The Preparation Of Collagen Peptides From Squid Skin And Its Effects On Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease, chronic,symmetry, multi-arthritis as the major clinical manifestations, its etiology and pathogenesisis still not completely illustrated. relieving the pain, reducing inflammation, protectingmuscle and joint function, treatment and prevention of serious complications is the maingoal of the current treatments. In this topic, the fish skin is used as a raw material toinvestigate preparation method of collagen peptide, and to discuss the action of aquaticcollagen peptide in arthritis treatment, meanwhile to study the property of the collagenpeptide in order to provide scientific basis for the investment of new medical foods to treatarthritis.The main research content and results are following:1. Enzymolysis technology optimization for production of free radical scavengingactivities of collagen peptides from squid skinThe squid skin was used as research materials and the main compositions weredetermined. The crude protein level of squid skin was high, with the content of19.25%.The collagen peptide from squid skin has been extracted by using protease method, basedon the protein degree of hydrolysis and hydroxyl radicals scavenging rate. Through singlefactor experiment and orthogonal test, the preparation technology conditions of fish skincollagen peptide were optimized. The results showed that the optimum addition of trypsinwas5%, the enzymolysis time was8hours, the temperature was50℃, pH8.0. Under thiscondition, the maximum DH (Degree of Hydrolysis) is26.1%, the rate of hydroxyl radicalscavenging is83.8%.2. The effects and mechanism of collagen peptide on in vitro proliferation andapoptosis of fibroblast-like synovial cells from rats with adjuvant arthritisUltrafiltration was used to purify the active peptide in the preparing technology.10KDa,5KDa,3KDa and1KDa molecular weight cut-off membranes were used tofractionate the trypsin hydrolysate of squid skin, and four ranges of molecular weightfractions (SCH1,5-10KDa; SCH2,3-5KDa; SCH3,1-3KDa; SCH4,＜1KDa) were obtained.SCH4which had the lowest molecular weight showed the highest restraining effect on theAA rats FLS. Teatment of the AA rats FLS with SCH4at0.5mg/ml for48h inhibited theproliferation of AA rats FLS cells by25.9%in both concentration-dependent andtime-dependent manners. Cell apoptosis morphological feature was observed under HE staining when AA rats FLS were treated with SCH4for24h and48h. Flow cytometryanalysis with Annexin V-FITC and PI double staining showed that SCH4induced earlyapoptosis and cellular necrosis in concentration-dependent manner on AA rats FLS. SCH4could enhance the activity of dihydrofolate reduetase.3. Primary research on the physico-chemical and functinonal properties ofcollagen peptideThe functional characteristics of SCH4such as dissolubility, viscosity,water-absorption, water-holding capacity, oil-absorption, foaming characteristics and foamstability, emulsifying ability and spectral feature were determined primaryly. Theultraviolet spectrum exhibited a maximum absorbance at220nm and280nm. SCH4showed good solubility over a wide pH range and low viscosity in the range of20-50℃;SCH4had a certain degree of water-absorption and water holding capacity; it showed nosignificantly effect of temperature on oil-absorption; It showed significantly effect of pHon foaming properties and emulsifying characteristics.