Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Int J Pharm ; 639: 122965, 2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37084836

RESUMO

Ivermectin (IVM) is a potent antiparasitic widely used in human and veterinary medicine. However, the low oral bioavailability of IVM restricts its therapeutic potential in many parasitic infections, highlighting the need for novel formulation approaches. In this study, poly(ε-caprolactone) (PCL) nanocapsules containing IVM were successfully developed using the nanoprecipitation method. Pumpkin seed oil (PSO) was used as an oily core in the developed nanocapsules. Previously, PSO was chemically analyzed by headspace solid-phase microextraction coupled to gas chromatography/mass spectrometry (HS-SPME/GC-MS). The solubility of IVM in PSO was found to be 4266.5 ± 38.6 µg/mL. In addition, the partition coefficient of IVM in PSO/water presented a logP of 2.44. A number of nanocapsule batches were produced by factorial design resulting in an optimized formulation. Negatively charged nanocapsules measuring around 400 nm demonstrated unimodal size distribution, and presented regular spherical morphology under transmission electron microscopy. High encapsulation efficiency (98-100%) was determined by HPLC. IVM-loaded capsules were found to be stable in nanosuspensions at 4 °C and 25 °C, with no significant variations in particle size observed over a period of 150 days. Nanoencapsulated IVM (0.3 mM) presented reduced toxicity to J774 macrophages and L929 fibroblasts compared to free IVM. Moreover, IVM-loaded nanocapsules also demonstrated enhanced in vitro anthelmintic activity against Strongyloides venezuelensis in comparison to free IVM. Collectively, the present findings demonstrate the promising potential of PCL-PSO nanocapsules to improve the antiparasitic effects exerted by IVM.


Assuntos
Ivermectina , Nanocápsulas , Humanos , Ivermectina/farmacologia , Ivermectina/química , Antiparasitários/farmacologia , Antiparasitários/química , Nanocápsulas/química , Polímeros , Poliésteres/química
2.
Carbohydr Polym ; 273: 118613, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34561011

RESUMO

Levan is a high-valued polysaccharide of fructose produced by several microbial species. These polysaccharides have been described as effective therapeutic agents in some human disease conditions, such as cancer, heart diseases and diabetes. The objective of this study was to examine the effect of levan (ß-(2 â†’ 6)-fructan) produced through sucrose fermentation by B. subtilis var. natto on the proliferation rate, cytotoxicity, and apoptosis of human neuroblastoma SH-SY5Y cells. It was obtained 41.44 g/L of levan in 18 h by biotechnological fermentation and SH-SY5Y cells were exposed to 1000 µg/mL of levan. The treatment with 1000 µg/mL of levan induced apoptosis in SH-SY5Y cancer cells by the significant increase in Annexin V/7-AAD and caspase 3/7 activation, but did not decrease proliferation or triggered a cytotoxic effect. 1000 µg/mL levan treatment is a promising therapeutic strategy for SH-SY5Y neuroblastoma cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Bacillus subtilis/metabolismo , Frutanos/farmacologia , Antineoplásicos/química , Antineoplásicos/metabolismo , Caspase 3/metabolismo , Caspase 7/metabolismo , Linhagem Celular Tumoral , Frutanos/biossíntese , Frutanos/química , Humanos
3.
Appl Biochem Biotechnol ; 193(5): 1585-1601, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33507495

RESUMO

This study evaluated the bioproduction of 1,3-propanediol by Lactobacillus diolivorans in the medium based on agro-industrial residues and vegetal biomass substituting the MRS medium components. It was performed on a set of acid treatments and batch fermentations assays with crude glycerol (TCG) from biodiesel production, corn steep liquor (CSL), and cactus cladode hydrolyzate (CCH). Firstly, it was carried out on batch fermentation with different pure glycerol concentrations in MRS medium which was carried out, and the best condition achieved 4.66 g/L and 0.61 g/g of 1,3-PDO production and yield, respectively. Then, the TCG was evaluated, and a discrete increase of 1,3-PDO was observed. The replacement of the MRS medium nutrients by CLS was assessed, at different concentrations, for bacteria growth, and 5% of CLS reproduced the same biomass formation compared to the bacteria growth in MRS medium. It was also added cactus cladode hydrolyzate as the only sugar source, which showed a 1,3-PDO production close to the medium with pure glucose. Finally, a B-complex vitamin was added to the batch fermentation medium composed of TCG, CLS, and CCH, replacing all the costly MRS components. In this medium, the production of 1,3-propanediol was 6.57 g/L with a yield of 0.75 g/g. It means an increment of 29% and 19%, respectively, compared to MRS medium. Therefore, the combination of treated crude glycerol, corn steep liquor, and cactus cladode hydrolyzate has excellent potential for 1,3-PDO production by L. diolivorans.


