Peptide From Rice Protein Lowers Blood Pressure in Hypertensive Rats by Blocking ACE

Lab and animal study. Rice protein was enzymatically digested with Alcalase for 2 hours. The hydrolysate was tested for ACE inhibitory activity in vitro. The specific ACE-inhibiting peptide (TQVY) was isolated and identified by amino acid sequencing. Both the crude hydrolysate and purified peptide were orally administered to spontaneously hypertensive rats (SHR) to measure blood pressure effects.

ACE inhibitors are among the most prescribed blood pressure medications in the world, but they come with side effects like persistent cough. This study shows that rice — one of the world's most consumed foods — contains peptide fragments that naturally inhibit ACE and lower blood pressure in animals. If validated in humans, rice-derived peptides could become a food-based approach to blood pressure management, either as functional foods or as natural supplements with potentially fewer side effects than pharmaceutical ACE inhibitors.

Bioactive peptides from food proteins are a growing field bridging nutrition and pharmacology. This study is part of a larger effort to find natural ACE inhibitors in everyday foods — similar peptides have been found in milk (lactotripeptides), fish, and soybeans. The advantage of food-derived peptides is their potential safety profile and accessibility. Rice-based peptides could be particularly impactful in Asian populations where rice is a dietary staple and hypertension is highly prevalent.

Single-dose study in rats — no chronic dosing data. Spontaneously hypertensive rats may not reflect human hypertension physiology. Oral bioavailability and peptide survival through human digestion was not assessed. No human data. Blood pressure was measured at limited timepoints. No safety or dose-response studies reported.