Effect of a high dose of vitamin D on a rabbit model of atherosclerosis

Mitigating diabetes-related complications: Empowering metformin with cholecalciferol and taurine supplementation in type 2 diabetic rats

BACKGROUND

Type 2 diabetes is one of the most prevalent chronic diseases worldwide, significantly impacting patients' quality of life. Current treatment options like metformin (MET) effectively counteract hyperglycemia but fail to alleviate diabetes-associated complications such as retinopathy, neuropathy, nephropathy, hepatopathy, and cardiovascular diseases.

AIM

To propose the supplementation of cholecalciferol (CHO) and taurine (TAU) to enhance MET efficacy in controlling diabetes while minimizing the risk of associated complications.

METHODS

The study involved sixty rats, including ten non-diabetic control rats and fifty experimental rats with type 2 diabetes induced by streptozotocin. The experimental rats were further subdivided into positive control and treatment subgroups. The four treatment groups were randomly allocated to a single MET treatment or MET combined with supplements either CHO, TAU, or both.

RESULTS

Diabetic rats exhibited elevated levels of glucose, insulin, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), glycated hemoglobin%, lipid markers, aspartate aminotransferase, and malondialdehyde, along with reduced levels of antioxidant enzymes (catalase and superoxide dismutase). The administration of CHO and TAU supplements alongside MET in diabetic rats led to a noticeable recovery of islet mass. The antioxidative, anti-inflammatory, and anti-apoptotic properties of the proposed combination therapy significantly ameliorated the aforementioned abnormalities.

CONCLUSION

The supplementation of CHO and TAU with MET showed the potential to significantly improve metabolic parameters and protect against diabetic complications through its antioxidative, anti-inflammatory, and anti-apoptotic effects.

Calcitriol modulates cholesteryl ester transfer protein (CETP) levels and lipid profile in hypercholesterolemic male rabbits: A pilot study

Vitamin D3 efficacy against cardiovascular disease prevention has been reported in many experimental studies. We aimed to investigate the effect of the calcitriol or active form of Vitamin D3 (1, 25(OH) 2D3) on serum cholesteryl ester transfer protein (CETP) levels in a rabbit model of atherosclerosis. New Zealand white male rabbits were fed with 1% cholesterol diet and randomly assigned into two groups (n = 6). The case group was administrated with 50000 calcitriol (IU/kg/per wk) and the control group which administrated with calcitriol solvent (sesame oil) for 2 months. Then, after two months the lipid profile, CETP and 25OHD3 levels were measured. The serum concentration of CETP was increased after treatment with calcitriol in case group as compared to the control group (41.75 ± 3.19 vs. 34.5 ± 2.3, ng/ml, P < 0.05). We also observed higher levels of the 25OHD3 in the calcitriol group at the 1^st month (16.3 ± 1.64 vs. 12.8 ± 1.33 ng/ml) and the 2^nd month (19.5 ± 2.14 vs. 12.5 ± 1.25 ng/ml) as compared with the control group. the significant increase in the level of HDL-C was observed in the case group than the control group (P < 0.01). In addition, serum levels of LDL- Cholesterol (LDL-C), Triglyceride (TG) were reduced after assessment at 1^st and 2^nd month after administration of calcitriol. Our research indicated the significant anti-atherogenic effects of calcitriol in the rabbit model of atherosclerosis. However, increased in CETP levels by calcitriol may know as an additional way, which interfere with the anti-atherogenic effects of calcitriol.

Associations of Serum Nitric Oxide with Vitamin D and Other Metabolic Factors in Apparently Healthy Adolescents

Introduction

Nitric oxide (NOx) is an important biomolecule which interacts with other molecules including 25(OH)D to mediate various metabolic pathways. Interactions and associations of NOx with 25(OH)D have been well studied both in vitro and in vivo, yet associations in apparently healthy adolescents have never been studied.

Methods

A total of 740 (245 boys and 495 girls) apparently healthy Saudi adolescents aged 10-17 years were included in this cross-sectional study, to determine the associations of NOx with 25(OH)D and other biomarkers in Saudi adolescents. Serum NOx, 25(OH)D, and other biochemical and anthropometric parameters were measured following standard protocols and manufacturers' guidelines.

Results

NOx level was significantly higher in boys than girls (p<0.001). In all subjects, NOx showed a significant inverse correlation with 25(OH)D. After stratification according to sex however this significant association was observed only in boys and not in girls. NOx was also significantly associated with BMI, serum triglycerides, and systolic blood pressure in all subjects.

Conclusion

The significantly inverse association of NOx and 25(OH)D among apparently healthy adolescents is influenced by sex and further strengthens the extraskeletal role of 25(OH)D in maintaining endothelial homeostasis in this age group, particularly in boys. Whether vitamin D correction can influence NOx production over time among adolescents remains to be proven.

Clinical trial of the effects of vitamin D supplementation on psychological symptoms and metabolic profiles in maintenance methadone treatment patients

BACKGROUND

Vitamin D deficiency may be associated with some complications including nonspecific musculoskeletal pain and periodontal disease in maintenance methadone treatment (MMT) patients. This study was designed to determine the effect of vitamin D supplementation on psychological symptoms and metabolic profiles in MMT patients.

