Two novel garlic-derived peptides (MGR and HDCF) potently blocked ACE in vitro (IC50 4.50 and 26.38 μM), survived digestion, and effectively lowered blood pressure in hypertensive rats by balancing the renin-angiotensin system.
IC50 4.50 μMMGR peptide from garlic — one of the most potent food-derived ACE inhibitors reported, approaching pharmaceutical-grade potency
What the researchers found
MGR (IC50 4.50 μM) and HDCF (IC50 26.38 μM) from garlic protein competitively inhibited ACE, survived gastrointestinal digestion, and lowered blood pressure in spontaneously hypertensive rats through renin-angiotensin system modulation.
Why it matters
These are exceptionally potent food-derived ACE inhibitors — MGR's IC50 of 4.50 μM approaches pharmaceutical-grade potency. Combined with gastrointestinal stability and demonstrated in vivo efficacy, these garlic peptides are strong candidates for functional food development.
The numbers in context
MGR: IC50 4.50 μM. HDCF: IC50 26.38 μM. Both competitive inhibitors. Both stable through simulated digestion. Both lowered blood pressure in SHR rats.
How the study worked
In silico screening of garlic protein hydrolysates followed by ACE inhibition assays. Stability tested under heat, pH extremes, and simulated digestion. In vivo antihypertensive effects tested in spontaneously hypertensive rats with single and continuous dosing. Mechanisms explored via renin-angiotensin system, renal/cardiac pathology, and endothelial function markers.
Who was studied
Spontaneously hypertensive rats
What this study cannot tell us
Animal study using spontaneously hypertensive rats, which don't perfectly model human hypertension. The doses used in rats may not translate directly to achievable concentrations from dietary garlic consumption. Human clinical trials are needed.
How to read the evidence
Moderate evidence combining in vitro enzyme assays with in vivo animal testing. The combination of potent ACE inhibition, gastrointestinal stability, and demonstrated blood pressure lowering in SHR is compelling but awaits human validation.
When this study was published
Published in 2024; represents current food-derived antihypertensive peptide research.
The bigger picture
Garlic has long been associated with cardiovascular benefits in traditional medicine. This study identifies specific peptides responsible, providing a molecular explanation for garlic's reputed blood pressure effects and creating opportunities for standardized garlic-based nutraceuticals with consistent, measurable potency.
Questions still open
- What dose of garlic or garlic supplement would deliver a clinically relevant amount of MGR and HDCF?
- Would these peptides work in human hypertensive patients as they do in SHR?
- Do these peptides interact with conventional ACE inhibitor medications?
Common questions
Does eating garlic lower blood pressure?
How do these garlic peptides compare to blood pressure medications?
Read the original research
Two novel angiotensin I-converting enzyme inhibitory peptides from garlic protein: In silico screening, stability, antihypertensive effects in vivo and underlying mechanisms.
Food chemistry, 435, 137537
Citation
Xiang, Lu; Zheng, Zhenjia; Guo, Xiaojing; Bai, Ruoxi; Zhao, Renjie; Chen, Haihua; Qiu, Zhichang; Qiao, Xuguang. (2024). Two novel angiotensin I-converting enzyme inhibitory peptides from garlic protein: In silico screening, stability, antihypertensive effects in vivo and underlying mechanisms.. Food chemistry, 435, 137537. https://doi.org/10.1016/j.foodchem.2023.137537