Protective effect of carbon dots derived from scrambled Coptidis Rhizoma against ulcerative colitis in mice.

Introduction: Ulcerative colitis (UC) is a chronic and progressive inflammatory disease of the intestines. The primary symptoms, such as bloody diarrhea, can result in weight loss and significantly diminish the patient's quality of life. Despite considerable research endeavors, this disease remains incurable. The scrambled Coptidis Rhizoma (SCR) has a rich historical background in traditional Chinese medicine as a remedy for UC. Drawing from a wealth of substantial clinical practices, this study is focused on investigating the protective effects and underlying mechanisms of the active component of SCR, namely SCR-based carbon dots (SCR-CDs), in the treatment of UC. Methods: SCR-CDs were extracted and isolated from the decoction of SCR, followed by a comprehensive characterization of their morphological structure and functional groups. Subsequently, we investigated the effects of SCR-CDs on parameters such as colonic length, disease activity index, and histopathological architecture using the dextran sulfate sodium (DSS)-induced colitis mice model. Furthermore, we delved into the assessment of key aspects, including the expression of intestinal tight junction (TJ) proteins, inflammatory cytokines, oxidative stress markers, and gut microbial composition, to unravel the intricate mechanisms underpinning their therapeutic effects. Results: SCR-CDs displayed a consistent spherical morphology, featuring uniform dispersion and diameters ranging from 1.2 to 2.8 nm. These SCR-CDs also exhibited a diverse array of surface chemical functional groups. Importantly, the administration of SCR-CDs, particularly at higher dosage levels, exerted a noteworthy preventive influence on colonic shortening, elevation of the disease activity index and colonic tissue impairment caused by DSS. These observed effects may be closely associated with the hygroscopic capability and hemostatic bioactivity inherent to SCR-CDs. Concurrently, the application of SCR-CDs manifested an augmenting impact on the expression of intestinal TJ proteins, concomitantly leading to a significant reduction in inflammatory cell infiltration and amelioration of oxidative stress. Additionally, SCR-CDs treatment facilitated the restoration of perturbed gut microbial composition, potentially serving as a fundamental mechanism underlying their observed protective effects. Conclusion: This study demonstrates the significant therapeutic potential of SCR-CDs in UC and provides elucidation on some of their mechanisms. Furthermore, these findings hold paramount importance in guiding innovative drug discovery for anti-UC agents.

A Novel Drug with Potential to Treat Hyperbilirubinemia and Prevent Liver Damage Induced by Hyperbilirubinemia: Carbon Dots Derived from Platycodon grandiflorum.

Platycodon grandiflorum (PG) is a traditional Chinese medicine with a long history, but its active compounds have not been reported. In this study, novel carbon dots (CDs), PG-based CDs (PGC-CDs), were discovered and prepared from PG via calcinations and characterized by transmission electron microscopy; high-resolution transmission electron microscopy; X-ray diffraction, fluorescence, ultraviolet-visible, and Fourier-transform infrared spectrometers; X-ray photoelectron spectroscopy; and high-performance liquid chromatography. In addition, the safety and antioxidant activity of PGC-CDs was evaluated by RAW264.7 cells and LO2 cells. The therapeutic effects of PGC-CDs on hyperbilirubinemia and liver protection were evaluated in a bilirubin-induced hyperbilirubinemia mice model. The experiment confirmed that the diameter range of PGC-CDs was from 1.2 to 3.6 nm. PGC-CDs had no toxicity to RAW264.7 cells and LO2 cells at a concentration of 3.91 to 1000 µg/mL and could reduce the oxidative damage of cells caused by H2O2. PGC-CDs could inhibit the increase levels of bilirubin and inflammation factors and increase the levels of antioxidants and survival rate, demonstrating that PGC-CDs possessed anti-inflammatory and anti-oxidation activity. PGC-CDs may reduce the content of bilirubin, so as to reduce a series of pathological lesions caused by bilirubin, which has potential in treating hyperbilirubinemia and preventing liver damage induced by hyperbilirubinemia.

[Primary culture and identification of rat glomerular microvascular endothelial cells].

The aim of the present study was to establish a simple and efficient method for isolation and culture of primary rat glomerular microvascular endothelial cells in vitro. The bilateral kidneys were taken from 7-10-day old Sprague-Dawley rats, and the renal cortex was separated. Glomeruli were obtained by cutting and continuously passing 200-mesh and 300-mesh sieves. After type IV collagenase digestion for 15-20 min, renal microvascular globules were collected for inoculation and culture. The cultured cells were identified by cell morphology observation and immunocytochemical staining with factor VIII related antigen. The results showed that the renal microvascular globules were irregularly spherical, without cysts, and the capillary loop structure was clear; after 3 days of primary culture, short spindle-shaped cells crawled out around the renal microvascular globules and gradually formed cell colonies, showing an "island-like shape" distribution; 4-5 days later, the cell colonies fused with each other; 6 days later, the cells covered the bottom of the dish, showing a typical monolayer, paving stone-like, mosaic arrangement. The immunocytochemical staining of factor VIII related antigen showed that the cytoplasm was lightly stained brownish red, and factor VIII related antigen-positive rate of cells was nearly 100%. The above results suggested that this study successfully established a method combining continuous screening and collagenase digestion for culture of primary rat glomerular microvascular endothelial cells in vitro. It provides an important tool cell for studying the mechanism of the occurrence and development of diabetic nephropathy.

[Primary culture and identification of mouse brain microvascular endothelial cells].

Objective To develop and establish a simple and repeatable method of primary culture of mouse brain microvascular endothelial cells (BMECs) of relatively high purity. Methods Isolated and cultured from the brain tissue of ICR mice aged 2-3 weeks old, the mouse BMECs were gained through physical fragmentation methods such as cutting up and passing through cell sieve, BSA density gradient centrifugation and chemical enzyme digestion. The digestion time of 1 g/L type II collagenase was strictly controlled within 15-20 minutes. The cultured cells were identified by cell morphological observation and immunocytochemical staining to detect factor VII-associated antigen. Results In 24 hours after seeding, the spindle-shaped or polygon-shaped cells began to migrate from the micro vessel segment and gradually gathered and grew in clusters; after 7 days, the fused cells showed a typical single layer and arranged in the shape of paving stone. VII-associated antigen showed positive in the cytoplasm which was brown red. The purity of microvascular endothelial cells was above 95%. Conclusion We have successfully established a simple and repeatable primary culture method for mouse BMECs of relatively high purity.