METHODS

This randomized, double-blind, placebo-controlled, clinical trial was carried out among 68 MMT patients. Participants were randomly allocated to receive either 50,000IU vitamin D supplements (n=34) or placebo (n=34) every 2weeks for 12weeks. Fasting blood samples were taken at baseline and post-intervention to evaluate relevant variables.

RESULTS

After the 12-week intervention, serum 25(OH) vitamin D levels significantly increased in the intervention group compared with the placebo group (+8.1±4.9 vs. -0.4±3.0, P<0.001). In addition, vitamin D supplementation significantly improved Pittsburgh Sleep Quality Index (-1.5±2.2 vs. -0.2±2.3, P=0.02) and Beck Depression Inventory (-4.8±7.3 vs. -1.5±6.1, P=0.04) compared with the placebo. Patients who received vitamin D supplements had significantly decreased fasting plasma glucose (-7.5±10.6 vs. +0.3±10.7mg/dL, P=0.004), serum insulin levels (-3.6±5.3 vs. -0.9±3.5 μIU/mL, P=0.01), homeostasis model of assessment-insulin resistance (-1.0±1.3 vs. -0.2±0.7, P=0.003), serum triglycerides (-9.6±30.8 vs. +15.6±30.2mg/dL, P=0.001), total- (-8.7±20.9 vs. +11.0±27.4mg/dL, P=0.001) and LDL-cholesterol (-11.1±17.9 vs. +5.9±27.5mg/dL, P=0.004) compared with the placebo. Additionally, vitamin D intake resulted in a significant decrease in serum high sensitivity C-reactive protein (-2.2±4.2 vs. +2.0±3.7mg/L, P<0.001), and significant increases plasma total antioxidant capacity (+26.2±99.8 vs. -86.3±127.5mmol/L, P<0.001) and glutathione levels (+292.3±172.4 vs. +48.9±208.9μmol/L, P<0.001) compared with the placebo. There was no significant effect of vitamin D supplementation on serum HDL-cholesterol, and other markers of insulin metabolism, inflammation and oxidative stress.

CONCLUSIONS

Totally, taking 50,000IU vitamin D supplement every 2weeks for 12weeks in MMT patients had beneficial effects on psychological symptoms and few metabolic profiles.

Vitamin D deficiency is associated with acute ischemic stroke, C-reactive protein, and short-term outcome

The aim of this study was to investigate whether vitamin D deficiency (VDD) is associated with acute ischemic stroke, inflammatory markers, and short-term outcome. 168 acute ischemic stroke patients and 118 controls were included. The modified Rankin Scale (mRS) was applied up to 8 h of admission (baseline) and after three-months follow-up, and blood samples were obtained up to 24 h of admission to evaluate serum levels of 25-hydroxivitamin D [25(OH)D] and inflammatory markers. Vitamin D levels classified the individuals in sufficient (VDS ≥ 30.0 ng/mL), insufficient (VDI 20.0-29.9 ng/mL), and deficient (VDD < 20.0 ng/mL) status. Patients had lower levels of 25(OH)D, higher frequency of VDD (43.45% vs. 5.08%, OR: 16.64, 95% CI: 5.66-42.92, p < 0.001), and higher inflammatory markers than controls (p < 0.05). Patients with VDD showed increased high sensitivity C-reactive protein (hsCRP) levels than those with VDS status (p = 0.043); those with poor outcome presented with lower 25(OH)D levels than those with good outcome (p = 0.008); moreover, 25(OH)D levels were negatively correlated with mRS after three-months follow-up (r = -0.239, p = 0.005). The associations between VDD and higher hsCRP levels and between 25(OH)D levels and poor outcome at short-term in acute ischemic stroke patients suggest the important role of vitamin D in the inflammatory response and pathophysiology of this ischemic event.

Atherosclerosis: a chronic inflammatory disease mediated by mast cells

Inflammation is a process that plays an important role in the initiation and progression of atherosclerosis and immune disease, involving multiple cell types, including macrophages, T-lymphocytes, endothelial cells, smooth muscle cells and mast cells. The fundamental damage of atherosclerosis is the atheromatous or fibro-fatty plaque which is a lesion that causes several diseases. In atherosclerosis the innate immune response, which involves macrophages, is initiated by the arterial endothelial cells which respond to modified lipoproteins and lead to Th1 cell subset activation and generation of inflammatory cytokines and chemoattractant chemokines. Other immune cells, such as CD4+ T inflammatory cells, which play a critical role in the development and progression of atherosclerosis, and regulatory T cells [Treg], which have a protective effect on the development of atherosclerosis are involved. Considerable evidence indicates that mast cells and their products play a key role in inflammation and atherosclerosis. Activated mast cells can have detrimental effects, provoking matrix degradation, apoptosis, and enhancement as well as recruitment of inflammatory cells, which actively contributes to atherosclerosis and plaque formation. Here we discuss the relationship between atherosclerosis, inflammation and mast cells.