Interesterified Fat Exposure Induces Metabolic and Locomotor Dysfunction in Drosophila melanogaster: Mechanistic Links to Oxidative Stress and Apoptotic Pathways.

To understand the impacts of interesterified fat (IF) on health, in this study, we investigated the effects of exposure to IF on behavioral and molecular parameters in D. melanogaster. For this purpose, flies were exposed to diets containing IF and non-interesterified fat (NIF), at 10 and 20% concentrations for 7 days. Exposure to IF resulted in significant alterations, including increased triglyceride levels and lipid peroxidation (particularly at 20%), reduced lifespan, impaired locomotor activity, and decreased antioxidant enzyme activities (SOD and CAT) at both concentrations. Conversely, IF exposure led to increased GST activity, enhanced Nrf2 and Hsp70 immunoreactivity, and elevated p38/total p38 ratio at 20%, culminating in a marked reduction in cell viability. NIF exposure also produced adverse effects, such as increased triglyceride levels and reduced lifespan (10% and 20%). It was associated with higher lipid peroxidation and reduced Nrf2 immunoreactivity at both concentrations. At 10%, NIF increased Hsp70 immunoreactivity and phospho-Akt levels, and decreased the phospho-p38/total p38 ratio, which remained low at 20%. In summary, exposure to both IF and NIF was detrimental to flies, inducing metabolic and locomotor impairments linked to oxidative stress and apoptotic mechanisms. However, the adverse effects were more pronounced with IF, indicating its greater toxicity in this model.