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1.
Environ Monit Assess ; 192(4): 246, 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32206882

RESUMO

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.


Assuntos
Monitoramento Ambiental , Oligoelementos , Usnea , Regiões Antárticas , Oligoelementos/análise , Usnea/química
2.
An Acad Bras Cienc ; 91(3): e20180994, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31596391

RESUMO

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.


Assuntos
Antioxidantes/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Extratos Vegetais/farmacologia , Usnea/química , Animais , Antioxidantes/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Humanos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Ratos , Ratos Sprague-Dawley
3.
Med Sci Monit ; 25: 7527-7537, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31589596

RESUMO

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.


Assuntos
Benzofuranos/farmacologia , Osteossarcoma/tratamento farmacológico , Usnea/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Medicina Tradicional Chinesa/métodos , Camundongos , Invasividade Neoplásica , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Usnea/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Biomed Pharmacother ; 120: 109446, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31542617

RESUMO

BACKGROUND AND AIMS: Usnea diff ;racta Vain. (U. diffracta) belonging to the Usnea genus, is widely used as a folk medicine for the treatment of ulcer, abdominal pain, diarrhea, malaria and so on. However, the antiatherogenic effect of U. diffracta has not yet been reported. This study aims to investigate the antiatherogenic effects of the ethanol extract of U. diffracta and its mechanism. METHOD: A high fat diet and VD3 were used to establish the atherosclerotic rat model, with 0.004 g/kg/d of simvastatin as a positive control, fed with 0.7, 1.4, and 2.8 g/kg/d of Usnea ethanol extract for 21 days. The blood, liver, and aorta samples from each rat were collected after the last administration. Pharmacodynamic effects were evaluated. The inflammation related factors, the gene expressions of Toll-like receptor 5 (TLR5), myeloid differentiating factor 88 (MyD88), and nuclear factor-κB (NF-κB) were detected. RESULTS AND CONCLUSIONS: Compared with the model group, simvastatin and ethanol extract of U. diffracta can significantly reduce the serum levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), Ca2+, AST, ALT, the liver contents of total cholesterol (TC), TG, AI and liver index, as well as significantly increase the contents of high-density lipoprotein cholesterol (HDL-C) both in serum and liver (p < 0.01 or p < 0.05). The serum level of ox-LDL can be significantly reduced by simvastatin, low and medium U. diffracta ethanol extract doses (p < 0.01). In addition, simvastatin and low dosage of U. diffracta ethanol extract can significantly reduce the liver content of LDL-C (p < 0.01). U. diffracta ethanol extract shows a positive antiatherogenic effect. Furthermore, the mechanism may be related to promoting the expression of serum IL-10 and inhibition of TLR5/NF-κB signaling pathway.


Assuntos
Aorta/efeitos dos fármacos , Aterosclerose/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Fígado/efeitos dos fármacos , Usnea/química , Animais , Aterosclerose/induzido quimicamente , Cálcio/sangue , Citocinas/efeitos dos fármacos , Dieta Hiperlipídica , Lipídeos/sangue , Modelos Animais , Ratos , Ratos Sprague-Dawley , Sinvastatina/farmacologia
5.
Fitoterapia ; 137: 104194, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31175954

RESUMO

Four unusual heterodimeric tetrahydroxanthones, usneaxanthones A-D (1-4) were isolated from lichen Usnea aciculifera Vain (Parmeliaceae). Their structures and absolute configurations, particularly the central and axial chiralities, were unambiguously demonstrated by a combination of spectroscopic data (1D, 2D NMR, HRESIMS), electronic circular dichroism (ECD) experiments, and single-crystal X-ray crystallographic analyses. Cytotoxic effects of isolated compounds (1, 2 and 4) were evaluated on HT-29 human colorectal cancer cells. Compound 4 showed potent cytotoxicity against HT-29 with IC50 values of 2.41 µM.


Assuntos
Antineoplásicos/farmacologia , Usnea/química , Xantonas/farmacologia , Antineoplásicos/isolamento & purificação , Células HT29 , Humanos , Estrutura Molecular , Vietnã , Xantonas/isolamento & purificação
6.
Phytochemistry ; 164: 86-93, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31102999

RESUMO

Specialised metabolites in lichens are generally considered repellent compounds by consumers. Nevertheless, if the only food available is lichens rich in specialised metabolites, lichenophages must implement strategies to overcome the toxicity of these metabolites. Thus, the balance between phagostimulant nutrients and deterrent metabolites could play a key role in feeding preferences. To further understand lichen-gastropod interactions, we studied the feeding behaviour and consumption in Notodiscus hookeri, the land snail native to sub-Antarctic islands. The lichen Usnea taylorii was used because of its simple chemistry, its richness in usnic acid (specialised metabolite) and arabitol (primary metabolite) and its presence in snail habitats. Choice tests in arenas with intact lichens versus acetone-rinsed lichens were carried out to study the influence of specialised metabolites on snail behaviour and feeding preference. Simultaneously, usnic acid and arabitol were quantified and located within the lichen thallus using HPLC-DAD-MS and in situ imaging by mass spectrometry to assess whether their spatial distribution explained preferential snail grazing. No-choice feeding experiments, with the pure metabolites embedded in an artificial diet, defined a gradual gustatory response, from strong repellence (usnic acid) to high appetence (D-arabitol). This case study demonstrates that the nutritional activity of N. hookeri is governed by the chemical quality of the food and primarily by nutrient availability (arabitol), despite the presence of deterrent metabolite (usnic acid).


