Evaluation of the Therapeutic Potential of Bioactive Materials Based on a Complex of Oxidovanadium(IV) and Exopolysaccharide Levan in a Model of Insulin Resistance in Mice

Bioactive compositions containing vanadium complexes have been a viable strategy for constructing more biocompatible and less toxic systems. Therefore, this work aim to develop a new composition formed by an oxidovanadium(IV) complex as levan. The acute oral toxicity and insulin resistance (IR) are investigated in an animal model using adult Swiss mice treated with daily injections of the synthetic glucocorticoid dexamethasone. The complex is characterized by electronic absorption (λ_max = 771 and 880 nm) and infrared spectroscopies (3359, 3167, 1606, 1342, 1072 cm^-1, and the VO at 937 cm^-1); NMR of the ¹H, ¹³C, and ⁵¹V (-427, -509, and -529 ppm), and electron paramagnetic resonance (g-factor = 1.985). The vanadium complex is classified in category 4, according to the acute toxicity protocol. IR in mice is accompanied by a rise in fasting blood glucose at seventh (2.2-fold) and 14th (threefold) days, triglyceride levels at seventh (2.6-fold) and 14th (threefold) days, and triglyceride/glucose index (TyG) at seventh (20%) and 14th (25%) days. The bioactive composition attenuated both the hyperglycemia (≈65%) and hypertriglyceridemia and TyG in a dose-dependent manner. The proposed composition shows promise in reducing IR induced by exogenous corticosteroid treatment.