The Rhei radix rhizoma-based carbon dots ameliorates dextran sodium sulphate-induced ulcerative colitis in mice

As an autoimmune disease of the colon, the incidence of ulcerative colitis (UC) remains high. Carbon dots (CDs), a new type of nanomaterials, display excellent biological activity and are expected to inspire a new treatment for UC. A green method was used to carbonise rhei radix rhizoma (RRR) and extract CDs to study their anti-ulcer activity. The RRR-based carbon dots (RRR-CDs) were characterised by electron microscopy, optical techniques, and other techniques. The results indicated RRR-CDs have abundant chemical groups, excellent solubility and tiny size (1.374 nm-4.533 nm), which may be conducive to the exertion of inherent activity. Using a classic dextran sodium sulphate (DSS)-induced UC mouse model, for the first time, it was demonstrated RRR-CDs have significant anti-ulcerative activity in improving DAI score (from 2.8 to 1.6), colon length (4.15 to 6.08), and histopathology in mice. The underlying mechanisms of anti-ulcerative activity may be related to haemostatic, antioxidant, and anti-inflammatory activities to protect the mucosal barrier. RRR-CDs have symptomatic and potential mechanisms of treatment and are expected to become a candidate drug for the treatment of UC. This not only further expands the basis for the biological activity of CDs, but provides a potential treatment plan for solving thorny diseases in clinical practice.