087: Production and Characterization of Adzuki Bean (Vigna Angularis) ß-Vignin Peptides and Their Comparison to Soybean ß-Conglycinin Peptides

Introduction

Diabetes is one of the four most significant noncommunicable diseases in the world since it accounts for two million deaths annually. Studies reported that adzuki bean consumption can help manage type-2 diabetes (T2D) outcomes. Further scientific research is needed to examine the role and potential of adzuki bean β-vignin peptides in managing T2D. The objective was to evaluate the chemical and biological activities of adzuki bean β-vignin peptides resulting from simulated gastrointestinal digestion in comparison to soybean β-conglycinin peptides.

Methods

Peptides from purified proteins from adzuki bean β-vignin and soybean β-conglycinin were obtained using the simulated gastrointestinal digestion. LC-QTOF-MS/MS was used to sequence and identify bioactive peptides from both proteins. Validation and comparison of the DPP-IV inhibitory activity were attained by luminescent-based DPP IV inhibition biochemical assay. In-silico analysis was used to determine pharmacokinetic behavior and assess the efficacy and potential toxicity risk of the peptides.

Results

Peptides from colonic digests found: Phe-Asn-Glu (FNE), Pro-Met (PM), and Val-Pro (VP) (molecular weights ranging from 214-409 Da) were identified with an adzuki bean β-vignin precursor. Peptides Ile-Pro-Ala (IPA) and Leu-Leu-Ser (LLS) (molecular weights ranging from 300-333 Da) were identified from the colonic digests, with a soybean β-conglycinin precursor. Luminescence-based inhibition confirmed that peptides identified from adzuki bean β-vignin digest and soybean β-conglycinin digest exhibited bioactivity as DPP-IV inhibitors, an FDA-approved diabetic medication. The IC50 of the sequenced peptides inhibited DPP IV activity as 0.08 µM (IPA), 0.72 µM (VP), and 9.09 µM (LLS). In-silico pharmacokinetic analysis revealed that the highest absorption rate was PM (85%), and the lowest was FNE (0%). All peptides did not exhibit genotoxicity based on the AMES test, suggesting none of the peptides were mutagenic. The results indicated the antidiabetic potential of adzuki bean β-vignin.

Significance

Peptides derived from adzuki bean β-vignin and soybean β-conglycinin were found to have health-enhancing properties via DPP-IV inhibition. Pharmacokinetic analysis suggested no adverse effects of using these peptides. This may guide the production of adzuki bean-based ingredients that could help manage T2D. It is important to examine the relationship between the mechanisms of action of adzuki bean β-vignin peptides and their antidiabetic benefits.

Authors: Shu Hang Kwan, Elvira Gonzalez de Mejia