Antimicrobial and toxicological activities of five medicinal plant species from Cameroon Traditional Medicine

<p>Abstract</p> <p>Background</p> <p>Infectious diseases caused by multiresistant microbial strains are on the increase. Fighting these diseases with natural products may be more efficacious. The aim of this study was to investigate the <it>in vitro </it>antimicrobial activity of methanolic, ethylacetate (EtOAc) and hexanic fractions of five Cameroonian medicinal plants (<it>Piptadeniastum africana</it>, <it>Cissus aralioides, Hileria latifolia, Phyllanthus muellerianus </it>and <it>Gladiolus gregasius) </it>against 10 pathogenic microorganisms of the urogenital and gastrointestinal tracts.</p> <p>Methods</p> <p>The fractions were screened for their chemical composition and <it>in vivo </it>acute toxicity was carried out on the most active extracts in order to assess their inhibitory selectivity.</p> <p>The agar well-diffusion and the micro dilution methods were used for the determination of the inhibition diameters (ID) and Minimum inhibitory concentrations (MIC) respectively on 8 bacterial species including two Gram positive species (<it>Staphylococcus aureus, Enterococcus faecalis)</it>, and six Gram negative <it>(Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Shigella flexneri, Salmonella typhi) </it>and two fungal isolates (<it>Candida albicans, Candida krusei)</it>. The chemical composition was done according to Harbone (1976), the acute toxicity evaluation according to WHO protocol and the hepatic as well as serum parameters measured to assess liver and kidney functions.</p> <p>Results</p> <p>The chemical components of each plant's extract varied according to the solvent used, and they were found to contain alkaloids, flavonoids, polyphenols, triterpens, sterols, tannins, coumarins, glycosides, cardiac glycosides and reducing sugars. The methanolic and ethylacetate extracts of <it>Phyllanthus muellerianus </it>and <it>Piptadeniastum africana </it>presented the highest antimicrobial activities against all tested microorganisms with ID varying from 8 to 26 mm and MIC from 2.5 to 0.31 mg/ml. The <it>in vivo </it>acute toxicity study carried out on the methanolic extracts of <it>Phyllanthus muellerianus </it>and <it>Piptadeniastrum africana </it>indicated that these two plants were not toxic. At the dose of 4 g/kg body weight, kidney and liver function tests indicated that these two medicinal plants induced no adverse effect on these organs.</p> <p>Conclusion</p> <p>These results showed that, all these plant's extracts can be used as antimicrobial phytomedicines which can be therapeutically used against infections caused by multiresistant agents.</p> <p>Phyllanthus muellerianus, Piptadeniastum africana, antimicrobial, acute toxicity, kidney and liver function tests, Cameroon Traditional Medicine</p

Phase II clinical trial of mutant Ras peptide vaccine in combination with GM-CSF and IL-2 in advanced cancer patients

3067 Background: Mutant ras oncogenes produce novel proteins that are processed and displayed through HLA molecules on tumor cells. Therefore, mutant ras is an attractive target for vaccine therapy. We have shown in a previous phase I trial that vaccination with mutant ras peptides produced specific immune responses (IR). Here we tested in a phase II trial the use of specific mutant ras peptides in combination with GM-CSF and IL-2 in advanced cancer patients carrying the ras mutation in their tumors. Methods: We treated 17 patients with advanced cancers (14 CRC, 1 NSCLC and 2 pancreatic) with 5000μg of the corresponding mutant ras peptide given SQ along with GM-CSF and IL-2. GM-CSF was given SQ on days -1,0,1,2 followed by ten days of low dose SQ IL-2. Vaccines were repeated every 5 weeks for a maximum of 15 cycles or until disease progression. Results: 11 patients who received 3 or more vaccinations were tested for immune response by measuring IFN-γ mRNA copies in PBMCs pre and post vaccination. 6/11 patients generated specific IR to the corresponding mutant ras vaccine. The median overall survival and the median progression-free survival for all patients were 25.8 and 13.1 months respectively. However, in the 6 patients with positive IR, it was 39.9 and 17.9 months compared to 18.5 and 15.6 months in the 5 patients who showed no IR. No grade IV toxicity occurred. Most adverse events were Grade I-II toxicities and resolved spontaneously. Grade III toxicities led to IL-2 dose reduction in 3/17 patients (18%). Conclusions: The study showed that vaccination of advanced cancer patients with mutant ras peptides in combination with GM-CSF and IL-2 is safe and can induce specific immune responses. Furthermore, those patients who generated IR showed better clinical outcome, as reflected by PFS and OS. So we believe that this vaccine may form a potentially promising approach in combination with other therapeutic modalities in advanced solid tumors. No significant financial relationships to disclose. </jats:p

Paradigma da ciência, do saber e do conhecimento e a educação para a complexidade: pressupostos e possibilidades para a formação docente Paradigm of science, of wisdom and knowledge and education to the complexity: assumptions and possibilities for teacher training

Centrando leituras sobre as bases teóricas do paradigma científico dominante, em seus fundamentos racionalistas-cientificistas, determinantes na ciência, no saber e nos conhecimentos trabalhados na escola, apresentamos a proposição de uma educação voltada para a complexidade. Tal proposição surge do chamado paradigma emergente, o qual visa superar as inércias e a reatividade tradicionais nos procedimentos de escolarização e de formação docente e caminhar em situações pró-ativas e em prótopias mobilizadoras para a implementação de ações curriculares e educativas que possibilitem uma formação mais aberta, flexível e inter-transcultural, que culmine com uma educação mais humana e convivencial.<br>Focusing readings on the theoretical foundations of the dominant scientific paradigm, in their rationalist-cientificist pleas, determinants in science, in knowing and in the knowledge learned at school, we present the proposition of an education geared towards complexity. This proposition is the so-called emerging paradigm, which aims at overcoming the inertia and reactivity in the traditional procedures for education and teacher training and walk into proactive situations and mobilizing protopias for the implementation of curriculum and educational training actions to promote a more open, flexible and inter-cross learning, which will result in a more human and convivial education