Estudo da atividade de flavonóides e de complexos de vanádio na glicemia de ratos diabéticos induzidos com aloxana

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-Graduação em Farmácia.Muitas espécies de plantas são conhecidas na medicina popular pelas propriedades hipoglicemiantes e pelo uso no tratamento do diabetes. Entre as utilizadas como hipoglicemiantes estão a Bauhinia forficata e a Cyathea phalerata, denominadas popularmente como "Pata de vaca" e "Xaxim", respectivamente. Entretanto, pouco se sabe a respeito da ação medicinal e composição micromolecular destas plantas. Recentemente foram isolados compostos presentes nas frações AcOEt e n-butanol das folhas da Bauhinia forficata , entre estes o majoritário, canferol 3,7-O-(a)-L-diramnosídeo que apresentou efeito hipoglicemiante. Do caule da Cyathea phalerata também foram isolados alguns flavonóides sendo o canferol 3-O-a-L-ramnopiranosil b-D-glicopiranosídeo o composto predominante. O presente trabalho teve como objetivos estudar os compostos isolados (glicosilados ou não) da Bauhinia forficata bem como do flavonóide isolado da Cyathea phalerata na atividade hipoglicemiante em ratos diabéticos e estudar a ação dos complexos dos flavonóides canferol 3,7-O-(a)-L-diramnosídeo e canferol 3-O-a-L-ramnopiranosil b-D-glicopiranosídeo com vanádio (IV) na glicemia de animais diabéticos, bem como, comparar a biopotência destes compostos (por diferentes vias de administração) com a insulina e o vanádio. Foram utilizados ratos Wistar machos entre 50-55 dias de idade. O diabetes foi induzido com 50 mg/kg de aloxana. Nos experimentos onde foram estudados os níveis glicêmicos, as dosagens foram realizadas nos tempos de 0, 1, 2, 3, 6, e 24 h após a administração dos compostos via oral ou intraperitoneal. A insulina 0,5 UI administrada por via intraperitoneal caracterizou um perfil de redução da glicemia típico em ratos normais e diabéticos. O composto canferol não apresentou ação hipoglicêmica significativa em nenhuma das doses utilizadas. A quercetina apresentou ligeiro efeito hipoglicemiante na dose de 100 mg/kg. O canferol 3-O-a-L-ramnopiranosil b-D-glicopiranosídeo isolado da Cyathea phalerata apresentou atividade hipoglicemiante nas doses de 50 e 100 mg/kg em todos os tempos estudados, tanto por via oral quanto intraperitoneal. O canferol 3,7-O-(a)-L-diramnosídeo, isolado das folhas da Bauhinia forficata reduziu significativamente a glicemia em ratos diabéticos quando administrado por via intraperitoneal num período de 0-24 h. Os complexos de vanádio (IV) foram estudados através de tratamentos por via oral e intraperitoneal em um período de 24 h em ratos diabéticos. O complexo canferol 3,7-O-(a)-L-diramnosídeo-VO (IV) 2:1 apresentou atividade hipoglicêmica significativa apenas quando administrado pela via intraperitoneal em todos os tempos estudados. Este complexo foi tão efetivo quanto o vanádio (IV) livre e apresentou cerca de 26% de potência comparado à insulina. Já o complexo canferol 3-O-a-L-ramnopiranosil b-D-glicopiranosídeo-VO (IV) 1:1 reduziu significativamente a glicemia quando administrado pela via intraperitoneal até as 24 h. Este complexo apresentou 83% de biopotência comparado à insulina e foi mais potente que o vanádio livre, que o composto pela mesma via e mais potente que o complexo canferol 3,7-O-(a)-L-diramnosídeo-VO(IV) 2:1 neste mesmo protocolo

Effect of Garlic extract on physiological and biochemical parameters of Rhamdia quelen and their response to an infestation with Ichthyophthirius multifiliis

The aim of the study was to investigate the effect of garlic extract on hematological, immune and metabolic systems of Rhamdia quelen juveniles and the animals’s resistance to Ichthyophthirius multifiliis. The fishes were fed twice daily during 77 days with diets containing 0%, 0.5%, 2.5% and 5% of garlic extract. After that, half of the animals of each treatment were submitted to the challenge with the parasite I. multifiliis, maintaining the diets. The other half of the animals were maintained in the original system receiving the dietary supplementation. The use of garlic extract in the diet did not promote significant changes in glycaemia, hepatic glycogen content, tissue and plasma aminotransferase activities, and tissue lipid peroxidation levels. On the other hand, it stimulated the synthesis of muscle glycogen and promoted a reduction of hepatic catalase activity. In terms of hematological and immune systems, the use of garlic extract increased the number of red blood cells, but reduced hemoglobin content. Furthermore, it was not able to change the total number of leukocytes and thrombocytes, but it promoted an increase in the number of basophils and reduced the monocyte count of the animals. The dietary supplementation with garlic extract did not act as a growth promoter for silver catfish juveniles, did not influence the basal metabolic homeostasis, immune or hematological responses of the fishes and did not improve the resistance to the infestation with the I. multifiliis in the concentrations and periods studie