Assuntos
Cactaceae/metabolismo , Lactobacillus/metabolismo , Propilenoglicóis/metabolismo , Fermentação/fisiologia , Glicerol/metabolismo , Microbiologia Industrial
4.
Int J Pharm ; 580: 119242, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32199961

RESUMO

Bacterial levan is a fructose homopolymer that offers great potential in biotechnological applications due to biocompatibility, biodegradability and non-toxicity. This biopolymer possesses diverse multifunctional features, which translates into a wide range of applicability, including in industry, consumer products, pharmaceuticals and biomedicine. Extensive research has identified great potential for its exploitation in human health. In addition, nanostructured systems have provided significant advances in the area of health, mainly with respect to disease diagnosis and treatment. While the functional properties of these natural polysaccharide-based polymers are desirable in these systems, research in this area has been limited to few natural polymers, such as chitosan, alginate and dextran, which obscures the true potential of levan in the production of nanostructured systems for biotechnological and medical applications. The present review considers the latest research in the field to focus on the use of levan as a promising biopolymer for the development of nanomaterials.


Assuntos
Frutanos/química , Nanoestruturas/química , Alginatos/química , Materiais Biocompatíveis/química , Biopolímeros/química , Quitosana/química , Sistemas de Liberação de Medicamentos/métodos , Humanos , Polímeros/química , Polissacarídeos/química
5.
Int J Biol Macromol ; 126: 291-297, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30583005

RESUMO

Lectins are carbohydrate-binding proteins broadly distributed in plants and have several biological functions, including antimicrobial action. Portulaca elatior is a Caatinga plant whose chemical composition and biotechnological potential have not been extensively studied. In this work, a lectin was isolated from P. elatior root extract and evaluated for antimicrobial activity. The P. elatior root lectin (PeRoL) showed native molecular mass of 33 kDa, pI 3.8 and is comprised of two subunits of 15 kDa linked by disulfide bonds. No sequence similarities with Viridiplantae proteins were observed. The PeRoL hemagglutinating activity (HA) was not affected by heating and was detected in a pH ranging from 4.0 to 8.0. Trehalose was identified as an endogenous inhibitor of PeRoL present in the roots. Bacteriostatic activity was detected against Enterococcus faecalis, Pseudomonas aeruginosa and Staphylococcus aureus (minimal inhibitory concentration of 8.1, 32.5 and 4.06 µg/mL, respectively). PeRoL induced the death of Candida albicans, Candida parapsilosis, Candida krusei, and Candida tropicalis cells, with a minimal fungicidal concentration of 16 µg/mL. The lectin (100 µg/mL) was not cytotoxic to human peripheral blood mononuclear cells (PBMCs) and did not show hemolytic activity. In conclusion, the roots of P. elatior contain a trehalose-binding, thermostable, and antimicrobial lectin.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Lectinas/farmacologia , Raízes de Plantas/química , Portulaca/química , Trealose/metabolismo , Sequência de Aminoácidos , Hemaglutinação/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Lectinas/isolamento & purificação , Peptídeos/química , Extratos Vegetais/farmacologia , Ligação Proteica
6.
Rev. Inst. Adolfo Lutz (Online) ; 73(2): 169-177, abr.-jun. 2014. graf, tab
Artigo em Português | LILACS, Sec. Est. Saúde SP | ID: lil-782600

