Isolation And Characterisation Of Immune Active Peptide From Xinjiang Fermented Camel Milk And Its Effect Of Immune Regulation

Objective: To indentify and clarify the primary structures of immune active peptide from Xinjiang fermented camel milk. And to observe the effect of immune regulation on balb/c mice. Methods: 1. Mixed fermentation of fresh camel milk by ten lactic acid bacterias and four yeasts, detecting pH, acidity, viable bacteria counts of lactic acid bacteria and yeast. 2. 3 peptides were separated by ultrafiltration, gel chromatography and other means. Evaluated splenocyte-stimulant effects of therr bioacfive peptides(0.25g/L、0.5g/L、0.75g/L) by splenocyte proliferation in vitro, identified the structures of peptide C by HPLC-MS/MS method. 3. Real-time fluorescence quantitative PCR(RT-PCR) was employed to detect the relative expressions of NF-κB、IFN-γ、IL-6、IL-12、IL-23、IL-27 mRNA. Results: 1. Fermented camel milk pH was lower after 2 weeks storaged, and its acidity was higher, viable bacteria counts of lactic acid bacteria was increased(P<0.05). 2. Medium dose group(0.25mg/ml) and high dose group(0.5mg/ml) fermented camel milk promote lymphocyte proliferation, and the stimulating index of peptide C(0.25mg/ml and 0.5mg/ml) were higher than no-treatment control group(P<0.05). 3. The massspectrometry showed that there were three sequences which were consistent to some sequences of the Glycosylation-dependent cell adhesion molecule 1(Glycam-1), Whey acidic protein and Alpha-lactalbumin. 4. The relative expressions of NF-κB、IL-6 mRNA are lower than no-treatment control group(P<0.05), and the IFN-γ、IL-12、IL-23、IL-27 mRNA are higher than no-treatment control group(P<0.05). Conclusion: The results of this study indicates that fermented camel milk promoted lymphocyte proliferation, which may be related to fermented camel milk promoted the expression of Th1 cytokines and adjusting the balance of Th1/Th2 cytokines.