Confounding factors of the expression of mTBI biomarkers, S100B, GFAP and UCH-L1 in an aging population.

OBJECTIVES: To evaluate some confounding factors that influence the concentrations of S100 calcium binding protein B (S100B), glial fibrillary acidic protein (GFAP), and ubiquitin carboxyl-terminal hydrolase L-1 (UCH-L1) in older individuals. Indeed, recent guidelines have proposed the combined use of S100B and the "GFAP-UCH-L1" mTBI test to rule out mild traumatic brain injuries (mTBI). As older adults are the most at risk of mTBI, it is particularly important to understand the confounding factors of those mTBI rule-out biomarkers in aging population. METHODS: The protein S100B and the "GFAP and UCH-L1" mTBI test were measured using Liaison XL (Diasorin) and Alinity I (Abbott), respectively, in 330 and 341 individuals with non-suspected mTBI from the SarcoPhAge cohort. RESULTS: S100B, GFAP and UCH-L1 were all significantly correlated with renal function whereas alcohol consumption, Geriatric Depression Score (GDS), smoking habits and anticoagulant intake were not associated with any of these three biomarkers. Body mass index (BMI) and age were associated with GFAP and UCH-L1 expression while sex and mini-mental state examination (MMSE) were only associated with GFAP. According to the manufacturer's cut-offs for mTBI rule-out, only 5.5 % of participants were positive for S100B whereas 66.9 % were positive for the "GFAP-UCH-L1" mTBI test. All positive "GFAP-UCH-L1" mTBI tests were GFAP+/UCH-L1-. Among individuals with cystatin C>1.55 mg/L, 25 % were positive for S100B while 90 % were positive for the mTBI test. CONCLUSIONS: Our data show that confounding factors have different impacts on the positivity rate of the "GFAP-UCH-L1" mTBI test compared to S100B.

Mechanisms of inhibition of advanced glycation end-products (AGEs) and α-glucosidase by Heliotropium bacciferum: Spectroscopic and molecular docking analysis.

Diabetes mellitus is characterized by hyperglycemia that makes insulin more prone to glycation and form advanced glycation end products (AGEs). Here, we report the effect of glyoxal (GO) on the formation of AGEs using human insulin as model protein and their structural modifications. The present investigation also reports the anti-AGE potential of Heliotropium bacciferum (Leaf) extracts. The phytochemical analysis of H. bacciferum revealed that free phenolic extract contains higher amount of total phenolic (3901.58 ± 17.06 mg GAE/100 g) and total flavonoid content (30.41 ± 0.32 mg QE/100 g) when compared to bound phenolic extract. Naringin and caffeic acid were identified as the major phenolic ingredients by UPLC-PAD method. Furthermore, bound phenolics extract showed significantly higher DPPH and superoxide radicals scavenging activity (IC50 17.53 ± 0.36 µg/mL and 0.306 ± 0.038 mg/ mL, respectively) (p ≤ 0.05). Besides, the bound phenolics extract also showed significant (p ≤ 0.05) chelating power (IC50 0.063) compared to free phenolic extract. In addition, bound phenolic extract could efficiently trap GO under physiological conditions. Spectroscopic investigation of GO-modified insulin illustrated changes in the tertiary structure of insulin and formation of AGEs. On the other hand, no significant alteration in secondary structure was observed by far UV-CD measurement. Furthermore, H. bacciferum extract inhibited α-glucosidase activity and AGEs formation implicated in diabetes. Molecular docking analysis depicted that GO bind with human insulin in both chains and forms a stable complex with TYR A: 14, LEU A:13, ASN B:3, SER A:12 amino acid residues with binding energy of - 2.53 kcal/mol. However, caffeic acid binds to ASN A:18 and GLU A:17 residues of insulin with lower binding energy of -4.67 kcal/mol, suggesting its higher affinity towards human insulin compared to GO. Our finding showed promising activity of H. bacciferum against AGEs and its complications. The major phenolics like caffeic acid, naringin and their derivatives could be exploited for the drug development for management of AGEs in diabetes.

Assessment of Broad-Spectrum Antimicrobial, Antibiofilm, and Anticancer Potential of Lactoferrin Extracted from Camel Milk.

