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1.
Pharm Biol ; 55(1): 1289-1294, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28274189

RESUMO

CONTEXT: Lasiodiplodan, an exocellular (1→6)-ß-d-glucan of molecular weight >1.4 × 106 Da produced by MMPI strain of Lasiodiplodia theobromae (Pat.) Griffon & Maubl. (Brotyosphaeriaceae) is known to exhibit anti-proliferative activity on breast cancer cells (MCF-7), anticoagulant activity when sulfonylated, and reduction in transaminase activity when administered in rats. OBJECTIVE: The effect of intracerebroventricular (I.C.V) injection of lasiodiplodan on neurotoxicity and behavioural changes induced by d-penicillamine was investigated. MATERIALS AND METHODS: Twenty-four male Wistar rats were initially separated in groups of six and treated with 0.15 µmol/µL of NaCl (Groups Ct and d-Pen) and 0.01 µg/µL of lasiodiplodan (Groups Las and Las + d-Pen). After 15 min, they received 6 µmol/µL of NaCl (Groups Ct and Las) and 2 µmol/µL of d-penicillamine (Groups d-Pen and Las + d-Pen). The animal behavior was observed in an open-field test for 60 min. Twenty-four h later, the animals were sacrificed and histopathological analysis and Thiobarbituric acid reactive substances (TBARS) production measurements were performed. RESULTS: Lasiodiplodan prevented neurotoxicity induced by d-penicillamine significantly reducing the production of TBARS (308%; p < 0.05), and behavioural signs; convulsive and pre-convulsive. No histopathological alterations in the cerebral cortex were observed. DISCUSSION AND CONCLUSION: The reduction of TBARS production and convulsive episodes suggests that the protector effect provided by lasiodiplodan passes thought an antioxidant path, possibly interfering in a cascade of neurochemical events, triggering cell death and convulsive episodes. These results demonstrated that lasiodiplodan can be effective in treating neurotoxicity, and reducing damage triggered by convulsions in neuropathies related to GABAergic system.


Assuntos
Comportamento Animal/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Penicilamina/toxicidade , Zearalenona/análogos & derivados , Animais , Comportamento Animal/fisiologia , Córtex Cerebral/metabolismo , Injeções Intraventriculares , Peroxidação de Lipídeos/fisiologia , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar , Zearalenona/administração & dosagem
2.
J Ind Microbiol Biotechnol ; 39(8): 1179-88, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22399240

RESUMO

Lasiodiplodan, an exopolysaccharide of the (1→6)-ß-D: -glucan type, is produced by Lasiodiplodia theobromae MMPI when grown under submerged culture on glucose. The objective of this study was to evaluate lasiodiplodan production by examining the effects of carbon (glucose, fructose, maltose, sucrose) and nitrogen sources (KNO(3), (NH(4))(2)SO(4), urea, yeast extract, peptone), its production in shake flasks compared to a stirred-tank bioreactor, and to study the rheology of lasiodiplodan, and lasiodiplodan's anti-proliferative effect on breast cancer MCF-7 cells. Although glucose (2.05 ± 0.05 g L(-1)), maltose (2.08 ± 0.04 g L(-1)) and yeast extract (2.46 ± 0.06 g L(-1)) produced the highest amounts of lasiodiplodan, urea as N source resulted in more lasiodiplodan per unit biomass than yeast extract (0.74 ± 0.006 vs. 0.22 ± 0.008 g g(-1)). A comparison of the fermentative parameters of L. theobromae MMPI in shake flasks and a stirred-tank bioreactor at 120 h on glucose as carbon source showed maximum lasiodiplodan production in agitated flasks (7.01 ± 0.07 g L(-1)) with a specific yield of 0.25 ± 0.57 g g(-1) and a volumetric productivity of 0.06 ± 0.001 g L(-1) h(-1). A factorial 2(2) statistical design developed to evaluate the effect of glucose concentration (20-60 g L(-1)) and impeller speed (100-200 rpm) on lasiodiplodan production in the bioreactor showed the highest production (6.32 g L(-1)) at 72 h. Lasiodiplodan presented pseudoplastic behaviour, and the apparent viscosity increased at 60°C in the presence of CaCl(2). Anti-proliferative activity of lasiodiplodan was demonstrated in MCF-7 cells, which was time- and dose-dependent with an IC(50) of 100 µg lasiodiplodan mL(-1).


