Ação da epiafzeliquina isolada da Bauhinia forficata (Fabaceae) na via sinalização da insulina em células ß pancreáticas

• Ano de defesa: 2014
• Autor(a) principal: Proenca, Neli Leite [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo
• Palavras-chave em Português: Diabetes mellitus type 2; Pata-de-vaca; Oxidative stress; INS 1-E; Antioxidant; Diabetes melitos tipo 2; Estresse oxidativo; Antioxidante
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=1356560; http://repositorio.unifesp.br/handle/11600/46636

Diabetes is recognized as a heterogeneous group of disorders with the common elements of hyperglycaemia and glucose intolerance due to insulin deficiency, impaired effectiveness of insulin action or both, being the most common non-communicable disease globally. The diabetes mellitus type 2 (DM2) is characterized by insulin resistance and relative insulin deficiency, and the specific reasons for the development of these abnormalities remain unknown. Insulin is a pleiotropic hormone produced by the pancreatic β cells, which also have metabolic effects on cell proliferation and differentiation. The intracellular action of this hormone is quite complex and involves a large number of proteins. The supply of synthetic drugs for the treatment of DM2 is currently quite wide. Despite this fact, the possibility of using a natural compound would be useful and perhaps could increase adherence to treatment of the disease. The Bauhinia forficata is the species that has the highest number of studies of the hypoglycemic activity and is widely used as teas and other herbal preparations. However, the exact mechanism of action of many cellular extracts and natural compounds remains unclear. Therefore, the objectives of this study were to investigate the antioxidant activity of the compound epiafzelechin (EEE), isolated from the leaf extract of Bauhinia forficata (Fabaceae), obtained in AcOEt (ethyl acetate) on glucose metabolism and its possible mechanisms. The toxicity of EEE was assessed by flow cytometry with 150 ƞM, 15 µM and 150 µM, after 1 or 24 h of treatment. Western blotting was used to assess the level of phosphorylation of JNK and AKT. Ins1-E cells were used in all experiments. Using dRibose 15 mM and 50 mM to cause oxidative stress, it was observed that the stimulus for oxidative stress with 15 mM d-Ribose showed no changes in the phosphorylation of AKT and JNK. Since the stimulation with 50 mM D-ribose leads to decreased phosphorylation of AKT and increased JNK, with an EEE concentration of 150 ƞM, can reverse the decrease in AKT phosphorylation, without altering JNK phosphorylation increased . Our results show that: 1) EEE does not alter cell viability and increases the percentage of cell death at a concentration of 150 µM, 2) EEE, at the concentration of 150 ƞM is able to reverse the reduction in phosphorylation of AKT, but does not reverse the increase in JNK phosphorylation induced by 50 mM D- ribose. Therefore, the EEE appears to be important in the metabolic pathway while it seems to have no effect on the inflammatory pathway.