Heme consumption reduces hepatic triglyceride and fatty acid accumulation in a rat model of NAFLD fed westernized diet

Studies have identified that serum-free hemoglobin subunits correlate positively with the severity of nonalcoholic fatty liver disease (NAFLD). However, the role of hemoglobin in the development of NAFLD remains unclear. In the present study, a rat model of NAFLD was developed, using a westernized diet high in saturated fat and refined sugar. Since a westernized diet is also high in red meat, we tested the effect of hemoglobin as a dietary source of heme in our model. Sprague-Dawley rats were fed ad libitum for 4 weeks either control diet (7% fat), westernized diet (WD, 18% fat + 1% cholesterol), hemoglobin diet (7% fat + 2.5% Hb), or westernized and hemoglobin diet (18% fat + 1% cholesterol + 2.5% Hb). Rats fed WD developed features of NAFLD, including insulin resistance and accumulation of liver fatty acids in the form of triglycerides, increased lipid peroxidation (F2-Isoprostanes), and liver fibrotic marker (hydroxyproline). Hemoglobin consumption significantly influenced several biomarkers of NAFLD and hepatic biochemistry, suggesting a possible interaction with diet and/or liver lipid pathways. The complex mechanisms of interaction between WD and hemoglobin in our rat model warrants further studies to examine the role of dietary heme on NAFLD