Ulcerative colitis (UC) is an inflammatory bowel disease that is persistent and nonspecific. There are several medications available for the treatment of UC. However, conventional UC medications have substantial adverse effects, low clinical effectiveness, and a high recurrence rate. Therefore, it is critical to discover new medicines that are both safe and effective for UC patients. Natural polysaccharides offer a wide range of pharmacological benefits, including anti-inflammatory, anti-virus, anti-tumor, anti-aging, immune enhancement, and gut flora regulation. In the therapy of UC, natural polysaccharides can modulate inflammatory factors, the immune system, and intestinal flora, and preserve the intestinal mucosa. It demonstrates a good curative effect and is of safety to use, thereby being a potential treatment for UC patients. This paper covers the structure, the pharmacological effects on UC, and the mechanisms of natural polysaccharides. Finally, limitations, challenges, and perspectives are discussed. It is hoped that the findings of this publication will inspire more natural polysaccharides research and provide a theoretical foundation for the creation of new UC medications.

Rheum tanguticum (R. tanguticum) has been widely used for the treatment of inflammatory diseases in clinical. However, limited research exist on the quality evaluation of various R. tanguticum locations, which has certain drawbacks. In this study, Fourier-transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC) were used to comparative study on the chemical contents of R. tanguticum, to clarify the relationship between the chemical contents and the spatial distribution of R. tanguticum. First of all, the FTIR spectra of 18 batches of R. tanguticum were examined. Following the cluster analysis, the FTIR spectra of various production locations differed. To some extent, establishing the double index analysis sequence of common and variation peaks may differentiate distinct production locations of medicinal materials. The HPLC fingerprint of R. tanguticum was constructed to further explore the link between components and their origin. PCA of common peaks of 18 batches of R. tanguticum indicated that R. tanguticum grown in Gannan and Qinghai had a tendency to separate t[2], however this trend was not noticeable. Then, OPLS-DA model was established, and the key differential components of R. tanguticum produced in Gannan and Qinghai were discovered to be R16, R37, R46, and R47 (Aloe emodin) (VIP ≥ 1 and P < 0.05). At last, Pearson’s test was used to examine the relationship between longitude, latitude, altitude, and composition. Longitude was significantly positively correlated with R28 and R30 (P < 0.05), and a very significantly positively correlated with R35, R36, R37, R46, and R47 (P < 0.01). Latitude was significantly negatively correlated with R34, R35, and R40 (P < 0.05), and extremely significantly negatively correlated with R28, R30, R36, R37, R46, and R47 (P < 0.01). Altitude was significantly positive correlation with R36 and R37 (P < 0.01). The results of our study can provide insights into R. tanguticum quality control and aid in establishing a natural medication traceability system.