Oral Carbon Dots Derived from Cimicifugae rhizome Carbonization Products to Ameliorate Ulcerative Colitis

Ulcerative colitis (UC) management remains challenging due to limitations of conventional therapies in disrupting the pathological cycle of ROS overproduction and gut microbiota dysbiosis. Inspired by traditional "carbonized herbs," this study developed Cimicifugae rhizome-derived carbon dots (CR-CDs) by one-step pyrolysis. CR-CDs exhibited robust multienzyme mimetic (SOD/CAT-like) activity, effectively scavenging ROS and suppressing the LPS-stimulated inflammatory response in vitro. In dextran sulfate sodium (DSS)-induced murine colitis, orally administered CR-CDs accumulated preferentially in inflamed colon tissue and targeted macrophages. Treatment significantly alleviated UC symptoms and histological damage while restoring tight junction proteins and improving the Nrf2/HO-1 antioxidant signaling. Additionally, CR-CDs rebalanced gut microbiota composition, suppressing the pathogenic Aeromonas hydrophila and enriching beneficial Rikenellaceae/Muribaculaceae. By integrating traditional carbonization wisdom with nanotechnology, CR-CDs present a dual-functional therapeutic platform addressing both oxidative stress and microbial dysbiosis in UC, with significant potential for clinical translation.