RESUMO

As cianobactérias são responsáveis pela produção de cianotoxinas que, uma vez acumuladas, podem causar sérios danos à saúde humana e animal. As microcistinas são o tipo mais comum de cianotoxinas e são promotoras de tumores hepáticos. O reservatório de Mundaú, localizado no município de Garanhuns-PE,foi o local escolhido por apresentar histórico de florações de cianobactérias produtoras de microcistinas.Neste trabalho foi investigada a presença de microcistinas em amostras de água bruta do reservatório do rio Mundaú utilizando-se as técnicas de Enzyme Linked Immunosorbent Assay (ELISA) e Cromatografia Líquida de Alta Eficiência (CLAE). Durante quinze meses consecutivos, as amostras de água foram coletadas em duplicata no ponto de captação deste manancial e analisadas por ambas metodologias ELISAe CLAE. A presença de microcistinas foi detectada em 100 % das amostras, confirmando-se a relevância do monitoramento de microcistinas em águas de abastecimento público, pois assim como o rio Mundaú,vários mananciais de Pernambuco apresentam florações de cianobactérias que podem ser tóxicas.Este trabalho deixou como legado a implantação da referida análise no Laboratório Central de Saúde Pública (LACEN-PE), e demonstrou sua importância como metodologia complementar à contagem das cianobactérias, para fornecer subsídios às ações preventivas de vigilância à saúde...


Assuntos
Humanos , Microbiologia da Água , Cianobactérias/patogenicidade , Cromatografia Líquida/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Microcistinas , Brasil
7.
Bioresour Technol ; 99(7): 2466-70, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17604160

RESUMO

Levan, a polysaccharide from Zymomonas mobilis, was hydrolyzed to obtain oligofructans or fructooligosaccharides with a degree of polymerization varying from 4 to 14. Fructooligosaccharides (FOS) are short chain fructans that beneficially affects the host by selective stimulation of growth and activity of one or a number of bacteria including probiotic bacteria in the colon. The hydrolysis was performed in a microwave oven to shorten the reaction time. The experiments showed that it is possible to maximize selected oligomers by interrupting the hydrolysis at the due time. The results allow one to infer that the procedure may also be useful for production of oligomers from other polysaccharides.


Assuntos
Frutanos/biossíntese , Micro-Ondas , Zymomonas/metabolismo , Cromatografia em Gel , Hidrólise
8.
Rev. bras. saúde ocup ; 32(116)jul.-dez. 2007.
Artigo em Português | LILACS | ID: lil-558324

RESUMO

Neste estudo, realizou-se uma avaliação do risco ocupacional relacionado ao uso de xilol, ao qual estão expostos técnicos de oito laboratórios de citologia e anatomia patológica que atendem a população do Recife e de cidades do interior de Pernambuco. A coleta das informações deu-se por meio de questionários que podiam ser respondidos marcando-se alternativas de múltipla escolha. Deu-se destaque às informações decorrentes do uso do xilol relacionadas à saúde ocupacional e à percepção de risco na manipulação e no descarte dos rejeitos. Os resultados mostraram que a utilização de equipamentos de proteção individual e coletiva está sendo negligenciada. Dentre os entrevistados, 80% observaram mudanças na saúde após alguns anos de exposição ao xilol. Mesmo assim, apenas 6,6% deles fazem controle anual da presença de xilol no organismo pela dosagem de ácido metilhipúrico na urina. Constatou se que 76,6% dos entrevistados descartam o resíduo diretamente na pia, pois não existe um local para descarte de rejeitos. Frente aos dados encontrados, sugere-se que há necessidade de educar o trabalhador numa visão prevencionista em relação aos riscos ocupacionais e ambientais provenientes do uso deste agente químico.


In this study a diagnosis of occupational exposure related to xylol use bytechnicians in cytology and anatomic pathology was carried out in eight laboratories which care for the population of Recife and towns in the interior of the state of Pernambuco. Data were obtained by multiple choice questionnaires. Emphasis was given to information concerning occupational health and perception of risk when using xylol and disposing waste. The results showed that personal and collective protection equipment have being neglected. Eighty percent of the people interviewed had noticed changes in health after they had been exposed to xylol for some years. However, only 6.6% of them went through annual evaluation to check the presence of xylene in their organisms, by methyl hippuric acid determination in urine. It was noticed that 76.6% of the people interviewed disposed waste directly into a sink, as there was not a proper place for waste disposal. Data showed the need for workers training on a preventive view in relation to occupational and environmental risks.


Assuntos
Compostos Químicos/efeitos adversos , Laboratórios , Riscos Ocupacionais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...