Search results for "None"
showing 10 items of 1921 documents
Comparative study of eco- and cytotoxicity during biotransformation of anthraquinone dye Alizarin Blue Black B in optimized cultures of microscopic f…
2017
The aim of this study was to select optimal conditions (C and N sources, initial pH and temperature) for biodecolorization of 0.03% anthraquinone dye Alizarin Blue Black B (ABBB) by microscopic fungi: Haematonectria haematococca BwIII43, K37 and Trichoderma harzianum BsIII33. The phenolic compounds, phytotoxicity (Lepidium sativum L.), biotoxicity (Microtox), cytotoxicity and yeast viability assay were performed to determine the extent of ABBB detoxification. Biodecolorization and detoxification of 0.03% ABBB in H. haematococca BwIII43 and T. harzianum BsIII33 cultures was correlated with extracellular oxidoreductases activity. In turn, secondary products, toxic to human fibroblasts and res…
Chemical Composition, In Vitro Antitumor and Pro-Oxidant Activities of Glandora rosmarinifolia (Boraginaceae) Essential Oil
2018
The biological properties of essential oils have been demonstrated in the treatment of several diseases and to enhance the bioavailability of other drugs. In natural habitats the essential oils compounds may play important roles in the protection of the plants as antibacterials, antivirals, antifungals, insecticides and also against herbivores by reducing their appetite for such plants or by repelling undesirable others. We analyzed by gas-chromatography mass spectrometry the chemical composition of the essential oil of aerial parts of Glandora rosmarinifolia (Ten.) D.C. Thomas obtained by hydrodistillation and verified some biological activities on a panel of hepatocellular carcinoma cell …
Stabilization and detection of hydrophylloquinone as di-O-methyl derivative
2016
Phylloquinone is a redox active naphthoquinone involved in electron transport in plants. The function of this reduced form remains unclear due to its instability, which has precluded detection. Herein, a simple method that permits the stabilization of the reduced form of phylloquinone by di-O-methylation and HPLC detection is described. Fil: Sussmann, Rodrigo A. C.. Universidade de Sao Paulo; Brasil Fil: de Moraes, Marcilio M.. Universidade de Sao Paulo; Brasil Fil: Cebrián Torrejón, Gerardo. Universidad de Valencia; España. Universidade de Sao Paulo; Brasil Fil: Porta, Exequiel Oscar Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - …
NF-κB Is a Potential Molecular Drug Target in Triple-Negative Breast Cancers.
2017
Breast cancer continues to cause significant burden in global health morbidity and mortality. Triple-negative breast cancers (TNBCs) are highly aggressive with poor prognosis and are characterized by lack of expression of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor (Her-2). TNBCs are often resistant to cytotoxic chemotherapy and pose major difficulty in achieving personalized medicine due to their molecular heterogeneity. There is increasing evidence that the aberrant activation of nuclear factor (NF)-κB signaling is a frequent characteristic of TNBCs. We evaluated the effects of different potential NF-κB inhibitors, such as bisindolylmaleimide I (BI…
Biocatalytic hydrogenation of the C=C bond in the enone unit of hydroxylated chalcones-process arising from cyanobacterial adaptations.
2018
To verify the hypothesis that cyanobacteria naturally biosynthesising polyphenolic compounds possess an active enzymatic system that enables them to transform these substances, such an ability of the biocatalytic systems of whole cells of these biota was assessed for the first time. One halophilic strain and seven freshwater strains of cyanobacteria representing four of the five taxonomic orders of Cyanophyta were examined to determine the following: (i) whether they contain polyphenols, including flavonoids; (ii) the resistance of their cultures when suppressed by the presence of exogenous hydroxychalcones—precursors of flavonoid biosynthesis and (iii) whether these photoautotrophs can tra…
Oxidative damage and disturbance of antioxidant capacity by zearalenone and its metabolites in human cells.
2017
Mycotoxin contamination of foods and feeds represent a serious problem worldwide. Zearalenone (ZEA) is a secondary metabolite produced by Fusarium species. This study explores oxidative cellular damage and intracellular defense mechanisms (enzymatic and non-enzymatic) in the hepatoma cell line HepG2 after exposure to ZEA and its metabolites (α-zearalenol, α-ZOL; β-zearalenol, β-ZOL). Our results demonstrated that HepG2 cells exposed to ZEA, α-ZOL or β-ZOL at different concentrations (0, 6.25, 12.5 and 25μM) showed: (i) elevated ROS levels (1.5- to 7-fold) based on the formation of the highly fluorescent 2',7'-dichlorofluorescein (DCF), (ii) increased DNA damage measured by the comet assay (…
Marinomonas blandensis sp. nov., a novel marine gammaproteobacterium.
2016
A novel Gram-staining-negative, chemoorganotrophic, moderately halophilic, strictly aerobic bacterium, strain MED121T, was isolated from a seawater sample collected at the Blanes Bay Microbial Observatory in the north-western Mediterranean Sea. Analysis of its 16S rRNA gene sequence, retrieved from the whole-genome sequence, showed that this bacterium was most closely related to Marinomonas dokdonensis and other Marinomonas species (96.3 and 93.3–95.7 % sequence similarities, respectively), within the family Oceanospirillaceae . Strain MED121T was included into a whole-genome sequencing study and, subsequently, it was characterized using a polyphasic taxonomic approach. It was found to be o…
Shikonin derivatives for cancer prevention and therapy.
2019
Abstract Phytochemicals gained considerable interest during the past years as source to develop new treatment options for chemoprevention and cancer therapy. Motivated by the fact that a majority of established anticancer drugs are derived in one way or another from natural resources, we focused on shikonin, a naphthoquinone with high potentials to be further developed as preventive or therapeutic drug to fight cancer. Shikonin is the major chemical component of Lithospermum erythrorhizon (Purple Cromwell) roots. Traditionally, the root extract has been applied to cure dermatitis, burns, and wounds. Over the past three decades, the anti-inflammatory and anticancer effects of root extracts, …
Shikonin Prevents Early Phase Inflammation Associated with Azoxymethane/Dextran Sulfate Sodium-Induced Colon Cancer and Induces Apoptosis in Human Co…
2018
Shikonin is the main active principle in the root of Lithospermum erythrorhizon, widely used in traditional Chinese medicine for its anti-inflammatory and wound healing properties. Recent research highlights shikonin's antitumor properties and capacity to prevent acute ulcerative colitis. The aim of the present study was to evaluate the ability of shikonin to prevent, in vivo, the early phases of colorectal cancer development, with special focus on its cytotoxic mechanism in vitro. We employed the azoxymethane/dextran sulfate sodium model of colitis in Balb/C mice. Body weight and drinking were monitored throughout the experiment, and length of colon and lesions of the colon were recorded o…
Lawsone derivatives target the Wnt/β-catenin signaling pathway in multidrug-resistant acute lymphoblastic leukemia cells.
2017
Abstract Multidrug resistance (MDR) represents a serious problem in cancer treatment. One strategy to overcome this obstacle is to identify agents that are selectively lethal to MDR cells. The aim of this study was to discover novel compounds against MDR leukemia and to determine the molecular mechanisms behind collateral sensitivity. A library of 1162 compounds was tested against parental, drug-sensitive CCRF-CEM cells using the resazurin assay. A total of 302 compounds showed reasonable activity (less than 50% cell viability). Eleven out of 30 lawsone derivatives revealed considerable collateral sensitivity in MDR P-glycoprotein (Pgp)-overexpressing CEM/ADR5000 cells. They reduced β-caten…