Assuntos
Ascomicetos/metabolismo , Reatores Biológicos , Neoplasias da Mama/patologia , Glucanos/biossíntese , Glucanos/química , Glucose/metabolismo , Ascomicetos/química , Ascomicetos/efeitos dos fármacos , Biomassa , Neoplasias da Mama/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Fermentação/efeitos dos fármacos , Glucanos/metabolismo , Glucose/farmacologia , Humanos , Cinética , Células MCF-7 , Maltose/metabolismo , Maltose/farmacologia , Nitrogênio/metabolismo , Reologia , Sacarose/metabolismo , Sacarose/farmacologia
3.
Molecules ; 17(12): 14298-309, 2012 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-23208465

RESUMO

Studies evaluating the toxicity caused by fungal exopolysaccharides of the ß-(1-->6)-D-glucan type are rare. In this study, the toxicological effects of sub-chronic treatments with lasiodiplodan (ß-(1-->6)-D-glucan from Lasiodiplodia theobromae MMPI) were evaluated in mice through the assessment of biochemical, hematological, and histopathological alterations. Thirty-two mice (16 male, 16 female) were used in this study divided in two groups; one group received lasiodiplodan (50 mg/kg body weight) daily for 28 days via gavage, and another (control group) received saline during the same period. Blood samples were collected via cardiac puncture for hematological and biochemical analyses. Liver, heart, kidney, and spleen were collected for histopathological analysis. Statistical analysis was performed through one-way analysis of variance and only p < 0.05 F-values were presented. Significant reduction in blood glucose in the male group (35%; p < 0.01), transaminases activity in both sexes (AST and ALT; ~35%; p < 0.05), and urea (20%; p < 0.01) in the female group was observed with the lasiodiplodan treatment. The results showed that sub-chronic treatments with lasiodiplodan did not generate hematological and histopathological alterations leading to signs of toxicity in healthy mice, independent of gender.


Assuntos
Coração , Rim , Fígado , Baço , beta-Glucanas , Animais , Relação Dose-Resposta a Droga , Feminino , Coração/efeitos dos fármacos , Humanos , Intubação Gastrointestinal , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Baço/efeitos dos fármacos , Baço/patologia , beta-Glucanas/administração & dosagem , beta-Glucanas/toxicidade
4.
World J Microbiol Biotechnol ; 28(1): 71-80, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22806781

RESUMO

Commercial oil-yielding seeds (castor, coconut, neem, peanut, pongamia, rubber and sesame) were collected from different places in the state of Tamil Nadu (India) from which 1279 endophytic fungi were isolated. The oil-bearing seeds exhibited rich fungal diversity. High Shannon-Index H' was observed with pongamia seeds (2.847) while a low Index occurred for coconut kernel-associated mycoflora (1.018). Maximum Colonization Frequency (%) was observed for Lasiodiplodia theobromae (176). Dominance Index (expressed in terms of the Simpson's Index D) was high (0.581) for coconut kernel-associated fungi, and low for pongamia seed-borne fungi. Species Richness (Chao) of the fungal isolates was high (47.09) in the case of neem seeds, and low (16.6) for peanut seeds. All 1279 fungal isolates were screened for lipolytic activity employing a zymogram method using Tween-20 in agar. Forty isolates showed strong lipolytic activity, and were morphologically identified as belonging to 19 taxa (Alternaria, Aspergillus, Chalaropsis, Cladosporium, Colletotrichum, Curvularia, Drechslera, Fusarium, Lasiodiplodia, Mucor, Penicillium, Pestalotiopsis, Phoma, Phomopsis, Phyllosticta, Rhizopus, Sclerotinia, Stachybotrys and Trichoderma). These isolates also exhibited amylolytic, proteolytic and cellulolytic activities. Five fungal isolates (Aspergillus niger, Chalaropsis thielavioides, Colletotrichum gloeosporioides, Lasiodiplodia theobromae and Phoma glomerata) exhibited highest lipase activities, and the best producer was Lasiodiplodia theobromae (108 U/mL), which was characterized by genomic sequence analysis of the ITS region of 18S rDNA.


