- 2025-10-31
- Nutrients 17(21)
- You Sun
- Xiaokang Niu
- Yifan Wang
- Qi Zhang
- Yan Liu
- Jingjing He
- Lingling Xu
- Ran Wang
- Jie Guo
Study Design
- Type
- Randomized Controlled Trial (RCT)
- Population
- 11 prediabetic individuals
- Methods
- Randomized crossover trial with four interventions: pure milk; lactose-hydrolyzed milk; lactose-hydrolyzed milk with mulberry leaf, corn silk, and resistant dextrin; and GOS milk with mulberry leaf and corn silk. In vitro enzyme inhibition assessed using DNS method (α‑amylase) and pNPG method (α‑glucosidase).
Objective
Postprandial hyperglycemia is a major risk factor for type 2 diabetes and cardiovascular disease. Inhibition of α-amylase and α-glucosidase can attenuate postprandial glycemic response (PPGR). This study aimed to investigate the inhibitory effects of mulberry leaf and corn silk on these enzymes in vitro and their impact on postprandial glucose (PG) levels in prediabetic individuals using milk-based matrices.Research design and methods
In vitro, enzyme inhibition was assessed using the DNS method (α-amylase) and pNPG method (α-glucosidase). A randomized crossover trial was conducted in 11 prediabetic individuals with four interventions: pure milk; lactose-hydrolyzed milk; lactose-hydrolyzed milk with mulberry leaf, corn silk, and resistant dextrin; and GOS milk with mulberry leaf and corn silk. PPGR was assessed by area under the glucose curve, 1 and 2 h PG, maximum PG, and 2 h glucose excursion. Paired Wilcoxon signed-rank tests were used for comparisons.Results
Mulberry leaf and corn silk extracts inhibited both enzymes dose-dependently, with synergistic effects. No significant differences in PPGR indices were observed across interventions in the overall prediabetic individuals. However, in the overweight subgroup, the combination of GOS milk supplemented with mulberry leaf and corn silk significantly reduced 1 h PG (median difference mmol/L [-1.05, -0.49]), maximum PG (-0.54 mmol/L [-0.75, -0.25]), and glucose excursion (-0.62 mmol/L [-0.75, -0.24]) compared to pure milk.Conclusions
Mulberry leaf and corn silk extracts inhibit α-amylase and α-glucosidase in vitro and may attenuate postprandial glucose excursions in overweight prediabetic individuals when delivered in a GOS milk matrix.