7 research outputs found

    The husk fiber of Cocos nucifera L. (Palmae) is a source of anti-neoplastic activity

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    In the present study, we investigated the in vitro anti-tumoral activities of fractions from aqueous extracts of the husk fiber of the typical A and common varieties of Cocos nucifera (Palmae). Cytotoxicity against leukemia cells was determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Cells (2 x 104/well) were incubated with 0, 5, 50 or 500 µg/mL high- or low-molecular weight fractions for 48 h, treated with MTT and absorbance was measured with an ELISA reader. The results showed that both varieties have almost similar antitumoral activity against the leukemia cell line K562 (60.1 ± 8.5 and 47.5 ± 11.9% for the typical A and common varieties, respectively). Separation of the crude extracts with Amicon membranes yielded fractions with molecular weights ranging in size from 1-3 kDa (fraction A) to 3-10 kDa (fraction B) and to more than 10 kDa (fraction C). Cells were treated with 500 µg/mL of these fractions and cytotoxicity was evaluated by MTT. Fractions ranging in molecular weight from 1-10 kDa had higher cytotoxicity. Interestingly, C. nucifera extracts were also active against Lucena 1, a multidrug-resistant leukemia cell line. Their cytotoxicity against this cell line was about 50% (51.9 ± 3.2 and 56.3 ± 2.9 for varieties typical A and common, respectively). Since the common C. nucifera variety is extensively cultured in Brazil and the husk fiber is its industrial by-product, the results obtained in the present study suggest that it might be a very inexpensive source of new antineoplastic and anti-multidrug resistant drugs that warrants further investigation

    Negative correlation between phospholipase and esterase activity produced by Fusarium isolates

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    Fusarium species have emerged as one of the more outstanding groups of clinically important filamentous fungi, causing localized and life-threatening invasive infections with high morbidity and mortality. The ability to produce different types of hydrolytic enzymes is thought to be an important virulence mechanism of fungal pathogens and could be associated with the environment of the microorganism. Here, we have measured the production of two distinct lipolytic enzymes, phospholipase and esterase, by sixteen Fusarium isolates recovered from the hospital environment, immunocompromised patients’ blood cultures, foot interdigital space scrapings from immunocompromised patients, and foot interdigital space scrapings from immunocompetent patients (4 isolates each). Fourteen of these 16 isolates were identified asFusarium solani species complex (FSSC) and two were identified as F. oxysporum species complex (FOSC). Some relevant genus characteristics were visualized by light and electron microscopy such as curved and multicelled macroconidia with 3 or 4 septa, microconidia, phialides, and abundant chlamydospores. All Fusarium isolates were able to produce esterase and phospholipase under the experimental conditions. However, a negative correlation was observed between these two enzymes, indicating that a Fusarium isolate with high phospholipase activity has low esterase activity and vice versa. In addition, Fusarium isolated from clinical material produced more phospholipases, while environmental strains produced more esterases. These observations may be correlated with the different types of substrates that these fungi need to degrade during their nutrition processes

    Chemical composition and antioxidant and antifungal properties of Mentha x piperita L. (peppermint) and Mentha arvensis L. (cornmint) samples

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    Essential oils and infusions from commercial peppermint sachets (CPS), and non-commercial genuine peppermint (NCP) and cornmint (NCC) samples were analyzed by GC/MS and LC/MS. Minimum inhibitory concentration (MIC) of mint oils against Fusarium moniliforme, Aspergillus niger and Aspergillus fumigates was determined. Antioxidant potential was monitored by total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and soybean oil oxidation tests. CPS and NCC oils had lower menthofuran content than NCP. Mint oils did not show a uniform standard of antifungal activity and they had the modest reducing ability. CPS and NCC infusions showed higher IC50 and lower TPC than NCP ones. In the soybean oxidation test, mint oils presented prooxidant behavior. CPS infusions showed antioxidant potential significantly (P<0.05, Tukey) lower than that from NCC and NCP infusions. NCP infusions were more efficient in delaying propagation reaction than NCC ones. This may be attributed to higher amount of rosmarinic acid and hesperidin in NCP

    The Structural Role of Gangliosides: Insights from X-ray Scattering on Model Membranes

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