Lactoferrin is a multifunctional glycoprotein present in mammalian milk. It possesses antimicrobial, antioxidant, immunomodulatory, and several biological functions. Owing to the current trend of increasing antibiotic resistance, our study was designed to purify lactoferrin from camel milk colostrum using cation exchange chromatography on the SP-Sepharose high-performance column. The purity and molecular weight of lactoferrin were checked by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The chromatogram of the purification procedure illustrated a single peak corresponding to lactoferrin, while the SDS-PAGE revealed 78 kDa molecular weight protein. Furthermore, lactoferrin protein and its hydrolysate form were assessed for its antimicrobial potential. The highest inhibitory effect of whole lactoferrin at the concentration (4 mg/ml) was observed against methicillin-resistant S. aureus (MRSA) and S. aureus, while 10 mg/ml concentration was effective against K. pneumonia, and 27 mg/ml was potent against multidrug-resistant (MDR) bacteria, P. aeruginosa. Likewise, MRSA was more sensitive toward iron-free lactoferrin (2 mg/ml) and hydrolyzed lactoferrin (6 mg/ml). The tested lactoferrin forms showed variability in minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) among tested bacteria. The scanning electron microscopy (SEM) analysis images revealed distortions of the bacterial cells exposed to lactoferrin. The antibiofilm effect differed depending on the concentration and the type of the bacteria; biofilm inhibition ranged from 12.5 to 91.3% in the tested pathogenic bacteria. Moreover, the anticancer activity of lactoferrin forms exhibited a dose-dependent cytotoxicity against human lung cancer cell line (A549).

Aggregation and cytotoxicity of food additive dye (Azorubine)-albumin adducts: a multi-spectroscopic, microscopic and computational analysis.

Protein and peptide misfolding is a central factor in the formation of pathological aggregates and fibrils linked to disorders like Alzheimer's and Parkinson's diseases. Therefore, it's essential to understand how food additives, particularly Azorubine, affect protein structures and their ability to induce aggregation. In this study, human serum albumin (HSA) was used as a model protein to investigate the binding and conformational changes caused by azorubine, a common food and drink colorant. The research revealed that azorubine destabilized the conformation of HSA at both physiological (pH 7.4) and acidic (pH 3.5) conditions. The loss of tryptophan fluorescence in HSA suggested significant structural alterations, particularly around aromatic residues. Far UV-CD analysis demonstrated disruptions in HSA's secondary structure, with a notable reduction in α-helical structures at pH 7.4. At pH 3.5, Azorubine induced even more extensive perturbations, resulting in a random coil conformation at higher azorubine concentrations. The study also investigated aggregation phenomena through turbidity measurements, RLS analysis, and TEM imaging. At pH 3.5, larger insoluble aggregates formed, while at pH 7.4, only conformational changes occurred without aggregate formation. Cytotoxicity assessments on neuroblastoma (SH-SY5Y) cells highlighted the concentration-dependent toxicity of albumin aggregates. Molecular dynamics simulations reaffirmed the stable interaction between azorubine and HSA. This research provides valuable insights into the mechanisms by which azorubine influences protein conformations. To further advance our understanding and contribute to the broader knowledge in this area, several future directions can be considered such as exploring other proteins, studying dose-response relationship, gaining mechanistic insights, biological relevance, toxicity assessment, identifying alternative food colorants, and mitigation strategies to prevent adverse effects of azorubine on serum proteins.Communicated by Ramaswamy H. Sarma.

Non-enzymatic glycation and aggregation of camel immunoglobulins induce breast cancer cell proliferation.

Glycation of biomolecules results in the formation of advanced glycation end products (AGEs). Immunoglobulin G (IgG) has been implicated in the progression of various diseases, including diabetes and cancer. This study purified three IgG subclasses (IgG1, IgG2, and IgG3) from Camelus dromedarius colostrum using ammonium sulfate fractionation and chromatographic procedures. SDS-PAGE was performed to confirm the purity and molecular weight of the IgG subclasses. Several biochemical and biophysical techniques were employed to study the effect of glycation on camel IgG using methylglyoxal (MGO), a dicarbonyl sugar. Early glycation measurement showed an increase in the fructosamine content by ~four-fold in IgG2, ~two-fold in IgG3, and a slight rise in IgG1. AGEs were observed in all classes of IgGs with maximum hyperchromicity (96.6%) in IgG2. Furthermore, glycation-induced oxidation of IgGs led to an increase in carbonyl content and loss of -SH groups. Among subclass, IgG2 showed the highest (39.7%) increase in carbonyl content accompanied by 82.5% decrease in -SH groups. Far UV-CD analysis illustrated perturbation of ß-sheet structure during glycation reaction with MGO. Moreover, glycation of IgG proceeds to various conformational states like aggregation and increased hydrophobicity. In addition, the cytotoxicity assay (MTT) illustrated the proliferation of breast cancer cells (MCF-7) with IgG2 treatment.