Assuntos
Benzofuranos/metabolismo , Caramujos/metabolismo , Álcoois Açúcares/metabolismo , Usnea/metabolismo , Animais , Benzofuranos/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Caramujos/química , Álcoois Açúcares/química , Usnea/química
7.
Acta Cir Bras ; 34(3): e201900305, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30892391

RESUMO

PURPOSE: To investigate the effects of the EtOAc extract of U. longissima which is uninvestigated previously on esophagogastric cancer induced in rats with N-methyl-N-nitro-N-nitrosoguanidin (MNNG). METHODS: The anticancer activity of EtOAc extract of U. longissima was examined in the esophagogastric adenocarcinoma models induced in rats with MNNG. EtOAc extract of U. longissima, 50 and 100 mg/kg oral doses were administered once daily for six months. MNNG induced differentiated and undifferentiated type adenocarcinomas in the esophageal and gastric tissues of rats. RESULTS: EtOAc extract of U. longissima obtained from U. longissima prevented gastric and esophageal cancerogenesis induced in rats with MNNG. EtOAc extract of U. longissima did not have a lethal effect at doses of 500, 1000 and 2000 mg/kg. The prominent anticarcinogenic activity of EtOAc extract of U. longissima 50 and 100 mg/kg suggests that it is not toxic and it is selective to the cancer tissue. CONCLUSION: This information may shed light on clinical implementation of EtOAc extract of U. longissima in future.


Assuntos
Acetatos/uso terapêutico , Adenocarcinoma/tratamento farmacológico , Antineoplásicos Fitogênicos/uso terapêutico , Extratos Vegetais/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Usnea/química , Animais , Masculino , Neoplasias Experimentais/tratamento farmacológico , Ratos , Ratos Wistar
8.
Fish Shellfish Immunol ; 87: 401-409, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30711494

RESUMO

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.


Assuntos
Doenças dos Peixes/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/veterinária , Lactococcus/efeitos dos fármacos , Oncorhynchus mykiss , Usnea/química , Animais , Relação Dose-Resposta a Droga , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/imunologia , Lactococcus/fisiologia
9.
Mol Phylogenet Evol ; 131: 125-137, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30385309

RESUMO

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.


Assuntos
Variação Genética , Usnea/química , Usnea/genética , Sequência de Bases , Teorema de Bayes , DNA Fúngico/genética , Geografia , Filogenia , Probabilidade , Especificidade da Espécie , Usnea/classificação
10.
Mycologia ; 110(6): 1047-1057, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30365393

RESUMO

Lichens are symbiotic associations consisting of a fungal (mycobiont) and one or more photosynthetic (photobionts) partners and are the dominant component, and most important primary producers, of Antarctic terrestrial ecosystems. The most common lichens in the maritime Antarctic are Usnea antarctica and U. aurantiacoatra, a so-called "species pair" in which U. antarctica shows asexual reproduction and propagation via soredia and U. aurantiacoatra forms ascospores in apothecia. Previous molecular analyses were not able to unambiguously distinguish the two morphotypes as species. Therefore, the goal of this study was to find out whether fast-evolving SSR (single sequence repeat) markers are able to separate morphotypes more clearly and help to clarify their taxonomy. We investigate 190 individuals from five mixed stands of both morphotypes collected in King George Island and Elephant Island (South Shetland Islands, Antarctica). Based on 23 microsatellite markers designed from sequenced genomes, discriminant analysis of principal components (DAPC), Bayesian clustering analysis, and coalescent-based estimation of gene flow show clear evidence for the existence of two different species distinguishable by reproductive mode. We did not detect any statistical association between genetic clusters and three previously reported chemical races of each species.