Presença de folhas e uso de AIB no enraizamento adventício, fluorescência da clorofila e ontogenia radicular em estacas de ‘Fepagro C 13’ e ‘Trifoliata

A estaquia é proposta como método alternativo para a propagação de porta-enxertos de citros, visando a garantia de obtenção de material clonal, especialmente em variedades com baixa taxa poliembriônica, e uma possível redução no período para a obtenção das mudas. O objetivo deste estudo foi avaliar a influência das folhas e da aplicação de ácido indolbutírico (AIB) sobre o enraizamento adventício, fluorescência da clorofila e caracterizar a ontogenia radicular em estacas dos porta-enxertos citrangeiro ‘Fepagro C 13’, e ‘Trifoliata’. Estacas semilenhosas foram coletadas em dezembro de 2018 e submetidas aos tratamentos: presença ou ausência de folhas com aplicação ou não de AIB (4000 mg L-1). Ao longo de 92 dias em casa de vegetação foram avaliados os percentuais de abscisão foliar, mortalidade de estacas, percentual de enraizamento e número de raízes por estaca. Também os dados da fluorescência inicial (Fo), máxima (Fm) e variável (Fv) da clorofila, a eficiência fotoquímica (Fv/Fm) e a razão Fv/Fo foram avaliados. Amostras de tecido da base da estaca foram coletadas para a realização do estudo anatômico. A presença das folhas nas estacas de ‘Fepagro C 13’ e ‘Trifoliata’ é essencial para o enraizamento adventício. O uso de auxina influencia a eficiência fotoquímica nas folhas das estacas. Em estacas de ‘Trifoliata’ as raízes adventícias originam-se a partir do câmbio vascular

Nitrogen source and pH interact and modulate lipase secretion in a non-clinical strain of Candida parapsilosis

Lipases (E.C. 3.1.1.3) are serine-hydrolases, and act on long chain fatty acid ester bonds. They exhibit specific and enantioselective activities, which are desirable for many industrial applications. This study aimed at screening and optimizing the production of lipases by wild yeast strains from a variety of substrates, as well as characterizing the enzyme. An initial selection was made in oxygenated oil-supplemented minimum medium, and the enzymatic activity of the supernatant was tested over p- nitrophenyl palmitate. One-hundred and twenty-four yeast strains from different substrates were tested, and twenty-three showed significantly higher lipolytic activity (p <0.01). One yeast in particular, QU110, showed best lipase production and therefore was selected for the optimization and characterization processes. This yeast exhibits enzyme secretion in initial pH 6.0, with olive oil and tryptone as carbon and nitrogen sources, respectively. There was a strong interaction between nitrogen source and initial pH, and pH 9.0 seems to inhibit enzyme secretion. The crude enzyme (cell-free supernatant) shows stability in surfactants and n-hexane, but not in ethanol or methanol. A Response Surface Model was created and optimal enzyme activity conditions were observed at 36°C and pH 8.0. The lipase is appropriate for transesterification reactions, as the enzyme is more stable in strong apolar solvents than moderately apolar ones. Also, secretion by pH was not reported elsewhere, which should be further investigated and contribute for other yeast bioprocesses as well

Antimicrobial and antioxidant screening of curcumin and pyrocatechol in the prevention of biodiesel degradation: oxidative stability

Owing to its hygroscopicity biodiesel may accumulate water during storage, which becomes favorable to the growth of microorganisms. In order to control microbial contamination, use of various chemical biocides has been studied. However, the addition of a natural substance simultaneously with antioxidant and microbial growth inhibition could prove advantageous in the prevention of biodiesel oxidation and microbial contamination. Curcumin and pyrocatechol are antioxidant agents, which also exhibit microbial growth inhibition abilities. This research effort aimed at evaluating the addition of curcumin and pyrocatechol to biodiesel produced from various vegetable sources (waste frying oil, soybean oil, cottonseed oil, sesame oil, macaúba almond oil and microalgae oil). The combined addition of 1% (w/w) water and curcumin (viz. 0.2% (w/w) for biodiesel from spent frying oil, 0.5% (w/w) for biodiesel from soybean oil, 0.1% (w/w) for biodiesel from cotton seed oil, 0.5% (w/w) for biodiesel from sesame seed oil, 0.2% (w/w) for biodiesel from macaúba almond oil, and 0.2% (w/w) for biodiesel from microalgae oil) were those processing variables that promoted the best fungistatic and antioxidant effects, allowing maintenance of an unfavorable environment for microbial growth in biodiesel inoculated with the ubiquitous filamentous mold Paecilomyces variotii Bainier.Project funding by CNPq (National Council for Scientific and Technological Development - Brazil) (CNPq Ref. No. 404808/ 2013-1, Project ‘Studies on Biodiesel: Development of analytical methods for the characterization and quality control, and research of new natural additives to improve the quality of this biofuel’), is hereby gratefully acknowledged. This work received support from CNPq, National Council for Scientific and Technological Development Brazil, in the form of Research Productivity (PQ) fellowships granted to Victor M. Balcão (Ref. No. 306113/2014-7) and Marco V. Chaud (Ref. No. 309598/2014-1). The authors have no conflicts of interest whatsoever to declare