Regional Variations in Pesticide Residue Detection Rates and Concentrations in Saudi Arabian Crops.

There is a scarcity of evidence on the levels of pesticide residues among common crops grown in the different regions of the Kingdom of Saudi Arabia (KSA). The present study aims to fill this gap. We collected samples across four regions of KSA (N = 41 from the west, N = 146 from the central, N = 131 from the north and N = 74 samples from the east). Food samples were extracted and cleaned using the modified quick, easy, cheap, effective, rugged and safe (QuEChERS) methodology. Tandem mass (LC-MS/MS and GC-MS/MS) was used to detect pesticide residues. The highest pesticide residue detection rate was 89.7% in the central region, followed by 88.5% in the north, 83.8% in the east and 70.7% in the western region (p = 0.01). Pesticide residue detection rates were significantly higher in fruits than vegetables (p = 0.02). Cypermethrin detection was most common overall, particularly in the Western region (p = 0.002), and pyraclostrobin concentration was the highest among all residues investigated. In conclusion, high detection rates of moderately hazardous pesticide residues were found in various crops across regions in KSA. Routine biomonitoring programs across KSA regions should be implemented, as well as public health campaigns to decrease pesticide residue consumption and exposure.

Structure-guided identification of potent inhibitors of ROS1 kinase for therapeutic development against non-small cell lung cancer.

Proto-oncogene tyrosine-protein kinase ROS (ROS1) is a member of the sevenless receptor, which affects epithelial cell differentiation and is highly expressed in a variety of tumor cells. The elevated expression and dysfunction of ROS1 have been involved in various malignancies, such as non-small cell lung cancer (NSCLC), stomach cancer, ovarian, breast cancer, cholangiocarcinoma, colorectal cancer, adenosarcoma, oesophageal cancer, etc. ROS1 has been postulated as a potential drug target in anticancer therapeutics. In this study, we carried out a virtual screening of phytochemicals against ROS1 to identify its potential inhibitors. The virtual screening process was performed on the ROS1 structure, where two phytochemicals, Helioscopinolide C and Taiwanin C, were identified. These compounds resulted from filters like Lipinski rule of five, PAINS filter, binding affinities values, and all-atom molecular dynamics (MD) simulations followed by principal component analysis (PCA) and essential dynamics. The findings of this study highlight the role of ROS1 in multiple physiological candidates and its therapeutic targeting using phytochemicals. This study suggests Helioscopinolide C and Taiwanin C as potential compounds for therapeutic development targeting ROS1-associated non-small cell lung cancer for clinical applications. Further in vitro and in vivo experiments are required to validate these findings.Communicated by Ramaswamy H. Sarma.

The effect of novel antihypertensive drug valsartan on lysozyme aggregation: A combined in situ and in silico study.

Protein misfolding can result in amyloid fiber aggregation, which is associated with various types of diseases. Therefore, preventing or treating abnormally folded proteins may provide therapeutic intervention for these diseases. Valsartan (VAL) is an angiotensin II receptor blocker (ARB) that is used to treat hypertension. In this study, we examine the anti-aggregating effect of VAL against hen egg-white lysozyme (HEWL) amyloid fibrils through spectroscopy, docking, and microscopic analysis. In vitro formation of HEWL amyloid fibrils was indicated by increased turbidity, RLS (Rayleigh light scattering), and ThT fluorescence intensity. 10 µM VAL, amyloid/aggregation was inhibited up to 83% and 72% as measured by ThT and RLS respectively. In contrast, 100 µM VAL significantly increases the fibril aggregation of HEWL. CD spectroscopy results show a stabilization of HEWL α-helical structures in the presence of 10 µM VAL while the increase in ß-sheet was detected at 100 µM concentration of VAL. The hydrophobicity of HEWL was increased at 100 µM VAL, suggesting the promotion of aggregation via its self-association. Steady-state quenching revealed that VAL and HEWL interact spontaneously via hydrogen bonds and van der Waals forces. Transmission electron microscopy (TEM) images illustrate that the needle-like fibers of HEWL amyloid were reduced at 10 µM VAL, while at 100 µM the fibrils of amyloid were increased. Additionally, our computational studies showed that VAL could bind to two binding sites within HEWL. In the BS-1 domain of HEWL, VAL binds to ASN59, ILE98, ILE58, TRP108, VAL109, SER50, ASP52, ASN59, ALA107, and TRP108 residues with a binding energy of -9.72 kcal mol-1. Also, it binds to GLU7, ALA10, ALA11, CYS6, ARG128, and ARG14 in the BS-2 domain with a binding energy of -5.89 kcal mol-1. VAL, therefore, appears to have dual effect against HEWL aggregation. We suggest that VAL stabilizes HEWL's aggregation-prone region (APR) at 10 µM, preventing aggregation. Also, we assume that at 100 µM, VAL occupies BS-2 beside BS-1 and destabilizes the folding structure of HEWL, resulting in aggregation. Further studies are needed to investigate the mechanism of action and determine its potential side effects.

