Effect of ethyl acetate extract of usnea longissima on esophagogastric adenocarcinoma in rats

Abstract 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.

Evaluación de la actividad antifúngica del extracto de Usnea laevis en hongos fitopatógenos / Evaluation of the antifungal activity of the lichenic extract of Usnea laevis in phytopathogenic fungi

Los líquenes son producto de una asociación simbiótica entre un hongo y alga y/o cianobacteria; esta simbiosis produce una serie de metabolitos secundarios o sustancias liquénicas únicas, las mismas que son aisladas a partir de sus extractos y que han presentado una marcada actividad antibiótica y antifúngica. Considerando que en el Ecuador no se tienen antecedentes acerca de este tipo de estudios, el objetivo planteado fue el evaluar la actividad antifúngica del extracto liquénico de Usnea laevis frente a hongos fitopatógenos. En el presente estudio las sustancias liquénicas almacenadas en el talo de Usnea laevis fueron extraídas con metanol y etanol. La actividad antifúngica in vitro de estos extractos fue probado frente a géneros de hongos fitopatógenos previamente aislados (Aspergillus, Penicillium y Rhizopus stolonifer); añadiéndolo al medio de cultivo Agar Papa Dextrosa (PDA) a una concentración de 0,5%; determinándose el porcentaje de inhibición. Los datos fueron analizados estadísticamente y se realizó la clasificación del extracto en base a su porcentaje de inhibición según la OILB. El extracto metanólico y etanólico de Usnea laevis mostró una mayor efectividad frente a Rhizopus stolonifer, inhibiendo más del 50% de su crecimiento, a diferencia de Penicillium y Aspergillus cuyo porcentaje de inhibición fue mucho menor y mostraron diferencias estadísticamente significativas. El extracto liquénico fue moderadamente tóxico para Rhizopus stolonifer, ligeramente tóxico para Aspergillus sp 1 y Penicillium sp e inocuo para Aspergillus sp 2.

A lichen is an organism product of a symbiotic association between a fungus and algae and / or cyanobacteria; this symbiosis produces many secondary metabolites or unique lichen substances, which are isolated from their extracts and show a marked antibiotic and antifungal activity. Considering there is no background on this type of studies in Ecuador, the aim of this study was to evaluate the antifungal in vitro activity of Usnea laevis extract on phytopathogenic fungi. The lichenic substances stored in the thallus of Usnea laevis were extracted with methanol and ethanol. The in vitro antifungal activity of these extracts was tested against phytopathogenic fungal genera previously isolated (Aspergillus, Penicillium and Rhizopus stolonifer) . They were adding to Potato Dextrose Agar (PDA) culture medium at a concentration of 0.5%, and the inhibition percentage was determined. Data were statistically analyzed and the extract was classified based on its inhibition percentage according to the OILB. Methanolic and ethanolic extracts of Usnea laevis showed greater effectiveness against Rhizopus stolonifer, inhibiting more than 50% of its growth, unlike Penicillium and Aspergillus, whose inhibition percentage was lower and showed significant differences. The liquid extract was also moderately toxic to Rhizopus stolonifer, slightly toxic to Aspergillus sp 1 and Penicillium sp and harmless to Aspergillus sp 2.

In vitro antimicrobial activity of the organic extract of Cladonia substellata Vainio and usnic acid against Staphylococcus spp. obtained from cats and dogs / Atividade antimicrobiana in vitro do extrato orgânico de Cladonia substellata Vainio e ácido úsnico frente Staphylococcus spp. obtidos de cães e gatos

ladonia substellata Vainio is a lichen found in different regions of the world, including the Northeast of Brazil. It contains several secondary metabolites with biological activity, including usnic acid, which has exhibited a wide range of biological activities. The aim of this study was to evaluate the in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid. Initially, Staphylococcus spp., derived from samples of skin and ears of dogs and cats with suspected pyoderma and otitis, were isolated and analyzed. In antimicrobial susceptibility testing against Staphylococcus spp., 77% (105/136) of the isolates were resistant to the antimicrobials tested. In the assessment of biofilm production, 83% (113/136) were classified as producing biofilm. In genetic characterization, 32% (44/136) were positive for blaZ, no isolate (0/136) was positive for the mecA gene, and 2% (3/136) were positive for the icaD gene. The in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid against Staphylococcus spp. ranged from 0.25mg/mL to 0.0019mg/mL, inhibiting bacterial growth at low concentrations. The substances were more effective against biofilm-producing bacteria (0.65mg/mL-0.42mg/mL) when compared to non-biofilm producing bacteria (2.52mg/mL-2.71mg/mL). Usnic acid and the organic extract of C. substellata can be effective in the treatment of pyoderma and otitis in dogs and cats caused by Staphylococcus spp.(AU)

