Improved antidiabetic potential of quercetin-loaded chitosan–lecithin nanoparticles for effective glycaemic control

Introduction Diabetes mellitus is a major global health challenge, causing significant morbidity and mortality. Quercetin (QTN), a natural flavonoid, has potential antidiabetic and insulin-sensitising effects. However, its clinical use is limited by poor solubility and bioavailability. We developed the QTN loaded chitosan–lecithin nanoparticles (QTN/LCHS-NPs) to enhance its therapeutic profile.Materials and methods QTN/LCHS-NPs were synthesised using a 20:1 lecithin:chitosan ratio. Characterisation included encapsulation efficiency (%EE), particle size and zeta potential (ZP). In vitro, drug release studies were conducted to evaluate release kinetics. In vivo, pharmacokinetic and pharmacodynamic studies were performed in male Wistar rats to assess bioavailability, antidiabetic activity and lipid-modulating effects.Results The optimised QTN/LCHS-NP formulation exhibited 79.72% %EE, diameter of 130.1 nm, and a ZP of 23.46 mV. In vitro release studies showed a biphasic pattern, with an initial burst release followed by a sustained release of 86.10% over 24 h. Bioavailability (area under the curve, AUC: 167.22 h⋅µg/mL) exceeded free QTN (AUC: 26.2 h⋅µg/mL). Fasting blood glucose decreased from 292.9 to 107.7 mg/dL, along with improved lipid profiles.Conclusions QTN/LCHS-NPs significantly enhanced the oral bioavailability of QTN and improved its antidiabetic and antihyperlipidaemic effects, demonstrating their potential as an effective delivery system for addressing metabolic disorders.