Genetic Variants of HNF4A, WFS1, DUSP9, FTO, and ZFAND6 Genes Are Associated with Prediabetes Susceptibility and Inflammatory Markers in the Saudi Arabian Population.

Prediabetes is a reversible, intermediate stage of type 2 diabetes mellitus (T2DM). Lifestyle changes that include healthy diet and exercise can substantially reduce progression to T2DM. The present study explored the association of 37 T2DM- and obesity-linked single nucleotide polymorphisms (SNPs) with prediabetes risk in a homogenous Saudi Arabian population. A total of 1129 Saudi adults [332 with prediabetes (29%) and 797 normoglycemic controls] were randomly selected and genotyped using the KASPar SNP genotyping method. Anthropometric and various serological parameters were measured following standard procedures. Heterozygous GA of HNF4A-rs4812829 (0.64; 95% CI 0.47-0.86; p < 0.01), heterozygous TC of WFS1-rs1801214 (0.60; 95% confidence interval (CI) 0.44-0.80; p < 0.01), heterozygous GA of DUSP9-rs5945326 (0.60; 95% CI 0.39-0.92; p = 0.01), heterozygous GA of ZFAND6-rs11634397 (0.75; 95% CI 0.56-1.01; p = 0.05), and homozygous AA of FTO-rs11642841 (1.50; 95% CI 0.8-1.45; p = 0.03) were significantly associated with prediabetes, independent of age and body mass index (BMI). Additionally, C-reactive protein (CRP) levels in rs11634397 (AA) with a median of 5389.0 (2767.4-7412.8) were significantly higher than in the heterozygous GA genotype with a median of 1736.3 (1024.4-4452.0) (p < 0.01). In conclusion, only five of the 37 genetic variants previously linked to T2DM and obesity in the Saudi Arabian population [HNF4A-rs4812829, WFS1-rs1801214, DUSP9-rs5945326, ZFAND6-rs11634397, FTO-rs11642841] were associated with prediabetes susceptibility. Prospective studies are needed to confirm the potential clinical value of the studied genetic variants of interest.

Agitation does not induce fibrillation in reduced hen egg-white lysozyme at physiological temperature and pH.

Several proteins and peptides tend to form an amyloid fibril, causing a range of unrelated diseases, from neurodegenerative to certain types of cancer. In the native state, these proteins are folded and soluble. However, these proteins acquired ß-sheet amyloid fibril due to unfolding and aggregation. The conversion mechanism from well-folded soluble into amorphous or amyloid fibril is not well understood yet. Here, we induced unfolding and aggregation of hen egg-white lysozyme (HEWL) by reducing agent dithiothreitol and applied mechanical sheering force by constant shaking (1000 rpm) on the thermostat for 7 days. Our turbidity results showed that reduced HEWL rapidly formed aggregates, and a plateau was attained in nearly 5 h of incubation in both shaking and non-shaking conditions. The turbidity was lower in the shaking condition than in the non-shaking condition. The thioflavin T binding and transmission electron micrographs showed that reduced HEWL formed amorphous aggregates in both conditions. Far-UV circular dichroism results showed that reduced HEWL lost nearly all alpha-helical structure, and ß-sheet secondary structure was not formed in both conditions. All the spectroscopic and microscopic results showed that reduced HEWL formed amorphous aggregates under both conditions.

Effect of Antihypertensive Drug (Chlorothiazide) on Fibrillation of Lysozyme: A Combined Spectroscopy, Microscopy, and Computational Study.

