RESUMO

Available treatments for leishmaniasis have been widely used since the 1940s but come at a high cost, variable efficacy, high toxicity, and adverse side-effects. 3,3',5,5'-Tetramethoxy-biphenyl-4,4'-diol (TMBP) was synthesized through laccase-catalysis of 2,6-dimethoxyphenol and displayed antioxidant and anticancer activity, and is considered a potential drug candidate. Thus, this study aimed to evaluate the anti-leishmanial effect of TMBP against promastigote and amastigote forms of Leishmania (L.) amazonensis and investigated the mechanisms involved in parasite death. TMBP treatment inhibited the proliferation (IC50 0.62-0.86 µM) and induced the death of promastigote forms by generating reactive oxygen species and mitochondrial dysfunction. In intracellular amastigotes, TMBP reduced the percentage of infected macrophages, being 62.7 times more selective to the parasite (CC50 53.93 µM). TMBP did not hemolyze sheep erythrocytes; indicative of low cytotoxicity. Additionally, molecular docking analysis on two enzyme targets of L. amazonensis: trypanothione reductase (TR) and leishmanolysin (Gp63), suggested that the hydroxyl group could be a pharmacophoric group due to its binding affinity by hydrogen bonds with residues at the active site of both enzymes. TMBP was more selective to the Gp63 target than TR. This is the first report that TMBP is a promising compound to act as an anti-leishmanial agent.

Assuntos

Antiprotozoários , Leishmania mexicana , Leishmania , Animais , Ovinos , Camundongos , Simulação de Acoplamento Molecular , Antiprotozoários/farmacologia , Antiprotozoários/química , Camundongos Endogâmicos BALB C

RESUMO

Obesity is associated with other diseases such as diabetes and cancer. Botryosphaeran, a fungal (1→3)(1→6)-ß-d-glucan, is described to present antimutagenic, hypoglycemic, hypocholesterolemic, and antitumor activities when administered by gavage over 15 days in rats and mice. Thus, the present study aims to analyze the metabolic effects of Botryosphaeran (12 mg/kg body weight/day) treatment over 30 days in obese Wistar male rats. Obesity was induced in the rats by a high-fat/high-sugar diet for 8 weeks. Control rats received a standard diet. On the 5th week, Botryosphaeran treatment commenced. Groups: control, obese, and obese+Botryosphaeran 30 days. In the 8th week, obesity was characterized. Feed intake, glucose and lipid profiles, glucose tolerance, and insulin sensitivity were analyzed. Obese rats showed accumulation of visceral adipose tissue, reduction of muscle mass, glucose intolerance, insulin resistance, hyperglycemia, and dyslipidemia. Botryosphaeran effectively reduced weight gains and the accumulation of retroperitoneal adipose tissue, corrected the levels of glucose, triglycerides, and very low-density lipoprotein-cholestrol, and improved insulin sensitivity. Treatment for 30 days was effective in maintaining the beneficial effects demonstrated by this ß-glucan when administered for 15 days without promoting side effects. Treatment with (1→3)(1→6)-ß- d-glucan presented anti-obesogenic and beneficial metabolic effects in Wistar rats; important for the treatment of obesity and its comorbidities.

Assuntos

Resistência à Insulina , beta-Glucanas , Animais , Glicemia , Dieta Hiperlipídica , Glucanos/farmacologia , Glucose , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Insulina , Lipoproteínas LDL , Masculino , Camundongos , Obesidade/metabolismo , Ratos , Ratos Wistar , Açúcares , Triglicerídeos/metabolismo , beta-Glucanas/farmacologia

