Effect of bovine colostrum on the growth inhibition and differentiation of human leukemic U937 cells

BACKGROUND: Colostrum is the breast milk of female mammals produced within in a short time after giving birth. It is thought to protect neonates from infection as well as to facilitate immune system maturation. In this study the effect of bovine colostrum on the proliferation and differentiation of human leukemic U937 cells was investigated to understand more about its immunomodulatory activity. RESULTS: Human mononuclear cells (MNCs) were stimulated with bovine colostrum (CS) and then filtered to obtain a conditioned medium (CM) (CS‐MNC‐CM). CS‐MNC‐CMs prepared with day 1 to day 4 colostrums inhibited U937 cells by 39.4–64.4%. The expressions of surface markers CD11b and CD14 on U937 cells in the treated groups were 30.6–33.5% and 40.0–42.6% respectively. High levels of cytokines IL‐1β, IFN‐γ and TNF‐α were detected in CS‐MNC‐CMs. CONCLUSION: Evidence indicates that colostrums stimulate human MNCs to secrete cytokines IL‐1β, IFN‐γ and TNF‐α which subsequently inhibit the growth of U937 cells and induce their differentiation into mature monocytes and macrophages. There is a possibility for bovine colostrum to be processed into an anti‐leukemia ingredient for use in health foods.