Amyloid fibrils abnormally accumulate together in the human body under certain conditions, which can result in lethal conditions. Thus, blocking this aggregation may prevent or treat this disease. Chlorothiazide (CTZ) is a diuretic and is used to treat hypertension. Several previous studies suggest that diuretics prevent amyloid-related diseases and reduce amyloid aggregation. Thus, in this study we examine the effects of CTZ on hen egg white lysozyme (HEWL) aggregation using spectroscopic, docking, and microscopic approaches. Our results showed that under protein misfolding conditions of 55 °C, pH 2.0, and 600 rpm agitation, HEWL aggregated as evidenced by the increased turbidity and Rayleigh light scattering (RLS). Furthermore, thioflavin-T, as well as trans electron microscope (TEM) analysis confirmed the formation of amyloid structures. An anti-aggregation effect of CTZ is observed on HEWL aggregations. Circular dichroism (CD), TEM, and Thioflavin-T fluorescence show that both CTZ concentrations reduce the formation of amyloid fibrils as compared to fibrillated. The turbidity, RLS, and ANS fluorescence increase with CTZ increasing. This increase is attributed to the formation of a soluble aggregation. As evidenced by CD analysis, there was no significant difference in α-helix content and ß-sheet content between at 10 µM CTZ and 100 µM. A TEM analysis of HEWL coincubated with CTZ at different concentrations validated all the above-mentioned results. The TEM results show that CTZ induces morphological changes in the typical structure of amyloid fibrils. The steady-state quenching study demonstrated that CTZ and HEWL bind spontaneously via hydrophobic interactions. HEWL-CTZ also interacts dynamically with changes in the environment surrounding tryptophan. Computational results revealed the binding of CTZ to ILE98, GLN57, ASP52, TRP108, TRP63, TRP63, ILE58, and ALA107 residues in HEWL via hydrophobic interactions and hydrogen bonds with a binding energy of -6.58 kcal mol-1. We suggest that at 10 µM and 100 µM, CTZ binds to the aggregation-prone region (APR) of HEWL and stabilizes it, thus preventing aggregation. Based on these findings, we can conclude that CTZ has antiamyloidogenic activity and can prevent fibril aggregation.

Sex-Specific Cut-Offs of Single Point Insulin Sensitivity Estimator (SPISE) in Predicting Metabolic Syndrome in the Arab Adolescents.

The Single Point Insulin Sensitivity Estimator (SPISE) is a novel surrogate marker for insulin sensitivity and was found comparable to the gold standard clamp test as well as for predicting the Metabolic Syndrome (MetS) in several populations. The present study aimed to assess for the first time, the validity of SPISE in predicting MetS among Arab adolescents. In this cross-sectional study, 951 Saudi adolescents aged 10−17 years were randomly recruited from different schools across Riyadh, Saudi Arabia. Anthropometrics were measured and fasting blood samples were collected for the assessment of glucose, lipid profile, adipokines, C-reactive protein and 25 hydroxyvitamin (OH) D. MetS was defined using the National Cholesterol Education Program's (NCEP) criteria with age-specific thresholds for adolescents. The SPISE as well as insulin resistance (HOMA-IR) indices were calculated. The over-all prevalence of MetS was 8.6% (82 out of 951). SPISE index was significantly lower in MetS than non-MetS participants in both sexes (5.5 ± 2.5 vs. 9.4 ± 3.2, p < 0.001 in boys and 4.4 ± 1.4 vs. 8.6 ± 3.2, p < 0.001 in girls). The SPISE index showed a significant inverse correlation with resistin, leptin, and C-reactive protein, and a significant positive correlation with adiponectin and 25(OH) D. Areas under the curve (AUC) revealed fair and good accuracy for predicting MetS 84.1% and 90.3% in boys and girls, respectively. The sex-specific cut-off proposed was SPISE index ≤6.1 (sensitivity 72.2% and specificity 83.9%) for boys and ≤6.46 (sensitivity 96.3% and specificity 73.4%), for girls. This study suggests that the SPISE index is a simple and promising diagnostic marker of insulin sensitivity and MetS in Arab adolescents.

Patterns of essential trace elements (Cr, Mn, Ni, and Se) in Saudi patients with type 2 diabetes mellitus.

