This research investigates the effects of bovine colostrums and their protein hydrolysates on human mononuclear cell (MNC) growth, on the secretion of cytokines (interleukin-1β, interferon-γ and tumor necrosis factor-α) as well as nitric oxide, and on the growth inhibition of human leukemic U937 cells. The results indicate that the colostrum hydrolysates obtained by porcine small-intestinal enzymes (PIS) exhibit more significant inhibitory effect on U937 cell growth than do the caseins (PIC) and the whey (PIW) hydrolysates (PIS 57.45%, PIC 42.58% and PIW 48.47% at 1,000 µg/mL). The greatest growth index of MNC, up to 1.43, was achieved by a treatment of PIS at 300 µg/mL for 3 days. The cytokines (IL-1β, TNF-α and IFN-γ) secretion of MNC by a treatment of PIS for 3 days (at 800 µg/mL) was 4,443.35, 325.04 and 4,649.67 pg/mL, respectively. The results suggest that bovine colostrum protein hydrolysates may be utilized in functional food.
Large quantities of protein-rich bovine colostrums are used for feeding calves or discarded as waste because this glutinous, yellowish fluid is also bitter tasting and coagulates easily upon heating. Such waste is a good source for the extraction of bioactive molecules such as proteins, growth factors, antimicrobial compounds and immunological components.
The results of this research shed light on the effects of bovine colostrums and their protein hydrolysates on the immunomodulatory activities and the growth inhibition of U937 cells. They may help in the discovery of new applications while reducing the considerable problem caused by waste disposal.
The use of food protein hydrolysates is widely accepted in the field of cosmetics and healthcare products. Bovine colostrum protein hydrolysate products can be useful to enhance human health. Our results point to the possibility that colostrums may be processed into an antileukemic drug or may be used as an immunomodulatory activity ingredient in health foods.