Computational screening of buffalo milk proteins identified novel short peptides (3-4 amino acids) that inhibit ACE (blood pressure regulation) and DPP-IV (blood sugar regulation), with IC50 values as low as 82.52 μM for DPP-IV inhibition.
KPW inhibits both ACE and DPP-IVA single tripeptide (KPW) from buffalo milk demonstrated dual activity against the enzymes targeted by blood pressure and diabetes medications, with IC50 values of 136 μM and 82 μM respectively
What the researchers found
Six novel peptides were identified from in silico proteolysis of buffalo milk proteins: two ACE inhibitors (KPW and RGP) and four DPP-IV inhibitors (RGP, KPW, FPK, and KFTW). Laboratory validation confirmed their activity:
ACE inhibition: KPW (IC50 = 136.28 ± 10.77 μM, competitive inhibitor) and RGP (IC50 = 104.72 ± 8.37 μM, competitive inhibitor).
DPP-IV inhibition: KPW (IC50 = 82.52 ± 10.37 μM, mixed-type inhibitor), FPK (IC50 = 126.57 ± 8.45 μM, mixed-type inhibitor), and KFTW (IC50 = 873.92 ± 32.89 μM, competitive inhibitor).
Notably, KPW inhibited both ACE and DPP-IV, making it a dual-activity peptide.
Why it matters
Food-derived bioactive peptides are gaining attention as natural alternatives or supplements to pharmaceutical drugs for blood pressure and blood sugar management. Buffalo milk is consumed by over 2 billion people globally and differs from cow milk in protein composition. Identifying bioactive peptides specific to buffalo milk could inform the development of functional foods, nutraceuticals, or dairy products with validated health benefits — particularly relevant in South Asian and Mediterranean regions where buffalo milk is a dietary staple.
How the study worked
Buffalo milk protein sequences were analyzed for similarity to cow milk proteins. In silico proteolysis simulated enzymatic digestion to generate theoretical peptides. Candidates were screened using the BIOPEP-UWM database (A values), PeptideRanker, Innovagen, peptide-cutter, and molecular docking. Selected peptides were synthesized and tested in vitro for ACE and DPP-IV inhibition. Lineweaver-Burk plots were used to determine inhibition type (competitive vs. mixed).
What this study cannot tell us
The IC50 values are in the micromolar range, which is considerably weaker than pharmaceutical ACE inhibitors (nanomolar) and DPP-IV inhibitors (nanomolar). Bioavailability — whether these peptides survive digestion and reach target enzymes in active form — was not assessed. No in vivo or clinical testing was performed. The in silico proteolysis may not accurately reflect actual enzymatic digestion conditions in the human gut. The study explicitly states it does not involve any clinical trial.
How to read the evidence
This is an in silico screening study with in vitro validation — early-stage research without any in vivo or clinical evidence. While the computational-to-experimental pipeline is well-executed, the micromolar IC50 values and lack of bioavailability data limit the practical significance.
When this study was published
Published in 2023, this is a recent study reflecting current computational approaches to bioactive peptide discovery from food proteins.
The bigger picture
The field of food-derived bioactive peptides has grown rapidly, driven by consumer interest in functional foods and the recognition that dietary proteins are precursors to peptide fragments with pharmacological activity. ACE-inhibitory peptides from cow milk (like IPP and VPP) have already been commercialized in health foods. This study extends the approach to buffalo milk and adds DPP-IV inhibition — relevant to diabetes management — as a dual bioactivity. The computational pipeline from protein sequence to validated bioactive peptide represents a scalable approach for mining any food protein for health-promoting peptides.
Questions still open
- Do these peptides survive actual gastrointestinal digestion and reach the bloodstream in sufficient concentrations to inhibit ACE or DPP-IV in vivo?
- Could the dual ACE/DPP-IV inhibitor KPW be developed as a functional food ingredient for people with both hypertension and type 2 diabetes?
- How do the bioactive peptide profiles of buffalo milk compare to cow, goat, and camel milk in terms of ACE and DPP-IV inhibition potential?
Common questions
Could drinking buffalo milk lower blood pressure or blood sugar?
How do these milk peptides compare to actual blood pressure or diabetes medications?
Read the original research
In silico identification of novel ACE and DPP-IV inhibitory peptides derived from buffalo milk proteins and evaluation of their inhibitory mechanisms.
Amino acids, 55(2), 161-171
Citation
Gu, Yuxiang; Li, Xing; Qi, Xiaofen; Ma, Ying; Chan, Eric Chun Yong. (2023). In silico identification of novel ACE and DPP-IV inhibitory peptides derived from buffalo milk proteins and evaluation of their inhibitory mechanisms.. Amino acids, 55(2), 161-171. https://doi.org/10.1007/s00726-022-03202-z