RESUMO

Several biological activities of the fungal exopolysaccharide (1 → 3)(1 → 6)-ß-d-glucan (botryosphaeran) have been described in the literature, but its effects on inflammation have not been evaluated. This study aimed to investigate the action of botryosphaeran on experimental mice models of carrageenan-induced acute pleurisy and acute paw edema, and complete Freund's adjuvant-induced persistent paw edema. All botryosphaeran doses tested (1.0, 2.5, 5.0, and 10.0 mg/kg birth weight [b.w.], orally administered) reduced leukocyte recruitment, nitric oxide (NO) levels, and protein extravasation in the pleural cavity. Botryosphaeran (5 mg/kg b.w.) did not diminish edema and mechanical hyperalgesia in the paw within 4 h; however, cold allodynia was alleviated within the first 2 h. In the persistent paw inflammation model, the effects of daily oral administration of botryosphaeran (5 mg/kg b.w.) were evaluated over 3 and 7 days. The fungal ß-glucan significantly reduced the levels of the cytokines, tumor necrosis factor(TNF)-α, interleukin (IL)-6), and IL-10, in the paw homogenates in both protocols, while paw edema and the levels of advanced oxidation protein products (AOPP) only diminished on Day 7. No effect in mechanical hyperalgesia was observed. Oral treatment for 3 or 7 days also decreased the plasma levels of NO, AOPP, TNF-α, and IL-10. On Day 7, the number of leukocytes in the blood was also reduced by this treatment. Importantly, botryosphaeran did not induce inflammation in mice when administered alone over 7 days. This study demonstrated the anti-inflammatory and antinociceptive potential of botryosphaeran in these experimental models, making this fungal ß-glucan a new possibility for complementary treating acute and chronic inflammation.

Assuntos

Hiperalgesia , beta-Glucanas , Administração Oral , Produtos da Oxidação Avançada de Proteínas/metabolismo , Animais , Edema/induzido quimicamente , Edema/tratamento farmacológico , Edema/patologia , Glucanos/efeitos adversos , Glucanos/farmacologia , Glucanos/uso terapêutico , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Interleucina-10 , Leucócitos/patologia , Camundongos , Nociceptividade , beta-Glucanas/efeitos adversos , beta-Glucanas/farmacologia , beta-Glucanas/uso terapêutico

RESUMO

Breast cancer is the most common cancer worldwide among the female population. The fungal exopolysaccharide botryosphaeran is a (1→3)(1→6)-ß-D-glucan with limited solubility in water that can be promoted through carboxymethylation. Thus, the aim of this study was to examine in-vitro anticancer effects of carboxymethylated-botryosphaeran (CM-BOT) on breast cancer MCF-7 cells cultivated in multicellular tumor spheroids (MCTS). CM-BOT (≥ 600 µ/ml) decreased the viability (resazurin assay) of MCF-7 grown in monolayers after 24 hr incubation. Although CM-BOT did not markedly alter viability of MCTS in the resazurin assay after 24, 48 or 72 hr, CM-BOT ≥ 600 µg/ml produced cell-death by apoptosis after 72 hr utilizing the triple staining assay and labeling dead cells with propidium iodide, which can also be visualized on the architecture of MCTS. CM-BOT (1000 µg/ml) inhibited cell proliferation, which resulted in MCTSs with smaller diameters than controls. CM-BOT at all concentrations examined decreased the ability of MCF-7 to form colonies and to migrate in the extracellular matrix. This is the first report using MCTS-architecture to study anti-tumor effects of ß-glucans. Our findings are important in the search for compounds for use in breast cancer therapy, or as adjuvants in reducing the adverse effects of mammary tumor chemotherapy.

Assuntos

Neoplasias da Mama , Neoplasias da Mama/tratamento farmacológico , Feminino , Glucanos/farmacologia , Glucanos/uso terapêutico , Humanos , Células MCF-7 , Esferoides Celulares

RESUMO

The oxidation process of 2,6-dimethoxyphenol (2,6-DMP) by laccase from Botryosphaeria rhodina MAMB-05 and the corresponding enzyme-mediator systems was studied using cyclic voltammetry (CV). The enzyme was classified as a high oxidation potential laccase (> 0.70) V vs. NHE) based on its Redox potential at different pHs. The cyclic voltammograms for 2,6-DMP (- 58.7 mV pH-1) showed that its oxidation potential decreased more significantly compared to the enzyme (- 50.2 mV pH-1) by varying the pH. The 2,2'-azino-bis[3-ethyl-benzothiazoline-6-sulfonic acid] diammonium salt (ABTS) and 2,2,6,6-tetramethylpiperidine 1-oxyl radical (TEMPO) mediators were effectively oxidized by laccase from B. rhodina MAMB-05. The influence of laccase on the comproportionation of ABTS and the ionic step of the oxidation of TEMPO was also studied using CV. A higher potential difference was observed between laccase and the substrate, and correlated with higher enzyme activity. For the laccase-mediator systems, there was no clear correlation of potential difference between laccase and mediators with enzyme activity towards 2,6-DMP. This observation suggests that there are other limiting parameters for enzyme activity despite Redox potential difference, especially during ionic steps of the mechanism.

