Anti-hyperglycemic activity of anthocyanins loaded in non-ionic niosomes

Anthocyanins (ACNs) are polyphenols that possess antioxidant and anti-inflammatory effects [1] In addition, it has been reported that the ACNs affect hyperglycemia and insulin secretion in diabetic animal models [2]. However, there is some controversy regarding their bioavailability. In the present study, the anti-hyperglycemic activity of oral delivery of ACN-loaded niosomes was investigated and evaluated.

Anthocyanins extracted from Vaccinium Meridionale Sw (Mortiño) by the Supercritical Fluid Extraction (SFE) method, and loaded into Niosomes, were prepared by agitation and sonication using non-ionic surfactant vesicles. The prepared niosomal formulation was characterized by its morphology using Transmission Electron Microscopy (TEM) and administrated in drinking water to obese, insulin resistant mice. We evaluated the effect of ACN-loaded niosomes on hyperglycemia, glucose and insulin intolerance and insulin blood levels in C57BL/6J mice fed with a high-fat diet (HFD). After 2 weeks of treatment, the animals were sacrificed, and blood samples were taken to evaluate glucose and insulin plasma levels and lipid profile.

We demonstrate that ACN-loaded niosomes were more effective in improving insulin resistance and glucose intolerance in mice fed an HFD, than ACN alone. Data showed no change in triglycerides, HDL and LDL cholesterol levels. However, administration of ACN-loaded niosomes reduced insulin, glucose and total cholesterol in mice fed with an HFD.

[1] Kim, H. J, Tsoy, I, Park, J. M, Chung, J. I. et al, FEBS Lett. 2006, 580, 1391 – 1397.

[2] Sasaki, R, Nishimura, N, Hoshino, H, Isa, Y. et al, Biochem. Pharmacol. 2007, 74, 1619 – 1627.