TaqI and ApaI Variants of Vitamin D Receptor Gene Increase the Risk of Colorectal Cancer in a Saudi Population.

BACKGROUND: Polymorphisms in the gene encoding the vitamin D receptor (VDR) affect the protective role of vitamin D against many types of cancers, including colorectal cancer (CRC). OBJECTIVE: The objective of this study was to assess the effect of four major polymorphisms of the VDR gene (ApaI, TaqI, BsmI and FokI) on the risk of CRC in a Saudi population. MATERIALS AND METHODS: This case-control study recruited 132 CRC patients from the oncology clinics at King Abdulaziz University Hospital and 124 healthy controls from the blood bank at King Fahad General Hospital, Jeddah, Saudi Arabia, between September 2017 and August 2018. All participants were Saudis and aged 20-80 years. Genomic DNA samples were extracted from the peripheral blood cells and amplified with polymerase chain reaction. The resulting fragments were digested with different endonucleases to reveal the genotypes using the restriction fragment length polymorphism technique. The genotype distribution and allele frequency, odds ratio (OR), risk ratio (RR) and P values were determined with contingency table analysis following Hardy-Weinberg equilibrium equation. RESULTS: For the ApaI single-nucleotide polymorphism (SNP) (rs7975232), only the heterozygous (Aa) genotype increased the risk of CRC (OR = 3.4, RR = 2.3, and P < 0.0001), whereas the TaqI SNP (rs731236) carriers with either the heterozygous (Tt) or homozygous (tt) genotype displayed an increased risk for the disease (OR = 6.18, RR = 4, P < 0.0001; OR = 3, RR = 2.4, P = 0.02, respectively). In contrast, heterozygous (Bb) and homozygous (bb) carriers of the BsmI SNP (rs1544410) had significantly lower risk for CRC (P < 0.0001). Finally, for the FokI SNP (rs2228570), there was no association with CRC risk. CONCLUSION: This study found that VDR SNPs ApaI and TaqI increase the risk of CRC, whereas BsmI reduces the risk of CRC in the selected Saudi population. Therefore, ApaI and TaqI SNPs could potentially be used as a diagnostic biomarker for CRC. However, the molecular mechanisms by which these variants increase or decrease the risk of CRC need to be investigated.

Antiglycation Activities and Common Mechanisms Mediating Vasculoprotective Effect of Quercetin and Chrysin in Metabolic Syndrome.

Multiple risk factors combine to increase the risk of vascular dysfunction in patients suffering from metabolic syndrome (MetS). The current study investigates the extent to which quercetin (Q) and chrysin (CH) protect against vascular dysfunction in MetS rats. MetS was induced by feeding rats a high-salt diet (3%) and fructose-enriched water (10%) for 12 weeks. Thoracic aorta was isolated from MetS rats and from control rats, with the latter being injured by methylglyoxal (MG). Aortae were incubated with CH and Q, and vascular reactivity was evaluated through the analysis of aortic contraction and relaxation in response to PE and ACh, respectively. The formation of advanced glycation end products (AGEs) and the free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) were also evaluated following the introduction of CH and Q. The increased vasoconstriction and impaired vasodilation in MetS aortae were significantly ameliorated by Q and CH. Similarly, they ameliorated glycation-associated exaggerated vasoconstriction and impaired vasodilation produced by MG in control aortae. In addition, both Q and CH were effective in reducing the formation of AGEs and inhibition of glycosylation in response to MG or fructose treatment. Finally, Q successfully scavenged DPPH free radicals while CH showed significant vasodilation of precontracted aorta that was inhibited by L-NAME. In conclusion, Q and CH provide protection against vascular dysfunction in MetS by interfering with AGEs formations and AGEs-associated vascular deterioration, with CH being largely dependent on NO-mediated mechanisms of vasodilation.