Assuntos

Elétrons , Lacase , Benzotiazóis , Catálise , Lacase/metabolismo , Oxirredução , Pirogalol/análogos & derivados , Ácidos Sulfônicos

RESUMO

The infection of mammalian cells by enveloped viruses is triggered by the interaction of viral envelope glycoproteins with the glycosaminoglycan, heparan sulfate. By mimicking this carbohydrate, some anionic polysaccharides can block this interaction and inhibit viral entry and infection. As heparan sulfate carries both carboxyl and sulfate groups, this work focused on the derivatization of a (1→3)(1→6)-ß-D-glucan, botryosphaeran, with these negatively-charged groups in an attempt to improve its antiviral activity. Carboxyl and sulfonate groups were introduced by carboxymethylation and sulfonylation reactions, respectively. Three derivatives with the same degree of carboxymethylation (0.9) and different degrees of sulfonation (0.1; 0.2; 0.4) were obtained. All derivatives were chemically characterized and evaluated for their antiviral activity against herpes (HSV-1, strains KOS and AR) and dengue (DENV-2) viruses. Carboxymethylated botryosphaeran did not inhibit the viruses, while all sulfonated-carboxymethylated derivatives were able to inhibit HSV-1. DENV-2 was inhibited only by one of these derivatives with an intermediate degree of sulfonation (0.2), demonstrating that the dengue virus is more resistant to anionic ß-D-glucans than the Herpes simplex virus. By comparison with a previous study on the antiviral activity of sulfonated botryosphaerans, we conclude that the presence of carboxymethyl groups might have a detrimental effect on antiviral activity.

Assuntos

Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Herpesviridae/efeitos dos fármacos , Ácidos Sulfônicos/química , beta-Glucanas/química , Animais , Antivirais/química , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Vírus da Dengue/fisiologia , Glucanos/química , Glucanos/farmacologia , Herpesviridae/fisiologia , Metilação , Células Vero , Internalização do Vírus/efeitos dos fármacos , beta-Glucanas/farmacologia

RESUMO

A hydrogel containing exocellular (1 → 6)-ß-D-glucan (lasiodiplodan, LAS) was developed and its wound healing potential was evaluated. ß-Glucans have attracted much interest by the cosmetic industry sector because of their bioactive and functional properties and in promoting skin health. In the present work an ß-glucan was studied as a healing biomaterial that has not hitherto been reported in the scientific literature. LAS produced by the ascomycete Lasiodiplodia theobromae MMPI was used in the formulation of a healing hydrogel. Physicochemical and microbiological quality parameters, antioxidant potential and stability of the formulation was evaluated. FTIR, thermal analysis and SEM techniques were also employed in the characterization. Wistar rats were used as a biological model to investigate the wound healing potential. Histological analyses of cutaneous tissue from the dorsal region were conducted after 4, 7, 10 and 14 days of treatment, and evaluated re-epithelialization, cell proliferation and collagen production. Physicochemical stability, microbiological quality and antioxidant potential, especially in relation to its ability to scavenge hydroxyl radicals were found. The hydrogel stimulated cell re-epithelialization and proliferation during all days of the treatment, and stimulated an increase of collagen fibers. Lasiodiplodan showed immunomodulatory activity in wound healing and this biomacromolecule could be an alternative compound in wound care.

Assuntos

Colágeno/química , Glucanos/química , Hidrogéis/química , Hidrogéis/farmacologia , Polissacarídeos/química , Cicatrização/efeitos dos fármacos , Animais , Ratos

