NanH and PknG putative virulence factors as a recombinant subunit immunogen against Corynebacterium pseudotuberculosis infection in mice.

Despite the economic and zoonotic relevance of caseous lymphadenitis, a competent immunoprophylaxis tool is still necessary. Here, we evaluated two putative virulence factors of Corynebacterium pseudotuberculosis, rNanH, and rPknG, as recombinant subunit vaccines in a murine model against the infection by C. pseudotuberculosis. Three groups of ten Balb/c mice each were inoculated with a sterile 0.9% saline solution (G1), rNanH (G2), or rPknG (G3) in formulations containing saponin as an adjuvant. The mice received two vaccine doses intercalated by a 21-day interval and were challenged with 2 × 104 CFU/mL of the C. pseudotuberculosis MIC-6 strain 21 days after the last immunization. The total IgG, IgG1, and IgG2a production levels increased significantly in the experimental groups (G2 and G3) on day 42. The highest levels of IgG2a antibodies in G2 and G3 were observed compared to IgG1 levels. G3 showed a significant (p < 0.05) humoral response through higher production of total IgG at day 42 when compared to G2. A significant increase of mRNA expression levels of interleukin (IL)-17, tumor necrosis factor, and interferon-γ was observed only in G2, while IL-4 was significantly produced only by G3. The levels of IL-10 and IL-12 obtained were not significant in any group. The survival rates after the challenge were 20% for G3 and 60% for G2 (p < 0.05). Our findings suggest that the formulation containing rNanH and saponin (G2) resulted in the best protection against the challenge and was able to elicit a Th1 immune response in mice, and can be considered as a promising antigen in the development of an effective vaccine against caseous lymphadenitis.

Evaluation of the effect of synthetic compounds derived from azidothymidine on MDA-MB-231 type breast cancer cells.

The present study aimed to investigate the effect of AZT derivates containing tellurium (Te) on human breast cancer cell lines and the mechanisms underlying cell death. The inhibitory effect of AZT and its derivatives (7m and 7r) was determined by the MTT assay (6.25, 12.5, 25, 50 and 100 µM in 24 and 48 h time points), meanwhile the induction of apoptosis and the cell cycle phases was investigated by flow cytometry. The MTT assay showed that AZT derivatives decreased the rate of cell proliferation at concentrations of 12.5 µM, while commercial AZT showed low antitumor potential. In flow cytometric analysis, we demonstrate that the AZT derivatives do not induce apoptosis at the concentration tested and promote the cell cycle arrest in the S phase. Besides, predicted absorption, distribution, metabolization, excretion and toxicity analysis suggest that the compounds possess a good pharmacokinetic profile and possibly less toxicity when compared to conventional AZT. These compounds containing tellurium in their formulation are potential therapeutic agents for breast cancer.

Extraction, isolation and in vitro evaluation of affinisine from Tabernaemontana catharinensis in human melanoma cells.

Plant compounds have been identified as new drug prototypes. In this line, this work aimed to isolate the indole alkaloid affinisine from Tabernaemontana catharinensis and test its antitumor activity. The alkaloid was isolated by silica gel open column chromatography from the ethanolic extract of the stem of T. catharinensis. Afterwards, this molecule was characterized by high-resolution mass spectrometry and nuclear magnetic resonance. In the next step, the cytotoxicity of the compound was tested against human melanoma cell lines (A375, WM1366 and SK-MEL-28) and a normal skin cell line (CCD-1059Sk) using a MTT (3-4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Cells treated with affinisine were evaluated by flow cytometry to analyze apoptosis and the induction of cell cycle arrest, to evaluate the dead mechanism. The metabolite was isolated in a 0.2% yield relative to the extract. Cytotoxic activity of the molecule was observed at 48 h, resulting in considerable growth inhibition rates in melanoma cells, especially in WM1366, which had the lowest IC50 (32.86 ± 2.54 µg/mL). The apoptosis rate was lower in A375 (56.66 and 86.71% with 57 and 65 µg/mL, respectively). Moreover, affinisine was able to significantly induce cell cycle arrest in different phases in the A375 and WM1366 cell lines. However, in SK-MEL-28 cells, cycle arrest was not observed. In summary, this compound significantly decreased the viability of tumor cells in a dose- and time-dependent manner for all evaluated lineages, reduced cell viability by the apoptosis mechanism and presented prominent activities of cell cycle arrest. In this way, the use of antineoplastic agents is among the most widely used therapeutic measures for the control and treatment of cancer. Affinisine is a promising prototype in the search for new drugs to treat cancer.