Serum vitamin D receptor (VDR) levels as a potential diagnostic marker for colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity worldwide, and there has been a significant increase in the incidence of CRC in recent decades. Therefore, there is an urgent need to identify blood biomarkers that can be used for early diagnosis. It is not yet clear whether the level of vitamin D and its receptor, vitamin D receptor (VDR), in the blood are helpful factors in the diagnosis of CRC. Therefore, the study focuses on determining the VDR serum level's contribution and other chemical parameters to the risk of CRC. A total of 189 Saudi participants (66 CRC patients and 123 control patients) aged 20-80 years old were enrolled in this case-control study. A serum sample was collected from each participant, and the levels of VDR and other bone profile tests were determined using ELISA or chemiluminescent assays. P values < 0.05 were considered statistically significant. The results showed a highly significant reduction in the levels of total vitamin D (P < 0.0001), VDR (P < 0.0001), vitamin D3 (P < 0.05), and calcium (P < 0.0001) in the serum of CRC patients compared to the controls. However, the alkaline phosphatase level was higher in CRC patients compared to the controls (P < 0.0001). None of the blood markers showed a significant correlation to the progression of CRC (P > 0.05). More investigation is needed to elucidate different physiological processes that can be affected by these blood biomarkers, therefore changing the carcinogenesis of CRC.

Relationship between Serum Vitamin D and Calcium Levels and Vitamin D Receptor Gene Polymorphisms in Colorectal Cancer.

BACKGROUND: Many epidemiological studies have shown that vitamin D deficiency is associated with various types of human cancers. The biological action of vitamin D and its metabolites is mediated by the transcription factor vitamin D receptor (VDR). The VDR gene is highly expressed in the colon and is involved in many biological functions. The aim of the current study was to assess the relationship between serum vitamin D metabolite and calcium levels with VDR polymorphisms in normal and colorectal cancer (CRC) patients. METHODS: Fifty Saudi CRC patients and fifty controls were enrolled in the study. The levels of total vitamin D, 25(OH)D3, and calcium were measured in serum. RESULTS: The homozygous genotype (aa) of the ApaI VDR polymorphism (rs7975232) was found to correlate with total serum vitamin D levels of CRC patients, while the heterozygous (Tt) TaqI VDR polymorphism (rs731236) was associated with serum calcium levels. In contrast, the BsmI and FokI VDR polymorphisms (rs1544410 and rs2228570, resp.) did not affect the serum levels of total vitamin D, 25-hydroxyvitamin D3, and calcium. CONCLUSION: Appropriate vitamin D levels were shown to be important in preventing the onset of CRC.

Synthesis and in vitro antitumor activity of novel acylspermidine derivative N-(4-aminobutyl)-N-(3-aminopropyl)-8-hydroxy-dodecanamide (AAHD) against HepG2 cells.

Naturally occurring polyamines like Putrescine, Spermidine, and Spermine are polycations which bind to the DNA, hence stabilizing it and promoting the essential cellular processes. Many synthetic polyamine analogues have been synthesized in the past few years, which have shown cytotoxic effects on different tumours. In the present study, we evaluated the antiproliferative effect of a novel, acylspermidine derivative, (N-(4-aminobutyl)-N-(3-aminopropyl)-8-hydroxy-dodecanamide) (AAHD) on HepG2 cells. Fluorescence staining was performed with nuclear stain (Hoechst 33342) and acridine orange/ethidium bromide double staining. Dose and the time-dependent antiproliferative effect were observed by WST-1 assays, and radical scavenging activity was measured by ROS. Morphological changes such as cell shrinkage & blebbing were analyzed by fluorescent microscopy. It was found that AAHD markedly suppressed the growth of HepG2 cells in a dose- and time-dependent manner. It was also noted that the modulation of ROS levels confirmed the radical scavenging activity. In the near future, AAHD can be a promising drug candidate in chalking out a neoplastic strategy to control the proliferation of tumour cells. This study indicated that AAHD induced anti-proliferative and pro-apoptotic activities on HCC. Since AAHD was active at micromolar concentrations without any adverse effects on the healthy cells (Fibroblasts), it is worthy of further clinical investigations.

Arginase overexpression and NADPH oxidase stimulation underlie impaired vasodilation induced by advanced glycation end products.

