Rapeseed proteins are a rich source of bioactive peptides. LY, RALP and GHS were previously identified from rapeseed protein hydrolysates as potent ACE and renin inhibiting peptides. In this study, the rapeseed peptides were individually evaluated for their molecular mechanisms and regulatory effects on components of the renin–angiotensin system in spontaneously hypertensive rats (SHR), including the mRNA and/or protein levels of angiotensin-converting enzyme (ACE), renin, ACE2, angiotensin II and angiotensin-(1–7) in myocardial tissues. Oral administration of 30 mg peptides/kg body weight every 2 days for five weeks significantly decreased the systolic blood pressure and the myocardial mRNA and protein levels of ACE and renin in SHR. LY, RALP and GHS also increased the expression of ACE2, angiotensin-(1-7) and Mas receptor levels, which may have mediated their antihypertensive activity. Dipeptide LY also inhibited angiotensin II protein expression in the heart tissue. Taken together, the finding demonstrates the multi-target physiological effects of the rapeseed peptides, beyond ACE and renin inhibition, which enhances knowledge of the antihypertensive mechanisms of food protein-derived peptides.

油菜籽蛋白是生物活性肽的丰富来源。LY，RALP和GHS先前已从油菜籽蛋白水解物中鉴定为有效的ACE和肾素抑制肽。在这项研究中，对油菜素肽的分子机制和对自发性高血压大鼠（SHR）的肾素-血管紧张素系统组成的调节作用进行了单独评估，包括血管紧张素转化酶（ACE）的mRNA和/或蛋白质水平，心肌组织中的肾素，ACE2，血管紧张素II和血管紧张素-（1-7）。每2天口服30 mg肽/ kg体重，持续5周，可显着降低SHR中的收缩压以及ACE和肾素的心肌mRNA和蛋白水平。LY，RALP和GHS也会增加ACE2，血管紧张素-（1-7）和Mas受体的表达，可能介导了它们的降压活性。二肽LY还抑制心脏组织中血管紧张素II蛋白的表达。综上所述，该发现证明了油菜籽肽的多靶点生理作用超出了ACE和肾素的抑制作用，从而增强了对食品蛋白质衍生肽的降压机制的认识。