Bioactive peptides from germinated soybean with antidiabetic potential by inhibition of DPP-IV, α-amylase and α-glucosidase enzymes

Póster presentado al 3er Congreso Internacional de Alimentos Funcionales y Nutracéuticos: "Diseño y desarrollo de alimentos funcionales y nutracéuticos para la nutrición humana", celebrado en Mazatlán, Sinaloa (México) del 20 al 22 de junio de 2018.

[Introduction]: Functional foods offer the possibility to modulate the absorption of sugars and insulin levels to prevent diabetes. Herein, we investigated the potential of germinated soybean peptides to modulate postprandial glycaemic response through inhibition of dipeptidyl peptidase IV (DPPIV), α-amylase (AMI) and α-glucosidase (GLU). [Methods]: A protein isolate from 6 day-old soybean sprouts was sequentially digested by pepsin-pancreatin. Protein hydrolysate and peptide fractions obtained by ultrafiltration (<5, 5-10 and >10 kDa) and subsequent semipreparative reverse phase liquid chromatography (F1, F2, F3 and F4) were screened for in vitro inhibition of DPPIV, AMI, GLU. [Results]: Protein hydrolysate inhibited DPPIV (IC50=1.4 mg/mL), AMI (40% inhibition at 3.3 mg/mL) and GLU (60% at 3.3 mg/mL). Peptides of 5-10 and >10 kDa were more effective to inhibit DPPIV (IC50=0.914 and 1.18 mg/mL, respectively), while peptides of 5-10 and <5 kDa showed a higher potency to inhibit AMI and GLU The 5-10 kDa subfraction F1 was characterized by the presence ß-conglycinin and glycinin peptides with poli-glutamine residues and the highest AMI inhibition. F2 and F3 showed the highest DPPIV inhibitory activity while F4 showed higher potency to inhibit both sucrase and maltase inhibitory activities of GLU. [Conclusion]: Germinated soybean protein showed a promising potential to be used as nutraceutic or functional ingredient for diabetes prevention.

The research leading to these results received funding from Ministry of Industry, Economy and Competitiveness (MINECO, Spain) [grant numbers AGL2017-83718-R and AGL2015-66886-R].

Peer Reviewed