BACKGROUND: Advanced glycation endproducts (AGEs) play a major role in the development of many vascular complications that are mediated by endothelial dysfunction. The present work aimed to investigate the mechanism by which AGEs impair vasodilation. METHODS: The effect of AGEs on vasodilation induced by acetylcholine or D NONOate was examined by incubating isolated rat aortae with different AGEs concentrations. ACh-induced nitric oxide generation was assessed using the fluorescent probe diaminofluorecein (DAF-FM). The effect of AGEs on expression of mRNA for arginase 2, NADPH oxidase and endothelial nitric oxide synthase (eNOS) were determined by real-time PCR. RESULTS: One-hour in vitro incubation of rat aortae with AGEs impaired endothelial-dependent vasodilation produced by ACh, while increasing D NONOate-induced vasodilation. Preincubation of aortae with l-ornithine, an arginase 2-inhibitor, prevented the impairment effect induced by AGEs on endothelial-dependent vasodilation. Superoxide scavenging by tempol or NADPH oxidase inhibition by apocynin also blocked the effect of AGEs. AGEs decreased ACh-induced NO production and this was inhibited by both l-ornithine and apocynin. Furthermore, AGEs exposure increased arginase mRNA expression but decreased mRNA expression for eNOS in isolated rat aortae. CONCLUSION: The present results indicate that AGEs impairs endothelial-dependent vasodilation, and this effect is mediated via arginase overexpression and NADPH oxidase stimulation.

Associations of Vitamin D Levels and Vitamin D Receptor Genotypes with Patient-Reported Outcome/Disease Activity in Patients with Rheumatoid Arthritis.

BACKGROUND: The aim of this study is to evaluate the prevalence of vitamin-D insufficiency and vitamin-D receptor (VDR) polymorphisms in rheumatoid arthritis (RA) patients and its association with disease activity and patient reported outcomes (PROs). METHODS: Eighty-two individuals were included in a cross-sectional study (41 RA patients, 41 controls). Prior to assessment, each patient completed a PRO questionnaire. Serum vitamin-D levels and genotyping for VDR were assessed. Vitamin-D deficient patients received vitamin-D supplementation. Re-assessment of disease activity (DAS28) was performed after 9-months. RESULTS: Low vitamin-D levels were more frequent in RA patients (p < 0.01). A negative, but insignificant, association with DAS-28 score was identified; whereas, there was a significant negative association with the PROs (p < 0.01). Vitamin-D supplementation was associated with significant improvement in the patients' scores for pain, fatigue, global assessment, physical disability, and quality of life. In contrast to the control group, the frequency of the recessive TaqI and FokI genotypes was higher in RA patients. CONCLUSIONS: In RA patients, serum vitamin-D level was significantly and inversely associated with both PROs and disease activity. The TaqI and FokI fragment length polymorphisms of VDR significantly contributed to the risk of RA. Having a significant positive impact on patient reported outcomes, vitamin-D supplementation may have a role in RA management.

Association of Paraoxonase 1 Polymorphism and Serum 25-Hydroxyvitamin D with the Risk of Cardiovascular Disease in Patients with Rheumatoid Arthritis.

BACKGROUND: Patients with rheumatoid arthritis (RA) have significantly increased cardiovascular (CV) morbidity and mortality that are not accounted for by traditional risk factors alone. Paraoxonase 1 (PON1) and 25-hydroxyvitamin D have been shown to be involved in the pathogenesis of CV diseases. Objective: This study aimed to investigate PON1 gene polymorphism and serum 25-hydroxyvitamin D concentrations in RA patients, and to determine their association with CV risk in RA. METHODS: Serum samples from 46 RA patients and 45 healthy controls were tested for PON1 R192Q genotypes and serum vitamin D concentrations. The cardiovascular risks were assessed by Q-risk. Lipoprotein cholesterol levels, traditional CV risk factors, medication use, and RA disease activity status were also assessed. RESULTS: PON1 polymorphism and low serum 25-hydroxyvitamin D were significantly associated with increased CV risk (p < 0.05). Compared to patients with either the PON1 QQ genotype or the QR genotype, patients with the RR genotype demonstrated decreased CV risk on multivariate analysis, controlling for traditional CV risk factors, C-reactive protein levels, prednisone use, and cholesterol-lowering medication use (p < 0.05). CONCLUSIONS: There was a relationship of the genetic determinants of paraoxonase 1 (PON1 192) and serum 25-hydroxyvitamin D to CV risk in RA patients. Paired measurement of paraoxonase 1 genotype and serum 25-hydroxyvitamin D can be used as biomarkers of CV risk in RA patients.