Assuntos
Fungos/enzimologia , Fungos/isolamento & purificação , Lipase/biossíntese , Óleos de Plantas , Sementes/microbiologia , Ascomicetos/enzimologia , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Sequência de Bases , Biodiversidade , DNA Fúngico/genética , Esterases/metabolismo , Ácidos Graxos/metabolismo , Fungos/classificação , Fungos/genética , Índia , Lipase/genética , Lipólise
5.
Molecules ; 16(9): 7488-501, 2011 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-21892127

RESUMO

Differential scanning calorimetry (DSC), thermogravimetry (TG) and Fourier-transform infra-red spectroscopy (FT-IR) analyses were performed to investigate changes in the physico-chemical properties of botryosphaerans, a family of exopolysaccharides (EPS) produced by the fungus Botryosphaeria rhodina MAMB-05 grown on glucose (EPS(GLC)), sucrose (EPS(SUC)) and fructose (EPS(FRU)). A slight endothermic transition and small mass loss attributable to the removal of water of hydration were observed in the DSC and TG analyses, respectively, for the three EPS samples. The FT-IR spectra confirmed no structural changes occurred during thermal treatment. Viscometry was utilized to obtain information on the rheological behaviour of the EPS in aqueous solutions. The Power Law and Cross Equations determined the natural pseudoplastic characteristics of the EPS. Comparatively, results obtained for EPS produced when B. rhodina MAMB-05 was grown on each of the three carbohydrate sources demonstrated similar apparent viscosity values for EPS(GLC) and EPS(SUC), while EPS(FRU) displayed the lowest apparent viscosity of the three botryosphaerans, suggesting a higher degree of ramification and lower Mw. EPS(GLC) and EPS(SUC) possessed similar degrees of ramification. The slight differences found in their viscosities can be explained by the differences in the type of branching among the three botryosphaerans, thus varying the strength of intermolecular interactions and consequently, consistency and viscosity. The physico-chemical studies of botryosphaerans represent the originality of this work, and the knowledge of these properties is an important criterion for potential applications.


Assuntos
Glucanos/química , Saccharomycetales/metabolismo , Varredura Diferencial de Calorimetria , Meios de Cultivo Condicionados , Frutose/metabolismo , Glucanos/isolamento & purificação , Glucanos/metabolismo , Glucose/metabolismo , Peso Molecular , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Sacarose/metabolismo , Termogravimetria , Viscosidade
6.
Biochem Genet ; 47(1-2): 80-91, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19160039

RESUMO

The present study is the first describing the sequencing of a fragment of the copper-oxidase domain of a laccase gene in the family Botryosphaeriaceae. The aim of this work was to assess the degree of genetic and evolutionary relationships of a laccase gene from Botryosphaeria rhodina MAMB-05 with other ascomycete and basidiomycete laccase genes. The 193-amino acid sequences of the copper-oxidase domain from several different fungi, insects, a plant, and a bacterial species were retrieved from GenBank and aligned. Phylogenetic analyses were performed using neighbor-joining, maximum parsimony, and Bayesian inference methods. The organisms studied clustered into five gene clades: fungi (ascomycetes and basidiomycetes), insects, plants, and bacteria. Also, the topologies showed that fungal laccases of the ascomycetes and basidiomycetes are clearly separated into two distinct clusters. This evidence indicated that B. rhodina MAMB-05 and other closely related ascomycetes are a new biological resource given the biotechnological potential of their laccase genes.


Assuntos
Ascomicetos/enzimologia , Ascomicetos/genética , Evolução Molecular , Lacase/genética , Ascomicetos/classificação , Filogenia
7.
Carbohydr Res ; 343(4): 793-8, 2008 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-18237722

RESUMO

Three D-glucans were isolated from the mycelium of the fungus Botryosphaeria rhodina MAMB-05 by sequential extraction with hot-water and hot aqueous KOH (2% w/v) followed by ethanol precipitation. Following their purification by gel permeation chromatography on Sepharose CL-4B, the structural characteristics of the D-glucans were determined by FT-IR and 13C NMR spectroscopy and, after methylation, by GC-MS. The hot-water extract produced a fraction designated Q1A that was a beta-(1-->6)-D-glucan with the following structure: [Formula: see text] The alkaline extract, when subjected to repeated freeze-thawing, yielded two fractions: K1P (insoluble) that comprised a beta-(1-->3)-D-glucan with beta-D-glucose branches at C-6 with the structure: [Formula: see text] and K1SA (soluble) consisting of a backbone chain of alpha-(1-->4)-linked D-glucopyranosyl residues substituted at O-6 with alpha-D-glucopyranosyl residues: [Formula: see text]


