuronal non-cancerous cells from Sprague-Dawley rats were also utilized to measure the effects of treatments on non-cancerous cells. Based on median inhibitory concentration values, the data belonged to non-cancerous cells (2486.71 mg/L) showed distinct towering compared to U87MG (80.93 mg/L) cells. The viability of non-cancerous and U87MG cells exposed to extract is decreased in a dose dependent manner. It was also showed that low concentrations of extract notably increased total antioxidant capacity on non-cancerous cells. In addition, various phenolic compounds in extract were detected through high-performance liquid chromatography. The recent results encourage that extract will be able to have therapeutic potential against glioblastoma.

Research for the lichen Usnea barbata metabolites.

This work presents investigations of biologically active metabolites of Usnea barbata lichen. Extraction conditions for usnic acid and other biologically active phytocomponents using various solvent systems were chosen. Modern analytical techniques were used to study composition of the obtained extracts; usnic acid and phenolic compound contents were estimated. Antioxidant activity and antimicrobial properties of lichen dry extract against bacteria Bacillus subtilis and Pseudomonas fluorescens were studied.

Synthesis and anti-inflammatory activity of novel triazole hybrids of (+)-usnic acid, the major dibenzofuran metabolite of the lichen Usnea longissima.

(+)-Usnic acid ((R)-2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione), a dibenzofuran isolated from the lichen Usnea longissima, has been chemically transformed to synthesize a series of sixteen novel triazole analogs by click chemistry approach. The synthesized compounds were tested for their anti-inflammatory potential against the cytokines TNF-[Formula: see text] and IL-1[Formula: see text] in U937 cell lines. The bromo enamines (2a, 2b), azido enamines (3a, 3b) and triazole analogs (4f, 4g, 4h, 5f, 5g and 5h) exhibited promising anti-inflammatory activity against TNF-[Formula: see text] with [Formula: see text] values ranging from 1.40 to 5.70 [Formula: see text]M. Most significantly, the [Formula: see text] values of compounds 5f (1.40 [Formula: see text]M) and 5h (1.88 [Formula: see text]M) are the lowest among the compounds tested and found close to that of standard prednisolone. Hence, these two compounds can be considered as lead molecules for further fine tuning to make highly potent anti-inflammatory therapeutic agents.

Usnic Acid Activity on Oxidative and Nitrosative Stress of Azole-Resistant Candida albicans Biofilm.

Several studies report that (+)-usnic acid, a lichen secondary metabolite, inhibits growth of different bacteria and fungi; however, the mechanism of its antimicrobial activity remains unknown. In this study, we explored the ability of usnic acid, obtained from Usnea amblyoclada, as an antibiofilm agent against azole-resistant and azole-sensitive Candida albicans strains by studying the cellular stress and antioxidant response in biofilms. The biofilm inhibitory concentration of usnic acid (4 µg/mL) exhibited a significant biofilm inhibition, 71.08 % for azole-resistant and 87.84 % for azole-sensitive C. albicans strains. Confocal scanning laser microscopy showed that the morphology of mature biofilm was altered (reduced the biomass and thickness) in the presence of usnic acid. The antifungal effect was mediated by an oxidative and nitrosative stress, with a significant accumulation of intracellular and extracellular reactive oxygen species detected by confocal scanning laser microscopy and by nitro blue tetrazolium, respectively. In fact, azole-resistant and azole-sensitive C. albicans biofilms treated at the biofilm inhibitory concentration of usnic acid presented 30-fold and 10-fold increased reactive oxygen species measurements compared to basal levels, respectively, and important nitric oxide generation, showing 25-fold and 60-fold increased reactive nitrogen intermediates levels with respect to the controls, respectively. Nonenzymatic and enzymatic antioxidant defenses were increased in both strains compared to biofilm basal levels as response to the increase of oxidant metabolites. The present study shows for the first time that usnic acid can alter the prooxidant-antioxidant balance, which may be the cause of the irreversible cell damage and lead to cell death. Our results suggest that usnic acid could be an alternative for the treatment of Candida infections, which deserves further investigation.

