ROS-driven, p53-mediated apoptosis in HepG2 cells induced byBlumea erianthacarbon quantum dots.

Carbon quantum dots (CQDs), owing to their small size, special surface functionalities, and remarkable fluorescence properties, have gained significant attention from researchers in the biomedical field. In the present work, CQDs were synthesized fromBlumea erianthaDC (BEDC) extract using green approach via microwave-assisted technique. The synthesized BEDC-CQDs were characterized using spectroscopic techniques to confirm their formation. Strong absorption peaks at 279.46 nm and 325.41 nm are attributed to the excitation ofπandnelectrons of C=C and C=O groups, respectively, indicating the formation of CQDs. HepG2 cells were treated with varying concentrations of BEDC-CQDs and gauged via MTT assay, flow cytometry, and western blot analysis. Reactive oxygen species (ROS) generation, and expression of p53 and MDM2 proteins were evaluated to determine the cytotoxic mechanism. BEDC-CQDs exhibited bright light-blue fluorescence under UV irradiation, with photoluminescence quantum yield 18.90%. X-ray diffraction peaks reveal the nano-crystalline nature of the BEDC-CQDs. High-resolution transmission electron microscopy analysis revealed that BEDC-CQDs are spherical particles with sizes ranging from 2.19 to 8.95 nm. The MTT assay of BEDC-CQDs on HepG2 cells demonstrated substantial cell cytotoxicity at a concentration of 50 μg ml^-1, with an IC₅₀value of 40.86 μg ml^-1. Flow cytometry results indicated that BEDC-CQDs induced apoptosis in HepG2 cells. Intracellular ROS levels were also found to be significantly increased in HepG2 cells after treatment with BEDC-CQDs. Western blot analysis further disclosed that the expression of p53 and MDM2 were increased by 6.282- and 3.836-fold, respectively, in BEDC-CQD treated HepG2 cells compared to the control. These observations suggest that the synthesized BEDC-CQDs could serve as a viable therapeutic agent against hepatocellular carcinoma and support further exploration of similar nanohybrids with other bioactive compounds.