## 4 Discussion  
The DPPH method is generally used to evaluate the antioxidant effects and the antioxidant capacity of active substances. The DPPH radical with a single electron is a stable free radical. In the presence of a free radical scavenger, the free radical pairs with its single electron to reduce its absorption, and this change can evaluate the antioxidant properties of active substances [20]. ABTS\({}^{+}\) free radicals become green during oxidization. When antioxidants exist, ABTS\({}^{+}\) reacts with antioxidants and decreases the color of ABTS\({}^{+}\) free radicals. The antioxidant effect can be evaluated by the degree of fading [21]. The hydroxyl free radical is a highly active and highly toxic oxygen-free radical, which is the main factor that leads to disease and aging and it can considerably harm the body [22]. In the present study, three methods were used to evaluate the antioxidant effects of Shuidouchi that was fermented with different techniques; the highest antioxidant activity of Shuidouchi was preliminarily obtained. Studies have shown that soybean isoflavones can significantly reduce lipid peroxidation and improve the levels of the blood total antioxidant status (TAS). It can effectively scavenge free radicals, stop the chain reaction of free radicals, and prevent the oxidation of unsaturated fatty acids in lipids and endothelial membranes, thus preventing many diseases that are caused by free radicals in vivo [23]. In the current study, the soybean isoflavone content in Shuidouchi was determined, and the Shuidouchi with the best antioxidant efficacy was designed. Studies have indicated that antioxygen is gradually applied in the clinical setting. Colitis can be inhibited because antioxygen scavenging free radicals inhibit peroxidation and inflammation [24]. Soybean isoflavone is the main source of the antioxidant capacity of soybeans, which exerts a good anti-inflammatory and anti-cancer role [25]. Thus, the current study also tests the intestinal protection of Shuidouchi by designing its best antioxidant effect. To some extent, DPPH scavenging free radicals indicated the antioxidant capacity of Shuidouchi; however, the effect and utilization rate of DPPH in organisms requires further study. Colitis is a type of intestinal inflammation, which includes ulcerative colitis, ischemic colitis, and pseudomembranous colitis. Ulcerative colitis exhibits the highest incidence, reaching 10/100,000 [26]. Studies have shown that patients with ulcerative colitis, who have a medical history of 10 y, have a greatly increased risk of colon cancer, posing a risk of almost 10% for patients with a medical history of 25 y [27]. Food therapy for the prevention of severe intestinal diseases is currently a widely studied  
Figure 15: Protein expression levels of IL-6, IL-12, and tumor necrosis factor-\(\alpha\) (TNF-\(\alpha\)) in the colon tissue of mice. SDC-L: 2 g/kg Shuidouchi extract treatment; SDC-H: 4 g/kg Shuidouchi extract treatment; sulfasalazine: 20 mg/kg sulfasalazine treatment. subject. In the present study, the animal model with colitis was treated with Shuidouchi that was fermented using an improved method and the preventive effects of such a method on colitis was observed. Colitis can cause the erosion and swelling of colonic mucosa, which can shorten the intestinal canal; as a result of the swollen and congested colon, the weight of the colon increases and the colon shortens, which leads to an increase in the ratio of the weight of the colon to the length of the colon. Previous studies indicated that this colon mass-to-colon length ratio is an important indicator of the degree of experimental ulcerative colitis. The higher the severity of colitis, the shorter the colon length in mice and the larger the colon mass-to-colon length ratio [28]. In the current study, mice with DSS-induced colitis showed a shorter colon and a larger colon weight-to-colon length ratio. Shuidouchi extract could significantly inhibit these changes and thus prevent colitis.