Assuntos
Ascomicetos/química , Parede Celular/química , Glucanos/química , Glucanos/isolamento & purificação , Micélio/química , Sequência de Carboidratos , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Carbohydr Res ; 343(14): 2481-5, 2008 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-18639868

RESUMO

Four exopolysaccharides (EPS) obtained from Botryosphaeria rhodina strains isolated from rotting tropical fruit (graviola, mango, pinha, and orange) grown on sucrose were purified on Sepharose CL-4B. Total acid hydrolysis of each EPS yielded only glucose. Data from methylation analysis and (13)C NMR spectroscopy indicated that the EPS from the graviola isolate consisted of a main chain of glucopyranosyl (1-->3) linkages substituted at O-6 as shown in the putative structure below: [carbohydrate structure: see text]. The EPS of the other fungal isolates consisted of a linear chain of (1-->6)-linked glucopyranosyl residues of the following structure: [carbohydrate structure: see text]. FTIR spectra showed one band at 891 cm(-1), and (13)C NMR spectroscopy showed that all glucosidic linkages were of the beta-configuration. Dye-inclusion studies with Congo Red indicated that each EPS existed in a triple-helix conformational state. beta-(1-->6)-d-Glucans produced as exocellular polysaccharides by fungi are uncommon.


Assuntos
Ascomicetos/química , Frutas/microbiologia , Glucanos/química , Polissacarídeos/química , beta-Glucanas/química , Ascomicetos/isolamento & purificação , Configuração de Carboidratos , Sequência de Carboidratos , Cromatografia Gasosa-Espectrometria de Massas , Glucanos/metabolismo , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Clima Tropical , beta-Glucanas/metabolismo
9.
Int J Biol Macromol ; 42(2): 172-7, 2008 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-18022685

RESUMO

Biopolymers such as exopolysaccharides (EPS) are produced by microbial species and possess unusual properties known to modify biological responses, among them are antimutagenicity and immunomodulation. Botryosphaeran, a newly described fungal (1-->3; 1-->6)-beta-d-glucan produced by Botryosphaeria rhodina MAMB-05, was administered by gavage to mice at three doses (7.5, 15 and 30mg/kgb.w.per day) over 15 days, and found to be non-genotoxic by the micronucleus test in peripheral blood and bone marrow. Botryosphaeran administered at doses of 15 and 30mg EPS/kgb.w. decreased significantly (p<0.001) the clastogenic effect of cyclophosphamide-induced micronucleus formation resulting in a reduction of the frequency of micronucleated cells of 78 and 82% in polychromatic erythrocytes of bone marrow, and reticulocytes in peripheral blood, respectively. The protective effect was dose-dependent, and strong anticlastogenic activity was exerted at low EPS doses. Variance analysis (ANOVA) showed no significant differences (p<0.05) among the median body weights of the groups of mice treated with botryosphaeran during experiments evaluating genotoxic and protective activities of botryosphaeran. This is the first report on the biological activity attributed to botryosphaeran.


Assuntos
Ascomicetos/química , Glucanos/química , Glucanos/farmacologia , Mutagênicos , Animais , Feminino , Glucanos/metabolismo , Masculino , Camundongos , Mutação/genética , Reticulócitos/efeitos dos fármacos
10.
Int J Biol Macromol ; 72: 588-98, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25239192

RESUMO

D-Glucans have triggered increasing interest in commercial applications in the chemical and pharmaceutical sectors because of their technological properties and biological activities. The glucans are foremost among the polysaccharide groups produced by microorganisms with demonstrated activity in stimulating the immune system, and have potential in treating human disease conditions. Chemical alterations in the structure of D-glucans through derivatization (sulfonylation, carboxymethylation, phosphorylation, acetylation) contributes to their increased solubility that, in turn, can alter their biological activities such as antioxidation and anticoagulation. This review surveys and cites the latest advances on the biological and technological potential of D-glucans following chemical modifications through sulfonylation, carboxymethylation, phosphorylation or acetylation, and discusses the findings of their activities. Several studies suggest that chemically modified d-glucans have potentiated biological activity as anticoagulants, antitumors, antioxidants, and antivirals. This review shows that in-depth future studies on chemically modified glucans with amplified biological effects will be relevant in the biotechnological field because of their potential to prevent and treat numerous human disease conditions and their clinical complications.


