Vitamin D3 attenuates cognitive deficits and neuroinflammatory responses in ICV-STZ induced sporadic Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by intracellular neurofibrillary tangles and extracellular Aβ deposition. Growing experimental evidence indicate diverse biological effects of vitamin D3 including antioxidant, neuroprotective, anti-inflammatory and cardiovascular benefits. However, the underlying neuroprotective mechanism of vitamin D3 is still largely elusive. Therefore, the present study was aimed to investigate the neuroprotective effects of vitamin D3 on ICV-STZ induced sporadic AD. Our study demonstrated that vitamin D3 pretreatment significantly improved spatial learning and memory functions and effectively mitigated ICV-STZ mediated neuronal oxidative stress, mitochondrial aberrations and improved cholinergic functions. Moreover, vitamin D3 attenuated hippocampal neuroinflammatory response and reduced neuronal death in cortex and hippocampus. Our findings indicated that prophylactic vitamin D3 supplementation ameliorated ICV-STZ mediated neurobehavioral alterations, oxidative stress and neuroinflammation thereby improving cholinergic functions and reversed degenerative changes in brain. Thus, our study further provides evidence for its therapeutic supplementation for various neurodegenerative disorders including AD.