High fructose diet-induced obesity worsens post-ischemic brain injury in the hippocampus of female rats

Abstract

Objectives: Cerebral ischemia is caused by a reduction of the blood flow in a specific area in the brain, triggering cellular cascades in the tissue that result in neuronal death. This phenomenon leads to neurological decline in patients with stroke. The extent of the injury after stroke could be related to the condition of obesity. Thus, we aim to analyze the effect of obesity induced by a high fructose diet (HFD) on the brain after cerebral ischemia in rats.Methods: We induced the obesity model in female Wistar rats with 20% fructose in water for 11 weeks. We then performed cerebral ischemia surgery (2-vessel occlusion), carried out the neurological test 6, 24 and 48 h post-ischemia and analyzed the histological markers.Results: The HFD induced an obese phenotype without insulin resistance. The obese rats exhibited worse neurological performance at 6 h post-ischemia and showed neuronal loss and astroglial and microglial immunoreactivity changes in the caudate putamen, motor cortex, amygdala and hippocampus at 48 h post-ischemia. However, the most commonly affected area was the hippocampus, where we found an increase in interleukin 1β in the blood vessels of the dentate gyrus, a remarkable disruption of MAP-2+ dendrites, a loss of brain-derived neurotrophic factor and the presence of PHF-tau. In conclusion, a HFD induces an obese phenotype and worsens the neuronal loss, inflammation and plasticity impairment in the hippocampus after cerebral ischemia.

Keywords: Brain ischemia; high fructose diet; loss of plasticity; neuronal loss: inflammation.