Fan Hongbing, Yu Wenlin, Liao Wang, Wu Jianping
Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Building, University of Alberta, Edmonton, AB T6G 2P5, Canada.
Cardiovascular Research Centre, University of Alberta, Edmonton, AB T6G 2R7, Canada.
Foods. 2020 Oct 1;9(10):1384. doi: 10.3390/foods9101384.
Spent hens are a major byproduct of the egg industry but are rich in muscle proteins that can be enzymatically transformed into bioactive peptides. The present study aimed to develop a spent hen muscle protein hydrolysate (SPH) with antihypertensive activity. Spent hen muscle proteins were hydrolyzed by nine enzymes, either individually or in combination; 18 SPHs were assessed initially for their in vitro angiotensin-converting enzyme (ACE) inhibitory activity, and three SPHs, prepared by Protex 26L (SPH-26L), pepsin (SPH-P), and thermoase (SPH-T), showed promising activity and peptide yield. These three hydrolysates were further assessed for their angiotensin-converting enzyme 2 (ACE2) upregulating, antioxidant, and anti-inflammatory activities; only SPH-T upregulated ACE2 expression, while all three SPHs showed antioxidant and anti-inflammatory activities. During simulated gastrointestinal digestion, ACE2 upregulating, ACE inhibitory and antioxidant activities of SPH-T were not affected, but those of SPH-26L and SPH-P were reduced. ACE inhibitory activity of gastrointestinal-digested SPH-T was not affected after the permeability study in Caco-2 cells, while ACE2 upregulating, antioxidant and anti-inflammatory activities were improved; nine novel peptides with five-eight amino acid residues were identified from the Caco-2 permeate. Among these three hydrolysates, only SPH-T reduced blood pressure significantly when given orally at a daily dose of 1000 mg/kg body weight to spontaneously hypertensive rats. SPH-T can be developed into a promising functional food ingredient against hypertension, contributing to a more sustainable utilization for spent hens while generating extra revenue for the egg industry.
淘汰蛋鸡是蛋品行业的主要副产品，但富含肌肉蛋白，这些蛋白可通过酶解转化为生物活性肽。本研究旨在开发具有降压活性的淘汰蛋鸡肌肉蛋白水解物（SPH）。用九种酶单独或组合水解淘汰蛋鸡的肌肉蛋白；最初评估了18种SPH的体外血管紧张素转换酶（ACE）抑制活性，由Protex 26L（SPH-26L）、胃蛋白酶（SPH-P）和嗜热酶（SPH-T）制备的三种SPH显示出良好的活性和肽产率。进一步评估了这三种水解物的血管紧张素转换酶2（ACE2）上调、抗氧化和抗炎活性；只有SPH-T上调了ACE2的表达，而所有三种SPH都显示出抗氧化和抗炎活性。在模拟胃肠道消化过程中，SPH-T的ACE2上调、ACE抑制和抗氧化活性不受影响，但SPH-26L和SPH-P的活性降低。在Caco-2细胞通透性研究后，胃肠道消化的SPH-T的ACE抑制活性不受影响，而ACE2上调、抗氧化和抗炎活性得到改善；从Caco-2渗透物中鉴定出9种具有五到八个氨基酸残基的新型肽。在这三种水解物中，当以1000mg/kg体重的日剂量口服给予自发性高血压大鼠时，只有SPH-T能显著降低血压。SPH-T可开发成为一种有前景的抗高血压功能性食品成分，有助于更可持续地利用淘汰蛋鸡，同时为蛋品行业创造额外收入。
