Vitamin D administration, cognitive function, BBB permeability and neuroinflammatory factors in high-fat diet-induced obese rats

Abstract

OBJECTIVES: The purpose of this research was to investigate the effects of vitamin D administration on cognitive function, nuclear factor-kappa B (NF-kappa B), brain-derived neurotrophic factor (BDNF) concentration in the hippocampus and blood-brain barrier (BBB) permeability in high-fat diet (HFD)-induced obese rats. METHODS: Male Wistar rats were fed either a control diet or HFD for 16 weeks (n = 20); then, each group was randomized into two subgroups supplemented orally with 500 IU kg(-1) vitamin D for 5 weeks. A Morris water maze (MWM) test was performed at the 21st week to examine cognitive function. BBB permeability was characterized by Evans blue dye in the hippocampus. BDNF and NF-kappa B concentrations in the hippocampus and serum vitamin D concentrations were also measured. RESULTS: HFD led to a significant delay in escape latency time and reduced time of MWM probe test because of increased NF-.B and decreased BDNF concentrations in the hippocampus. Vitamin D supplementation in the HFD group significantly reduced body weight, NF-kappa B concentrations, BBB permeability and increased BDNF concentrations in the hippocampus. CONCLUSIONS: Vitamin D reversed HFD-induced cognitive impairments by reduction of the NF-kappa B and elevation of BDNF concentrations and modulation of the BBB permeability in rats' hippocampus.