Efeito alelopático de extrato aquoso de Piper aduncum L. e Piper tectoniifolium Kunth na germinação e crescimento de Lactuca sativa L.

Made available in DSpace on 2016-10-10T03:52:19Z (GMT). No. of bitstreams: 5 Efeito_Alelopático_de Extrato Aquoso de Piper Aduncum L.....pdf: 37103 bytes, checksum: a54d35e004ff302dd25073dbaec2d7b5 (MD5) license_url: 52 bytes, checksum: 2f32edb9c19a57e928372a33fd08dba5 (MD5) license_text: 24259 bytes, checksum: f1f24f769b03eb8f9cd3f53c1090841c (MD5) license_rdf: 24658 bytes, checksum: 9d3847733d3c0b59c7c89a1d40d3d240 (MD5) license.txt: 1887 bytes, checksum: 445d1980f282ec865917de35a4c622f6 (MD5) Previous issue date: 2007-07A alelopatia pode ser definida como um processo pelo quais produtos do metabolismo secundário de um determinado vegetal são liberados, impedindo a germinação e o desenvolvimento de outras plantas relativamente próximas [1]. A resistência ou tolerância aos metabólitos secundários é uma característica espécieespecífica, tendo algumas espécies sensíveis como Lactuca sativa L. (alface), Lycopersicon esculentum Miller (tomate) e Cucumis sativus L. (pepino), consideradas plantas indicadoras de atividade alelopática.[2]. A família Piperaceae tem cerca de 12 gêneros e 1400 espécies distribuídas em todas as regiões tropicais e subtropicais. No Brasil ela é representada por cinco gêneros e aproximadamente 460 espécies. Na região de Maringá, Paraná, Brasil, há matas secundárias onde vicejam espécies pertencentes ao gênero Piper Linnaeus, como P. amalago var. medium Linnaeus, P. aduncum Linnaeus, P. arboreum Aublet, P. crassinervium H.B.K., P. diospyrifolium Kunth e P. gaudichaudianum Kunth. Essas espécies têm hábito arbustivo ou subarbustivo e ocorrem em touceiras [3]. As espécies estudadas de Piper têm um amplo uso popular, pois possuem propriedades medicinais, ou seja, possuem um ou mais princípio ativo que lhe confere alguma propriedade terapêutica, tais como atividade antimicrobiana, cicatrizante, analgésica, antihemorrágica, adstringente, entre outras [4]. Piper aduncum L. é um arbusto (3-8 m), comumente encontrada no sudeste do Brasil. É largamente usada na medicina popular para tratar inflamações e dores de estômago. A investigação fitoquímica desta espécie mostrou a presença de derivados de ácido benzóico, de chromanas e flavonóides com atividades antibacteriana e citotoxicas. [5]. Muitos estudos revelam que o extrato da parte aérea de Piper aduncum é largamente utilizado por possuir propriedades anti-bacterianas, sendo significativamente mais ativo de encontro a Gram-positivas, incluindo Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Cryptococcus neoformans, Mycobacteria intracellulare, Micrococcus luteus e Pseudomonas aeruginosa, confirmando assim o seu grande uso popular e, também para detectar novas fontes de agentes antibacterianos. [4]. Apesar de não se ter ainda muitos estudos sobre os efeitos do extrato de Piper tectoniifolium Kunth, seja possível que os seus compostos químicos sejam semelhantes ou próximos da Piper aduncum e, portanto, conferindo-lhes várias propriedades em comum, uma vez que apresentam efeitos alelopáticos semelhantes. O objetivo do presente trabalho foi identificar efeitos alelopáticos do extrato feito da parte aérea de Piper aduncum e Piper tectoniifolium na germinação e no crescimento de plântulas de Lactuca sativa (alface).SimPublicad