RESUMO

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Factors increasing the risks for CVD development are related to obesity, diabetes, high blood cholesterol, high blood pressure and lifestyle. CVD risk factors may be treated with appropriate drugs, but prolonged can use cause undesirable side-effects. Among the natural products used in complementary and alternative medicines, are the ß-ᴅ-glucans; biopolymers found in foods (cereals, mushrooms), and can easily be produced by microbial fermentation. Independent of source, ß-glucans of the mixed-linked types [(1 → 3)(1 → 6)-ß-ᴅ-glucans - fungal, and (1 → 3)(1 → 4)-ß-ᴅ-glucans - cereal] have widely been studied because of their biological activities, and have demonstrated cardiovascular protective effects. In this review, we discuss the roles of ß-ᴅ-glucans in various pathophysiological conditions that lead to CVDs including obesity, dyslipidemia, hyperglycemia, oxidative stress, hypertension, atherosclerosis and stroke. The ß-glucans from all of the sources cited demonstrated potential hypoglycemic, hypocholesterolemic and anti-obesogenicity activities, reduced hypertension and ameliorated the atherosclerosis condition. More recently, ß-glucans are recognized as possessing prebiotic properties that modulate the gut microbiome and impact on the health benefits including cardiovascular. Overall, all the studies investigated unequivocally demonstrated the dietary benefits of consuming ß-glucans regardless of source, thus constituting a promising panaceutical approach to reduce CVD risk factors.

Assuntos

Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/prevenção & controle , beta-Glucanas/farmacologia , beta-Glucanas/uso terapêutico , Animais , Fármacos Antiobesidade/farmacologia , Fármacos Antiobesidade/uso terapêutico , Anticolesterolemiantes/farmacologia , Anticolesterolemiantes/uso terapêutico , Fermentação/efeitos dos fármacos , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico

RESUMO

A photoelectrochemical biosensing strategy for the highly sensitive detection of the flavonoid rutin was developed by synergizing the photoelectrocatalytic properties of hematite (α-Fe2O3) decorated with palladium nanoparticles (PdNPs) and the biocatalysis towards laccase-based reactions. The integration of α-Fe2O3.PdNPs with a polyphenol oxidase as a biorecognition element yields a novel biosensing platform. Under visible light irradiation, the photoactive biocomposite can generate a stable photocurrent, which was found to be directly dependent upon the concentration of rutin. Under the optimal experimental conditions, the cathodic photocurrent, measured at 0.33 V vs. Ag/AgCl, from the square-wave voltammograms presented a linear dependence on the rutin concentration within the range of 0.008-30.0 × 10-8 mol L-1 (sensitivity: 1.7 µA·(× 10-8 M-1)·cm-2), with an experimental detection limit (S/N = 3) of 8.4 × 10-11 mol L-1. The proposed biosensor device presented good selectivity towards rutin in the presence of various organic compounds and inorganic ions, demonstrating the potential application of this biosensing platform in complex matrices. This bioanalytical device also exhibited excellent operational and analytical properties, such as intra-day (standard deviation, SD = 0.21%) and inter-day (SD = 1.30%) repeatability, and long storage stability (SD = 2.80% over 30 days).Graphical abstract.

Assuntos

Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Compostos Férricos/química , Rutina/urina , Adulto , Enzimas Imobilizadas/química , Compostos Férricos/efeitos da radiação , Humanos , Lacase/química , Luz , Limite de Detecção , Masculino , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Paládio/química , Paládio/efeitos da radiação , Processos Fotoquímicos , Chá/química , Vinho/análise , Adulto Jovem

RESUMO

Studies demonstrate that obesity can increase tumor development. Botryosphaeran, a fungal (1→3)(1→6)-ß-D-glucan, presents antimutagenic, antiproliferative and pro-apoptotic activities. This study evaluated the effects of botryosphaeran on tumor development and metabolic and hematological parameters in tumor-bearing obese and non-obese rats. Obesity was induced by a high-fat and high-sugar diet, while control rats received standard diet and water without sugar for 10 weeks. On 8th-week, Walker-256 tumor cells were inoculated in the rats, and treatment with botryosphaeran (12 mg/Kg b.w.) started. Groups:control tumor-CT, control tumor botryosphaeran-CTB, obese tumor-OT and obese tumor botryosphaeran-OTB. On 10th-week, tumor development, cachexia, metabolic and hematological parameters were analyzed. Tumor development and cachexia were significantly higher in the OT group compared to the CT group, and botryosphaeran attenuated these parameters. OT rats presented accumulation of adipose tissue, reduced muscle mass, glucose intolerance, insulin resistance, hyperglycemia, anemia, leukocytosis, and thrombocytopenia. Botryosphaeran corrected insulin resistance and hyperglycemia, modulated cholesterol levels, and increased leukocyte and lymphocytes in obese rats, which can be attributable to an inflammatory response against the Walker-256 tumor, contributing to a lower tumor development. Our data demonstrated that botryosphaeran was effective in attenuating tumor growth and in improving the metabolic and hematological profiles of the tumor-bearing rats, demonstrating its potential role in the cancer's management.

