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.
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.
Dyrskog
Stig Eric Underbjerg
SE
Department of Endocrinology and Metabolism C, Aarhus University Hospital, Aarhus Sygehus THG, 8000 Aarhus C., Denmark. stig.dyrskog@ki.au.dk
Jeppesen
Per Bendix
PB
Colombo
Michele
M
Abudula
Reziwanggu
R
Hermansen
Kjeld
K
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
D001786:Blood Glucose; D045786:Diterpenes, Kaurane; D005230:Fatty Acids, Nonesterified; D005960:Glucosides; D013549:Sweetening Agents; D014280:Triglycerides; C012043:stevioside; D002784:Cholesterol