Assuntos
Biotecnologia , Glucanos/química , Glucanos/uso terapêutico , Acetilação , Glucanos/síntese química , Humanos , Metilação , Estrutura Molecular , Fosforilação , Solubilidade
11.
Int J Biol Macromol ; 72: 125-30, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25128096

RESUMO

ß-D-Glucans are known to present antitumor, anticancer, and anti-inflammatory activities that are influenced by their own antioxidant capacity. The antioxidant activity of botryosphaeran, an exopolysaccharide of the (1 → 3;1 → 6)-ß-D-glucan type produced by the Botryosphaeria rhodina MAMB-05 was evaluated and compared to some other ß-D-glucans (lasiodiplodan an exocellular (1 → 6)-ß-D-glucan from Lasiodiplodia theobromae, laminarin and curdlan), and oligosaccharides, disaccharides, and monosaccharides in a study of scavenging activities of free radicals in-vitro. Botryosphaeran displayed high total antioxidant activity (80%) as well as good scavenging activity against hydroxyl radical (90.6%), superoxide anion (37%), hydrogen peroxide (38%), and nitric oxide radical (90%). No reducing power, metal-chelating capacity or inhibition of lipid peroxidation was observed for these ß-D-glucans. The results demonstrated that botryosphaeran exhibited effective antioxidant activity as supported by many different assays, suggesting that this ß-D-glucan may serve as a source of a new bioactive compound with effective antioxidant activity.


Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Glucanos/farmacologia , beta-Glucanas/farmacologia , Benzotiazóis/química , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Óxido Nítrico/metabolismo , Ácidos Sulfônicos/química , Superóxidos/química
12.
Int J Biochem Cell Biol ; 67: 14-24, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26255117

RESUMO

Fungal ß-d-glucans of the (1→3)-type are known to exhibit direct antitumor effects, and can also indirectly decrease tumor proliferation through immunomodulatory responses. The underlying molecular mechanisms involved in decreasing tumor formation, however, are not well understood. In this study, we examined the antiproliferative role and mechanism of action of three different fungal exocellular ß-glucans in MCF-7 breast cancer cells. The ß-glucans were obtained from Botryosphaeria rhodina MAMB-05 [two botryosphaerans; (1→3)(1→6)-ß-d-glucan; one produced on glucose, the other on fructose] and Lasiodiplodia theobromae MMPI [lasiodiplodan; (1→6)-ß-d-glucan, produced on glucose]. Using the cell proliferation-MTT assay, we showed that the ß-glucans exhibited a time- and concentration-dependent antiproliferative activity (IC50, 100µg/ml). Markers of cell cycle, apoptosis, necrosis and oxidative stress were analyzed using flow cytometry, RT-PCR and Western blotting. Exposure to ß-glucans increased apoptosis, necrosis, oxidative stress, mRNA expression of p53, p27 and Bax; the activity of AMP-activated protein-kinase, Forkhead transcription factor FOXO3a, Bax and caspase-3; and decreased the activity of p70S6K in MCF-7 cells. In the presence of hydrogen peroxide, the fungal ß-glucans increased oxidative stress, which was associated with reduced cell viability. We showed that these ß-glucans exhibited an antiproliferative effect that was associated with apoptosis, necrosis and oxidative stress. This study demonstrated for the first time that the apoptosis induced by ß-glucans was mediated by AMP-activated protein-kinase and Forkhead transcription factor, FOXO3a. Our findings provide novel mechanistic insights into their antiproliferative roles, and compelling evidence that these ß-glucans possess a broad range of biomodulatory properties that may prove useful in cancer treatment.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Fatores de Transcrição Forkhead/genética , Polissacarídeos Fúngicos/farmacologia , Regulação Neoplásica da Expressão Gênica , beta-Glucanas/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Feminino , Proteína Forkhead Box O3 , Fatores de Transcrição Forkhead/agonistas , Fatores de Transcrição Forkhead/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Células MCF-7 , Estresse Oxidativo/efeitos dos fármacos , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
13.
Carbohydr Polym ; 127: 390-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25965498