In vitro propagation of Ocimum basilicum L. (Lamiaceae) / Propagação in vitro de Ocimum basilicum L. (Lamiaceae) - DOI: 10.4025/actascibiolsci.v25i2.2034

Ocimum basilicum L. (sweet basil), of the family Lamiaceae, is rich in aromatic essential oils and valuable for its pharmaceutical, aromatic and culinary properties. The present study describes the procedure for micropropagation of O. basilicum using cotiledonary leafs from in vitro geminated plants. Cotyledons from in vitro germinated seeds were used as initial explants, put in MS (Murashige and Skoog, 1962) medium with 0.2mg.L-1 NAA (1-Naphthalene acetic acid) in combination with 05mg.L-1 BAP(6-Benzyl aminopurine) and kept at 28 ± 1ºC, 16-h light photoperiod and 48µmol.m-2.s-1 luminous density flow, for 45 days. The highest efficiency of shoot formation after 45 days occurred in the medium containing 5mg.L-1 BAP and 0,2mg.L-1 NAA. The presence of NAA inhibited root formation, when combined with different concentrations of cytokinin (BAP, 1 to 5mg.L-1). Higher BAP concentrations induced an increase in the number of explants with shoots and a higher number of shoots/cotyledon

Ocimum basilicum L. (manjericão) pertencente à família das Lamiaceae é rico em óleos essenciais aromáticos e valorizado por suas propriedades farmacêuticas, aromáticas e culinárias. Neste trabalho descrevemos o procedimento para micropropagação de O. basilicum utilizando cotilédones de sementes germinadas in vitro. Estas foram utilizadas como explante inicial, colocadas em meio MS (Murashige e /skoog, 1962), com 0,2mg.L-1 de ANA em combinação com BAP nas variações de 05mg.L-1 e mantidas à 28 ± 1C, fotoperíodo de 16h de luz e densidade de fluxo luminoso de 48µmol.m-2.s-1 por 45 dias. Maior eficiência na formação de brotos foi obtida utilizando 5mg.L-1 BAP e 0,2mg.L-1 ANA. A presença de ANA inibiu a formação de raízes quando combinada com diferentes concentrações de citocinina (BAP, 1 a 5mg.L-1). Altas concentrações de BAP induziram aumento no número de explantes com brotos e no número de brotos/cotilédone

Leptospirosis diagnosis using Nested-PCR

Leptospirosis is a worldwide sanitary problem. Its clinical signs resemble that of other diseases like Dengue and Flu, and it is difficult to distinguish between them. Currently available diagnostic methods shown low sensitivity and specificity. Efforts have been made to develop simpler, faster and more efficient diagnostic methods. The aim of this work was to evaluate and optimize a Nested-PCR method for diagnosis of leptospirosis. Primers were designed to amplify a 264 bp region within the LipL32 gene. The sensitivity and specificity of the assay was evaluated using seven saprophytic serovars and 35 pathogenic serovars. This technique showed to be very specific for pathogenic serovars, however it lacked sensitivity. In order to enhance the sensitivity, another primer pair was designed which amplify a 183 bp region within the 264 bp region in lipL32 gene, and used in a Nested-PCR assay. This approach was much more sensitive than traditional PCR.

A leptospirose constitui um problema sanitário de importância mundial. Esta doença caracteriza-se por apresentar sintomas muito parecidos com os de outras doenças como a dengue e a gripe e, clinicamente é difícil de distingui-las. Técnicas de diagnóstico da leptospirose atualmente disponíveis apresentam baixa sensibilidade e ou especificidade. Por isso, tem havido um grande esforço no sentido de desenvolver testes rápidos e eficientes, baseados em técnicas de biologia molecular. Este trabalho objetivou a avaliação e otimização do Nested-PCR, para o diagnóstico de leptospirose. Para isso foi desenhado um par de primers que amplifica uma região de 264 pb do gene LipL32. A sensibilidade e especificidade do teste foram avaliadas utilizando 7 sorovares saprófitas e 35 sorovares patogênicos. Este PCR mostrou-se específico para leptospiras patogênicas, porém a sensibilidade não foi muito alta. Com o objetivo de melhorar a sensibilidade do teste , foi desenhado outro par de primers que amplifica uma região de 183 pb do gene LipL32, interna a de 264 pb para a realização do Nested-PCR. Nesta reação foi utilizado como DNA molde o produto da primeira amplificação. O Nested-PCR mostrou-se mais sensível que o PCR normal, pois foi capaz de detectar um baixo número de células bacterianas.