title: Angiotensin-converting enzyme inhibitory activity of Lactobacillus helveticus strains from traditional fermented dairy foods and antihypertensive effect of fermented milk of strain H9.
abstract: Hypertension is a major global health issue which elevates the risk of a large world population to chronic life-threatening diseases. The inhibition of angiotensin-converting enzyme (ACE) is an effective target to manage essential hypertension. In this study, the fermentation properties (titratable acidity, free amino nitrogen, and fermentation time) and ACE-inhibitory (ACEI) activity of fermented milks produced by 259 Lactobacillus helveticus strains previously isolated from traditional Chinese and Mongolian fermented foods were determined. Among them, 37 strains had an ACEI activity of over 50%. The concentrations of the antihypertensive peptides, Ile-Pro-Pro and Val-Pro-Pro, were further determined by ultra performance liquid chromatography with quadrupole-time-of-flight mass spectrometry. The change of ACEI activity of the fermented milks of 3 strains exhibiting the highest ACEI activity upon gastrointestinal protease treatment was assayed. Fermented milks produced by strain H9 (IMAU60208) had the highest in vitro ACEI activity (86.4 ± 1.5%), relatively short fermentation time (7.5 h), and detectable Val-Pro-Pro (2.409 ± 0.229 µM) and Ile-Pro-Pro (1.612 ± 0.114 µM) concentrations. Compared with the control, a single oral dose of H9-fermented milk significantly attenuated the systolic, diastolic, and mean blood pressure of spontaneously hypertensive rats (SHR) by 15 to 18 mmHg during the 6 to 12 h after treatment. The long-term daily H9-fermented milk intake over 7 wk exerted significant antihypertensive effect to SHR, but not normotensive rats, and the systolic and diastolic blood pressure were significantly lower, by 12 and 10 mmHg, respectively, compared with the control receiving saline. The feeding of H9-fermented milk to SHR resulted in a significantly higher weight gain at wk 7 compared with groups receiving saline, commercial yogurt, and captopril. Our study identified a novel probiotic L. helveticus strain originated from kurut sampled from Tibet (China), which is a valuable resource for future development of functional foods for hypertension management.
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China; Synergetic Innovation Center of Food Safety and Nutrition, Jiang Nan University, Wuxi, Jiang Su 214122, China.
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Xue
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Yuyu
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Lai-yu
authors.initials: LY
authors.lastname: Kwok
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Menghe
authors.initials: M
authors.lastname: Bilige
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China.
authors.forename: Lai
authors.initials: L
authors.lastname: Mang
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Huhhot 010018, P. R. China; Synergetic Innovation Center of Food Safety and Nutrition, Jiang Nan University, Wuxi, Jiang Su 214122, China. Electronic address: hepingdd@vip.sina.com.
authors.forename: Heping
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000032:analysis*; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000032:analysis*; D001794:Blood Pressure / Q000187:drug effects; D002681:China; D003611:Dairy Products / Q000032:analysis / Q000382:microbiology; D004032:Diet; D005285:Fermentation; D006973:Hypertension / Q000188:drug therapy; D052198:Lactobacillus helveticus / Q000378:metabolism*; D008297:Male; D008892:Milk / Q000737:chemistry* / Q000382:microbiology; D009842:Oligopeptides / Q000008:administration & dosage / Q000032:analysis; D019936:Probiotics; D051381:Rats; D011918:Rats, Inbred SHR; D018609:Tibet; D015014:Yogurt / Q000032:analysis / Q000382:microbiology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D009842:Oligopeptides; C489032:isoleucyl-prolyl-proline; C489031:valyl-prolyl-proline
keywords: Lactobacillus helveticus; angiotensin-converting enzyme inhibitory activity; antihypertensive; fermented milk; spontaneously hypertensive rats