Avaliação da atividade anti-inflamatória intestinal de Cnidoscolus aconitifolius (Mill.) I.M. Johnst no modelo de indução por TNBS em ratos
Carregando...
Data
2018-06-11
Autores
Moya Dalmau, Lesvi
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A Doença Inflamatória Intestinal (DII) inclui duas principais doenças: a Doença de Crohn e a Retocolite Ulcerativa, ambas caracterizadas por períodos de exacerbação dos sintomas acompanhados por intervalos prolongados de remissão. Apesar da etiologia ser pouco elucidada, sabe-se da influência de fatores genéticos, imunológicos e ambientais. A terapia farmacológica atual não é eficaz para todos os pacientes, apresenta alto custo e desencadeia diversos efeitos colaterais, portanto é necessário o desenvolvimento de novas terapias sendo que as plantas medicinais e componentes presentes na dieta, devido as suas propriedades antioxidantes e/ou imunomoduladora, apresentam uma opção atrativa como terapia complementar. A espécie Cnidoscolus aconitifolius (Mill.) I.M. Johnst, popularmente conhecida como chaya, foi selecionada dada sua composição química, rica em fibra e compostos antioxidantes e suas atividades antioxidante e anti-inflamatória testadas em outras afecções. O objetivo deste trabalho foi avaliar a atividade anti-inflamatória intestinal das folhas escaldadas e desidratadas de chaya em duas formas: como extrato metanólico 70% (100, 200 e 300 mg/kg, via oral por gavage) e como farinha incorporada na dieta nas concentrações 5, 10 e 20%, no modelo de indução de inflamação intestinal pelo ácido trinitrobenzenosulfonico (TNBS) em ratos. Para tanto, foram avaliados os parâmetros clínicos gerais (ingestão diária de alimentos, peso corporal, diarréia), parâmetros macroscópicos da lesão (escore da inflamação, extensão da lesão relação peso/comprimento cólico e aderência), bioquímicos (avaliação da mieloperoxidase, glutationa total e fosfatase alcalina) e microscópicos (hematoxilina-eosina e PAS/Alcian Blue). No extrato metanólico, realizou-se analise fitoquímica, determinação do conteúdo de fenóis totais, capacidade de sequestro de radicais livres e a avaliação da atividade antioxidante pelo ensaio de lipoperoxidação lipídica em membranas de cérebros de ratos. Análises fitoquímicas mostraram principalmente presença de compostos fenóis, flavonoides, flavononas, xantonas, chalconas, auronas, flavononas, saponinas, cumarinas e bases quaternárias. O contéudo de fenóis totais quantificou 160,555mg equivalente de ácido gálico (EAG)/g de extrato. No ensaio DPPH o extrato apresentou uma concentração eficiente (CE50) de 28,3μg/ml vs. 1.90μg /ml do ácido gálico, mas fraca atividade antioxidante no modelo de lipoperoxidação lipídica, com uma concentração inibitória média (IC50) de 703,28μg/ml vs. 0,71± 0,1μg/ml de quercetina. O tratamento com o extrato não melhorou o processo inflamatório cólico induzido pelo TNBS nos parâmetros macroscópico e bioquímicos avaliados. A dieta enriquecida em todas as concentrações testadas conseguiu evitar a depleção do conteúdo de GSH. A concentração de 20% conseguiu diminuir a atividade da MPO. Nenhuma alteração significativa foi observada na atividade da fosfatase alcalina. Todas as concentrações testadas melhoraram a citoarquitetura epitelial e mantiveram a camada de muco sobre o epitélio intestinal quando comparado com o grupo controle-TNBS. O presente estudo demonstrou que chaya quando incorporada na ração nas concentrações 5, 10 e 20%, mostra atividade antioxidante no processo inflamatório cólico induzido por TNBS em ratos. Esses efeitos podem estar relacionados à fibra e aos compostos fenólicos, sugerindo que este alimento pode ser útil para prevenir ou tratar a recidiva de DII.