Assuntos

Caquexia , Neoplasias , Animais , Caquexia/etiologia , Caquexia/prevenção & controle , Glucanos , Obesidade/complicações , Ratos , Ratos Wistar

RESUMO

Surface-enhanced Raman spectroscopy (SERS) became a useful analytical technique with the development of appropriate metallic substrates. The need for SERS substrates that immobilize metallic nanoparticles prompted this work to search for an appropriate material. This work presents the preparation, characterization and application of a SERS substrate for crystal violet (CV) detection, as the probe molecule. The inner layer of the substrate is a thin film of the fungal ß-D-glucan, botryosphaeran, covered by a thin layer of silver nanoparticles (AgNPs). The nanoparticles were produced by laser ablation, a fast and clean method for their preparation, and the layers were assembled by casting. Scanning electron and atomic force microscopies, UV-VIS and Raman spectroscopy and X-ray diffraction allowed the characterization of the surface of the substrate. Analysis by Raman spectroscopy showed promising results for SERS amplification on the substrate. Detection of CV reached enhancement factors up to 106 orders of magnitude, compared to normal Raman spectra. Linearity was observed for analyses on the SERS substrate at concentration ranges of 0.005 to 1 µmol L-1. The assembly reached the detection of 12 pmol cm-2 of CV, which corresponds to 96 fg of the probe molecule contained in the area of the substrate effectively interacting with the laser. The substrate was more efficient than silver colloids to perform SERS.

Assuntos

Nanopartículas Metálicas , Análise Espectral Raman , Violeta Genciana , Polissacarídeos , Prata

RESUMO

Obesity is an important risk factor in tumor development. Botryosphaeran, a (1 â†’ 3)(1 â†’ 6)-ß-D-glucan, produced by the fungus Botryosphaeria rhodina (MAMB-05), is a high molecular mass, water-soluble exopolysaccharide. It consists of a main chain of (1 â†’ 3)-linked ß-d-glucose units, with a degree of branching of ~22% at carbon-6 with glucose and gentiobiose residues linked through ß-(1 â†’ 6)-bonds, and presents a triple helix conformation. Botryosphaeran presents anticlastogenic, antiproliferative, pro-apoptotic and anti-obesogenic activities. This study evaluated the effects of botryosphaeran on tumor development in obesity and analyzed its mechanism of action. Obesity was induced in male Wistar rats by a high-fat/high-sugar diet. After 9 weeks, rats were divided into two groups: Obese Tumor (OT) and Obese Tumor Botryosphaeran (OTB), and inoculated with 1 × 107 Walker-256 tumor cells, and treatment with botryosphaeran (30 mg/kg b.w./day via gavage for 15 days) commenced. On the 11th week, biological parameters, tumor development, metabolic profile, erythrogram and protein expression were evaluated. Botryosphaeran significantly reduced tumor growth, body-weight loss and cachexia. Furthermore, botryosphaeran decreased mesenteric fat and insulin resistance, corrected macrocytic anemia, and increased Forkhead transcription factor-3a (FOXO3a) activity. Our study demonstrated the potential role of botryosphaeran in the management of cancer in tumor-bearing obese rats by increasing insulin sensitivity and FOXO3a activity.

Assuntos

Caquexia/tratamento farmacológico , Glucanos/farmacologia , Neoplasias/tratamento farmacológico , Obesidade/tratamento farmacológico , Animais , Ascomicetos/química , Caquexia/etiologia , Caquexia/genética , Caquexia/patologia , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Proteína Forkhead Box O3/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glucanos/química , Glucose/metabolismo , Humanos , Insulina/genética , Resistência à Insulina/genética , Masculino , Neoplasias/etiologia , Neoplasias/genética , Neoplasias/patologia , Obesidade/complicações , Obesidade/genética , Obesidade/patologia , Ratos

