A novel pentapeptide, Val-Leu-Thr-Gly-Trp (VLTGW), isolated from red mold rice showed potent ACE inhibitory activity (IC50 17.4 μM), stability across temperature and pH, and blood pressure lowering in spontaneously hypertensive rats, supporting further evaluation of VLTGW as a functional food.
A novel pentapeptide, Val-Leu-Thr-Gly-Trp (VLTGW), was isolated from red mold rice (RMR) and identified as an ACE inhibitory peptide.
VLTGW showed potent in vitro ACE inhibitory activity with an IC50 of 17.4 μM.
VLTGW was highly selective for ACE over renin.
VLTGW was stable across wide temperature and pH ranges.
VLTGW significantly lowered blood pressure in spontaneously hypertensive rats.
The antihypertensive effect of VLTGW in SHRs was accompanied by changes in renin-angiotensin and nitric oxide markers.
This study looked for blood-pressure-lowering compounds in red mold rice, a traditional fermented food made with Monascus fungi. The researchers isolated a small protein fragment (a peptide with five amino acids, called VLTGW) that blocks angiotensin-converting enzyme (ACE), a key enzyme the body uses to raise blood pressure. The peptide was a strong ACE inhibitor in lab tests and was much more selective for ACE than for a related enzyme, renin, which the authors suggest could mean fewer unintended effects. The peptide also held up well under different conditions, keeping over 90% of its activity across temperatures from 20 to 80 °C and across a very wide pH range (2.0 to 12.0). This suggests it might survive food processing and different environments. In spontaneously hypertensive rats, VLTGW significantly lowered blood pressure. The effect came with lower ACE activity and angiotensin II levels, and higher nitric oxide, which helps blood vessels relax. This research suggests red mold rice could be a source of peptides that help regulate blood pressure and supports further study of VLTGW as a functional food ingredient. The findings come from lab tests and rats, so they do not show whether the peptide works in people. Human studies would be needed to find that out.
Liu Y, Wang T, Meng Z, Han X, Huang W, Li M. (2026). A Novel Angiotensin I-Converting Enzyme Inhibitory Pentapeptide from Red Mold Rice: Identification, Stability, In Vivo Antihypertensive Effects, and Underlying Mechanisms.. Journal of agricultural and food chemistry. https://doi.org/10.1021/acs.jafc.6c01654