Ursolic acid and luteolin-7-glucoside improves rat plasma lipid profile and increases liver glycogen content through glycogen synthase kinase-3

In the present study, two phytochemicals - ursolic acid (UA) and luteolin-7-glucoside (L7G) - were assessed in vivo in healthy rats regarding effects on plasma glucose and lipid profile (total cholesterol, HDL and LDL), as well as liver glycogen content, in view of their importance in the aetiology of diabetes and associated complications. Both UA and L7G significantly decreased plasma glucose concentration. UA also significantly increased liver glycogen levels accompanied by phosphorylation of glycogen synthase kinase-3 (GSK3). The increase in glycogen deposition induced by UA (mediated by GSK3) could have contributed to the lower plasma glucose levels observed. Both compounds significantly lowered total plasma cholesterol and low-density lipoprotein levels, and, in addition, UA increased plasma high-density lipoprotein levels. Our results show that UA particularly may be useful in preventable strategies for people at risk of developing diabetes and associated cardiovascular complications by improving plasma glucose levels and lipid profile, as well as by promoting liver glycogen deposition.MFA and CMS were supported by the Foundation for Science and Technology, Portugal, through the grants SFRH/BD/12527/2003 and SFRH/BD/42566/2007, respectively. This work was supported by the Foundation for Science and Technology, Portugal, research grant POCI/AGR/62040/2004

Avaliação da biomassa produzida a partir de fermentação por Yarrowia lipolytica de resíduo agroindustrial de mandioca (Manihot esculenta) em distintas concentrações de glicose

Considering the high potential of Brazil for agricultural production, as well as the growing demand for research in the microbial area, yeasts such as Yarrowia lipolytica (YL) have been used in bioconversion processes that can bring nutritional value to the production of several products with greater value aggregate in the animal food supplement industry. In this work, three different strains of yeast YL (QU31, QU69 and QU123) were used to evaluate the production of proteins and lipids under different concentrations of glucose (0, 4, 8 and 12%) using cassava peel (Manihot esculenta) as a source of carbon and urea as a source of nitrogen. The use of cassava peel as a carbon source for fermentation with YL proved to be advantageous, since initially the residue had 1.66% of lipids and after the process it showed a gain of up to 1839.5%, while for protein it presented increments that varied from 234.04 to 1674.46%. In the vast majority of cases, the increase in the glucose content in the culture medium promoted a decrease in the levels of lipids and proteins.A cultura da mandioca apresenta alta relevância socioeconômica para o Brasil. Entretanto, na região Oeste Considerando o elevado potencial do Brasil para a produção agrícola, bem como a crescente demanda por pesquisas na área microbiana, tem se utilizado leveduras como a Yarrowia lipolytica (YL) em processos de bioconversão que possam trazer valorização nutricional para produção de diversos produtos com maior valor agregado na indústria de suplementos alimentares&nbsp; de uso animal. Neste trabalho foram utilizadas três cepas diferentes da levedura YL (QU31, QU69 e QU123) para avaliar a produção de proteínas e lipídeos sob diferentes concentrações de glicose (0, 4, 8 e 12%) utilizando casca de mandioca (Manihot esculenta) como fonte de carbono e ureia como fonte de nitrogênio. O uso da casca de mandioca como fonte de carbono para fermentação com YL se mostrou vantajoso, visto que inicialmente o resíduo possuía 1,66% de lipídios e após o processo apresentou ganho de até 1839,5%, enquanto para proteína apresentou incrementos que variaram&nbsp; de 234,04 até 1674,46%. Na ampla maioria dos casos o aumento do teor de glicose no meio de cultura promoveu diminuição nos teores de lipídeos e proteínas

Development of Non-Natural Flavanones as Antimicrobial Agents

With growing concerns over multidrug resistance microorganisms, particularly strains of bacteria and fungi, evolving to become resistant to the antimicrobial agents used against them, the identification of new molecular targets becomes paramount for novel treatment options. Recently, the use of new treatments containing multiple active ingredients has been shown to increase the effectiveness of existing molecules for some infections, often with these added compounds enabling the transport of a toxic molecule into the infecting species. Flavonoids are among the most abundant plant secondary metabolites and have been shown to have natural abilities as microbial deterrents and anti-infection agents in plants. Combining these ideas we first sought to investigate the potency of natural flavonoids in the presence of efflux pump inhibitors to limit Escherichia coli growth. Then we used the natural flavonoid scaffold to synthesize non-natural flavanone molecules and further evaluate their antimicrobial efficacy on Escherichia coli, Bacillus subtilis and the fungal pathogens Cryptococcus neoformans and Aspergillus fumigatus. Of those screened, we identified the synthetic molecule 4-chloro-flavanone as the most potent antimicrobial compound with a MIC value of 70 µg/mL in E. coli when combined with the inhibitor Phe-Arg-ß-naphthylamide, and MICs of 30 µg/mL in S. cerevesiae and 30 µg/mL in C. neoformans when used alone. Through this study we have demonstrated that combinatorial synthesis of non-natural flavonones can identify novel antimicrobial agents with activity against bacteria and fungi but with minimal toxicity to human cells