Multiple hypoglycemic mechanisms of chickpea protein hydrolysate: Insights from simulated digestion to intestinal transport

While hypoglycemic protein hydrolysates have been widely studied for single-target enzyme inhibition, multi-mechanistic candidates with improved gastrointestinal bioavailability remain essential for effective glycemic regulation. In this study, chickpea protein hydrolyzed by Aspergillus oryzae protease (CP_AoN) was digested in vitro, and a potent fraction 7 (F7) was isolated to show strong concurrent inhibitions of dipeptidyl peptidase IV (DPP-IV, IC₅₀ of 0.09 mg/mL), α-glucosidase (0.12 mg/mL), and α-amylase (0.06 mg/mL). Based on Caco-2 cell model, F7 exhibited great in situ inhibitions of DPP-IV (1.86 × 10⁵ luminescence units), sucrase (42.22%), maltase (51.44%), and glucose transport (50.65%) at 0.20 mg/mL. It crossed the intestinal epithelium via paracellular diffusion and identified 120 antidiabetic peptides, with 105 stable against brush border peptidases and 32 transported intact. Peptides bearing N-terminus of tyrosine and C-terminus of tryptophan/leucine contributed to superior intestinal stability and permeability. CP_AoN could be used as a promising hypoglycemic ingredient for glycemic control.