Natural rubber latex coated with calcium phosphate for biomedical application

Natural rubber latex (NRL) is a flexible biomembrane that possesses angiogenic properties and has recently been used for guided bone regeneration, enhancing healing without fibrous tissue, allergies or rejection. Calcium phosphate (Ca/P) ceramics have chemical, biological, and mechanical properties similar to mineral phase of bone, and ability to bond to the host tissue, although it can disperse from where it is applied. Therefore, to create a composite that could enhance the properties of both materials, NRL biomembranes were coated with Ca/P. NRL biomembranes were soaked in 1.5 times concentrated SBF solution for seven days, avoiding the use of high temperatures. SEM showed that Ca/P has been coated in NRL biomembrane, XRD showed low crystallinity and FTIR showed that is the carbonated type B. Furthermore, hemolysis of erythrocytes, quantified spectrophotometrically using materials (Ca/P, NRL, and NRL + Ca/P) showed no hemolytic effects up to 0.125 mg/mL (compounds and mixtures), indicating no detectable disturbance of the red blood cell membranes. The results show that the biomimetic is an appropriate method to coat NRL with Ca/P without using high temperatures, aiming a new biomembrane to improve guided bone regeneration

Enzyme-linked immunosorbent assay using recombinant envelope protein 2 antigen for diagnosis of Chikungunya virus

Abstract Background Chikungunya (CHIKV) virus is an important mosquito-borne virus causing outbreaks of acute febrile illness with arthropathy. The detection of specific antibodies against CHIKV is used for diagnosis after the acute viremic phase of the disease. However, a major challenge for serologic diagnosis of CHIKV and other alphaviruses is the cross-reactivity of antibodies to common antigens among these viruses. In the present study, we have developed an enzyme-linked immunosorbend assay using a recombinant envelope protein 2 of CHIKV produced in Escherichia coli system, as a capture antigen. Results High titers (1600 to 12,800) of anti-CHIKV antibodies were detected in human sera analyzed by the CHIKV assay, suggesting it may detect low levels of the antibodies presence. On the other side, cross-reactivity was not observed in mouse hyperimmune sera to Mayaro virus and other alphaviruses analyzed by the CHIKV immunosorbend assay, suggesting it is a CHIKV-specific test. Fifty-nine human serum samples of CHIKV infection suspected cases were tested for immunoglobulin G (IgG) and M (IgM) antibodies detection using the CHIKV immunosorbend assay. A total of 44% (26/59) of samples were positive for IgG to CHIKV, determining 89.66% sensitivity and 100% specificity when the assay is compared to a CHIKV-specific neutralization assay. In addition, 40.6% (24/59) of samples were positive for IgM, determining 92.48% sensitivity and 79.04% specificity by a Bayesian method in the absence of a gold standard. Moreover, CHIKV immunosorbend assay showed similar sensibilities to a commercial immunochromatography assay (Lumiquick, USA) for CHIKV IgG and IgM detection. Conclusion In short, we have developed a rapid, simple, specific and sensitive CHIKV immunosorbend assay for IgG and IgM detection and our results showed potential applicability on the diagnosis of infections by this virus

Infection with Saint Louis encephalitis virus in the city of Ribeirao Preto, Brazil: report of one case

Saint Louis encephalitis virus (SLEV) is a mosquito-borne flavivirus from the Americas. In this report we describe aspects of the laboratory diagnosis of a patient with an acute febrile illness induced by SLEV that was initially diagnosed as dengue by positive IgM-ELISA. Infection with this virus is probably not rare in Brazil, but cases remain undiagnosed. It is necessary to improve the surveillance system, including laboratories, for the diagnosis of SLEV in Brazil

Novel ultraviolet absorbers derived from cashew nut shell liquid: spectrophotometric, in silico and in vitro assays

The cashew nut shell liquid (CNSL) constituents were isolated by our group leading to four mixtures and seventeen pure compounds, which had chromophoric groups similar to organic ultraviolet (UV) absorbers. In addition, C15 and C8 CNSL-derivatives molecules were rationally planned as UV absorbers. Mixtures and isolated CNSL compounds were demonstrated to be non-phototoxic when evaluated in a phototoxicity assay using the yeast Saccharomyces cerevisiae. Considering the absorption values on the UV range, 6 compounds showed appropriate SPF values regarding the spectrophotometric test. Additionally, in silico and in vitro evaluations were performed, showing non-oral bioavailability, as well as non-mutagenic, non-genotoxic and non-phototoxic properties for the tested compounds. These results contribute favorably to the aimed use of the compounds under analysis as novel organic UV absorbers that have as precursor the phenolic lipid component of CNSL, a waste product obtained as the by-product of cashew nut food processing