OBJECTIVES: Type 2 diabetes mellitus (T2DM) outcomes were observed to be influenced by circulating trace elements' status. The differences and correlations between serum levels of chromium (Cr), manganese (Mn), nickel (Ni), and selenium (Se) in Saudi patients with and without T2DM as well as those with prediabetes (pre-DM) were examined in this retrospective cross-sectional study. METHODS: Anthropometrics and fasting blood samples were collected from 119 patients with T2DM (aged 41-64 years), 95 non-T2DM (aged 27-55 years), and 80 with pre-DM (aged 35-57 years). An inductively coupled plasma-mass spectrometer was used to measure trace minerals in the blood. RESULTS: T2DM patients had significantly lower Mn serum concentrations than controls. There was no difference in Cr and Ni levels between groups. Serum Mn and Ni levels were lower in pre-DM subjects than controls. Serum Se concentrations were higher in pre-DM and T2DM patients than controls. In T2DM patients, serum Cr and Mn levels were inversely correlated with glucose, while Ni and Se levels were positively correlated with glucose in the T2DM group. CONCLUSIONS: Because of their roles in glucose metabolism, impaired trace element status may also play a role in T2DM pathogenesis. Appropriate dietary control and mineral supplementation are recommended.

Circulating hepcidin and its associations with low-grade inflammation and iron indices among Arab adults with and without T2DM.

We investigated the correlations of serum and dietary intake of iron with low-grade inflammation as well as with circulating hepcidin in adult Arabs with or without type 2 diabetes mellitus (T2DM). Three hundred and twelve (N=312) Saudi adult males and females with a mean age of 56.3 ± 6.5 years were included and divided into two groups, the control group (n=151, 43 males, 108 females), and T2DM group (n=161, 58 males, 103 females). Data included demographic characteristics, medical history, and dietary intake using food frequency and a 24-hour dietary recall for 1 day. Anthropometric measurements were noted and fasting blood samples extracted for the analysis of glucose, lipids, iron indices, hepcidin, 25(OH)D and endotoxin using commercially available assays. Hepcidin levels among T2DM participants were significantly higher than the control group (P<0.001). In all participants, serum hepcidin was positively associated with WHR, HbA1c, TG and TSAT while inversely associated with LDL-C and ferritin. Using hepcidin as dependent variable and age, anthropometrics, blood pressure, glucose, lipids, 25(OH)D, serum iron, transferrin and ferritin as independent variables showed that only glucose and WHR significantly predicted hepcidin by as much as 33.5% of the variances perceived (P<0.001). Sub-analysis in female participants revealed that endotoxin, iron and 25(OH)D were significant predictors of hepcidin, predicting 26.8% of the variances perceived (P<0.001). To conclude, the present study suggests that hepcidin is significantly linked with major cardiometabolic parameters, while its influence in iron indices, including low grade inflammation, appears to be stronger in females.

Association of Vitamin D Knowledge, Behavior and Attitude with BMI Status among Arab Adults.

This study aims to investigate the association of vitamin D (VD) knowledge, behavior, and attitude with BMI status among Saudi adults. This cross-sectional online survey included a total of 774 participants (M/F: 239/535). Knowledge about the overall sources of VD was highest in OB participants in correctly identifying sunlight (95.1%; p < 0.001) while significantly more OW participants answered food (83.1%; p = 0.04) and fortified food (66.5%; p = 0.02). However, 18.9% of OB participants also wrongly identified air as a VD source and this was significantly higher than in other groups (p = 0.03). OW participants were 50% less likely to identify salmon and fish oil (odds ratio, OR 0.5 (95% Confidence interval, CI 0.4-0.7); p < 0.01) and 40% more likely to identify chicken (OR 1.4 (1.0-1.9); p < 0.05) as dietary sources of VD than controls. On the other hand, OB participants were almost three times more likely to know that sunlight exposure is the main source of VD than controls (OR 2.65 (1.2-6.0); p < 0.05). In conclusion, while VD knowledge overall was apparently high in Saudi adults regardless of BMI status, the quality of knowledge among OB and OW individuals appear inconsistent, particularly in terms of identifying the right VD sources. Public health awareness campaigns should include the correction of VD misconceptions so that high-risk populations are able to make well-informed decisions in achieving optimal VD levels.

Associations of Bone Mineral Density with RANKL and Osteoprotegerin in Arab Postmenopausal Women: A Cross-Sectional Study.