RESUMO

Laccase from Botryosphaeria rhodina MAMB-05 was covalently immobilized on carboxymethyl-botryosphaeran by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) in aqueous solution. This approach was employed to fabricate a novel laccase-based biosensor to electrochemically quantify quercetin (QCT), using a simple carbon black paste electrode as a transducer. The proposed biosensor was characterized by electrochemical impedance spectroscopy and Nyquist plots were used to evaluate the immobilization of the enzyme. For determining QCT, variables were optimized, that included experimental conditions for laccase immobilization, pH of the supporting electrolyte, and instrumental parameters of the electroanalytical technique. From square-wave-voltammograms, a linear dependence between the cathodic current peak and QCT concentration was observed within the range 4.98-50.0 × 10-8 mol L-1, with a theoretical detection limit of 2.6 × 10-8 mol L-1. The proposed method was successfully applied to determine QCT in beverages, pharmaceuticals, and biological samples. The proposed biosensor device presented good selectivity in the presence of uric acid, various inorganic ions, as well as other phenolic compounds, demonstrating the potential application of this biosensing platform in chemically complex solutions. Operational and analytical stability of the laccase-biosensor were evaluated, and good intra-day (SD = 1.23%) and inter-day (SD = 2.32%) repeatability, and long storage stability (SD = 3.47%) are presented.

Assuntos

Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Glucanos/química , Lacase/química , Quercetina/análise , Limite de Detecção , Soluções , Água/química

RESUMO

AIMS: Cancer is a multifactorial disease characterized by an uncontrolled growth of cells that can lead to cachexia-anorexia syndrome. Botryosphaeran, a fungal (1 â†’ 3)(1 â†’ 6)-ß-D-glucan produced by Botryosphaeria rhodina MAMB-05, has presented antimutagenic, antiproliferative, pro-apoptotic, hypoglycemic and hypocholesterolemic effects. This study evaluated the effects of botryosphaeran (30 mg/kg b.w./day) on tumor development and cachexia syndrome in Walker-256 tumor-bearing rats, and also the metabolic and hematological profiles of these animals. MATERIALS AND METHODS: Male Wistar rats were divided into 3 groups: control (C), control tumor (CT) and control tumor botryosphaeran (CTB). On the first day, 1 × 107 Walker-256 tumor cells were inoculated subcutaneously into the right flank of the CT and CTB rats, and concomitantly treatment with botryosphaeran (30 mg/kg b.w./day) started. After the 15th day of treatment, biological parameters, tumor development, cachexia, glucose and lipid profiles, hemogram and protein expression were analyzed. KEY FINDINGS: Botryosphaeran significantly reduced tumor development (p = 0.0024) and cancer cachexia, modulated the levels of glucose, triglycerides and HDL-cholesterol, and corrected macrocytic anemia. Botryosphaeran also increased significantly the bax expression in the tumor tissue (p = 0.038) demonstrating that this (1 â†’ 3)(1 â†’ 6)-ß-D-glucan is increasing the apoptosis of tumor cells. p53, p27, bcl-2, caspase-3 and Forkhead transcription factor 3a (FOXO3a) protein expression were similar among the groups. SIGNIFICANCE: This study demonstrated that botryosphaeran was effective in decreasing tumor development and cachexia by direct and indirect mechanisms increasing apoptosis and improving the metabolic and hematological profiles.

Assuntos

Apoptose/efeitos dos fármacos , Caquexia/tratamento farmacológico , Carcinoma 256 de Walker/tratamento farmacológico , Glucanos/administração & dosagem , Animais , Caquexia/etiologia , Carcinoma 256 de Walker/patologia , Glucanos/farmacologia , Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Ensaios Antitumorais Modelo de Xenoenxerto

RESUMO

Laccase was immobilized on a glassy carbon electrode layered with multi-walled carbon nanotubes using a film of botryosphaeran, a fungal (1 → 3)(1 → 6)-ß-D-glucan. This novel biosensing platform was characterized by electrochemical impedance spectroscopy and scanning electron microscopy, and applied for the determination of dopamine. Experimental variables such as enzyme concentration, pH value and operational parameters of the electroanalytical technique were optimized. Using square-wave voltammetry, there was a linear dependence of peak current and dopamine concentration within the range of 2.99-38.5 µmol L-1 with a limit of detection of 0.127 µmol L-1. The biosensor was successfully applied in the determination of dopamine in pharmaceutical injection and synthetic biological samples, and presented good selectivity even in the presence of uric acid and ascorbic acid, as well as other phenolic compounds. The different aspects regarding the operational stability of the laccase biosensor were evaluated, demonstrating good intra-day and inter-day repeatability, and long-storage stability. Furthermore, this biosensor was evaluated in the indirect determination of spironolactone by using the analytical signal of dopamine, presenting a limit of detection of 0.94 µmol L-1. The results obtained in the analysis of spironolactone in commercial pharmaceutical samples were satisfactory.

