Caseinophosphopeptides and their cell modulating potential.

In the context of the EU research project FAIR-CT 98-3077, studies were carried out to investigate caseinophosphopeptides (CPP) as potential ingredients for functional food and pharmaceutical applications. CPP preparations were produced by enrichment of CPP from hydrolytic casein digests. Enzyme preparations used for hydrolysis were PTN 3.0 S, Alcalase, Bioprotease P conc, Proteinase DS. Cytochemical studies were carried out to examine the cytotoxic potential or cell modulating activities of CPP using human cancer cell lines (HL-60, Caco-2) and non-malignant polymorphonuclear leukocytes (PML) from oral cavity. PML cells isolated by magnetic cell sorting using CD-15-antibody-labelled paramagnetic beads were used for the first time for testing food-derived peptides. Cell activity was measured by formazan dye formation. Effects on enterocytic differentiation properties of Caco-2 cells were examined by transepithelial membrane resistance of Caco-2 cell monolayers and brush border associated alkaline phosphatase activity. In conclusion, (1) no deleterious cytochemical consequences (apoptotic, antiproliferative or general cytotoxic effects) were observed on presenting a range of CPP preparations to various human cell systems, indicating that these compounds can be rated harmless at a cellular level, (2) stimulation of IgG-secretion into culture supernatant of PBL points to possible immunoenhancing properties of CPP preparations.