The Effects of Route of Feeding and Lipid Emulsions on Oxidative Stress in Neonates

Parenteral Nutrition (PN) is used when nutrient intake via the digestive tract is not possible. In these circumstances, clinicians resort to the intravenous administration of nutrition. The inability to consume nutrients enterally is often due to functional failure of the gastrointestinal tract. As such, premature infants are at high risk for malnutrition as their shortened gestation results in low nutrient stores. PN as a form of nutritional support is often necessary to sustain life but is commonly associated with adverse health effects. Parenteral nutrition-associated liver disease (PNALD) has been widely reported in preterm infants, and oxidative stress in the liver may contribute to its onset. This study aims to investigate the effects of the route of feeding on oxidative stress and whether PN-associated organ damage is exacerbated by the nutrient composition of PN emulsions. The effects of enteral and parenteral nutrition will be compared, and the relationship between the lipid emulsions, Intralipid and SMOFlipid, and oxidative stress will be assessed. Intralipid is the most commonly available lipid emulsion and is a soybean oil-based emulsion that is completely devoid of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). SMOFlipid is a new lipid emulsion with novel fatty acid composition; it has been the focus of research and has been cautiously adopted in neonatal care for “off-label” use. The objective of this study is to characterize the impact of the route of feeding (enteral or parenteral) and the choice of the lipid emulsion product on indices of oxidative stress. We first hypothesize that the use of parenteral nutrition, in place of enteral feeding, will increase markers of oxidative stress. We also predict that the Intralipid emulsion will enhance the development of oxidative stress, therefore contributing to deleterious complications. Historical samples used from completed studies in Yucatan miniature piglets. The treatment groups included: PN diet of SMOFlipid, EN diet of SMOFlipid, PN diet of Intralipid, EN diet of Intralipid, and a sow-fed control group. Markers of oxidative stress include thiobarbituric acid reactive substance (TBARS) assay and total antioxidant capacity using the ferric reducing antioxidant power (FRAP) assay. Vitamin E concentrations in the plasma were measured via UPLC. Future directions include analyzing myeloperoxidase activity, and the antioxidant enzyme activity of glutathione peroxidase, catalase, and superoxide dismutase.