Navegando por Palavras-chave "Actinobactéria"

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    Bioprospecção de actinomicetos com potencial anticâncer em sedimentos marinhos de praias e ilhas da estância balneária de Ubatuba, SP
    (Universidade Federal de São Paulo (UNIFESP), 2020-02-04) Souza, Bruna Viana De [UNIFESP]; Jimenez, Paula Christine [UNIFESP]; Universidade Federal de São Paulo
    With the increasing need of new drugs for treatment of complex diseases, that still don’t have a selective and effective treatment, as cancer and neurodegenerative diseases, the bioprospection of natural drugs has grown a bit more each day. For the past few decades, the oceans have been showing their irrefutable pharmacological importance, mainly when related to new molecules isolated from actinomycetes. The objective of this study was to analyze the anticancer potential of crude extracts produced by actinomycetes, isolated from the marine sediment of Ubatuba, Brasil. Samples of sediment from 10 different beaches and islands, in the chosen area, were collected and pre-treated by two different methodologies, in order to favor the growth of the bacteria desired, then isolated using three distinct culture media, with variated nutritional supply. In total, 92 strains were isolated and cryopreserved, and 80 strains were grown in liquid media, extracted with solvent and tested for cytotoxicity in human colorectal cancer cells (HCT-116). Among the tested extracts, in qualitative MTT assay for HCT-116 cells, 20 demonstrated cell growth inhibition greater than 75% on the higher of the two concentrations used, 5µg/mL and 50µg/ mL, with 4 of them being active in both concentrations, and all were evaluated to obtain its IC50. Therefore, the strains BRB 539, BRB 592, BRB 607 e BRB 609, were proven to fit the prestablished standards for activity and pharmacologically interesting strains (IC50 < 4 µg/mL; R2 > 0,8500), and submitted to a quantitative cytotoxic essay using a cell line panel, formed by 3 cancerous cell lines (Sk-Mel-19, 501-Mel, MCF-7) and one non-tumor cell line (RPE-1). Moreover, the strains BRB 592 and BRB 607, were selected as more interesting for the study, analyzed in a cell growth vs cytotoxicity assay, and identified as Bacillus subtilis spizizenii and Micromonospora aurantiaca, respectively. Both identified species are known for their capability of producing active biocompounds, mainly with antibiotic and anticancer activity, proving the pharmacological relevance of the marine microorganisms inhabiting the sediments in the region of Ubatuba.
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    Bioprospecção de microorganismos recuperados do sedimento do litoral de são paulo com potencial anticâncer
    (Universidade Federal de São Paulo, 2018-09-24) Rigato, Dhiego Botelho [UNIFESP]; Jimenez, Paula Christine [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The oceans have proven to be an immeasurable source of new molecules with pharmacological applications, especially among microorganisms from the diverse Actinobacteria class. The goal of this study was to bioprospect the anticancer potential of extracts produced by marine actinobacteria recovered from sediments collected on the coast of São Paulo. Sediment samples were collected across 10 sites on the coast of São Paulo and processed by two methods and three culture media. Purified strains were grown in liquid media and extracted using ethyl acetate. The 231 extracts obtained from the respective strain were analyzed for cytotoxicity against HCT-116 cells (human colorectal carcinoma) by the MTT assay at two concentrations (5 µg/mL e 50 µg/mL). Extracts that inhibited greater than 75% of cell growth in both concentration were selected for quantitative approach. Values for the IC50 for 25 extracts were obtained after 72h incubation with tree tumor cell lines (HCT-116, MM200, MCF7) and one non-tumor cell line (RPE). Two extracts (BRB-094 and BRB-104), the producers of which were identified as members of the Streptomyces genera, were then selected according to their chemical and biological profile for further studies of cell viability and morphological analysis. BRB-094 caused a significant decrease in the number of viable cells after 48h and 72h incubation at the highest concentration tested (0.5µg/mL). Regarding the number of non-viable cells, the extract induced a significant increase at both concentrations tested (0.5µg/mL and 0.1µg/mL). This result suggests that cells exposed to this extract may be undergoing a process of death. BRB-104, on the other hand, caused a significant decrease in the number of viable cells without increasing the number of non-viable cells, which may be suggestive of an effect on the reduction of cell proliferation. These results have shown that the coast of São Paulo holds a rich biotechnological potential in the marine microorganisms.