LEUVEN, Belgium—A recent study published in the International Journal of Obesity found stevioside treatment was associated with improved insulin signaling and antioxidant defense in both the adipose tissue and the vascular wall, leading to inhibition of atherosclerotic plaque development and inducing plaque stabilization (2010;34: 569-77). Twelve-week-old mice were treated with stevioside (10 mg kg−1, n=14) or placebo (n=20) for 12 weeks.
Stevioside had no effect on weight and triglycerides, but lowered glucose and insulin. Stevioside treatment improved adipose tissue maturation, and increased glucose transport, insulin signaling and antioxidant defense in white visceral adipose tissues. Together, these increases were associated with a two-fold increase of adiponectin. In addition, stevioside reduced plaque volume in the aortic arch by decreasing the macrophage, lipid and oxidized low-density lipoprotein (ox-LDL) content of the plaque. The higher smooth muscle cell-to-macrophage ratio was indicative for a more stable plaque phenotype. The decrease in ox-LDL in the plaque was likely due to an increase in the antioxidant defense in the vascular wall, as evidenced by increased Sod1, Sod2 and Sod3. Circulating adiponectin was associated with improved insulin signaling and antioxidant defense in both the adipose tissue and the aorta of stevioside-treated mice.
