## 4 Biological Activities of Ginger Polysaccharides
### Anti-Coliitis Effects  
Ulcerative colitis (UC) is a chronic inflammatory digestive tract disease which is related to the severity of inflammation and has the characteristics of high recurrence rate and difficult cure. At present, the commonly used therapeutic drugs have certain side effects on human body, so people gradually seek compounds from natural sources, including polysaccharides, to treat UC [61; 62; 63]. In one study, the therapeutic effect of ginger polysaccharide (GP) on UC was investigated in mice with dextran sulfate sodium (DSS)-induced colitis. Eight-week-old male mice were randomly divided into a control group, model group, 5-ASA group, and GP group. In addition to the control group, the mice in other groups were infected with UC by drinking 3% DSS drinking water freely, and the models were made for 10 consecutive days. The 5-ASA group and GP groups were gavaged with 5-ASA and GP on days 1, 3, 5, 7, and 9, respectively. The control and model groups were gavaged with normal saline. We observed and recorded the weight, diarrhea, blood in stool, and other physiological symptoms of the mice every day, and we evaluated the disease activity index (DAI). On the 10 th day, the eyeball blood of mice was collected, the length of the colon and the weight index of the spleen were measured, and the organs were histopathological examined. Fecal samples of mice were collected for gut microbial analysis. The degree of colon tissue damage and the expression of pro-inflammatory factors were also detected. The results showed that the mouse model of DSS-induced colitis had the characteristics of decreased colon length, weight loss, and broken colon epithelium. After treatment with GP, the colon shortening was inhibited, and the weight loss trend and DAI index were alleviated. The pathological results showed that the model group mice had serious mucosal injury and fibrosis-related mucosal and submucosal collagen deposition, while the GP group showed that the disease process of the mice was delayed, and the GP significantly improved the degree of inflammation and the scope of lesions of the colon. It had protective effects on the injury induced by DSS. Using ELISA to detect the expression level of pro-inflammatory factors, such as TNF-\(\alpha\), IL-6, IL-1\(\beta\), IL-17A, and IFN-\(\gamma\) in tissues, it was found that the expression level of pro-inflammatory factors increased significantly in the model group, and the expression level of pro-inflammatory factors decreased significantly after GP treatment. This indicates that GP can inhibit the pathological inflammation of colitis by down-regulating the expression of pro-inflammatory factors. To detect the effect of DSS induction on the intestinal flora of mice and the effect of GP on the intestinal flora of mice, 165 rRNA gene amplification sequencing in the fecal matter was used for analysis. The results showed that the microenvironment of the intestinal bio-community in the model group mice was destroyed, and the abundance of bacterial colonies and the uniformity and diversity of bacterial species were reduced. GP group restored the imbalance and change of intestinal flora induced by DSS at different classification levels. In addition, GP can also protect the epithelial barrier and significantly reduce the apoptosis of colon epithelial cells, which plays an important role in the treatment of colitis. Based on these results, it can be seen that GP can effectively alleviate the symptoms of UC, regulate intestinal inflammation by inhibiting the level of pro-inflammatory factors, maintain the integrity of intestinal barrier, and regulate intestinal flora [29]. In addition, Zingiber officinala polysaccharides (ZOP) and ZOP-1 also had a significant anti-inflammatory effect on RAW264.7 cells cultured in vitro. ZOP and ZOP-1 showed no cytotoxicity to RAW264.7 and could promote its proliferation at the concentration range of 10-500 \(\mathrm{\SIUnitSymbolMicro g}\)/mL.