The anticancer activity of milk rich in conjugated linoleic acid

ABSTRACT Milk samples enriched in conjugated linoleic acid (CLA) were obtained from buffalos fed on special diet supplemented with olive oil and sunflower oil mixture (1:1) with monensin oil to enhance the production of CLA. The effect of CLA rich milk on cancer growth was studied both in vitro and in vivo. For the in vitro study, the viability of 3 cancer cell lines, HeLa, HepG-2, and MCF-7, and the viability was examined by neutral red assay following the culture with special media containing CLA rich milk. For the in vivo study, ninety female mature mice were used in two experiments, 45 mice in each experiment, to investigate the effect of feeding milk rich in CLA on life span and the survival rate of mice transplanted with Ehrlich Ascites Carcinoma cells (EACC). Results of the in vitro study showed that both normal milk as well as milk rich in CLA enhanced cell survival of the cancer cell lines. However, the viability of these cells was significantly reduced (80%) when lipid fractions of milk samples were used instead of whole milk. This effect may be due to the essential fatty acid component of CLA rich milk which enhanced the inhibition of cancer cells’ growth. Our results were confirmed when the viability of cancer cells was significantly decreased when CLA was added to their incubation media. Data from the in vivo study showed that the life span of tumor transplanted mice fed milk rich in CLA was longer than that of mice transplanted fed either a normal diet or fed normal milk diets. We concluded that milk rich in CLA has clear anticancer activity in vitro and in vivo. Our results reveal that the action is due to the unsaturated fatty acids, especially CLA which may enhance cancer cells to enter apoptosis.