Abstract: Peptides of VPP and IPP with potent inhibitory activity on angiotensin I-converting enzyme (ACE) and hypertensive function were purified from the sour milk fermented with Lactobacillus helveticus JCM 1004 and Lactobacillus casei subsp. Casei ATCC393 by using four-step reverse-phase HPLC.The concentrations of VPP and IPP providing 50% inhibition of ACE (IC50) were 8.89 and 5.17 M,respectively.The most effective values of 12.3±3.7、17.9±4.2、25.3±4.3 and 16.8±3.4、25. 5±4.6、29.1±3.5 mmHg of decreasing systolic blood pressure (SBP) of spontaneously hypertensive rats after gastric intubation of VPP at the dosages of 0.90、1.80、3.60 mg/kg of body weight/day or IPP at the dosages of 0.60、1.20、1.80 mg/kg of body weight/day were obtained, respectively. Outstanding significance in the differences was showed in above results.

Key words: sour milk, VPP, IPP, ACE, antihypertensive