The Possible Effects of Vitamin D3 on AlCl3-Induced Histological and Morphometric Alterations of Adult Male Albino Rat Hippocampus.

Abstract

Context: Alzheimer's disease (AD) is a challenging neurodegenerative disease, and Vitamin D was proved to have neuroprotective effects.

Aim: This study was conducted to evaluate the potential neuroprotective effects of Vitamin D3 supplementation on AlCl₃-induced AD rat model in different hippocampal subregions (CA1, CA2, and CA3). It also aimed to compare the protective effects of protective versus therapeutic effects of Vitamin D3 regiments on the number of degenerated neurons and the neuronal layer thickness.

Materials and methods: Twenty-four adult male Albino Wister rats were sorted into GI: control; GII: AlCl₃-AD model (100 mg/kg) orally for 42 days; GIII: Rats were co-treated with AlCl₃ (as GII) and Vitamin D₃ (400 IU/kg/day) orally for 42 days; GIV: Rats were treated with AlCl₃ for 42 days then with Vitamin D₃ for further 2 weeks. Sagittal sections (5 μ) from paraffin-processed brains previously fixed in 10% neutral-buffered formalin were stained with hematoxylin and eosin to evaluate the thickness and number of degenerated neurons in the hippocampal CA1, CA2, and CA3 subregions.

Statistical analysis: The results of this study were expressed as mean ± standard deviation and analyzed by using IBM SPSS Statistics for Windows, version 23 (IBM SPSS, IBM Corp., Armonk, N.Y., USA). P < 0.05 was considered statistically significant.

Results: Vitamin D₃ supplementations modulated the degenerative changes observed in the hippocampus of AD rat model. In all hippocampal subregions, the thickness was higher in rats treated with Vitamin D₃ after the AD induction than rats treated with Vitamin D₃ during AD induction. However, this increase was only significant in CA2. Comparison of the number of degenerated neurons between both groups treated with Vitamin D₃ revealed that in CA1, the number of degenerated neurons did not statistically differ between the two groups. However, it was insignificantly lower in CA2 in rats treated with Vitamin D₃ after the AD induction, and in CA3, it was insignificantly lower in rats treated with Vitamin D₃ during the AD induction.

Conclusions: Vitamin D₃ was found to be effective in ameliorating histological and morphometric alterations in AlCl₃-induced AD in rat model and could be proposed as both preventive and therapeutic supplements in high-risk AD patients.