Desenvolvimento de uma formulação cólon específica visando o tratamento da colite ulcerativa

Micro and nanoparticulate systems as drug delivery carriers have achieved successful therapeutic use by enhancing efficacy and reducing toxicity of potent drugs. The improvement of pharmaceutical grade polymers has allowed the development of such therapeutic systems. Microencapsulation is a process in which very thin coatings of inert natural or synthetic polymeric materials are deposited around microsized particles of solids or around droplets. Products thus formed are known as microparticles. Xylan is a natural polymer abundantly found in nature. It is the most common hemicellulose, representing more than 60% of the polysaccharides existing in the cell walls of corn cobs, and is normally degraded by the bacterial enzymes present in the colon of the human body. Therefore, this polymer is an eligible material to produce colon-specific drug carriers. The aim of this study was to evaluate the technological potential of xylan for the development of colon delivery systems for the treatment of inflammatory bowel diseases. First, coacervation was evaluated as a feasible method to produce xylan microcapsules. Afterwards, interfacial cross-linking polymerization was studied as a method to produce microcapsules with hydrophilic core. Additionally, magnetic xylan-coated microcapsules were prepared in order to investigate the ability of producing gastroresistant systems. Besides, the influence of the external phase composition on the production and mean diameter of microcapsules produced by interfacial cross-linking polymerization was investigated. Also, technological properties of xylan were determined in order to predict its possible application in other pharmaceutical dosage forms

Efeito anti-inflamatório e antioxidante do extrato hidroalcóolico de Turnera subulata na colite ulcerativa induzida por ácido acético em ratos

Inflammatory bowel diseases is composed by a set of chronic and inflammatory disorders, among them is ulcerative colitis (UC). UC treatment is based on anti-inflammatory administration; however, this group of drugs clearly leads to development of undesirable side effects, what stimulate the search for new therapies alternatives. The aim of this study was to evaluate the effect of hydroalcholic Turnera subulata extract on acetic acid-induced acute UC in rats. UC was induced by 1 mL injection of 4% acetic acid via rectal in Wistar mouse. 42 animals were distributed among 6 experimental groups: Control, UC, Sulfasalazine 500 mg/Kg/day (SSZ), T. subulata 50mg/Kg/day (TS 50), T. subulata 100mg/Kg/day (TS 100), T. subulata 200mg/Kg/day (TS 200). Throughout the experiment, body weight, food and water ingestion was daily evaluated. At the end of the experiment, the animals were euthanized and a colon fragment was observed by macroscopic analysis. Colon fragments were also collected for microscopic analysis and oxidative stress evaluation. The means from each group was compared by ANOVA test with a significance level of 5% (p<0.05) using GraphPad Prism Software. As results, we can clearly observe that SSZ group had the greater body weight decrease among the groups throughout the experiments, 14.78%, as well as, the lowest food intake, 6.23 g of food/day. The animals treated with T. subulata extracts showed no important body weight loss when compared to control. UC group showed the highest tissue damage macroscope score, 6.5, while TS 50 showed the lowest tissue damage score: 1. Microscope evaluation showed the presence of edema, haemorraghia and ulceration in all group of animals, except for Control. Nevertheless, TS 50 showed the lowest inflammatory damage among all groups. Oxidative stress analysis revealed that T. subulata treatment modulate catalase and superoxide dismutase activity, we also observed a decrease in protein and lipid peroxidation in response to extract administration. Taken together, these results shows that T. subulata extract exerts anti-inflammatory and anti-oxidant effects on experimental UC.

Efeito anti-inflamatório e antioxidante do extrato hidroalcóolico de Turnera subulata na colite ulcerativa induzida por ácido acético em ratos

