The Functional Evaluation Of Oryzanol From Rice Bran On Acute Colitis In Mice And Study Its Primary Mechanism Study

China is the largest rice producer in the world and an annual output is over200million tons. Bran, byproducts of rice processing, is producted about14million tons per year in China. Rice bran is polysaccharide, protein, fat, cellulose, mineral and vitamin B family, three allyl phenol and other physiological functions of active substances. Among them, the content of oryzanol is one the richest components in rice bran.Oryzanol, a fat-soluble saponification substance, is a complex of cycloartenol and phytosterol alcohol ferulic acid esters. It has many physiological functions, such as antioxidation, scavenging free radicals, reducing blood fat and so on. In recent years, investigators found oryzanol possibly exists the function of antiinflammation. Researchers combined application of oryzanol and other anti-inflammatory drugs for prevention and treatment of inflammation in the clinic, and found oryzanol can enhance curative effect, but it lacks experimental evidences and the mechanism is unclear. In this study, we evaluated the function of oryzanol from rice bran on acute colitis in mice and study its primary mechanism study.The animal model of dextran sulfate sodium (DSS) has been widely used in the inflammation studies. DSS-induced colitis model is very similar with human of colitis, and they have similar pathogenesis, pathologic characteristics, clinical manifestation and parts of cytokines. Three days before modeling, oryzanol is mice in corn oil and consecutively gavaged for10days and mice are drinking5%DSS water for7days to establish acute colitis model to induce inflammation. In this study, we use DSS to induce acute ulcerative colitis.After treatment of DSS, the mice showed laziness, loss of their appetites and other pathologic charcteristics, particularly, their weights have been reduced dramatically. The disease active index (DAI) of control group, DSS group and oryzanol group (DSS+oryzanol) are0.31±0.42,9.21±2.32and7.18±2.02, respectively. Comparing with DSS group mice, oryzanol can partly decrease the DAI in the mice (P<0.05), but it still exist significant difference between control group and oryzanol protection group in mice. The weights of control group, DSS group and oryzanol group (DSS+oryzanol) are19.85±1.05,15.23±1.02and16.88±0.98grams, respectively. Comparing with DSS group mice, oryzanol can partly increase the weight in the mice (P<0.05), but it still exist significant difference between control group and oryzanol protection group in mice. The weight and length of the colon of animals has been evaluated, and DSS results significantly increase in weight and reduce length of colon in mice (P<0.05). Comparing DSS group, oryzanol group can decrease the weight of mice and increase length in mice (P<0.05). The spleen enlargement has been discovered in DSS group and spleen weight is evaluated among three groups (P<0.05). We found DSS will increase the weight of spleen and oryzanol can partly reduce the weight of mice. It suggests oryzanol has protection role on DSS-induced acute colitis and oryzanol exist antiinflammationary role.Pathological changes of colon were analyzed by HE staining. After treatment of DSS, colonic epithelium mucosa was dissipated and seriously damaged, and structure of the crypt also damage and become unclear. Lymphocytes and neutrophils were infiltrated into colonic tissues, and the number of goblet cells was decreased. Comparing with DSS group, oryzanol can decrase lymphocytes and neutrophils infiltration in colonic tissues and inhibits DSS-induced goblet cells decrease. It suggest that oryzanol can ameliorate acute colitis in mice and alleviate inflammation.COX-2and iNOS are the most inflammatory factors in the colitis, and overexpressions of mRNAs of COX-2and iNOS play a vital role in inflammation. To investigate the possible mechanism of oryzanol to prevent inflammation, the mRNAs of COX-2and iNOS have been studied by quantitative real-time PCR (qPT-PCR). After treatment of DSS, Cox-2and iNOS mRNA expression levels significantly increase in colonic tissues in mice (Comparing with control group). Comparing with DSS group, oryzanol can significantly inhibit expression of Cox-2and iNOS in colonic tissues. It suggests that oryzanol can inhibit colitis thorugh decreasing the expression of Cox-2and iNOS in mice.Taken together, we first confirm oryzanol can ameliorate DSS-induced acute colitis in mice and it has obviously anti-inflammatory role. Oryzanol can inhibit expression of inflammatory factors such as Cox-2and iNOS to inhibit colits. Our study provides strong evidences of oryzanol in the inflammation. It will help us to develop oryzanol-related functional products and make full use of byproducts of rice. The antiinflammatoray role of oryzanol may ameliorate colitis patience by adding oryzanol in diet or oryzanol diet. It also may be potentially used in clinic in the future.