Antihypertensive Peptide ENWAAL Derived from Coix Glutelin and Its Effect on the Expression of SHR Renin–Angiotensin System

Hypertension is one major risk factor of cardiovascular diseases, and RAS plays vital role during the development of hypertension. To obtain a novel antihypertensive peptide, Coix glutelin was hydrolyzed by trypsin and further separated by Sephadex G10. Based on 751 identified sequences, pharmacophore mapping, molecular docking, and in silico proteolysis were applied to screen and optimize the candidate sequence. Finally, a novel peptide, ENWAAL, was generated with IC50 of 210.57 μM, which acted with ACE in a competitively inhibitory pattern. The in vivo antihypertensive effect was evaluated in SHRs. Significant improvements were observed in hypertension-related characteristics, including blood pressure, cardiac structure and function, and serum angiotensin II (Ang II) level. In the brain, quantitative real-time PCR analysis revealed significant downregulation of angiotensin II type 1 receptor (AT1R) mRNA expression, concomitant with upregulation of angiotensin-converting enzyme 2 (ACE2) and MAS receptor. The protein expression of ACE and AT1R in the ENWAAL group also significantly decreased. This study can provide a candidate antihypertensive drug targeting RAS.