Naringenin-citric acid carbon dots attenuate acute colitis by regulating oxidative stress, inflammation, and gut dysbiosis.

Ulcerative colitis (UC) is driven by excessive oxidative stress, persistent inflammation, and gut microbial dysbiosis, but current treatments often yield limited benefits and cause unwanted systemic adverse effects. In this study, carbon dots (NC-CDs) were synthesized from naringenin and citric acid through a simple one-step hydrothermal method. The obtained NC-CDs are uniformly sized at approximately 3 nm with abundant surface oxygen-containing groups, affording good water solubility and robust free radical scavenging activity. In vitro tests confirmed the favorable biocompatibility of NC-CDs, which effectively eliminated intracellular ROS and inhibited the production of pro-inflammatory cytokines. In a DSS-induced colitis mouse model, oral NC-CDs selectively accumulated in inflamed colonic regions, thereby relieving mucosal damage, improving colitis symptoms, and recovering gut microbial balance. In comparison with an uncarbonized naringenin-citric acid precursor mixture, NC-CDs exhibit superior therapeutic efficacy, demonstrating that the unique nanostructure of carbon dots, rather than simple free small-molecule precursors, contributes to the potent anti-colitis performance. This work suggests that carbon dots derived from natural compounds are promising therapeutic agents for UC treatment.