RESUMO

D-Glucans possess immunomodulatory activities and potential for the development of new therapeutic agents. Biological activities can be enhanced in these biopolymers through chemical derivatization, e.g., carboxymethylation. This work presents the carboxymethylation, characterization and the evaluation of antioxidant activities of the exocellular (1 → 6)-ß-D-glucan produced by Lasiodiplodia theobromae MMPI. Thermal analysis indicated that the native and carboxymethylated polysaccharides presented four stages of mass-loss. The first stage occurred at 125°C (loss of water) with two consecutive events of mass loss (200-400°C) attributed to polymer degradation and the fourth stage between 425 and 620°C (final decomposition). Scanning electron microscopy analysis indicated that the gross morphological features of lasiodiplodan were ruptured following carboxymethylation. X-ray diffractometry analysis demonstrated that the native and carboxymethylated polysaccharides presented a non-crystalline structure. Carboxymethylation contributed to improving the polysaccharide's water solubility and antioxidant capacity.


Assuntos
Antioxidantes/química , Ascomicetos/química , beta-Glucanas/química , Antioxidantes/metabolismo , Ascomicetos/metabolismo , Metilação , Tamanho da Partícula , beta-Glucanas/metabolismo
14.
Int J Biol Macromol ; 77: 214-21, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25795388

RESUMO

There is growing interest in the anticancer and immunomodulatory potential of fungal ß-d-glucans. In the present study, the modulation of gene expression via RT-qPCR and cell cycle kinetics via flow cytometry were assessed in human normal and tumor (Jurkat) lymphocytes after treatment with botryosphaeran (a fungal (1→3)(1→6)-ß-d-glucan) from Botryosphaeria rhodina MAMB-05. Cell cultures were treated with botryosphaeran either alone, or in combination with doxorubicin (DXR), in a post-treatment protocol. The expression of genes involved in immunomodulatory processes, apoptosis and cell cycle control, as well as ß-d-glucans cell receptors were assessed. Flow cytometry analysis identified tetraploid Jurkat cells in G1 phase when treated with botryosphaeran combined with DXR. This antiproliferative effect in G1 may be associated with down-regulation of the expression of genes involved in the G1 checkpoint. The repression of the CCR5 gene following botryosphaeran treatment, either alone or in combination with DXR, in tumor lymphocytes indicates a possible affinity of this particular (1→3)(1→6)-ß-d-glucan for the receptor CCR5. Therefore, botryosphaeran action appears to be involved in the repression of genes related to the G1 phase of the cell cycle and possibly in the interaction of the botryosphaeran, either alone, or in combination with DXR, with the CCR5 receptor.


Assuntos
Ciclo Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glucanos/farmacologia , Linfócitos/citologia , Linfócitos/metabolismo , Apoptose/efeitos dos fármacos , Humanos , Imunomodulação/efeitos dos fármacos , Células Jurkat , Cinética , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia
15.
Carbohydr Res ; 338(16): 1691-8, 2003 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-12873424

RESUMO

The exopolysaccharide, Botryosphaeran, produced by the ligninolytic, ascomyceteous fungus Botryosphaeria sp., was isolated from the extracellular fluid by precipitation with ethanol, and purified by gel permeation chromatography to yield a carbohydrate-rich fraction (96%) composed mainly of glucose (98%). Infra-red and 13C NMR spectroscopy showed that all the glucosidic linkages were in the beta-configuration. Data from methylation analysis and Smith degradation indicated that Botryosphaeran was a (1-->3)-beta-D-glucan with approx 22% side branching at C-6. The products obtained from partial acid hydrolysis demonstrated that the side branches consisted of single (1-->6)-beta-linked glucosyl, and (1-->6)-beta-linked gentiobiosyl residues.


