title: Peptides-Derived from Thai Rice Bran Improves Endothelial Function in 2K-1C Renovascular Hypertensive Rats.
abstract: In recent years, a number of studies have investigated complementary medical approaches to the treatment of hypertension using dietary supplements. Rice bran protein hydrolysates extracted from rice is a rich source of bioactive peptides. The present study aimed to investigate the vasorelaxation and antihypertensive effects of peptides-derived from rice bran protein hydrolysates (RBP) in a rat model of two kidney-one clip (2K-1C) renovascular hypertension. 2K-1C hypertension was induced in male Sprague-Dawley rats by placing a silver clip around the left renal artery, whereas sham-operated rats were served as controls. 2K-1C and sham-operated rats were intragastrically administered with RBP (50 mg kg(-1) or 100 mg kg(-1)) or distilled water continuously for six weeks. We observed that RBP augmented endothelium-dependent vasorelaxation in all animals. Administration of RBP to 2K-1C rats significantly reduced blood pressure and decreased peripheral vascular resistance compared to the sham operated controls (p < 0.05). Restoration of normal endothelial function and blood pressure was associated with reduced plasma angiotensin converting enzyme (ACE), decreased superoxide formation, reduced plasma malondialdehyde and increased plasma nitrate/nitrite (p < 0.05). Up-regulation of eNOS protein and down-regulation of p47phox protein were found in 2K-1C hypertensive rats-treated with RBP. Our results suggest that RBP possesses antihypertensive properties which are mainly due to the inhibition of ACE, and its vasodilatory and antioxidant activity.
authors.affiliation: Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. kukkaiorachorn@gmail.com.
authors.forename: Orachorn
authors.initials: O
authors.lastname: Boonla
authors.affiliation: Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. upa_ku@kku.ac.th.
authors.forename: Upa
authors.initials: U
authors.lastname: Kukongviriyapan
authors.affiliation: Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ppoung@kku.ac.th.
authors.forename: Poungrat
authors.initials: P
authors.lastname: Pakdeechote
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. veerapol@kku.ac.th.
authors.forename: Veerapol
authors.initials: V
authors.lastname: Kukongviriyapan
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. patc_pan@kku.ac.th.
authors.forename: Patchareewan
authors.initials: P
authors.lastname: Pannangpetch
authors.affiliation: Department of Food Technology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand. suptha@kku.ac.th.
authors.forename: Supawan
authors.initials: S
authors.lastname: Thawornchinsombut
mesh_terms: D000818:Animals; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000473:pathology; D006977:Hypertension, Renal / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D007668:Kidney / Q000098:blood supply; D008026:Ligation; D008297:Male; D012275:Oryza / Q000737:chemistry*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
keywords: 2K-1C renovascular hypertension; Thai rice bran; angiotensin converting enzyme; endothelial function; nitric oxide; oxidative stress; rice bran peptides; vasorelaxation