Research On Anti-inflammatory Activity Of Bioactive Peptides

Inflammation and itching are common diseases in human beings,both of them repeated episodes will seriously affect the quality of life of patients.Most of anti-inflammatory and itching drugs currently in use have side effects.Therefore,it is urgent to research new substances which are non-toxic,harmless and could effectively anti-itch.This thesis mainly researched the anti-inflammatory effect of bioactive peptide Y7 and S6 in mice,and explored the mechanism of anti-inflammatory preliminarily.In addition,other feature(the relieving itching effect)of bioactive peptide Y7 was studied.Firstly,by establishing DSS colitis model,the two delivery methods of intraperitoneal injection and intragastrical administration were used to study the effectiveness of Y7 and S6 on the body weight of mice,clinical scores,the length of the gut and intestinal tissue.The results showed that there were two ways to give Y7 and S6,which could significantly reduce the weight loss and clinical score of mice,effectively alleviated the mouse intestinal shortening,reduced the degree of intestinal tissue damage,and showed anti-inflammatory effects.Specially,the effects by intragastrical administration were much better than those of intraperitoneal administration.For example,when the body weight of mice dropped to the lowest point,intraperitoneal injection Y7 and S6 to mice,the weight loss were respectively 88.26%and 79.67%,obviously higher than 76.98%;intragastrical administration of Y7 and S6,the results were 86.19%and 86.96%,which showed far higher than 75.32%.Secondly,by Q-PCR experiments,16 kinds of genes of the colonic mucosa were tested preliminaryly for studying the mechanism of anti-inflammatory molecules.The results showed that different ways of administration,different periods of illness,anti-inflammatory mechanism of Y7 and S6 had some differences.However,after the overall comparison,anti-inflammatory mechanism of Y7 and S6 were closely related to KI-67,IL-10,TFF3 and Occludin,Claudin3 to be significantly upregulated.These basis of experiments suggest a clue for promoting cell proliferation and maintaining normal intestinal non-immune status,preventing epithelial cell apoptosis,protecting the integrity of the colonic mucosa and reducing the permeability of the cell.In addition,by establishing the 4-AP itching model,antipruritic effect of Y7 was preliminarily tested.The results showed that Y7 had a significant antipruritic effect on the skin itching.By human skin tests using double-blind experiment,the antipruritic effect of Y7 on itching caused by mosquito bites was tested.The results showed that:Y7 could suppress the itching caused by the mosquito bites,which suggested it to have swelling and anti-inflammatory effects.In summary,the bioactive peptides Y7 and S6 had significantly anti-inflammatory effects,but there were some differences between the intragastrical and intraperitoneal injection on anti-inflammatory effects.The way by intragastrical administration was relatively better,which provided a theoretical basis for the realization of Edible active peptides.In addition,Y7 had some antipruritic effect.