부산대학교 도서관

BACKGROUND AND PURPOSE:: Bovine glycomacropeptide (BGMP) is a natural milk peptide that is produced naturally in the gastrointestinal tract during digestion. Glycomacropepide has intestinal anti-inflammatory activity, but the mechanism of action is unknown. Here we have characterized the effects of BGMP on monocytes. EXPERIMENTAL APPROACH:: We have used human THP-1 cells as an in vitro monocyte model. The effect of BGMP on the secretion of tumour necrosis factor (TNF), interleukin (IL)-1β and IL-8 was assessed, as well as the involvement of the NF-κB and MAP kinase signalling pathways. The stimulatory effect of BGMP was also tested in human peripheral blood monocytes. KEY RESULTS:: BGMP up-regulated the secretion of TNF, IL-1β and IL-8 in a concentration-dependent fashion. The biological activity was exerted by the intact peptide, because cytokine secretion was not affected by protease inhibitors. The secretion of IL-8 and specially TNF and IL-1β was blocked by PD98059, SP600125, SB203580 and Bay11-7082, suggesting the involvement of the MAP kinases p38, c-Jun N-terminal kinase and ERK and particularly the NF-κB pathway, although IL-8 secretion was independent of p38. BGMP was shown to elicit the phosphorylation of IκB-α and the nuclear translocation of the NF-κB subunits p50 and p65. The effect of BGMP on cytokine secretion was validated in human primary blood monocytes. CONCLUSIONS AND IMPLICATIONS:: BGMP stimulates human monocytes, operating via MAP kinase and NF-κB pathways. BGMP may exert an indirect intestinal anti-inflammatory effect by potentiating host defences against invading microorganisms.