Prefrontal Cortex and Hippocampus Inflammation in Mice Fed High-Carbohydrate or High-Fat Diets

We previously reported that a high-carbohydrate diet (HCD) induced systemic inflammation and higher gene expression of proinflammatory mediators in the liver, skeletal muscle, and brain than a high-fat diet (HFD). However, the differences between the groups were less pronounced in the brain. In this study, we extended the evaluation of inflammation to specific areas of the brain. In this study, we evaluated the gene expression of caspase 2, caspase 3, caspase 9, cyclooxygenase-2 (Cox 2), inducible nitric oxide synthase (iNOS), interleukin (IL), IL-6, IL-1β, IL-10, IL-4, tumor necrosis factor-alpha (TNF-α), integrin subunit alpha m (Itgam), S100 protein (S100), allograft inflammatory factor 1 (Aif1), and glial fibrillary acidic protein (Gfap) in the prefrontal cortex and hippocampus of male Swiss mice that were fed with HCD or HFD for 8 weeks. The HCD group exhibited higher IL-1β expression, whereas the HFD group showed higher TNF-α expression in the prefrontal cortex. In the hippocampus, TNF-α expression was higher in the HFD group. IL-1β and TNF-α are proinflammatory cytokines that have been associated with impaired brain function and numerous brain disorders. Our results indicate that both HCD and HFD promote prefrontal cortex inflammation; however, the hippocampus seems more sensitive to a HFD than HCD.