Screening Of Highly Active Anti-inflammatory Peptides And Study On Its Mechanism

Inflammation is the body's series of cellular and molecular responses to external damage,tissue damage,and infectious pathogen stimulation,and it is the body's adaptive immune response.Oxidative stress is one of the important causes of inflammation.Chronic inflammation promotes the development of cardiovascular and chronic diseases such as atherosclerosis,hyperlipidemia,asthma and autoimmune diseases.It is the main cause of rheumatoid arthritis and an independent risk factor for cancer and diabetes.It seriously harms human health.Therefore,it is urgently needed a safe and effective solution.In recent years,a lots of scientific research continuously shows that food derived peptides have good anti-inflammatory effects.Therefore,this article focused on the anti-inflammatory activity of food-derived peptides.The main research work and its conclusions were as follows:(1)Screening of highly active anti-inflammatory peptides.Bovine collagen peptides,soybean peptides,corn germ peptides,wheat gluten peptides were selected as materials.Anti-inflammatory peptides with high activity were screened out by comparing their molecular structure characteristics,inflammatory factors and antioxidant activity.Scientific research showed that wheat gluten peptides contained more hydrophobic amino acids and positively charged amino acids that are proportional to the anti-inflammatory activity(40.428% and 14.144% of the total amino acids,respectively).Wheat gluten peptides showed significant DPPH scavenging activity and ABTS scavenging activity(IC50 is 0.764 mg/mL and 0.294 mg/mL,respectively).They could significantly inhibit the secretion of ROS reactive oxygen free radicals,inhibit pro-inflammatory factors IL-1? and promote the secretion of anti-inflammatory factors IL-10.Correlation analysis proved that the greater the content of hydrophobic amino acids and positively charged amino acids of the polypeptides,the stronger the ability of peptides to resist oxidation and inhibit the secretion of ROS active oxygen free radicals,and the better its anti-inflammatory effects.In summary,among the four peptides,the wheat gluten peptides have the highest anti-inflammatory activity.(2)Study on the anti-colitis activity of wheat gluten peptide.The effect of different doses of wheat gluten peptides on the improvement of DSS-induced ulcerative colitis in mice and its effects on pro-inflammatory factors and oxidative stress-related indicators in the colon tissue of mice were studied.The experiment results showed that wheat gluten peptides significantly slowed down the weight loss,shortened colon length,and increased clinical symptom scores in colitis mice.Wheat gluten peptides significantly inhibited the MPO activity in the colon tissue of mice with colitis,and reduced the content of pro-inflammatory factors TNF-?,IL-6 and IL-1?.At the same time,wheat gluten peptides also reduced the content of MDA and GSH in the oxidative stress-related indicators of the colon tissue of colitis mice,and significantly increased the content of GSH-Px and SOD activity.(3)Study on the anti-inflammatory mechanism of wheat gluten peptides on colitis in mice.The regulation of wheat gluten peptides on the intestinal flora of colitis mice and its influence on the expression of NF-?B and MAPK signal pathways were studied by using DSS-induced mouse ulcerative colitis model.The results showed that wheat gluten peptides increased the diversity of intestinal flora and the content of beneficial bacteria,reduced the content of harmful bacteria,enhanced the body's immunity,thereby reducing the risk of intestinal inflammation In addition,wheat gluten peptides significantly inhibited the activation of NF-?B and MAPK signaling pathways by reducing the phosphorylation levels of p38,JNK,p65 and I?B? proteins in mouse colon tissues(p<0.05).thereby delaying inflammation in mice with colitis process.