title: High molecular weight poly-gamma-glutamic acid regulates lipid metabolism in rats fed a high-fat diet and humans.
abstract: We investigated the effect of high molecular weight polygamma- glutamic acid (hm gamma-PGA) on adiposity and lipid metabolism of rats in the presence of an obesity-inducing diet. Thirty-two Sprague-Dawley rats were fed either a normal-fat (11.4% kcal fat, NFC) or high-fat (51% kcal fat, HFC) diet. After 5 weeks, half of each diet-fed group was treated with hm gamma-PGA (NFP or HFP) for 4 weeks. The HFC group had significantly higher body weight, visceral fat mass, fasting serum levels of total cholesterol, LDL cholesterol, and leptin, and lower serum HDL cholesterol level compared with those of the NFC group (p < 0.05). Treatment with hm gamma-PGA decreased body weight gain and perirenal fat mass (p<0.05), fasting serum total cholesterol, and mRNA expression of glucose-6- phosphate dehydrogenase (G6PD), regardless of dietary fat contents (p < 0.01). However, hm gamma-PGA increased serum HDL cholesterol in the HFC group (p < 0.05). In vitro, 3-hydroxy-3-methylglutaryl coenzyme-A (HMGCoA) reductase activity was suppressed by the addition of hm gamma-PGA. In agreement with observations in animal study, the supplementation of hm gamma-PGA (150 mg/day) to 20 female subjects in an 8-week double-blind, placebocontrolled study resulted in a tendency to decrease total cholesterol and LDL cholesterol concentrations. We thus conclude that dietary supplementation of hm gamma-PGA may act as a hypocholestrolemic agent, secondary to its inhibitor effect on HMG-CoA reductase, and decrease abdominal adiposity by decreasing hepatic lipogenesis. The present study is an important first step in establishing the effect of hm gamma-PGA on cholesterol levels in rats and humans.
authors.affiliation: Department of Food and Nutrition, Kookmin University, Seoul 136-702, South Korea.
authors.forename: Ji Ho
authors.initials: JH
authors.lastname: Park
authors.forename: Jae-Chul
authors.initials: JC
authors.lastname: Choi
authors.forename: Moon-Hee
authors.initials: MH
authors.lastname: Sung
authors.forename: Jae-Heon
authors.initials: JH
authors.lastname: Kang
authors.forename: Moon-Jeong
authors.initials: MJ
authors.lastname: Chang
mesh_terms: D050154:Adiposity / Q000187:drug effects*; D000818:Animals; D000924:Anticholesteremic Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism*; D050218:Body Fat Distribution; D001835:Body Weight; D004032:Diet / Q000379:methods*; D004311:Double-Blind Method; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D008055:Lipids / Q000097:blood; D008970:Molecular Weight; D010919:Placebos / Q000008:administration & dosage; D011099:Polyglutamic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D016896:Treatment Outcome
chemical_list: D000924:Anticholesteremic Agents; D008055:Lipids; D010919:Placebos; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D006903:Hydroxymethylglutaryl CoA Reductases; D005954:Glucosephosphate Dehydrogenase