The Effects of Lipid Emulsions and Human Breast milk on Adipogenesis

Adequate nutrition is requisite for proper growth and development of newborn. Breast milk (BM) is recommended as the infant’s sole source of nutrition for the first 6 months of life. Maternal diet and health condition such as obesity is known to impact BM composition. However, for preterm newborn with immature gastrointestinal tract, total parenteral nutrition (TPN) is a life-saving therapy. Lipid emulsions (LE) are critical components of total parenteral nutrition (TPN), providing energy and essential fatty acids. Omega (n)-3 and n-6 polyunsaturated fatty acids (PUFA) are essential fatty acids, which play crucial role in the growth and development of the newborn. Intralipid, SMOFlipid and Omegaven are the lipid emulsion formulas available for TPN, containing n-6 to n-3 PUFA ratios of 7.8:1, 2.7:1 and 0.2:1, respectively. Previous reports have shown that BM with higher n-6 PUFA increased cellular events similar to insulin resistance and programmed fat cells to accumulate more lipids. We investigated the effects of LE and BM on adipogenesis in 3T3-L1 cells. Intralipid treated 3T3-L1 cells showed a higher ratio of n-6:n-3 PUFA, and a higher mRNA expression of lipogenic and adipogenic genes, while Omegaven treated cells showed the opposite effect. Furthermore, BM of obese mothers showed higher levels of malondialdehyde (MDA), a marker of oxidative stress, as well as higher levels of pro-inflammatory cytokines, compared to BM from lean mothers. In addition, BM from lean mothers with higher n-6:n-3 PUFA ratio increased lipogenesis in 3T3-L1 cells. Our findings suggest that the composition of LE and BM affects adipogenesis in 3T3-L1 cells.