Abstract
Background: Rubia cordifolia L. (RCL) Carbonisata is a typical calcined natural medicinal plant, which has been used for thousands of years for hemostasis. At present, some studies have shown that some components of processed RCL Carbonisata can enhance hemostasis, but the specific hemostatic material basis is still unclear. Novel carbon dots (CDs) were obtained from Rubia cordifolia L. and named RCL-CDs to explore the hemostatic effect and mechanism of RCL-CDs obtained from Rubia cordifolia L. Methods: RCL-CDs were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet visible spectroscopy (UV-Vis), fluorescence spectroscopy (FL), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The hemostatic effect of RCL-CDs was evaluated in a mouse tail amputation model and liver scratch model, and the hemostatic mechanism was explored using a capillary coagulation model and coagulation parameters. Results: The particle size distribution of RCL-CDs ranged from 1.74 nm to 9.78 nm, the maximum population was 3-4 nm, and the average particle size was 3.82 nm. The RCL-CDs were approximately spherical with a lattice spacing of 0.206 nm. The quantum yield (QY) of RCL-CDs is 1.09%, and there is a distinct diffraction peak at 2θ = 24.76°. The elemental composition of RCL-CDs was mainly C (65.28%), O (30.10%), and a small amount of N (4.62%). Pharmacological experiments showed that bleeding time and bleeding volume were reduced in mice treated with RCL-CDs. It is worth noting that the low-, medium- and high-dose RCL-CD groups can significantly reduce the blood loss, while the high-dose RCL-CD group can significantly reduce the bleeding time of the mouse tail amputation model and liver scratch model. Additionally, the fibrinogen level (FIB) and platelet counts (PLT) increased and prothrombin time (PT) decreased in rats after treatment with RCL-CDs. Conclusions: RCL-CDs have a significant hemostatic effect, and the mechanism may be exogenous coagulation and activation of fibrinogen. This explains the material basis of the hemostatic effect of RCLC and opens new avenues for more in-depth investigation. In addition, new insights into the potential biomedical applications of CDs in the field of nanohemostasis are provided and a solid foundation for the discovery of novel hemostatic agents is established.