Nanoencapsulation is a promising strategy for the development of novel therapeutic agents from crude aqueous extracts derived from Gmelina arborea Roxb. and Spondias pinnata (L.f) Kurz stem bark against type 2 diabetes mellitus. In this study, G. arborea and S. pinnata aqueous extracts encapsulated chitosan-tripolyphosphate nanoparticles (GAE-CS-TPP, SAE-CS-TPP) were prepared following the ionic gelation method and were characterized via various methods. The prepared nanoparticles were evaluated for their in vitro antidiabetic activity following the reported procedures. The antidiabetic potential of the GAE-CS-TPP and SAE-CS-TPP nanoparticles were evaluated against alpha-amylase, alpha-glucosidase, DPP-IV enzymes, glucose uptake, and glucose adsorption assays. SEM analysis revealed that the GAE-CS-TPP and SAE-CS-TPP were spherical-shaped with an average diameter of 138 +/- 30 nm and 129 +/- 19 nm respectively. The encapsulation efficiencies and the loading capacities of GAE-CS-TPP and SAE-CS-TPP were (57.64 +/- 2.38 % and 0.25 +/- 0.07 %) and (68.21 +/- 0.66 % and 0.79 +/- 0.17 %) respectively. The alpha-glucosidase, DPP-IV enzyme inhibitory activities (8.09 +/- 0.99 and 7.95 +/- 0.68 mg/mL,) of GAE-CS-TPP nanoparticles were more potent than that of G. arborea aqueous extract by 3.89 and 3.12 folds respectively. In conclusion, GAE-CS-TPP and SAE-CS-TPP nanoparticles exert antidiabetic activity to be used in pharmaceutical formulations to combat hyperglycemia in diabetes.
