Synthesis of a garlic protein-derived ACE inhibitory peptide and exploration of its antihypertensive mechanisms using integrated network pharmacology, transcriptomics, and in vitro cellular experiments

Bioactive peptides are promising candidates in the management of hypertension. This study aimed to synthesize a garlic-derived angiotensin I converting enzyme (Ang I) inhibitory peptide (HDCF) and elucidate its antihypertensive mechanisms by integrated network pharmacology and transcriptomics analyses combined with cellular experiments. HDCF was successfully fabricated using a solid-phase peptide synthesis strategy, with a yield of 81.17% ( w / w ) and a purity of 98.46% ( w / w ). Network pharmacology analysis identified five key genes (insulin, renin, angiotensin I converting enzyme, nitric oxide synthase 3, and endothelin 1) in the protein-protein interaction network between HDCF and hypertension-related targets. The administration of HDCF showed dose-dependent blood pressure-lowering activity in spontaneously hypertensive rats and alleviated endothelial dysfunction. Transcriptomics analysis identified differentially expressed genes and linked them to Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways, revealing the association between the antihypertensive effects of HDCF and endothelial dysfunction-related pathways (such as the cGMP-PKG signaling pathway). In Ang II-induced human umbilical vein endothelial cells, HDCF treatment substantially raised nitric oxide levels via upregulating the PI3K/Akt/eNOS signaling pathway and subsequently activated the cGMP/PKG signaling pathway. Taken together, the improvement of endothelial dysfunction by HDCF was an important pathway for its antihypertensive effect. These findings further elucidated the antihypertensive mechanism of HDCF and supported its application in functional foods and pharmaceuticals.