Assuntos
Ascomicetos/metabolismo , Glucanos/química , Glucanos/isolamento & purificação , Acetilação , Animais , Ascomicetos/química , Sequência de Carboidratos , Cromatografia em Gel , Glucanos/biossíntese , Hidrólise , Espectroscopia de Ressonância Magnética , Metilação , Dados de Sequência Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
16.
PLoS One ; 9(5): e98207, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24858012

RESUMO

Recent studies have demonstrated that the anti-diabetic drug, metformin, can exhibit direct antitumoral effects, or can indirectly decrease tumor proliferation by improving insulin sensitivity. Despite these recent advances, the underlying molecular mechanisms involved in decreasing tumor formation are not well understood. In this study, we examined the antiproliferative role and mechanism of action of metformin in MCF-7 cancer cells treated with 10 mM of metformin for 24, 48, and 72 hours. Using BrdU and the MTT assay, it was found that metformin demonstrated an antiproliferative effect in MCF-7 cells that occurred in a time- and concentration-dependent manner. Flow cytometry was used to analyze markers of cell cycle, apoptosis, necrosis and oxidative stress. Exposure to metformin induced cell cycle arrest in G0-G1 phase and increased cell apoptosis and necrosis, which were associated with increased oxidative stress. Gene and protein expression were determined in MCF-7 cells by real time RT-PCR and western blotting, respectively. In MCF-7 cells metformin decreased the activation of IRß, Akt and ERK1/2, increased p-AMPK, FOXO3a, p27, Bax and cleaved caspase-3, and decreased phosphorylation of p70S6K and Bcl-2 protein expression. Co-treatment with metformin and H2O2 increased oxidative stress which was associated with reduced cell number. In the presence of metformin, treating with SOD and catalase improved cell viability. Treatment with metformin resulted in an increase in p-p38 MAPK, catalase, MnSOD and Cu/Zn SOD protein expression. These results show that metformin has an antiproliferative effect associated with cell cycle arrest and apoptosis, which is mediated by oxidative stress, as well as AMPK and FOXO3a activation. Our study further reinforces the potential benefit of metformin in cancer treatment and provides novel mechanistic insight into its antiproliferative role.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Feminino , Proteína Forkhead Box O3 , Humanos , Hidrogênio/farmacologia , Oxidantes/farmacologia
17.
Carbohydr Polym ; 92(2): 1908-14, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23399236

RESUMO

An exocellular ß-(1→6)-D-glucan (lasiodiplodan) produced by a strain of Lasiodiplodia theobromae (MMLR) grown on sucrose was derivatized by sulfonation to promote anticoagulant activity. The structural features of the sulfonated ß-(1→6)-D-glucan were investigated by UV-vis, FT-IR and (13)C NMR spectroscopy, and the anticoagulant activity was investigated by the classical coagulation assays APTT, PT and TT using heparin as standard. The content of sulfur and degree of substitution of the sulfonated glucan was 11.73% and 0.95, respectively. UV spectroscopy showed a band at 261 nm due to the unsaturated bond formed in the sulfonation reaction. Results of FT-IR and (13)C NMR indicated that sulfonyl groups were inserted on the polysaccharide. The sulfonated ß-(1→6)-D-glucan presented anticoagulant activity as demonstrated by the increase in dose dependence of APTT and TT, and these actions most likely occurred because of the inserted sulfonate groups on the polysaccharide. The lasiodiplodan did not inhibit the coagulation tests.


Assuntos
Anticoagulantes/química , Anticoagulantes/farmacologia , Ascomicetos/química , Ácidos Sulfônicos/química , beta-Glucanas/química , beta-Glucanas/farmacologia , Antitrombinas/farmacologia , Ascomicetos/crescimento & desenvolvimento , Testes de Coagulação Sanguínea , Heparina/farmacologia , Humanos , Solubilidade , Sacarose/química , Trombina/antagonistas & inibidores , Água/química
18.
Appl Biochem Biotechnol ; 170(7): 1792-806, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23749470