Inflammatory bowel diseases is composed by a set of chronic and inflammatory disorders, among them is ulcerative colitis (UC). UC treatment is based on anti-inflammatory administration; however, this group of drugs clearly leads to development of undesirable side effects, what stimulate the search for new therapies alternatives. The aim of this study was to evaluate the effect of hydroalcholic Turnera subulata extract on acetic acid-induced acute UC in rats. UC was induced by 1 mL injection of 4% acetic acid via rectal in Wistar mouse. 42 animals were distributed among 6 experimental groups: Control, UC, Sulfasalazine 500 mg/Kg/day (SSZ), T. subulata 50mg/Kg/day (TS 50), T. subulata 100mg/Kg/day (TS 100), T. subulata 200mg/Kg/day (TS 200). Throughout the experiment, body weight, food and water ingestion was daily evaluated. At the end of the experiment, the animals were euthanized and a colon fragment was observed by macroscopic analysis. Colon fragments were also collected for microscopic analysis and oxidative stress evaluation. The means from each group was compared by ANOVA test with a significance level of 5% (p<0.05) using GraphPad Prism Software. As results, we can clearly observe that SSZ group had the greater body weight decrease among the groups throughout the experiments, 14.78%, as well as, the lowest food intake, 6.23 g of food/day. The animals treated with T. subulata extracts showed no important body weight loss when compared to control. UC group showed the highest tissue damage macroscope score, 6.5, while TS 50 showed the lowest tissue damage score: 1. Microscope evaluation showed the presence of edema, haemorraghia and ulceration in all group of animals, except for Control. Nevertheless, TS 50 showed the lowest inflammatory damage among all groups. Oxidative stress analysis revealed that T. subulata treatment modulate catalase and superoxide dismutase activity, we also observed a decrease in protein and lipid peroxidation in response to extract administration. Taken together, these results shows that T. subulata extract exerts anti-inflammatory and anti-oxidant effects on experimental UC.

Efeitos do potencial probiótico Enterococcus faecium 32 e de sua associação com o extrato da alga marinha Caulerpa mexicana no tratamento de colite experimental murina

Ulcerative colitis comprising an inflammatory bowel disease, whose most severe consequence is the development of intestinal neoplasia. The drugs currently used to treat the disease trigger a variety of serious adverse effects and are not effective in many cases. Recent studies demonstrated the effectiveness of natural products for the treatment of inflammatory processes. Seaweed extracts and their purified products have shown protective effects in models of inflammation and the association of traditional therapies with probiotics has significantly improved the clinical symptoms of ulcerative colitis. Therefore, the aims of this study include evaluating the potential effects of the use of probiotic strain Enterococcus faecium 32 (Ef32), the methanolic extract of the green seaweed Caulerpa mexicana (M.E.) and their concomitant administration in a murine model of colitis induced by dextran sodium sulfate (DSS). Accordingly, C57BL /6 mice were pretreated orally with Ef32 (109 CFU/ml) for seven days. In the seven days following, the colitis was induced by administration of 3% DSS (w/v) diluted in the animals drinking water. During this period, animals were treated daily with Ef32 and the M.E. (2.0 mg/kg) every other day by intravenous route. The development of colitis was monitored by the disease activity index (DAI), which takes into account the loss of body weight, consistency and presence of blood in stools. After euthanasia, the colon was removed, its length measured and tissue samples were destined for histological analysis and culture for cytokine quantification. The levels of cytokines in the culture supernatant of the colon were measured by ELISA. The treatments with the probiotic Ef32 or the M.E. alone or the combination of these two substances provoked significant improvement as to weight loss and DAI, and prevented the shortening of the colon in response to DSS. The isolated treatments triggered a slight improvement in intestinal mucosal tissue damage. However, their combination was able to completely repair the injury triggered by DSS. The association was also able to reduce the levels of all the cytokines analyzed (IFN-&#947;, IL-4, IL-6, IL-12, IL-17A and TNF-&#945;). On the other hand, the treatment with Ef32 did not interfere with the levels of TNF-&#945;, whereas treatment with M.E. did not alter the levels of IL-6. Moreover, the treatment with Ef32 not interferes in TNF-&#945; levels, whereas treatment with M.E. did not alter the levels of IL-6. Therefore, the potential probiotic Ef32 and M.E. and especially when these samples were associated proved promising alternatives in the treatment of ulcerative colitis as demonstrated in an experimental model because of its beneficial effects on morphological and clinical parameters, and by reducing the production of proinflammatory cytokines of Th1, Th2 and Th17

Efeitos do alcalóide indólico caulerpina, obtido de alga do gênero caulerpa, em modelo de colite experimental murina