Assuntos

Técnicas Biossensoriais/métodos , Dopamina/análise , Glucanos/química , Lacase/química , Espironolactona/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Enzimas Imobilizadas/química , Limite de Detecção , Nanotubos de Carbono/química

RESUMO

Sulfated polysaccharides are known to display activity against enveloped viruses, such as herpes and dengue. The aim of this work was to assess the antiviral activity of botryosphaeran, a fungal exocellular (1 → 3)(1 → 6)-ß-d-glucan devoid of sulfate groups, and its chemically sulfonated derivatives, against herpes simplex virus (HSV), dengue virus (DENV) and poliovirus (PV). The natural parent polysaccharide inhibited acyclovir-sensitive HSV (HSV-KOS) infection in Vero cells (IC50 of 39.3 µg mL-1), while the IC50 against acyclovir-resistant HSV (HSV-AR) was 47.5 µg mL-1. Botryosphaeran was derivatized by sulfonylation with chlorosulfonic acid to prepare two sulfonated derivatives, S1 and S2, with degrees of substitution (DS) of 0.4 and 1.1, respectively. Antiviral evaluation of S1 and S2 gave the IC50 of 3.0 and 2.4 µg mL-1 against HSV-KOS, and 7.3 and 2.7 µg mL-1 against HSV-AR, respectively. This study demonstrated for the first time that native botryosphaeran inhibited HSV infection, albeit moderately, while its sulfonated derivatives developed high activity against viral infection. DENV inhibition was weak for botryosphaeran, but remarkably stronger for S1 and S2. All compounds were inactive against PV, as it lacked a viral envelope. The presence of sulfate groups and the DS were confirmed to be important features for antiviral activity.

Assuntos

Antivirais/química , Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Glucanos/química , Glucanos/farmacologia , Simplexvirus/efeitos dos fármacos , Ácidos Sulfônicos/química , Animais , Chlorocebus aethiops , Poliovirus/efeitos dos fármacos , Células Vero

RESUMO

The present study reports on the remediation of an effluent from the wood-laminate industry using Pleurotus ostreatus EB 016 in combination with photo-Fenton oxidation. Fermentation of the effluent with P. ostreatus EB-016 was carried out in agitated flasks to evaluate the influence of pH, and concentrations of carbon and nitrogen sources by a multivariate approach. Subsequently, bioassays was conducted in an air-lift bioreactor using the pre-optimized conditions. In addition, photo-Fenton oxidative treatment was employed to degrade recalcitrant compounds, and the ecotoxicity of the effluents were evaluated using Escherichia coli as a biological model. The crude effluent presented high contents of total phenolics (1,220 mg/L), solids (18.45 g/L) and color intensity (8,333 CU), besides high values of chemical (COD 2,477 mg O2./L) and biochemical (BOD5, 8,450 mg O2/L) oxygen demand. Another feature was the high inhibition on Escherichia coli (71%). Reduction of 64% COD was obtained under optimized conditions (pH5.7, 7.5 g/L sucrose, 4.0 g/L ammonium nitrate) in agitated flasks after 10 days treatment. In the air-lift reactor, 50.6% COD and 29.9% total phenols were removed after 10 days. Combination of biotreatment with photo-Fenton oxidation resulted in removal of 99.2% COD and 92.2% phenolics and absence of inhibition on Escherichia coli.