RESUMO

The effects of soybean and castorbean meals were evaluated separately, and in combinations at different ratios, as substrates for lipase production by Botryosphaeria ribis EC-01 in submerged fermentation using only distilled water. The addition of glycerol analytical grade (AG) and glycerol crude (CG) to soybean and castorbean meals separately and in combination, were also examined for lipase production. Glycerol-AG increased enzyme production, whereas glycerol-CG decreased it. A 2(4) factorial design was developed to determine the best concentrations of soybean meal, castorbean meal, glycerol-AG, and KH2PO4 to optimize lipase production by B. ribis EC-01. Soybean meal and glycerol-AG had a significant effect on lipase production, whereas castorbean meal did not. A second treatment (2(2) factorial design central composite) was developed, and optimal lipase production (4,820 U/g of dry solids content (ds)) was obtained when B. ribis EC-01 was grown on 0.5 % (w/v) soybean meal and 5.2 % (v/v) glycerol in distilled water, which was in agreement with the predicted value (4,892 U/g ds) calculated by the model. The unitary cost of lipase production determined under the optimized conditions developed ranged from US$0.42 to 0.44 based on nutrient costs. The fungal lipase was immobilized onto Celite and showed high thermal stability and was used for transesterification of soybean oil in methanol (1:3) resulting in 36 % of fatty acyl alkyl ester content. The apparent K m and V max were determined and were 1.86 mM and 14.29 µmol min(-1) mg(-1), respectively.


Assuntos
Ascomicetos/enzimologia , Biocombustíveis/microbiologia , Glycine max/microbiologia , Lipase/biossíntese , Lipase/química , Modelos Biológicos , Ricinus communis/microbiologia , Biocombustíveis/análise , Simulação por Computador , Ativação Enzimática , Estabilidade Enzimática , Enzimas Imobilizadas , Lipase/isolamento & purificação
19.
Mycobiology ; 39(3): 187-93, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22783102

RESUMO

Botryosphaeran, a water-soluble exopolysaccharide of the ß-(1 → 3;1 → 6)-D-glucan type that has been isolated from the culture medium of Botryosphaeria rhodina MAMB-05 grown in submerged fermentation using glucose as the sole carbon source, was previously demonstrated to be non-genotoxic in peripheral blood and bone marrow, and exhibited strong anticlastogenic activity. In the present study, the effects of botryosphaeran were investigated in streptozotocin-induced diabetic rats as well as in high-fat diet-fed hyperlipidemic Wistar rats. The plasma glucose level was reduced by 52% in the diabetic group of rats after administration of 12 mg botryosphaeran/kg body weight of the rats (b.w.)/day by gavage over 15 days. A reduction in the median ration intake was accompanied by an increase in the median body weight gain, as well as the efficiency of food conversion. These results demonstrate that botryosphaeran has protective effects by reducing the symptoms of cachexia in Diabetes mellitus. Botryosphaeran administered by gavage at a concentration of 12 mg botryosphaeran/kg b.w./day over 15 days also reduced the plasma levels of total cholesterol and low density lipoprotein-cholesterol by 18% and 27%, respectively, in hyperlipidemic rats. Based on these findings, we conclude that botryosphaeran possesses hypoglycemic and hypocholesterolemic properties in conditions of diabetes mellitus and hyperlipidemia, respectively, and may be used as an oral anti-diabetic agent.

20.
J Microbiol Biotechnol ; 21(10): 1036-42, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22031027

RESUMO

The exopolysaccharide botryosphaeran (EPS(GLC); a (1--> 3)(1-->6)-ß-D-glucan from Botryosphaeria rhodina MAMB- 05) was sulfonated to produce a water-soluble fraction (EPS(GLC)-S) using pyridine and chlorosulfonic acid in formamid. This procedure was then repeated twice to produce another fraction (EPSGLC-RS) with a higher degree of substitution (DS, 1.64). The purity of each botryosphaeran sample (unsulfonated and sulfonated) was assessed by gel filtration chromatography (Sepharose CL-4B), where each polysaccharide was eluted as a single symmetrical peak. The structures of the sulfonated and re-sulfonated botryosphaerans were investigated using ultraviolet-visible (UV-Vis), Fourier-transform infrared (FT-IR), and (13)C nuclear magnetic resonance ((13)C NMR) spectroscopies. EPS(GLC) and EPS(GLC)-RS were also assayed for anticoagulation activity, and EPS(GLC)-RS was identified as an anticoagulant.


Assuntos
Anticoagulantes/química , Glucanos/química , Anticoagulantes/metabolismo , Anticoagulantes/farmacologia , Ascomicetos/química , Ascomicetos/metabolismo , Coagulação Sanguínea/efeitos dos fármacos , Glucanos/metabolismo , Glucanos/farmacologia , Humanos , Estrutura Molecular , Relação Estrutura-Atividade
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