Cladonia substellata Vainio é um líquen encontrado em diversos continentes do mundo, inclusive no nordeste do Brasil, possui vários metabólitos secundários com atividade biológica, entre eles, o ácido úsnico, que tem apresentado uma vasta gama de atividades biológicas. O objetivo deste trabalho foi avaliar a atividade antimicrobiana in vitro do extrato orgânico de C. substellata e do ácido úsnico purificado. Para isto, foram isolados Staphylococcus spp. de amostras de pele e orelha de cães e gatos com suspeita de piodermatite e otite. No teste de sensibilidade aos antimicrobianos frente Staphylococcus spp., 77% (105/136) foram resistentes. Na avaliação da produção de biofilme 83% (113/136) foram classificadas como produtoras de biofilme. Na caracterização genotípica, 32% (44/136) foram positivos para o gene blaZ, nenhum isolado (n=136) foi positivo para o gene mecA, e 2% (3/136) foram positivos para o gene icaD. A atividade antimicrobiana in vitro do extrato orgânico de C. substellata e do ácido úsnico purificado para Staphylococcus spp. variou de 0,25mg/ml a 0,0019mg/ml, inibindo o crescimento bacteriano em baixas concentrações. Foram mais eficazes contra bactérias produtoras de biofilme (0,65mg/ml-0,42mg/ml) quando comparadas às não produtoras de biofilme (2,52mg/ml-2,71mg/ml). Viabilizando a utilização do ácido úsnico e do extrato orgânico de C. substellata, no tratamento de otite e piodermatite em cães e gatos com o envolvimento de Staphylococcus spp.(AU)

Simultaneous determination of 3 phenolic acids in Usnea by HPLC-ESI-MS/MS / 中国中药杂志

A quick HPLC-ESI-MS/MS method was established for simultaneous determination of three chemical compositions in Usnea, including usnic acid, diffractaic acid, and ramalic acid. The separation was performed on a chromatographic column of Agilent ZORBAX SB-C, (4.6 mm x 250 mm, 5 µm), and the mobile phase was methanol (0.05% formic acid)-0.05% formic acid solution (4 mmol ammonium acetate), with an isocratic elution at a flow rate of 0.8 ml · min⁻¹. Multiple reaction monitoring scanning mode (MRM) was performed combined with the ion switching technology in positive and negative ion switching mode to apply for the quantitative determination. The calibration curves for the above three compounds were linear in corresponding injection amount. Their average recoveries were 95.0%-105.1%, with RSDs of 1.1%-5.2%. The method was simple, rapid, accurate with high repeatability, which could provide a reference for overcalling evaluation the quality of Usnea.

Three New Non-reducing Polyketide Synthase Genes from the Lichen-Forming Fungus Usnea longissima

Usnea longissima has a long history of use as a traditional medicine. Several bioactive compounds, primarily belonging to the polyketide family, have been isolated from U. longissima. However, the genes for the biosynthesis of these compounds are yet to be identified. In the present study, three different types of non-reducing polyketide synthases (UlPKS2, UlPKS4, and UlPKS6) were identified from a cultured lichen-forming fungus of U. longissima. Phylogenetic analysis of product template domains showed that UlPKS2 and UlPKS4 belong to group IV, which includes the non-reducing polyketide synthases with an methyltransferase (MeT) domain that are involved in methylorcinol-based compound synthesis; UlPKS6 was found to belong to group I, which includes the non-reducing polyketide synthases that synthesize single aromatic ring polyketides, such as orsellinic acid. Reverse transcriptase-PCR analysis demonstrated that UlPKS2 and UlPKS4 were upregulated by sucrose; UlPKS6 was downregulated by asparagine, glycine, and alanine.

Lichen Mycota in South Korea: The Genus Usnea

Usnea Adans. is a somewhat rare lichen in South Korea, and, in nearly two decades, no detailed taxonomic or revisionary study has been conducted. This study was based on the specimens deposited in the lichen herbarium at the Korean Lichen Research Institute, and the samples were identified using information obtained from recent literature. In this study, a total of eight species of Usnea, including one new record, Usnea hakonensis Asahina, are documented. Detailed descriptions of each species with their morphological, anatomical, and chemical characteristics are provided. A key to all known Usnea species in South Korea is also presented.

