Antimicrobial, antioxidant, anti-inflammatory activities and phytoconstituents of extracts from the roots of Dissotis thollonii Cogn. (Melastomataceae)

Abstract Background Dissotis thollonii Cogn. belonging to the Malastomataceae family is used in the West Region of Cameroon for the treatment of inflammation, kidney diseases, pregnancy control and sinusitis. Despite the traditional use of this plant, no scientific report or information was found in the literature regarding neither its biological activity nor its chemical constituents. Aim of the study The present work was designed to determine the antimicrobial, antioxidant and anti-inflammatory activities of different extracts of the roots of D. thollonii Cogn. as well as the isolation and identification of the chemical constituents of this plant. Materials and methods The tests for antimicrobial, antioxidant and anti-inflammatory activities were performed over the MeOH, EtOAc, n-BuOH and aqueous extracts. Compounds were isolated from EtOAc and n-BuOH extracts of the roots of D. thollonii Cogn. through column chromatography and their structures were determined by means of NMR and MS analysis, and published data. Results According to the antimicrobial and antioxidant assays, the EtOAc and n-BuOH extracts were submitted to further separation and purification. This led to the isolation of twelve compounds identified as 3,3′-di- O -methylellagic acid 4′- O-β -D-xylopyranoside 1 , 3- O -methylellagic acid 4′- O-β -D-arabinopyranoside 2 , casuarinin 3 , betulinic acid 4 , β -sitosterol-3- O -D-glucopyranosyl-6′-mirystate 5 , cellobiosylsterol 6 , β -sitosterol 7 , β -sitosterol-3- O-β -D-glucopyranoside 8, arjunolic acid 9 , 3,3′-di- O -methylellagic acid 10 , ellagic acid 11 , and 3,3′-di- O -methylellagic acid 4′- O - β -D-glucopyranoside 12 . The EtOAc extract was the only antimicrobial active sample [diameter of the zone of inhibition (DZI) of 10 mm against Staphyloccocus aureus ] among all the tested extracts. The analysis of fractions of this extract revealed the presence of bioactive compounds with a described antimicrobial activity such as β -sitosterol, β -sitosterol-3- O-β -D-glucopyranoside and arjunolic acid. By using Trolox as the standard drug, all extracts showed antioxidant activity against DPPH in the following order of scavenging ability: Trolox > nBuOH > EtOAc > MeOH > WE (water extract). The ABTS •+ scavenging ability was similar to that found for the DPPH assay, being Trolox > n-BuOH > MeOH > EtOAc > WE. Along with the DPPH and ABTS assays, the FRAP assay showed the scale n-BuOH > MeOH > WE > EtOAc. The phytochemical study of the EtOAc and n-BuOH extracts revealed the presence of important known antioxidant compounds such as ellagic acid derivatives, arjunolic acid, betulinic acid and β -sitosterol. The anti-inflammatory properties of D. thollonii extracts were investigated using RAW 264.7 murine macrophage cells. The MeOH extract reduced the stimulated NO production in a concentration-dependent manner. 86% reduction was observed at the highest tested concentration of 100 μg/ml (IC 50 = 5.9 μg/ml). The n-BuOH extract showed higher dose dependent reduction of NO formation (IC 50 = 6.5 μg/ml) than the EtOAc extract (IC 50 = 18.1 μg/ml), whereas the water extract had no significant influence on the NO production. All the extracts did not have any influence on the macrophage viability. The phytochemical investigation of the EtOAc and n-BuOH extracts revealed that the main compounds identified do have potent anti-inflammatory properties. Conclusion The biological and phytochemical characterization of the root extracts of D. thollonii validates the use of this plant for the treatment of inflammation and sinusitis, thus providing evidence that this plant extracts, as well as some of the isolated compounds, might be potential sources of antioxidant and anti-inflammatory drugs

Trajetória docente em educação física: percursos formativos e profissionais Teacher's trajectory in physical education: formative and professional routes

O presente estudo teve como objetivo analisar a trajetória docente em Educação Física. Os percursos formativos e profissionais de quatro professores de Educação Física, com mais de 25 anos de intervenção profissional em escolas estaduais da cidade de Florianópolis foram investigados. Para analisar a trajetória docente foram utilizadas três fontes de coletas de informações: a) entrevistas semi-estruturadas com os professores de Educação Física; b) entrevistas semi-estruturadas com três colegas de trabalho; c) análise documental. A técnica da análise de conteúdo foi utilizada na análise das informações. Os resultados revelaram que os professores, ao mesmo tempo em que tiveram experiências positivas diversificadas durante suas formações iniciais, vivenciaram experiências negativas muito similares, destacando-se a distância entre suas experiências formativas e a realidade das escolas públicas. Como estratégia de continuidade do percurso formativo, os docentes realizaram cursos de pós-graduação em nível de especialização e de capacitação profissional. A entrada na carreira possibilitou sentimentos tanto de sobrevivência quanto de descoberta, sobressaindo-se o choque com a realidade. No decorrer de seus percursos profissionais, assumiram cargos comissionados e de confiança nas escolas em que atuavam. O desinvestimento amargo predomina no percurso profissional de apenas um professor, enquanto os demais demonstram aguardar a aposentadoria de forma mais serena. Como expectativas relacionadas à aposentadoria, pretendem desenvolver atividades profissionais diversificadas, não retornando à docência escolar.<br>This study aimed to analyze the professional trajectory of Physical Education (PE) teachers. The formative and professional routes of four PE teachers, with more than twenty-five years of professional activity in state schools in the city of Florianopolis were investigated. To analyze the teaching trajectory it was used three sources of information: a) semi-structured interviews with the PE teachers; b) semi-structured interviews with three workmates; c) documental analysis. The technique of content analysis was used for information analysis. The results revealed that the teachers, by the same time they had different positive experiences during their initial training, they had very similar negative experiences, emphasizing the distance between University's experiences and the reality of public schools. As a strategy to continue in the formative course, teachers made post-graduation courses, for expertise and professional improvement. The start in the career made possible feelings of survive and discovery, emphasizing the contrast to the reality. During professional journey, they received activities of reliance at schools they worked. The hard disinvestment predominates in the professional journey of only one teacher, but the other demonstrated to wait for retirement in a soft way. Concerning expectations related to the retirement, they intend to develop different professional activities, but not returning to teaching activities