stevioside and Diabetes-Mellitus--Type-1

Steviol glycosides, isolated from the plant Stevia rebaudiana (Bertoni) Bertoni, have been used as safe sweetening agents for more than 30 years. Beneficial effects of high doses of steviol glycosides on hyperglycemia and hypertension have been previously described when these abnormalities are present. This study was designed to evaluate the effects of steviol glycosides on blood glucose and on blood pressure (BP) in 3 groups of individuals. This was a randomized, double-blind, placebo-controlled, long-term study in three groups of patients: Group 1: subjects with Type 1 diabetes; Group 2: subjects with Type 2 diabetes; and Group 3: subjects without diabetes and with normal/low-normal BP levels. The subjects in each group were randomly allocated to active treatment (the steviol glycoside stevioside: 250mg t.d.s.) or to placebo treatment and followed-up for 3 months. Post-treatment systolic BP, diastolic BP, glucose and glycated hemoglobin (HbA1c) were not significantly different from baseline measurements, except for the placebo Type 1 diabetics group where a significant difference was observed for systolic BP and glucose. No side effects were observed in the two treatment groups. This study shows that oral steviol glycosides, taken as sweetener are well tolerated and have no pharmacological effect.

Topics: Adult; Aged; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diterpenes, Kaurane; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucosides; Glycated Hemoglobin; Humans; Hypotension; Insulin; Male; Middle Aged; Pilot Projects; Sweetening Agents

The purpose of the present study was to compare the effect of the oral treatment (gavage) with Stevia rebaudiana (Bert.) Bertoni (SRB) and stevioside (STV) on glycaemia and gluconeogenesis of 15-h fasted rats. For this purpose, the rats received SRB (20 mg/kg x day), STV (5.5 mg/kg x day) or an equal volume of water (controls) during 15 days. To measure hepatic gluconeogenesis, liver perfusion and isolated hepatocytes were used. Glycaemia and gluconeogenesis from L-alanine (5 mM), L-glutamine (5 mM) and L-lactate (2 mM) were decreased (P < 0.05) after pre-treatment with SRB. However, the treatment with STV did not influence glycaemia and gluconeogenesis. Moreover, to get further information about the mechanism by which SRB leaves inhibit gluconeogenesis their potential role as a PPARgamma agonist was investigated. The data showed absence of activation of PPARgamma receptors. In summary, our results showed that the reduction of glycaemia promoted by the treatment with SRB leaves was mediated, at least in part, by an inhibition of hepatic gluconeogenesis. However, this effect did not involve stevioside and the activation of PPARgamma receptors.

Topics: Administration, Oral; Animals; Diabetes Mellitus, Type 1; Diterpenes, Kaurane; Gluconeogenesis; Glucose; Glucosides; Hypoglycemic Agents; Liver; Male; Phytotherapy; Plant Extracts; Plant Leaves; Rats; Rats, Wistar; Stevia