Background and objective: There is limited information as to the association of several key bone markers with bone mineral density (BMD) in understudied ethnic groups. This study investigated the relationship between circulating levels of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-Β ligand (RANKL) with BMD in Arab postmenopausal women. Materials and methods: In this cross-sectional study, a total of 617 Saudi postmenopausal women from the Osteoporosis Registry of the Chair for Biomarkers of Chronic Diseases were included. Anthropometric data, BMD, and biochemical data were retrieved from the registry. Participants were stratified into three groups based on T-score; n = 169 with osteoporosis, n = 282 with osteopenia, and n = 166 normal. Analysis of bone markers including RANKL, OPG, osteocalcin, and N-terminal telopeptide (NTx) was completed using commercially available bioassays. Results: The results suggested that OPG was significantly and positively correlated with age in the osteoporosis group (r = 0.29, p < 0.05), while it was inversely correlated with BMD femoral neck left (r = −0.56, p < 0.001) and BMD femoral neck right (r = −0.37, p < 0.05) in the same group. Moreover, RANKL showed a significant inverse correlation with NTx in the osteopenia group (r = −0.37, p < 0.05). Furthermore, the RANKL/OPG ratio had a positive and significant correlation with BMI (r = 0.34, p < 0.05), BMD femoral neck left (r = 0.36, p < 0.05) and BMD femoral neck right (r = 0.35, p < 0.05) in the osteopenia group. By contrast, it showed a significant inverse correlation with waist to hip ratio in the osteoporosis group (r = −0.38, p < 0.05). Multiple regression analysis showed that OPG contributes to BMD variations in the osteopenia group (p = 0.03). Conclusions: In conclusion, changes in circulating levels of RANKL and OPG might be a protective mechanism contrary to the increased bone loss in postmenopausal women.

Binding Studies of Caffeic and p-Coumaric Acid with α-Amylase: Multispectroscopic and Computational Approaches Deciphering the Effect on Advanced Glycation End Products (AGEs).

Alpha-amylase (α-amylase) is a key player in the management of diabetes and its related complications. This study was intended to have an insight into the binding of caffeic acid and coumaric acid with α-amylase and analyze the effect of these compounds on the formation of advanced glycation end-products (AGEs). Fluorescence quenching studies suggested that both the compounds showed an appreciable binding affinity towards α-amylase. The evaluation of thermodynamic parameters (ΔH and ΔS) suggested that the α-amylase-caffeic/coumaric acid complex formation is driven by van der Waals force and hydrogen bonding, and thus complexation process is seemingly specific. Moreover, glycation and oxidation studies were also performed to explore the multitarget to manage diabetes complications. Caffeic and coumaric acid both inhibited fructosamine content and AGE fluorescence, suggesting their role in the inhibition of early and advanced glycation end-products (AGEs). However, the glycation inhibitory potential of caffeic acid was more in comparison to p-coumaric acid. This high antiglycative potential can be attributed to its additional -OH group and high antioxidant activity. There was a significant recovery of 84.5% in free thiol groups in the presence of caffeic acid, while coumaric attenuated the slow recovery of 29.4% of thiol groups. In vitro studies were further entrenched by in silico studies. Molecular docking studies revealed that caffeic acid formed six hydrogen bonds (Trp 59, Gln 63, Arg 195, Arg 195, Asp 197 and Asp 197) while coumaric acid formed four H-bonds with Trp 59, Gln 63, Arg 195 and Asp 300. Our studies highlighted the role of hydrogen bonding, and the ligands such as caffeic or coumaric acid could be exploited to design antidiabetic drugs.

Elucidating the binding and inhibitory potential of p-coumaric acid against amyloid fibrillation and their cytotoxicity: Biophysical and docking analysis.