Assuntos

Reatores Biológicos/microbiologia , Peróxido de Hidrogênio/química , Resíduos Industriais/análise , Ferro/química , Indústria Manufatureira , Pleurotus/crescimento & desenvolvimento , Eliminação de Resíduos Líquidos/métodos , Madeira/química , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Oxirredução

RESUMO

In this study, (1→3)(1→6)-ß-D-glucan (botryosphaeran) from Botryosphaeria rhodina MAMB-05 was used, for the first time, to immobilize laccase on a carbon black paste electrode modified with gold nanoparticles. The physicochemical characterization of the proposed laccase-biosensor was performed using transmission electron microscopy and electrochemical impedance spectroscopy. The performance of this novel bio-device was evaluated by choosing hydroquinone as a typical model of a phenolic compound. For hydroquinone determination, experimental variables such as enzyme concentration, pH and operational parameters of the electroanalytical technique were optimized. From square-wave voltammograms, a linear dependence between the cathodic current peak and the hydroquinone concentration was observed within the range 2.00-56.5µmolL-1, with a theoretical detection limit of 0.474µmolL-1. The proposed method was successfully applied to determine hydroquinone in dermatological cream, and samples from biological and environmental niches. The proposed biosensor device presented good selectivity in the presence of uric acid, various inorganic ions, as well as other phenolic compounds, demonstrating the potential application of this biosensing platform in complex matrices. Operational and analytical stability of the laccase biosensor were evaluated, and demonstrated good intra-day (SD=0.3%) and inter-day (SD=3.4%) repeatability and long storage stability (SD=4.9%).

Assuntos

Ascomicetos/enzimologia , Técnicas Biossensoriais/métodos , Enzimas Imobilizadas/química , Glucanos/química , Hidroquinonas/análise , Lacase/química , Fuligem/química , Técnicas Biossensoriais/instrumentação , Estabilidade Enzimática , Desenho de Equipamento , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química

RESUMO

The ascomycetous fungus, Botryosphaeria rhodina MAMB-05, secretes a (1→3)(1→6)-ß-D-glucan, and the scaled-up production of this ß-glucan results in large amounts of mycelial biomass being produced that represent a potentially cost-effective biosorbent for rare-earth elements. High sorption capacities for both La(III) and Sm(III) were demonstrated for viable and autoclaved lyophilized fungal mycelium. Fourier-transformed infra-red absorption spectra and the point of zero charge (PZC) were similar for the viable and inactive fungal mycelia. The rare-earth lanthanide elements (La and Sm) binding increased at initial pH values greater than 5.0, which was also observed for the PZC determination. The maximum La(III) uptake capacity was observed at lower amounts of La(III) ions in solution, decreasing from 100.0 to 25.3% when the initial lanthanide concentration increased from 15 to 100 mg/L. Lanthanide biosorption by B. rhodina MAMB-05 mycelia followed the Langmuir model, and the affinity of biosorbent functional groups was similar for La(III) and Sm(III).

Assuntos

Ascomicetos/metabolismo , Lantânio/metabolismo , Samário/metabolismo , Adsorção , Ascomicetos/química , Ascomicetos/crescimento & desenvolvimento , Biodegradação Ambiental , Biomassa , Concentração de Íons de Hidrogênio , Lantânio/química , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Samário/química

RESUMO

Sulfonated derivatives of lasiodiplodan (LAS-S) with different degrees of substitution (1.61, 1.42, 1.02 and 0.15) were obtained and characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal and solubility analyses. Antimicrobial, antioxidant and cytotoxic potential were also assessed. The sulfonation was confirmed by FTIR analysis with specific bands at 1250 cm-1 (S=O, strong asymmetrical stretching vibration) and at 810 cm-1 (C-O-S, symmetrical vibration associated with the C-O-SO3 group) in the sulfonated samples. SEM demonstrated that sulfonation promoted morphological changes on the surface of the biopolymer with heterogeneous fibrillary structures appearing along the surface following chemical modification. LAS-S showed high thermal stability, with mass loss due to oxidation at temperatures close to 460 °C. Sulfonation increased the solubility of LAS, and in addition, increased the antimicrobial activity, especially against Candida albicans (fungicidal) and Salmonella enterica Typhimurium (bacteriostatic). Native lasiodiplodan (LAS-N) showed higher OH˙ removal capacity, while LAS-S had higher ferric ion reducing antioxidant power (FRAP) potential. LAS-N and LAS-S did not demonstrate lethal cytotoxicity against wild and mutant strains of Saccharomyces cerevisiae. Samples with higher degree of substitution (1.42 and 1.61) showed lower potential to induce oxidative stress.