Assuntos
Repetições de Microssatélites , Filogenia , Usnea/classificação , Usnea/genética , Regiões Antárticas , Teorema de Bayes , Ecossistema , Fluxo Gênico , Genoma Fúngico , Ilhas , Técnicas de Tipagem Micológica , Análise de Componente Principal , Usnea/fisiologia
11.
Fungal Biol ; 122(8): 731-737, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30007424

RESUMO

Few studies have investigated the genetic diversity of populations of common and widespread lichenized fungi using microsatellite markers, especially the relationships between different measures of genetic diversity and environmental heterogeneity. The main aim of our study was to investigate the population genetics of a widespread and mainly clonally reproducing Usnea subfloridana at the landscape scale, focusing on the comparison of lichen populations within hemiboreal forest stands. Particular attention has been paid to the genetic differentiation of lichen populations in two geographically distinct regions in Estonia and the relationships between forest characteristics and measures of genetic diversity. We genotyped 578 Usnea thalli from eleven lichen populations using seven specific fungal microsatellite markers. Measures of genetic diversity (allelic richness, Shannon's information index, Nei's unbiased genetic diversity, clonal diversity, the number of multilocus genotypes, the number of private alleles, and the minimum number of colonization events) were calculated and compared between Usnea populations. Shared haplotypes, gene flow and AMOVA analyses suggest that unconstrained gene flow and exchange of multilocus genotypes exist between the two geographically remote regions in Estonia. Stand age, mean circumference of the host tree, size of forest site and tree species composition did not show any significant influence on allelic richness, Shannon's information index, Nei's unbiased genetic diversity, clonal diversity, the number of private alleles, and the minimum number of colonization events of U. subfloridana populations. Therefore it was concluded that other factors of habitat heterogeneity could probably have a more significant effect on population genetics of U. subfloridana populations.


Assuntos
Fluxo Gênico , Variação Genética , Usnea/classificação , Usnea/genética , Estônia , Florestas , Genética Populacional , Genótipo , Técnicas de Genotipagem , Repetições de Microssatélites , Técnicas de Tipagem Micológica
12.
Z Naturforsch C J Biosci ; 73(7-8): 291-296, 2018 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-29596056

RESUMO

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.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Fatores Biológicos/farmacologia , Usnea/metabolismo , Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Bacillus subtilis/efeitos dos fármacos , Benzofuranos/isolamento & purificação , Benzofuranos/farmacologia , Fatores Biológicos/isolamento & purificação , Testes de Sensibilidade Microbiana , Fenóis/isolamento & purificação , Fenóis/farmacologia , Pseudomonas fluorescens/efeitos dos fármacos , Solventes
13.
Nat Prod Res ; 32(9): 1088-1094, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29092623

RESUMO

A new pheophytin, (132S, 17S, 18S)-132-hydroxy-20-chloro-ethylpheophorbide a (3), along with two known analogues (1-2) were isolated from the lichen Usnea diffracta Vainio (Parmeliaceae). Among them, compound 3 was a rare C-20-chloro type pheophytin obtained from lichens. Their structures were elucidated by extensive spectroscopic analysis, and all the compounds were obtained for the first time from U. diffracta. Compounds (1-3) were evaluated for their xanthine oxidase (XO) inhibitory activities in vitro, and the results showed that 1-3 possessed significant enzyme inhibitory actions with IC50 values of 46.9 ± 3.8, 75.9 ± 7.4 and 42.1 ± 1.7 µg/mL, respectively.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Líquens/química , Feofitinas/química , Usnea/química , Avaliação Pré-Clínica de Medicamentos/métodos , Medicamentos de Ervas Chinesas/química , Concentração Inibidora 50 , Estrutura Molecular , Feofitinas/farmacologia , Plantas Medicinais/química , Xantina Oxidase/antagonistas & inibidores
14.
Environ Monit Assess ; 190(1): 13, 2017 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-29230543

RESUMO

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.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Metais/análise , Usnea/química , Regiões Antárticas , Ascomicetos , Cádmio/análise , Ilhas , Chumbo/análise , Líquens/química , Mercúrio/análise , Quinolonas , Espectrofotometria Atômica
15.
Molecules ; 23(1)2017 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-29280946

RESUMO

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.


Assuntos
Líquens/química , Metabolômica/métodos , Extratos Vegetais/análise , Espectrometria de Massas em Tandem/métodos , Usnea/química , Usnea/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Fungos , Metanol/química , Compostos Fitoquímicos/metabolismo , Extratos Vegetais/química
16.
Pak J Pharm Sci ; 30(4): 1213-1217, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29039316

RESUMO

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.


