title: Intracerebroventricular administration of soy protein hydrolysates reduces body weight without affecting food intake in rats.
abstract: Some studies suggest that increased consumption of soy protein hydrolysates may cause body weight loss but the mechanism of action is unknown. The objective of this investigation was to determine whether intracerebroventricular (i.c.v.) infusion of soy protein hydrolysates decrease food intake and body weight. Adult male Sprague Dawley rats (n = 24) received i.c.v. injections of soy hydrolysate I (SH I) or soy hydrolysate II (SH II) three times weekly for 2 weeks. Krebs solution and leptin were used as negative and positive controls respectively. SH I (6.5-20 kDa with a strong band at 14 kDa) was produced by hydrolysis with alcalase, and SH II (approximately 2 kDa) was obtained by hydrolysis and ultrafiltration. Leptin successfully reduced body weight (-1.60 g) 24 h (p = 0.0093) after the third injection. SH I caused significant (p = 0.0009) decreases in body weight (-1.70 g) 24 h after the third injection but not after 48 h. SH II showed a tendency to prevent body weight gain but this effect was short of statistical significance (p < 0.40). Food intake was not affected by any of the soy hydrolysate treatments but leptin injection did cause significant decreases in food intake (p < 0.05). Data suggest that soy alcalase hydrolysate can decrease, in the short term, the rate of body weight gain independently of food consumption. This preliminary data show that soy peptides may play a role on body weight regulation, possibly by increasing energy utilization.
authors.affiliation: Department of Food Science & Human Nutrition, University of Illinois at Urbana-Champaign, 228 Edward Madigan Laboratory, 1201 West Gregory Drive, Urbana, IL 61801, USA.
authors.forename: Nerissa
authors.initials: N
authors.lastname: Vaughn
authors.forename: Anthony
authors.initials: A
authors.lastname: Rizzo
authors.forename: Dolores
authors.initials: D
authors.lastname: Doane
authors.forename: J Lee
authors.initials: JL
authors.lastname: Beverly
authors.forename: Elvira
authors.initials: E
authors.lastname: Gonzalez de Mejia
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000502:physiology; D018592:Cross-Over Studies; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000187:drug effects*; D007276:Injections, Intraventricular; D020738:Leptin / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D009765:Obesity / Q000188:drug therapy; D011492:Protein Hydrolysates / Q000008:administration & dosage / Q000494:pharmacology; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D030262:Soybean Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D015431:Weight Loss / Q000187:drug effects
chemical_list: D020738:Leptin; D011492:Protein Hydrolysates; D030262:Soybean Proteins