Inflammatory Bowel Disease (IBD) comprise two major diseases, Crohn's disease and Ulcerative Colitis, both characterized by periods of exacerbation of symptoms accompanied by prolonged remission intervals. Although the etiology is not certain elucidated, the influence of genetic, immunological and environmental factors is well known. The current pharmacological therapy is not effective for all patients, due to a high cost and triggers several side effects. Therefore, it is necessary to develop new therapies and medicinal plants with their antioxidant and/or immunomodulatory properties are an attractive option as complementary therapy. Cnidoscolus aconitifolius (Mill.) I.M. Johnst, popularly known as chaya, was selected because of its chemical composition, rich in fiber and antioxidant compounds and its antioxidant and anti-inflammatory activity tested in other diseases. The aim of this study was to evaluate the intestinal anti-inflammatory activity of the blanched and dehydrated Chaya leaves in two preparations: as a 70% methanol extract (100, 200 and 300 mg/kg, oral route by gavage) and as flour incorporated in the diet at 5%, 10% and 20% concentrations in the experimental model of intestinal inflammation induced by trinitrobenzenesulfonic acid (TNBS) in rats. For that, clinical parameters (daily food intake, body weight, diarrhea), macroscopic damage (score, lesion extension, weight/length ratio and adherence), biochemical parameters (quantification of total glutathione content, myeloperoxidase and alkaline phosphatase activities) and microscopic analysis (hematoxylin-eosin and PAS/ Alcian Blue for evaluation of mucins) were performed. On the methanol extract was made phytochemical analysis, determination of total phenol content, free radical scavenging activity using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) model and an evaluation of antioxidant activity by lipid peroxidation assay in membranes of rat brains. Phytochemical analysis showed mainly the presence of phenols, flavonols, flavonones, xanthones, saponins, coumarins and quaternary bases. The quantification of total phenols shows 160,555mg gallic acid equivalents (GAE)/g extract. In the DPPH assay the extract showed an EC50 of 28,3 μg/ml vs. 1.90 μg/ml of gallic acid and a model of lipid peroxidation, but weak antioxidant activity in lipid peroxidation model with an IC50 of 196.8 μg/ml vs. 0,71± 0,17 μg/ml of quercetin. The extract did not improve the colonic inflammatory process induced by TNBS on macroscopic and biochemical analysis. The enriched diet in all tested concentrations was able to avoid depletion of the GSH content. The concentration of 20 % was able to decrease MPO activity. No significant change was observed in alkaline phosphatase activity. All concentrations tested improved epithelial cytoarchitecture and maintained the mucus layer on intestinal epithelium by comparing with control-TNBS group. This study demonstrated that when chaya is incorporated to a diet at 5, 10 and 20% concentrations shows antioxidant activity. These effects may be related to the presence of dietary fiber and the phenolic compounds present in the species, suggesting that this food may be useful to prevent or avoid recurrence of IBD.
Inflammatory Bowel Disease (IBD) comprise two major diseases, Crohn's disease and Ulcerative Colitis, both characterized by periods of exacerbation of symptoms accompanied by prolonged remission intervals. Although the etiology is not certain elucidated, the influence of genetic, immunological and environmental factors is well known. The current pharmacological therapy is not effective for all patients, due to a high cost and triggers several side effects. Therefore, it is necessary to develop new therapies and medicinal plants with their antioxidant and/or immunomodulatory properties are an attractive option as complementary therapy. Cnidoscolus aconitifolius (Mill.) I.M. Johnst, popularly known as chaya, was selected because of its chemical composition, rich in fiber and antioxidant compounds and its antioxidant and anti-inflammatory activity tested in other diseases. The aim of this study was to evaluate the intestinal anti-inflammatory activity of the blanched and dehydrated Chaya leaves in two preparations: as a 70% methanol extract (100, 200 and 300 mg/kg, oral route by gavage) and as flour incorporated in the diet at 5%, 10% and 20% concentrations in the experimental model of intestinal inflammation induced by trinitrobenzenesulfonic acid (TNBS) in rats. For that, clinical parameters (daily food intake, body weight, diarrhea), macroscopic damage (score, lesion extension, weight/length ratio and adherence), biochemical parameters (quantification of total glutathione content, myeloperoxidase and alkaline phosphatase activities) and microscopic analysis (hematoxylin-eosin and PAS/ Alcian Blue for evaluation of mucins) were performed. On the methanol extract was made phytochemical analysis, determination of total phenol content, free radical scavenging activity using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) model and an evaluation of antioxidant activity by lipid peroxidation assay in membranes of rat brains. Phytochemical analysis showed mainly the presence of phenols, flavonols, flavonones, xanthones, saponins, coumarins and quaternary bases. The quantification of total phenols shows 160,555mg gallic acid equivalents (GAE)/g extract. In the DPPH assay the extract showed an EC50 of 28,3 μg/ml vs. 1.90 μg/ml of gallic acid and a model of lipid peroxidation, but weak antioxidant activity in lipid peroxidation model with an IC50 of 196.8 μg/ml vs. 0,71± 0,17 μg/ml of quercetin. The extract did not improve the colonic inflammatory process induced by TNBS on macroscopic and biochemical analysis. The enriched diet in all tested concentrations was able to avoid depletion of the GSH content. The concentration of 20 % was able to decrease MPO activity. No significant change was observed in alkaline phosphatase activity. All concentrations tested improved epithelial cytoarchitecture and maintained the mucus layer on intestinal epithelium by comparing with control-TNBS group. This study demonstrated that when chaya is incorporated to a diet at 5, 10 and 20% concentrations shows antioxidant activity. These effects may be related to the presence of dietary fiber and the phenolic compounds present in the species, suggesting that this food may be useful to prevent or avoid recurrence of IBD.
Descrição
Palavras-chave
Doença Inflamatória Intestinal, TNBS, Cnidoscolus aconitifolius, chaya, alimento funcional, functional food, Inflammatory Bowel Disease