As doenças inflamatórias intestinais são enfermidades onde a tolerância e homeostase da resposta inflamatória estão comprometidas, gerando lesões teciduais e favorecendo o surgimento de neoplasias. Há dois importantes exemplos de doenças inflamatórias intestinais, a colite ulcerativa, foco do modelo desse estudo, e a doença de Crohn. Os medicamentos utilizados no tratamento dessas doenças desencadeiam diversos efeitos adversos; além disso, em alguns pacientes, eles não são eficazes. Os extratos de algas têm demonstrado várias atividades biológicas, entre elas a atividade anti-inflamatória. Os extratos das algas do gênero Caulerpa foram utilizados em vários estudos, onde modelos inflamatórios foram analisados, entre eles o modelo de colite ulcerativa. A utilização do extrato metanólico da C. mexicana como terapêutica nesse modelo atenuou o quadro clinico desenvolvido pelos animais. Sendo assim, o presente estudo teve como objetivo analisar a ação terapêutica da Caulerpina (CLP), extraída da C. racemosa, no modelo murino de colite ulcerativa. Camundongos C57BL/6 machos foram expostos a uma solução de Dextrana Sulfato de Sódio (DSS) a 3% por sete dias. A partir do primeiro dia de exposição ao DSS os animais foram tratados em dias alternados com a CLP nas doses de 4 e 40 mg/kg e com a dexametasona (3 mg/kg) por via oral. O desenvolvimento da doença foi analisado através do índice de atividade da doença (IAD), que leva em consideração a perda de peso corporal, a consistência e a presença de sangue nas fezes. Após a eutanásia, o cólon foi removido e mensurado, e amostras do tecido colônico foram destinadas a análise histológica e à cultura para dosagem de citocinas. Os níveis de citocinas no sobrenadante da cultura do cólon foram mensurados por ELISA. O tratamento com a CLP (4 mg/kg) desencadeou significativa melhora quanto à perda de peso corporal e ao IAD, e atenuou o encurtamento do cólon em resposta ao DSS. Tal dose foi capaz de reduzir os níveis de citocinas pró-inflamatórias analisadas (TNF-&#61537;, IFN-&#61543;, IL-6, IL-17), mas não teve efeito significativo nas citocinas anti-inflamatórias IL-10 e TGF-&#61538;. O tratamento com a CLP (40 mg/kg) não foi eficaz quanto a perda de peso e ao IAD, além de não ter atenuado a redução do cólon em resposta ao DSS. Essa dose conseguiu reduzir os níveis das citocinas pró-inflamatórias, porém não os níveis de IL-6. O tratamento com a dexametasona obteve melhora discreta quanto à perda de peso corporal e ao IAD, porém não atenuou a redução do cólon em resposta ao DSS. Esse tratamento também conseguiu reduzir todas as citocinas pró-inflamatórias testadas. Deste modo a CLP (4 mg/kg) demonstrou ser uma alternativa promissora no tratamento da colite ulcerativa, em razão dos seus efeitos benéficos sobre parâmetros clínicos, morfológicos e moleculares do modelo em estudo

Micropartículas poliméricas à base de xilana e Eudragit® S-100 contendo mesalazina visando à liberação cólon-específica

Colon-specific drug delivery systems have attracted increasing attention from the pharmaceutical industry due to their ability of treating intestinal bowel diseases (IBD), which represent a public health problem in several countries. In spite of being considered a quite effective molecule for the treatment of IBD, mesalazine (5-ASA) is rapidly absorbed in the upper gastrointestinal tract and its systemic absorption leads to risks of adverse effects. The aim of this work was to develop a microparticulate system based on xylan and Eudragit® S- 100 (ES100) for colon-specific delivery of 5-ASA and evaluate the interaction between the polymers present in the systems. Additionaly, the physicochemical and rheological properties of xylan were also evaluated. Initially, xylan was extracted from corn cobs and characterized regarding the yield and rheological properties. Afterwards, 10 formulations were prepared in different xylan and ES100 weight ratios by spray-drying the polymer solutions in 0.6N NaOH and phosphate buffer pH 7.4. In addition, 3 formulations consisting of xylan microcapsules were produced by interfacial cross-linking polymerization and coated by ES100 by means of spray-drying in different polymer weight ratios of xylan and ES100. The microparticles were characterized regarding yield, morphology, homogeneity, visual aspect, crystallinity and thermal behavior. The polymer interaction was investigated by infrared spectroscopy. The extracted xylan was presented as a very fine and yellowish powder, with mean particle size smaller than 40&#956;m. Regarding the rheological properties of xylan, they demonstrated that this polymer has a poor flow, low density and high cohesiveness. The microparticles obtained were shown to be spherical and aggregates could not be observed. They were found to present amorphous structure and have a very high thermal stability. The yield varied according to the polymer ratios. Moreover, it was confirmed that the interaction between xylan and ES100 occurs only by means of physical aggregation

Prevention of bacterial translocation using β-(1-3)-D-glucan in small bowel ischemia and reperfusion in rats

To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria

Prevention of bacterial translocation using β-(1-3)-D-glucan in small bowel ischemia and reperfusion in rats

To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria

Prevention of bacterial translocation using β-(1-3)-D-glucan in small bowel ischemia and reperfusion in rats

To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria

Prevention of bacterial translocation using β-(1-3)-D-glucan in small bowel ischemia and reperfusion in rats

To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria