Kiwi-derived N-doped green carbon dots: Antioxidant and anti-inflammatory potential for hyperglycemia control

Diabetes mellitus is a major global health problem characterized by chronic hyperglycemia, which can lead to serious complications if left untreated. In the recent years, the development of novel diagnostic and therapeutic tools for diabetes has become increasingly important. Among emerging approaches, the green synthesis of nanomaterials has drawn significant interest due to its eco-friendly nature. This study investigates the use of kiwifruit as a sustainable carbon precursor with triethanolamine as a nitrogen dopant for the phyto-mediated production of carbon dots (K-NCDs) utilizing a simple solvothermal technique. The produced K-NCDs were thoroughly characterized using UV–Visible spectroscopy, fluorescence spectrophotometry, FT-IR, X-ray diffraction (XRD), transmission electron microscopy, and others. The K-NCDs had an average size of 9.2±3 nm, a ζ-potential of -26.1±1.85 mV, and a quasi-spherical morphology. They exhibited an intense green emission under the excitation of 275 nm, with FT-IR analysis proving nitrogen doping and XRD verifying their amorphous structure. Biological activity evaluation demonstrated potent antioxidant and hypoglycemic effects.At a concentration of 5 mg/mL, K-NCDs achieved 99.6 % 2,2-diphenyl-1-picrylhydrazyl inhibition and a dose-dependent catalase-like activity. They also inhibited α-amylase, a key target for managing type 2 diabetes, by 79.7±2.66%. In vitro insulin-sensitizing assays on insulin-resistant HepG2 and PANC-1 cells revealed enhanced glucose at concentrations of 25-100 μg/mL. Moreover, oral hypoglycemic efficacy was confirmed in a streptozocin-induced diabetic rat model following a single 400 mg/kg oral dose. The study findings support the use of K-NCDs as a promising, eco-friendly therapeutic option for hyperglycemia.