Poster Topical Area: Dietary Bioactive Components
Location: Hall D
Poster Board Number: 338
Animal and human studies indicate that lupin seeds consumption has positive effects on hyperglycemia and insulin resistance present in type-2 diabetes. There is limited information regarding the molecular mechanism of lupin proteins to decrease serum glucose levels. Objective: This study aimed to assess the mechanism of action of protein hydrolysates from Andean L. mutabilis in glucose metabolism in vitro. Methods: Protein hydrolysates from defatted lupin flour were obtained by pancreatin-pepsin digestion (semipurified g-conglutin, SCgh) or pepsin-pancreatin digestion (simulated gastro-intestinal digestion, SGDh); or from isolated g-conglutin digestion (purified g-conglutin, Cgh). Effects on glucose metabolism were evaluated in a dual cell culture system of intestinal epithelial cells/adipocytes or intestinal epithelial cells/hepatocytes. In addition, confocal laser scanning microscopy depicting two-dimensional ﬂuorescence detection and quantiﬁcation determined by the intensity (AU) over area (μm2) of glucose transporter type 4 (GLUT-4) in adipocytes after SCgh, SGDh and Cgh treatment was performed. Results: SCgh, SGDh and Cgh at 5 mg/mL inhibited dipeptidyl peptidase IV activity (100%, 61.6%, 53.6%, respectively), and increased glucose uptake (9.7 ± 0.3, 10.9 ± 2.9, 13.2 ± 0.8 mM, respectively) in comparison to untreated adipocytes (p < 0.01). Augmented membrane translocation of GLUT-4 could explain increased glucose uptake upon lupin protein hydrolysates treatment. Cgh stimulation elicited greater translocation than SCgh, or SGDh. In this model, insulin-induced glucose uptake was potentiated by addition of L. mutabilis hydrolysates. In addition, L. mutabilis hydrolysates decreased gluconeogenesis by hepatocytes (54.4%, 59.6% and 57.8%, respectively) in comparison to the untreated cells (p < 0.01), and reduced phosphoenolpyruvate carboxykinase expression. Conclusion: L. mutabilis protein hydrolysates could affect glucose metabolism by inhibiting DPP-IV enzymatic activity, improving insulin receptor sensitivity and inhibiting hepatic gluconeogenesis. These results strengthen the recommendation for the consumption of legumes, as part of the traditional diet, for the general population.
University of Illinois International Programs and Universidad Tecnológica Equinoccial
Universidad Tecnológica Equinoccial
Quito, Ecuador, Pichincha, Ecuador