Carbon Quantum Dots in Palmyra Palm Jaggery: Evaluation of Antioxidative and Cytocompatibility Features

Abstract

Carbon quantum dots (C-QDs), the zero-dimensional carbon nanostructures, have attracted considerable attention because of their tremendous physical, chemical, and biological features. Food-borne C-QDs identification and their biological behavior assessment have been the most debated research in recent years. Thus, in this study, food-borne C-QDs were isolated from palmyra palm jaggery (PPJ). The optical, structural, and crystalline features of C-QDs were characterized. Additionally, we evaluated the antioxidant and cytocompatibility properties of C-QDs using an in vitro method. Transmission electron microscopic images revealed that C-QDs are semi-spherical with 10–35 nm in diameter. As a result of cytotoxicity test indicates that C-QDs reduced the cell viability by around 26% and 24% at 400 µg/mL exposure for 24 and 48 h, respectively. An acridine orange/ethidium bromide (AO/EB) staining effect ascribed to C-QDs enhanced cell death in human mesenchymal stem cells (hMSCs) through apoptosis. The LysoRed staining showed the internalization of C-QDs in hMSCs. Based on the mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) level assessment, the C-QDs do not induce MMP depletion and ROS generation in hMSCs even at high concentration exposure. SOD, GSR, and p53 genes were downregulated in hMSCs treated with C-QDs, but NFKB1 was significantly upregulated. Overall, the C-QDs isolated from PPJ are antioxidative and non-toxic. The C-QDs could be used as antioxidant agents in food formulations.