RESUMO
Responses to germination and initial growth of Lactuca sativa (lettuce) submitted to organic extracts and purified compounds of Cladonia verticillaris ("salambaia") were analyzed in this work. The experiments were conducted in laboratory conditions using extracts and pure compounds at different concentrations. None of the assays showed any influence on the germination of L. sativa seeds using C. verticillaris extracts; however, modifications in leaf area and seedling hypocotyl and root development occurred. In the growth experiments, seedlings exposed to ether or acetone extract showed diminished hypocotyl growth in detriment to the root stimulus, compared to controls. Increases in extract concentrations led to the formation of abnormal seedlings. To determine the allelochemicals of C. verticillaris, its principal components, fumarprotocetraric and protocetraric acids, were isolated and then analyzed by high performance liquid chromatography (HPLC). When the seedlings were exposed to the two acids separately, presented increased leaf area at all concentrations. In contrast, hypocotyl and root stimulus was observed only in the presence of protocetraric acid at different concentrations. Fumarprotocetraric as well as protocetraric acids, isolated and purified from C. verticillaris and Parmotrema dilatatum respectively, influenced the development of L. sativa seedlings at high concentrations, indicating a possible bioherbicide potential of these acids.
Assuntos
Agentes de Controle Biológico , Misturas Complexas/farmacologia , Germinação/efeitos dos fármacos , Lactuca/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Saccharomycetales/química , Sementes/efeitos dos fármacos , Lactuca/crescimento & desenvolvimentoRESUMO
We describe here the extraction and identification of several classes of phenolic compounds from the lichens Parmotrema dilatatum (Vain.) Hale, Parmotrema tinctorum (Nyl.) Hale, Pseudoparmelia sphaerospora (Nyl.) Hale and Usnea subcavata (Motyka) and determined their anti-tubercular activity. The depsides (atranorin, diffractaic and lecanoric acids), depsidones (protocetraric, salazinic, hypostictic and norstictic acids), xanthones (lichexanthone and secalonic acid), and usnic acid, as well seven orsellinic acid esters, five salazinic acid 8',9'-O-alkyl derivatives and four lichexanthone derivatives, were evaluated for their activity against Mycobacterium tuberculosis. Diffractaic acid was the most active compound (MIC value 15.6mug/ml, 41.6 microM), followed by norstictic acid (MIC value 62.5 microg/ml, 168 microM) and usnic acid (MIC value 62.5 microg/ml, 182 microM). Hypostictic acid (MIC value 94.0 microg/ml, 251 microM) and protocetraric acid (MIC value 125 microg/ml, 334 microM) showed moderate inhibitory activity. The other compounds showed lower inhibitory activity on the growth of M. tuberculosis, varying from MIC values of 250 to 1370 microM.
Assuntos
Antituberculosos/farmacologia , Líquens/química , Mycobacterium tuberculosis/efeitos dos fármacos , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Usnea/química , Antituberculosos/isolamento & purificação , Testes de Sensibilidade Microbiana , Fenóis/isolamento & purificação , Extratos Vegetais/químicaRESUMO
Microparticles will probably play a promising role in the future of chemotherapy. These polymeric delivery systems are capable of maximizing the therapeutic activity while reducing side effects of anti-cancer agents. Usnic acid (UA) is a secondary metabolite produced by lichens, which exhibits an anti-tumour activity. In this study, PLGA-microspheres containing usnic acid from Cladonia substellata were prepared by the double emulsion method, with or without PEG as stabilizer. The morphology of the microspheres was examined by optical and scanning electron microscopy. The in vitro kinetic profile of usnic acid loaded-microspheres was carried out by dissolution testing. The usnic acid content was analysed by HPLC. The cytotoxicity of free and encapsulated usnic acid was evaluated against HEp-2 cells using the MTT method. The anti-tumour assay was performed in mice against Sarcoma-180 tumour (UA 15 mg kg(-1) weight body/day) during 7 days. Animals were then sacrificed and tumour and organs were excised for histopathological analysis. Microspheres presented a smooth spherical surface with a mean diameter of 7.02 +/- 2.72 microm. The usnic acid encapsulation efficiency was approximately 100% (UA 10 mg 460 mg(-1) microspheres). A maximum release of 92% was achieved at the fifth day. The IC50 values for free and encapsulated usnic acid were 12 and 14 microg ml(-1), respectively. The encapsulation of usnic acid into microspheres promoted an increase of 21% in the tumour inhibition as compared with the free usnic acid treatment. In summary, usnic acid was efficiently encapsulated into PLGA-microspheres and the microencapsulation improved its anti-tumour activity.
Assuntos
Antineoplásicos/farmacologia , Benzofuranos/farmacologia , Animais , Antineoplásicos/análise , Antineoplásicos/uso terapêutico , Benzofuranos/análise , Benzofuranos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Portadores de Fármacos , Composição de Medicamentos/métodos , Ácido Láctico , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos , Microscopia Eletrônica de Varredura , Microesferas , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros , Sarcoma 180/tratamento farmacológicoRESUMO
The activity of ten compounds isolated from Brazilian lichen over the release of hydrogen peroxide and nitric oxide was evaluated in the culture of peritoneal macrophage cells from mice. Salazinic, secalonic A and fumarprotocetraric acids were the compounds that induced the greatest release of H2O2, whereas 12R-usnic and diffractaic acids induced the release of NO. These results indicate that lichen products have potential immunological modulating activities.
Assuntos
Fatores Biológicos/farmacologia , Líquens , Macrófagos Peritoneais/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Fatores Biológicos/administração & dosagem , Fatores Biológicos/uso terapêutico , Brasil , Peróxido de Hidrogênio/metabolismo , Macrófagos Peritoneais/metabolismo , Masculino , Medicina Tradicional , Camundongos , Óxido Nítrico/metabolismo , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêuticoRESUMO
A solid-phase extraction and chromatography-flame ionization detection (GC-FID) method has been developed for the routine analysis of psoralen, bergapten, isopimpinellin and pimpinellin in creams and pomades employed in Brazil for the treatment of vitiligo. The calibration curve for psoralen was linear in the range 10-100 microg ml(-1), for bergapten 5-90 microg ml(-1), for pimpinellin 10-90 microg ml(-1) and for isopimpinellin 5-100 microg ml(-1). The best recoveries of the furanocoumarins in the creams analysed were 94-97%, whereas in the pomades, recoveries were 94-96%. The R.S.D. of the quantitative-analysis of the furanocoumarins in the products analyses were within 5%.
Assuntos
Cumarínicos/análise , Preparações Farmacêuticas/química , Calibragem , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Vochysia divergens Pohl (Vochysiaceae) is a tree commonly found in wet soils of 'Pantanal' of Mato Grosso, Brazil, and used in folk medicine against infections and asthma. We have studied different extracts and some isolated compounds from this plant for antibacterial activity. From the extracts of the stem bark beta-sitosterol, betulinic acid and sericic acid were isolated. The minimal inhibitory concentration (MIC) for Staphylococcus aureus were: ethanolic extract (MIC = 1.5 mg/ml); ethyl acetate extract (MIC = 2.0 mg/ml); and sericic acid (MIC = 1.0 mg/ml). Escherichia coli was resistant until 5 mg/ml.