Unlocking the potential of garlic by-product protein: Ultrasound-induced structural modification and fabrication of an ACE inhibitory peptide targeting endothelial dysfunction

This study aimed to explore the potential of ultrasound pretreatment to modify garlic by-product proteins and assist in the production of angiotensin I-converting enzyme (ACE) inhibitory peptides with protective effects against endothelial dysfunction. The ultrasound treatment disrupted intermolecular interactions and induced protein unfolding, leading to reduced α-helix content, decreased particle size and zeta potential, and enhanced ACE inhibitory activity of the enzymatic hydrolysates. Following optimal ultrasound-assisted (500 W) enzymatic hydrolysis, HDCF was successfully fabricated using a conventional isolation-purification-identification procedure, demonstrating the practical feasibility of producing computationally predicted peptides. HDCF protected human umbilical vein endothelial cells from Angiotensin II (Ang II)-induced oxidative damage by inhibiting intracellular reactive oxygen species production, modulating oxidation-related enzyme expression, and activating the Keap1/Nrf2 pathway. Furthermore, Ang II-induced inflammatory disorders were effectively mitigated by HDCF, through balancing pro- and anti-inflammatory cytokines, reducing cell adhesion molecules, and inhibiting the NF-κB signaling pathway. HDCF also reduced endothelial apoptosis by downregulating the ASK1-mediated mitochondrial apoptosis pathway. These results demonstrate ultrasound-induced modification of garlic proteins, present a sustainable strategy to valorize garlic by-products, and advance our understanding of this garlic-derived peptide in improving endothelial dysfunction for potential applications in functional foods or nutraceuticals.