title: Preventive effects of a soy-based diet supplemented with stevioside on the development of the metabolic syndrome and type 2 diabetes in Zucker diabetic fatty rats.
abstract: The world witnesses an explosive increase in diabetes, demanding intensified prevention and treatment not least for the low-income population. The plant, Stevia rebaudiana Bertoni, has been used for the treatment of diabetes in traditional medicine. We have previously demonstrated that stevioside, a diterpene glycoside isolated from the plant Stevia rebaudiana Bertoni, possesses insulinotropic, glucagonostatic, antihyperglycemic, and blood pressure-lowering effects in animal studies. We have also found that a dietary supplement, Abalon, of soy protein, isoflavones, and cotyledon fiber has beneficial effects on cardiovascular risk markers in type 2 diabetes. The aim of this study was to investigate if the combination of stevioside and a dietary supplement of soy protein possesses beneficial qualities in the treatment of type 2 diabetes and the metabolic syndrome. We randomized male Zucker diabetic fatty rats into 4 groups and fed them the different test diets for 10 weeks: (A) standard carbohydrate-rich laboratory diet (chow), (B) chow+stevioside (0.03 g/kg body weight [BW] per day), (C) 50% soy (Abalon)+50% chow (adjusted for vitamins and minerals), and (D) 50% soy (Abalon)+50% chow+stevioside 0.03 g/kg BW per day. We measured plasma glucose, blood pressure, weight, and food intake once weekly. The animals were equipped with an intra-arterial catheter, and at week 10, the conscious rats underwent an intra-arterial glucose tolerance test (2.0 g/kg BW). Stevioside exerts beneficial effects in type 2 diabetic Zucker diabetic fatty rats, that is, lowers blood glucose (area under the glucose curve [AUC(30min)]: group A vs B, a 19% reduction; and group C vs D, a 12% reduction; P<.001). We did not detect any effect on insulin or glucagon responses. After 2 weeks of treatment, a decrease in the systolic blood pressure was observed in the stevioside-treated groups (P<.01). Abalon had beneficial effects on cardiovascular risk markers, that is, (1) lowers total cholesterol (P<.01), (2) reduces triglycerides (P=.01), and (3) reduces free fatty acids (P<.001). The combination of stevioside and soy supplementation appears to possess the potential as effective treatment of a number of the characteristic features of the metabolic syndrome, that is, hyperglycemia, hypertension, and dyslipidemia. A long-term human study of the concept in type 2 diabetic subjects is needed to verify these promising results in animal diabetes.
authors.affiliation: Department of Endocrinology and Metabolism C, Aarhus University Hospital, Aarhus Sygehus THG, 8000 Aarhus C., Denmark. stig.dyrskog@ki.au.dk
authors.forename: Stig Eric Underbjerg
authors.initials: SE
authors.lastname: Dyrskog
authors.forename: Per Bendix
authors.initials: PB
authors.lastname: Jeppesen
authors.forename: Michele
authors.initials: M
authors.lastname: Colombo
authors.forename: Reziwanggu
authors.initials: R
authors.lastname: Abudula
authors.forename: Kjeld
authors.initials: K
authors.lastname: Hermansen
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000178:diet therapy / Q000517:prevention & control*; D045786:Diterpenes, Kaurane / Q000494:pharmacology*; D005215:Fasting; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005960:Glucosides / Q000494:pharmacology*; D008297:Male; D024821:Metabolic Syndrome / Q000178:diet therapy / Q000517:prevention & control*; D051381:Rats; D011924:Rats, Zucker; D045730:Soy Foods; D013549:Sweetening Agents / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D045786:Diterpenes, Kaurane; D005230:Fatty Acids, Nonesterified; D005960:Glucosides; D013549:Sweetening Agents; D014280:Triglycerides; C012043:stevioside; D002784:Cholesterol