Assuntos
Anti-Inflamatórios/farmacologia , Derivados de Benzeno/farmacologia , Edema/prevenção & controle , Agregação Plaquetária/efeitos dos fármacos , Usnea/química , Animais , Ácido Araquidônico/antagonistas & inibidores , Derivados de Benzeno/isolamento & purificação , Carragenina , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Feminino , Humanos , Masculino , Ratos
17.
Biomed Pharmacother ; 94: 930-936, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28810520

RESUMO

OBJECTIVES: Usnea is a lichen of Usnea diffracta Vain and Usnea longissima Ach, which belongs to the genus Usnea Adans of Usneaceae. Usnea exerts numerous pharmacological activities, while its lipid regulatory activities remain unreported. This study aims to evaluate the effects of aqueous and ethanol extracts of Usnea on the regulation of lipid metabolism and to explore the possible mechanism. METHODS: Hyperlipidemia rat model was established by feeding with high-fat diet for 45days. Therapy rats were intragastrically administered with simvastatin (0.004g/kg/d), Usnea aqueous extract (2.766g/kg/d), or Usnea ethanol extract (2.766g/kg/d) for 20days. Pharmacodynamic effects, including body weight, serum and liver lipid levels, total bile acid (TBA), aspartate aminotransferase (AST), alanine aminotransferase (ALT), liver index, and hepatic morphological changes were evaluated. To explore the mechanisms, the lipase activities and protein expressions related to lipid metabolism were detected. RESULTS: Compared with the model group, aqueous and ethanol extracts of Usnea can slow down the weight gain of rats, significantly reduce the serum levels of total cholesterol, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and the liver contents of TG, LDL-C, as well as significantly increase the contents of high-density lipoprotein cholesterol in serum. In addition, aqueous and ethanol extracts of Usnea can significantly reduce the serum contents of AST and ALT. Furthermore, ethanol extract of Usnea can also significantly reduce the TBA content in serum and liver index. Liver tissue pathological observation showed that aqueous and ethanol extracts of Usnea can improve cell degeneration to a certain extent. Aqueous and ethanol extracts of Usnea can significantly reduce sterol regulatory element-binding proteins-1c, and liver X receptor α (LXR-α) protein expressions. Furthermore, aqueous extract of Usnea can significantly increase hepatic lipase activity and promote apoprotein A5 (ApoA5) protein expression. CONCLUSIONS: These findings strongly suggest that the aqueous and ethanol extracts of Usnea play significant roles in regulating lipid metabolism, and the ethanol extract exhibits higher activity than the aqueous extract. The mechanism of the regulation of lipid metabolism by Usnea aqueous extract may involve the increased ApoA5 protein expression via inhibition of the LXR-α signal pathway; however, the mechanism of the regulation of lipid metabolism by Usnea ethanol extract remains to be further studied.


Assuntos
Metabolismo dos Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Usnea/química , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Dieta Hiperlipídica/efeitos adversos , Medicamentos de Ervas Chinesas/farmacologia , Etanol/química , Feminino , Hiperlipidemias/sangue , Hiperlipidemias/tratamento farmacológico , Fígado/efeitos dos fármacos , Fígado/metabolismo , Receptores X do Fígado/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Triglicerídeos/sangue
18.
Mol Divers ; 21(2): 273-282, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28130662

RESUMO

(+)-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.


Assuntos
Anti-Inflamatórios/síntese química , Anti-Inflamatórios/farmacologia , Benzofuranos/química , Benzofuranos/metabolismo , Triazóis/síntese química , Triazóis/farmacologia , Usnea/metabolismo , Anti-Inflamatórios/química , Química Click , Humanos , Interleucina-1beta/metabolismo , Triazóis/química , Fator de Necrose Tumoral alfa/metabolismo , Células U937
19.
Planta Med ; 83(3-04): 326-333, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27648556

RESUMO

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.


Assuntos
Azóis/farmacologia , Benzofuranos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Benzofuranos/química , Benzofuranos/isolamento & purificação , Biomassa , Farmacorresistência Fúngica , Líquens/química , Líquens/metabolismo , Testes de Sensibilidade Microbiana , Microscopia Confocal , Nitrosação/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Usnea/química
20.
Fungal Biol ; 120(10): 1165-74, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27647234

RESUMO

Very little is known whether and how air pollution impacts genetic diversity of lichenized fungi that are well-known indicators of environmental quality. We studied the genetic variation of eight Usnea subfloridana populations in Pinus sylvestris-dominated boreal forest stands in southern Estonia, Northern Europe; four of these populations were exposed to long-term dust pollution released from unpaved road. The mean bark pH of lichen phorophyte differed considerably between polluted and unpolluted forest stands. We genotyped 274 Usnea thalli using nine specific fungal microsatellite markers. Genetic variation measures were calculated and compared between populations from different habitats. Allelic richness, Shannon's information index, and genetic diversity of lichen populations were significantly higher in unpolluted forest sites than in polluted forest sites. We conclude that environmental disturbances caused by alkaline dust pollution had negative impact on the genetic variation of U. subfloridana, a common species of lichenized fungi.


Assuntos
Poluentes Atmosféricos/farmacologia , Variação Genética/efeitos dos fármacos , Líquens/microbiologia , Usnea/efeitos dos fármacos , Usnea/genética , Poluentes Atmosféricos/química , Poeira/análise , Repetições de Microssatélites , Filogenia , Usnea/isolamento & purificação
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