Oral administration of zein-based nanoparticles reduces glycemia and improves glucose tolerance in rats

This is the authors' abstract. We don't add key points for this paper.

The aim was to evaluate the effect of zein-based nanoparticles on the glucose homeostasis, following oral administration to Wistar rats. For this purpose, bare nanoparticles (NP, with tropism for the upper intestinal regions) and poly(ethylene glycol)-coated nanoparticles (NP-PEG), with the capability to reach the ileum and cecum of animals, were evaluated. Both formulations were spherical in shape, displaying sizes around 200 nm and a negative surface zeta potential. The oral administration of a single dose of these nanoparticles to animals (50 mg/kg) induced a significant decrease of the glycemia, compared control rats and in animals treated with the free protein (p < 0.001). Moreover, these nanoparticles improved the glycemic control against an intraperitoneal glucose tolerance test; particularly NP-PEG. These findings would be due to an increased release of glucagon-like peptide-1 (GLP-1) by l-cells, which are more abundant in distal regions of the intestine. In fact, the GLP-1 blood levels of animals treated with nanoparticles were significantly higher than controls (about 40 % and 60 % for NP and NP-PEG groups, respectively). This higher capability of NP-PEG, with respect to NP, to increase the release of GLP-1 and control glycemia would be related to its ability to reach the distal areas of the small intestine.