Study Of The Protective Effects Of Three Kinds Apostichopus Japonicus Products On Intestinal Mucosal Immunity

Gut contacts with the external environment most intimately in the body, which is covered with a huge area of mucous system. Structure and function of the intestinal mucosa itself, as well as the intestinal flora, constitute a powerful intestinal mucosa barrier, resulting in harmful bacteria and viruses difficult to break through the defense and invade into the body. Ulcerative colitis (UC) is a common inflammatory bowel disease. Its pathological changes involve the colonic mucosa and submucosa with clinical effects of diarrhea, abdominal pain, mucous bloody stool, tenesmus, etc. Cyclophosphamide is a common clinical antitumor drug and also an immunosuppressant. It can cause damage to the gastrointestinal mucosa resulting in adverse reactions while playing the anti-tumor role. Sea cucumber is valuable as food and drug resources, which has a variety of nutritional benefits. Apostichopus japonicus is one edible sea cucumber species with the best quality in China. The main purpose of this paper was to investigate the protective effects of three kinds Apostichopus japonicus products (dried, instant and enzymatic Apostichopus japonicus) on intestinal mucosa injury caused by chemotherapeutic cyclophosphamide or ulcerative colitis. It will provide theoretical basis for answering the urgent issue, whether it is suitable for the patients with cancer or ulcerative colitis to eat sea cucumber. This study contributes to improve the life quality of special populations and bring good news to the patients with tumor or ulcerative colitis.This paper is mainly divided into two parts:I. Protective effects of three kinds Apostichopus japonicus products on colonic mucosal immunity of mice with ulcerative colitis. Based on TNBS induced ulcerative colitis mice model, mice were given three kinds Apostichopus japonicus products by gavage. The protective effects of Apostichopus japonicus were evaluated based on histology observation and detecting mRNA expression level of characteristic inflammatory factors and intestinal mucosal immune-related indicators. The results showed that mice treated with TNBS got mild ulcerative colitis, while Apostichopus japonicus could reduce inflammation and improve the colonic mucosa damage. Specific performances were as follows:down-regulated mRNA level of proinflammatory factor TNF-α, IL-1β and IFN-y/IL-4, which indicates improved Thl/Th2 balance and reduced the condition of ulcerative colitis in mice; increased the expression of proliferation protein PCNA and lowed the expression of apoptosis protein bax to maintain the integrity of the intestinal mucosa epithelial cells; promoted the expression of mucosal adaptive immune effector IgA and its receptor plgR; increased specific intestinal communities, such as probiotic bifidobacterium and lactobacillus, which indicates improved bacterial balance.2. Protective effects of three kinds Apostichopus japonicus products on small intestinal mucosal immunity of mice under chemotherapy. Based on intestinal mucosal damaged mice model induced by intraperitoneal injection of cyclophosphamide, the mice were given three kinds Apostichopus japonicus products by gavage. The protective effects of Apostichopus japonicus were evaluated by detecting the intestinal mucosa immune-related indicators. According to the results, Apostichopus japonicus could ameliorate the intestinal mucosa damage caused by chemotherapeutic cyclophosphamide. Specific performances were as follows: mitigated the body weight decrease, increased the immune organ indexs, which indicate innate immune improved; increased the cytoskeleton protein expression of small intestine, protected the villi integrity; improved expression of lysozyme, which is a representative factor of mucosal chemical barrier, to increase the intestinal resistance to harmful bacteria; promoted the expression of mucosal immune effect factor IgA and its receptor pIgR, improved the mucosal immune function; reversed the ratio of bacteroidetes and firmicutes, increased the abundance of bifidobacteria, recovered the diversity, structure and composition of intestinal flora, regulating intestinal flora. In addition, three kinds Apostichopus japonicus products showed different effects in terms of regulating intestinal flora, and the dried one was better, which might be related to its higher contents of polysaccharide and protein.In summary, three kinds Apostichopus japonicus products could ameliorate the intestinal mucosal damage caused either by ulcerative colitis or by cyclophosphamide. The effects were regarding as that Apostichopus japonicus could maintain the integrity of intestinal mucosa, improve the expression of intestinal mucosal barrier effectors and regulate gut microbiota. The results of this study provide theoretical basis for whether it is suitable for patients with cancer or ulcerative colitis to eat sea cucumber and which processing method is more suitable for patients.