P-Coumaric acid (p-CA) is a plant metabolite with anti-inflammatory and antioxidant effects. Due to its therapeutic potential, p-CA has attracted much attention from the scientific community lately. Oxidative stress, amyloid formation, and impaired proteasomal degradation are hallmarks of neurodegenerative diseases like Alzheimer's (AD) and are targets for developing therapeutics against such conditions. Here, we have investigated the anti-amyloidogenic properties of p-coumaric acid on hen egg white lysozyme (HEWL). Heat, pH, and agitation (55 °C, pH 2.0, 600 rpm) stress were used to induce amyloid formation in lysozyme. The aggregates characterization was done by turbidity, Rayleigh light scattering (RLS), and thioflavin-T (ThT) assays. Moreover, ANS (1-anilino naphthalene sulphate) binding assay and circular dichroism (CD) were employed to unveil protein hydrophobicity and secondary structure perturbation, respectively. Lysozyme demonstrated increased hydrophobicity and transition of α-helix to ß-sheet under aggregating conditions. Moreover, co-incubation of lysozyme with p-coumaric acid attenuates the process of amyloid in a concentration dependent manner. At 50 and 200 µM concentrations of p-coumaric acid, lysozyme retained its native-like folded structure. Cytotoxicity protection on human SK-N-SH neuroblastoma cell line was also observed using MTT assay and phase contrast microscopy. In addition, transmission electron microscopy (TEM) reaffirms the fibrillar nature of lysozyme aggregates and their attenuation by p-coumaric acid. The steady state fluorescence revealed that the mode of fluorescence quenching for the HEWL-p-coumaric acid interaction is static rather than dynamic. Moderate strength of binding in order of 104 M-1 exists between HEWL and p-coumaric acid. Thermodynamic parameters (∆H and ∆S) obtained from van't Hoff plot suggested spontaneous reaction with hydrophobic interaction. A slight micro-environmental change in HEWL around Tyr residue was observed during the binding process with the help of synchronous fluorescence. Molecular docking analysis reported the involvement of amino acid residues (TRP63, LEU75, ASP101, LYS97) to form a complex between HEWL-p-coumaric acid. The observed anti-amyloidogenic and inherent antioxidative properties of p-coumaric acid could be helpful to design a neuroprotective agent.

Associations of zinc-α-2-glycoprotein with metabolic syndrome and its components among adult Arabs.

Epidemiological studies suggest that the Zinc-α-2-glycoprotein (ZAG) plays significant physiological roles. In this study we investigate whether ZAG could be considered as a clinical biomarker in the diagnosis and prognosis of metabolic syndrome (MetS) in Saudi population. As such insights urgently required for management of MetS. Thus, we have determined serum levels of ZAG in patients with MetS and normal individuals. We have also assessed the correlation between ZAG and different components of MetS. In this case-control study, clinical information of 200 Saudi male and female subjects (age range 30-65) with MetS (n = 100) and healthy controls (n = 100) were extracted from the database of the Chair of Biomarkers of Chronic Disease (CBCD) in King Saud University (KSU), Riyadh, Saudi Arabia. MetS was screened according to NCEP ATP III criteria (National Cholesterol Education Program Adult Treatment Panel III). Fasting glucose and lipid profile levels were measured using Konelab. Serum TNF-α, IL- 6, CRP and ZAG levels were measured using commercially available assays. There was an age-dependent significant increase in ZAG level among MetS subjects than controls (43.8 ± 19.5 vs 48.1 ± 14.8; P = 0.04). A significant inverse correlation between ZAG and serum HDL-cholesterol (r = - 0.20, P < 0.05) was observed. Whereas, triglycerides (r = 0.25, P < 0.01), waist circumference (WHR) (r = 0.17, P < 0.05) and CRP (r = 0.24, P < 0.01) were all significantly and positively associated with ZAG. Circulating ZAG is associated with MetS in an age-dependent manner. Serum ZAG is a potential biomarker for MetS.

Angiogenin Levels and Their Association with Cardiometabolic Indices Following Vitamin D Status Correction in Saudi Adults.

Angiogenin (ANG), a multifunctional protein known to induce blood vessel formation, is a potential biomarker for cardiovascular diseases; however, whether it is affected by vitamin D supplementation is not known. This interventional study in vitamin D-deficient Saudi adults was designed to investigate it. A total of 100 vitamin D-deficient Saudi adults aged 30-50 years were randomly selected to undergo 6-month vitamin D supplementation. Circulating levels of fasting glucose, lipids, vitamin D, apolipoproteins (AI, AII, B, CI, CII, CIII, E, and H), and ANG were measured using commercially available assays at baseline and after six months. Overall, vitamin D levels increased significantly post intervention. With this, levels of apo-CIII and apo-E significantly increased (p-values of 0.001 and 0.009, respectively) with a significant parallel decrease in apo-B (p = 0.003). ANG levels were significantly positively associated with most apolipoproteins and inversely correlated with HDL-cholesterol. Post intervention, the changes in ANG levels were positively correlated with apo-E (r = 0.32; p < 0.01 in all subjects and r = 0.40; p < 0.05 in males). Vitamin D supplementation may modestly affect ANG levels. The association observed between ANG and apo-E is worthy of further investigation since both biomarkers have been linked to neurodegenerative disorders.