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

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.

An evidence for the transcriptional regulation of iodothyronine deiodinase 2 by progesterone in ovarectomized rats

Recent literature lacks studies on the effects of progesterone withdrawal on peripheral conversion of thyroxin (T4) into triiodothyronine (T3) by iodothyronine deiodinase 2 (D2) in different body tissues. The present study aimed to assess the possible relation of progesterone to T4, T3, and D2 in ovarectomized rats. Thirty female Wistar rats were included into a sham-operated control group and an ovarectomized group. Four months following the surgical procedures, measurements of estradiol, progesterone, free T4, free T3, and thyroid-stimulating hormone (TSH) were done. Also, estradiol/progesterone and T4/T3 ratios were calculated. Tissue homogenates from the kidney, liver, brain, thyroid, mandible, and femur were used to assess expression of D2 mRNA. The estradiol/progesterone ratio showed a significant increase in ovarectomized rats. T4 showed a significant increase in contrast to T3 which showed a highly significant decrease following ovariectomy. The T4/T3 ratio was significantly increased in ovarectomized rats. In addition, D2 expression was significantly attenuated in all tissue homogenates of the ovarectomized group. The present work showed a significant positive correlation between T4 and T3 in the sham-operated control rats, which was abolished in ovarectomized rats. A negative significant correlation between progesterone and T4 was revealed in ovarectomized rats. There was also a significant positive correlation between progesterone and D2 expression in the ovarectomized group. The results of the present study hypothesize that progesterone withdrawal may underlie the decrement in D2 expression, with consequent reduction in the peripheral conversion of T4 into T3 leading to a hypothyroid state

Estrogen deficiency reduces the expression of estrogen receptor-beta in Wistar rats` periodontal tissues.

OBJECTIVE: To assess the effect of ovariectomy on the expression of estrogen receptor-beta (ER-beta) in periodontal ligament and alveolar bone. METHODS: This animal study was conducted at King Fahad Research Center, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia from March to October 2012. Thirty 12-week-old female Wistar rats were divided into 2 groups (15 each): ovariectomized (OVX) and sham-operated. Levels of estrogen and progesterone in the sera were measured using the enzyme linked immunosorbent assay (ELISA). To detect the expression of ER-beta, immunostaining was performed on the tibia, alveolar bone, and periodontal ligament specimens followed by quantitative histomorphometric analysis. RESULTS: Estrogen (p=0.001) and progesterone (p=0.007) levels were significantly decreased in the OVX rats compared to their controls. Histologically, the thickness and area percentage of the tibia and alveolar bone trabeculae were significantly reduced in OVX rats compared to the controls (p=0.001). The periodontal ligament fibers in the control group exhibited well-organized and appropriately oriented fibers, while in the OVX group they appeared disrupted with loss of orientation. The ER-beta expression in the OVX rats was significantly decreased in the periodontal tissues (p=0.005) and tibia (p=0.008). CONCLUSION: Estrogen deficiency resulted in a significant decrease in the expression of ER-beta in both tibia and periodontal tissues.

An evidence for the transcriptional regulation of iodothyronine deiodinase 2 by progesterone in ovarectomized rats.

Recent literature lacks studies on the effects of progesterone withdrawal on peripheral conversion of thyroxin (T4) into triiodothyronine (T3) by iodothyronine deiodinase 2 (D2) in different body tissues. The present study aimed to assess the possible relation of progesterone to T4, T3, and D2 in ovarectomized rats. Thirty female Wistar rats were included into a sham-operated control group and an ovarectomized group. Four months following the surgical procedures, measurements of estradiol, progesterone, free T4, free T3, and thyroid-stimulating hormone (TSH) were done. Also, estradiol/progesterone and T4/T3 ratios were calculated. Tissue homogenates from the kidney, liver, brain, thyroid, mandible, and femur were used to assess expression of D2 mRNA. The estradiol/progesterone ratio showed a significant increase in ovarectomized rats. T4 showed a significant increase in contrast to T3 which showed a highly significant decrease following ovariectomy. The T4/T3 ratio was significantly increased in ovarectomized rats. In addition, D2 expression was significantly attenuated in all tissue homogenates of the ovarectomized group. The present work showed a significant positive correlation between T4 and T3 in the sham-operated control rats, which was abolished in ovarectomized rats. A negative significant correlation between progesterone and T4 was revealed in ovarectomized rats. There was also a significant positive correlation between progesterone and D2 expression in the ovarectomized group. The results of the present study hypothesize that progesterone withdrawal may underlie the decrement in D2 expression, with consequent reduction in the peripheral conversion of T4 into T3 leading to a hypothyroid state.

Estrogenicity of outer scales of onion on uteri of immature mice.

We aimed to investigate the estrogen-like activities of the outer scales of onion and garlic on the uteri of immature mice. This work compared the estrogenic effects induced by estradiol with the effects of plant extract (onion, garlic) in models of immature mice (n = 72). The animals were divided into 6 groups, with 12 animals in each group, as follows: Group I (control group), Group II (estradiol-treated group), Group III (onion extract treated group), Group IV (onion extract treated group after blockage of estrogen receptors), Group V (garlic extract treated group), and Group VI (garlic extract treated group after blockage of estrogen receptors). Uterine wet weight/body mass ratios were determined. Uterotrophic bioassay, immunohistochemical assay for estrogen receptor and proliferative marker Ki67, uterine contractility, and serum estrogen levels were investigated. Onion extract induced proliferative changes in the uterus, it also increased the uterine mass and epithelial cell height. Also, the frequency and amplitude of myometrial contractility were significantly increased in the group treated with onion extract. This estrogenic activity could be attributed to the quercetin and daidzein content, and activation of estrogenic receptors, as these effects disappeared after blockage of E2 receptors. Our results support the possible estrogenic properties of the onion extract, which could be attributed to quercetin and daidzein, but not that of garlic extract.