The Immune Activities On Macrophage Of Bioactive Oligopeptides Derived From Milk

Lactobacillus helveticus is often used in the production of fermentedmilk or milk production. In recent years, the study of bioactiveingredients in the fermented milk draws a lot of attentions from foodindustry, particularly the study of bioactivity oligopeptides.This paper studies the immune regulation activities on BALB/cmouse peritoneal macrophages of oligopeptide derived fromLactobacillus helveticus fermented milk in order to evaluate its potentialvalue as a functional food ingredient and make a preliminary inquiry ofits mechanism.This paper mainly includes the following contents:(1) MTT assay, neutral red phagocytosis method and induced nitricoxide secretion method were used in order to evaluate mouse peritonealmacrophages immune-active effect and finally selected GLPN out ofobtained Lactobacillus helveticus LH0906fermented milk-derivedoligopeptides (QEPVL/DELQ/LPLP/GLPN).(2) The cytokine levels of TNF-α, IL-1β and IL-6were detected withELISA method to assay detail immune-active effect of GLPN. The resultshows significant improvement of all biomarkers with GLPN at the concentration of0.1mg/mL and no over expression of inflammatorycytokines are observed even at the concentration of0.5mg/mL under thetreatment of LPS.(3) Structure analogs were designed and synthesized by usingAla-scan and termination truncation. GLPN and its structure analogs werecompared in the MTT assay and nitric oxide secretion method. The resultshows that none of the amino acid residues in GLPN sequence can bereplaced in promoting macrophage proliferation and the N-terminalglycine, leucine in second place play a greater role in promotingmacrophage secretion of nitric oxide relative to other amino acidresidues.