A study on the antioxidant, cytotoxicity, and coagulation potential of carbon quantum dots derived from the leaves of Lagerstroemia speciosa

The green synthesis of carbon quantum dots (CQDs) from natural sources offers a sustainable approach in nanotechnology. In this study, CQDs were synthesized from Lagerstroemia speciosa leaves (LS-CQDs) and extensively characterized for their optical, structural, and biological properties. LS-CQDs exhibited UV-Vis absorption peaks at 247 and 351 nm, blue fluorescence, a mean particle size of 3.7 nm with a 0.22 nm d-spacing, and surface functional groups including -OH, -COOH, and -CH 3 . They demonstrated strong antioxidant activity, with a DPPH scavenging IC 50 of 66.34 μg mL -1 , and a hydrogen peroxide scavenging IC 50 of 319.48 μg mL -1 , highlighting their free radical neutralization ability. Cytotoxicity assessments confirmed LS-CQDs to be non-genotoxic, with minimal hemolysis (<2% at 2–200 μg mL -1 ), demonstrating excellent biocompatibility. Coagulation assays revealed a concentration-dependent anticoagulant effect, significantly prolonging PT (47 s) and aPTT (49 s) at 200 μg mL -1 , suggesting potential therapeutic applications in hypercoagulability associated with obesity-related cardiovascular diseases (CVDs). The dual-function antioxidant and anticoagulant properties of LS-CQDs underscore their potential as therapeutic agents for managing oxidative stress and coagulation disorders. This study highlights the promise of plant-derived nanomaterials in biomedical applications, warranting further exploration for clinical and commercial translation.