Milk fat globule membrane isolate induces apoptosis in HT-29 human colon cancer cells

A native milk fat globule membrane (MFGM) isolate obtained from raw milk was assessed for its anticarcinogenic capacity using a colon cancer cell line (HT-29). To prevent microbial contamination and eliminate the presence of lipopolysaccharide (LPS) in the milk used for MFGM isolation, the milk was obtained from the mammary glands of cows using a catheter. Cell proliferation assays demonstrated a reduction of exponentially growing cancer cells of up to 53%, expressed as DNA synthesis (BrdU test), after 72 h stimulation with 100 mu g of MFGM protein per mL. Using a similar MFGM concentration, the sulforhodamine B assay resulted in 57% reduction of cell density after 48 h incubation. This bioactivity was comparable to that of known anticancer drugs, 0.1 mM melphalan and 20 mu M C2-ceramide, which achieved a cell division reduction of 25 and 40%, respectively, under the same experimental conditions. The toxic effect of the MFGM extracts on HT-29 cells was confirmed by the significant reduction in lactate dehydrogenase enzyme (LDH) by the residual viable cells. An increase of caspase-3 activity (up to 26%) led to the conclusion that MFGM has an apoptotic effect on HT-29 cancer cells.