Secondary Metabolite Profiling of Species of the Genus Usnea by UHPLC-ESI-OT-MS-MS.

Lichens are symbiotic associations of fungi with microalgae and/or cyanobacteria, which are considered among the slowest growing organisms, with strong tolerance to adverse environmental conditions. There are about 400 genera and 1600 species of lichens and those belonging to the Usnea genus comprise about 360 of these species. Usnea lichens have been used since ancient times as dyes, cosmetics, preservatives, deodorants and folk medicines. The phytochemistry of the Usnea genus includes more than 60 compounds which belong to the following classes: depsides, depsidones, depsones, lactones, quinones, phenolics, polysaccharides, fatty acids and dibenzofurans. Due to scarce knowledge of metabolomic profiles of Usnea species (U. barbata, U. antarctica, U. rubicunda and U. subfloridana), a study based on UHPLC-ESI-OT-MS-MS was performed for a comprehensive characterization of their secondary metabolites. From the methanolic extracts of these species a total of 73 metabolites were identified for the first time using this hyphenated technique, including 34 compounds in U. barbata, 21 in U. antarctica, 38 in U. rubicunda and 37 in U. subfloridana. Besides, a total of 13 metabolites were not identified and reported so far, and could be new according to our data analysis. This study showed that this hyphenated technique is rapid, effective and accurate for phytochemical identification of lichen metabolites and the data collected could be useful for chemotaxonomic studies.

The contents and distributions of cadmium, mercury, and lead in Usnea antarctica lichens from Solorina Valley, James Ross Island (Antarctica).

Lichens are efficient and cost-effective biomonitors of the environment. Their geographic distribution together with their slow growth rate enable investigation of the deposition patterns of various elements and substances. In this research, levels of cadmium, lead, and mercury in Usnea antarctica lichens in the area of James Ross Island, Antarctica, were investigated. The lichens were microwave-digested, and the metals were determined by means of atomic absorption spectrometry with graphite furnace and a direct mercury analyzer. Median total contents of Cd, Hg, and Pb were 0.04, 0.47, and 1.6 mg/kg in whole lichens, respectively. The bottom-up distributions of these metals in the fruticose lichen thalli were investigated, and it was revealed that the accumulation patterns for mercury and lead were opposite to that for cadmium. The probable reason for this phenomenon may lie in the inner structure of thalli. The total contents of metals were comparable with those published for other unpolluted areas of maritime Antarctica. However, this finding was not expected for mercury, since the sampling locality was close to an area with some of the highest mercury contents published for Antarctic lichens. In short, lichens proved their usability as biological monitors, even in harsh conditions. However, the findings emphasize the need to take into account the distributions of elements both in the environment and in the lichen itself.

In vivo anti-inflammatory and anti-platelet aggregation activities of longissiminone A, isolated from Usnea longissima.

Secondary metabolite, longissiminone A (1) was isolated from a lichen, Usnea longissima. It was screened for its' in vivo anti-inflammatroy and anti-platelet aggregation activities. Compound 1 showed moderate in vivo anti-inflammatory activity as well as moderately active against the aggregation induced by arachidonic acid at different doses.

Usnea cornuta Körb. and Usnea glabrescens (Vainio) Vainio sens. Lat.: Species to be protected in the peninsula of Edough (Algeria).

In the Mediterranean region, Edough Peninsula (Algerian Northeast) has a significant procession of rare plant species biogeographical interest. This communication is based on specimens collected by the author during the realization of a lichen herbarium when her attention was attracted by the striking presence of a fruticose lichen of Usnea genus, on a hawthorn at the entrance of a private neglected garden. One of the harvested species proved to be after identification, Usnea glabrescens (Vainio) Vainio sens. Lat. A second species was harvested meanwhile a few meters away, on a cork oak and identified as Usnea cornuta Körber species ever recorded in Algeria before.