Advance in studies on chemical constituents and pharmacological activity of lichens in Usnea genus / 中国中药杂志

<p><b>OBJECTIVE</b>To summarize the studies on chemical constituents and pharmacological activities of lichens of Usnea genus.</p><p><b>METHOD</b>A systematic literature survey was conducted to classifiy and summarize chemical constituents of lichens of Usnea genus, and sum up current studies on main pharmacological activities of lichens of the genus.</p><p><b>RESULT</b>Lichens of Usnea genus contained multiple chemical constituents, primarily including mono-substituted phenyl rings, depsides, anthraquinones, dibenzofurans, steroids, terpenes, fatty acids and polysaccharides, with such biological activities as antitumor, antibacterial, anti-inflammation, anti-oxidation and antithrombosis.</p><p><b>CONCLUSION</b>This essay provides reference for further studies and development of lichens of Usnea genus.</p>

Chemical constituents from Usnea longgisima, a traditional mongolian medicine / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of the whole lichen of Usnea longissima.</p><p><b>METHOD</b>The compounds were separated by silica gel, Sephadex LH-20 chromatography and high performance liquid chromatography (HPLC). The structures of the compounds isolated were identified by physico-chemical properties and spectral analysis.</p><p><b>RESULT</b>Ten compounds were isolated and their structures were identified as (4aR,9bS)-2,6-diactyl-3,4a,7,9-tetrahydroxy-8,9b-dimethyl-1-oxo-1,4,4a, 9b-tetrahydrodibenzo [b,d]furan (1), (+)-usnic acid (2), orcinol (3), 18R-hydroxydihydroalloprotolichensterinic acid (4), 5, 8-epidioxy-5alpha, 8alpha-ergosta-6, 22E-dien-3beta-ol (5), ethyl everninate (6), arabitol(7), apigenin 7-O-beta-D-glucuronide (8), 3-hydroxy-5-methoxy-2-methylbenzoic acid(9), friedelin(10).</p><p><b>CONCLUSION</b>Compound 1 was a new compound. Compound 8 was isolated from genu Usnea for the first time and compounds 3, 4 and 7 were isolated from U. longissima for the first time.</p>

Determination of atranol, lecanorin, ethyl orsellinate and methyl orsellinate in Usnea diffracta by RP-HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>To develop a RP-HPLC method for determining the contents of atranol, lecanorin, ethyl orsellinate and methyl orsellinate in Usnea diffracta.</p><p><b>METHOD</b>A Kromasil-C18 column (4.6 mm x 250 mm, 5 microm) was used at 25 degrees C with the mobile phases of acetonitrile -1% acetic acid in a gradient manner. The flow rate was set at 1.0 mL x min(-1). The detection wavelength was 280 nm.</p><p><b>RESULT</b>The correlation coefficients of atranol, lecanorin, ethyl orsellinate, and methyl orsellinate were higher than 0.999. Recoveries were from 102.9% to 95.30%; with RSD from 2.3% to 1.9%.</p><p><b>CONCLUSION</b>The method is quick, simple and repeatable for simultaneous determination of atranol, lecanorin, ethyl orsellinate and methyl orsellinate in U. diffracta.</p>

New dibenzofuran and anthraquinone from Usnea longissima / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of Usnea longissima.</p><p><b>METHOD</b>The compounds were isolated and purified by the methods of solvent extraction and chromatographic technique, and their structures were identified on the basis of the analyses of spectral data.</p><p><b>RESULT</b>Two compounds were obtained and identified as 3, 6-diacetyl-2, 7, 9-trihydroxy-8, 9b-dimethyl-1 [9bH]-dibenzofuranone(1) and 1, 3, 8-trihydroxy4, 6-dimethyl-9, l0-anthracenedione(2), respectively.</p><p><b>CONCLUSION</b>Compounds 1 and 2 were new compounds and were named as longiusnine and longissimausnone, respectively.</p>

Studies on chemical constituents from herbs of Usnea longissima / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of Usnea longissima.</p><p><b>METHOD</b>The compounds were isolated and purified by the methods of solvent extraction and chromatographic technique, and their structures were identified on the basis of the analysis of spectral data or comparison with those of authentic sample.</p><p><b>RESULT</b>Thirteen compounds were obtained and identified as ethyl hematommate (1), friedelin (2), beta-amyrin (3), beta-sitosterol (4), methyl-2,4-dihydroxy-3,6-dimethylbenzoate (5), barbatinic acid (6), zeorin (7), ethyl orsellinate (8), 3beta-hydroxy-glutin-5-ene (9), oleanolic acid (10), (+)-usnic acid (11), methylorsellinate (12), and 4-methyl-2,6-dihydroxy-benzaldehyde (13).</p><p><b>CONCLUSION</b>Compounds 2, 3, 5, and 8-10 were isolated from this genus for the first time, and compounds 1,4 were obtained from this plant for the first time.</p>