Geraniol alleviates diabetic cardiac complications: Effect on cardiac ischemia and oxidative stress.

The present study was planned to assess the possible protective effect of geraniol on cardiovascular complications in an animal model with diabetes. Diabetes was induced in rats by a single streptozotocin injection. In the treated group, geraniol (150mgkg-1day-1) was administered orally starting from the 15th day after induction of diabetes, and ending after 7 weeks; diabetic control rats were given vehicle for the same period. At the end of the study, cardiac contractility was assessed by using a Millar microtip catheter in anesthetised rats, and cardiac conductivity determined by a surface ECG. Serum levels of glucose, cholesterol, triglyceride and adiponectin as well as urine 8-isoprostane were determined. In addition, cardiac superoxide dismutase (SOD) and catalase activity were measured. Geraniol administration significantly alleviated the attenuated cardiac systolic function associated with diabetes as indicated by inhibiting the decrease in the rate of rise (dP/dtmax) in ventricular pressure and the increase in systolic duration observed in diabetic rats. In addition, geraniol alleviated impaired diastolic function as shown by inhibiting the decrease in the rate of fall (dP/dtmin) in ventricular pressure and increased isovolumic relaxation constant (Tau) observed in diabetic rats. ECG recordings showed that geraniol prevented any increase in QTc and T-peak-T-end intervals, and markers of LV ischemia and arrhythmogenesis, seen in diabetic animals. Geraniol suppressed the exaggerated oxidative stress as evidenced by preventing the increase in 8-isoprotane. In diabetic heart tissue, geraniol prevented the inhibition in catalase activity but did not affect the heart SOD. Geraniol partially reduced hyperglycemia, prevented the hypercholesterolemia, but did not affect the serum level of adiponectin in diabetic animals. Results obtained in this study suggest that geraniol provides a potent protective effect against cardiac dysfunction induced by diabetes. This ameliorative effect could be attributed to its suppression of oxidative stress.

Antimicrobial Activity of Biocompatible Microemulsions Against Aspergillus niger and Herpes Simplex Virus Type 2.

BACKGROUND: Microemulsions (MEs), which consist of oil, water, surfactants, and cosurfactants, have recently generated considerable interest as antimicrobial agents. OBJECTIVES: To determine the antifungal and antiviral activities of three ME formulations (MEa, MEb, and MEc) that differ in their hydrophilicity. METHODS: The ME formulas were produced by mixing different fractions of Tween 80, Span 20, ethanol, oil, isopropyl myristate, and distilled water. The antifungal activity of the ME formulas against Aspergillus niger, A. flavus, Bacillus, Candida albicans, and C. glabrata were determined by the solid medium diffusion cytotoxicity test against the mitochondria, measuring the minimum inhibitory concentration, dry biomass, and leakage of potassium, and characterizing the cell morphology. The antiviral activities of the ME formulas against the herpes simplex virus type 2 (HSV-2) were determined using the cytopathic effect assay. RESULTS: Significant antimicrobial activities were recorded against A. niger and herpes simplex virus type 2 (HSV-2) when treated with MEb that had hydrophobic nanodroplets with an average diameter of 4.7 ± 1.22 nm. A volume of 0.1 mL of MEb (10 mL of potato dextrose broth) inhibited the germination of A. niger cells, reduced their dry biomass, enhanced the leakage of potassium from the cell membranes, affected their mitochondria, and altered the shape of their conidia, in addition to enlarging them. MEb was able to destroy the HSV-2 virus at a 200-fold dilution in Dulbecco's modified eagle medium. CONCLUSIONS: The water-in-oil ME with equivalent surfactant-to-oil ratio (MEb) has great potential as an antifungal and antiviral agent.