Stevioside inhibits artherosclerosis in obese insulin-resistant mice
MedWire News: A Belgian study has found that the natural sweetner stevioside reduces atherosclerosis in obese insulin-resistant mice.
Stevioside treatment was associated with increased adiponectin and insulin sensitivity and improved antioxidant defense in both the adipose tissue and the vascular wall, leading to inhibition of atherosclerotic plaque development and inducing plaque stabilization, the researchers report.
“Stevioside is a non-caloric natural sweetener that does not induce a glycemic response, making it attractive as sweetener to diabetics and others on carbohydrate-controlled diets,” note B Geeraert and team from the Catholic University of Leuven.
They looked at the effects of the sweetener on the expression of factors involved in the regulation of adipose tissue maturation, insulin signaling, inflammation and oxidative stress in the adipose tissue and aorta in relation to atherosclerosis in obese insulin-resistant mice.
In all, 14 mice were treated with 10 mg/kg stevioside and 20 with placebo for 12 weeks.
Stevioside treatment had no effect on weight and triglyceride levels, but lowered levels of glucose and insulin, improved adipose tissue maturation, and increased glucose transport, insulin signaling and antioxidant defense in white visceral adipose tissue, compared with placebo. These increases were in turn associated with a two-fold increase in adiponectin.
Stevioside also reduced plaque volume in the aortic arch by decreasing the macrophage, lipid and oxidized low-density lipoprotein content of the plaque, and increased expression of the antioxidant superoxide dismutases (Sods) 1,2 and 3. Circulating adiponectin was associated with improved insulin signaling and antioxidant defense in both the adipose tissue and the aorta of stevioside-treated mice.
Writing in the International Journal of Obesity, the researchers conclude: “The improved antioxidant defense can be attributed mainly to increased expressions of Sods.”
They recommend large-scale studies in humans and suggest that “the action of stevioside for preventing insulin resistance in obese persons requires further attention.”
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By Joel Levy