Novel Properties of Old Propranolol-Assessment of Antiglycation Activity through In Vitro and In Silico Approaches.

Hypertension has earned the "silent killer" nickname since it may lead to a number of comorbidities, including diabetes and cardiovascular diseases. Oxidative stress and protein glycation play vital roles in the pathogenesis of hypertension. Several studies have shown that they profoundly account for vascular dysfunction, endothelial damage, and disruption of blood pressure regulatory mechanisms. Of particular note are advanced glycation end products (AGEs). AGEs alter vascular tissues' functional and mechanical properties by binding to receptors for advanced glycation end products (RAGE), stimulating inflammation and free radical-mediated pathways. Propranolol, a nonselective beta-adrenergic receptor antagonist, is one of the most commonly used drugs to treat hypertension and cardiovascular diseases. Our study is the first to analyze propranolol's effects on protein glycoxidation through in vitro and in silico approaches. Bovine serum albumin (BSA) was utilized to evaluate glycoxidation inhibition by propranolol. Propranolol (1 mM) and BSA (0.09 mM) were incubated with different glycating (0.5 M glucose, fructose, and galactose for 6 days and 2.5 mM glyoxal and methylglyoxal for 12 h) or oxidizing agents (chloramine T for 1 h). Biomarkers of protein glycation (Amadori products (APs), ß-amyloid (ßA), and advanced glycation end products (AGEs)), protein glycoxidation (dityrosine (DT), kynurenine (KYN), and N-formylkynurenine (NFK)), protein oxidation (protein carbonyls (PCs), and advanced oxidation protein products (AOPPs)) were measured by means of colorimetric and fluorimetric methods. The scavenging of reactive oxygen species (hydrogen peroxide, hydroxyl radical, and nitric oxide) and the antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl radical and ferrous ion chelating (FIC) assays)) of propranolol were also evaluated. Additionally, in silico docking was performed to showcase propranolol's interaction with BSA, glycosides, and AGE/RAGE pathway proteins. The products of protein glycation (↓APs, ↓ßA, ↓AGEs), glycoxidation (↓DT, ↓KYN, ↓NFK), and oxidation (↓PCs, ↓AOPPs) prominently decreased in the BSA samples with both glycating/oxidizing factors and propranolol. The antiglycoxidant properties of propranolol were similar to those of aminoguanidine, a known protein oxidation inhibitor, and captopril, which is an established antioxidant. Propranolol showed a potent antioxidant activity in the FIC and H2O2 scavenging assays, comparable to aminoguanidine and captopril. In silico analysis indicated propranolol's antiglycative properties during its interaction with BSA, glycosidases, and AGE/RAGE pathway proteins. Our results confirm that propranolol may decrease protein oxidation and glycoxidation in vitro. Additional studies on human and animal models are vital for in vivo verification of propranolol's antiglycation activity, as this discovery might hold the key to the prevention of diabetic complications among cardiology-burdened patients.

Preliminary evaluation of the antiglycoxidant activity of verapamil using various in vitro and in silico biochemical/biophysical methods.

Introduction: Glycoxidative stress is essential for linking glucose disturbances and cardiovascular diseases. Unfortunately, contemporary antidiabetic drugs do not have an antiglycative effect but only lower blood glucose levels. Therefore, there is an intense search for substances that could inhibit protein glycation and prevent diabetic complications. A potential antioxidant activity has been demonstrated with verapamil, a phenylalkylamine derivative belonging to selective calcium channel blockers. Verapamil has a well-established position in cardiology due to its wide range of indications and good safety profile. Nevertheless, the antidiabetic activity of verapamil is still unclear. We are the first to comprehensively evaluate the verapamil's effect on protein glycoxidation using various in vitro and in silico models. Methods: Bovine serum albumin (BSA) was used to assess the rate of glycoxidation inhibition by verapamil. As glycating factors, sugars (glucose, fructose, and ribose) and aldehyde (glyoxal) were used. Chloramine T was used as an oxidizing agent. Aminoguanidine (protein glycation inhibitor) and Trolox (antioxidant) were used as control substances. The biomarkers of oxidation (total thiols, protein carbonyls, advanced oxidation protein products), glycation (Amadori products, ß-amyloid, advanced glycation end products [AGEs]), and glycoxidation (tryptophan, kynurenine, N-formylkynurenine, dityrosine) were evaluated using colorimetric and fluorimetric methods. The mechanism of antiglycative activity of verapamil was assessed using in silico docking to study its interaction with BSA, glycosidases, and seventeen AGE pathway proteins. Results: In all in vitro models, biomarkers of protein glycation, oxidation, and glycoxidation were significantly ameliorated under the influence of verapamil. The glycoxidation inhibition rate by verapamil is comparable to that of potent antiglycating agents and antioxidants. The molecular docking simulations showed that verapamil bound preferentially to amino acids prone to glycoxidative damage out of an α-glucosidase's active center. Among all AGE pathway proteins, verapamil was best docked with the Janus kinase 2 (JAK2) and nuclear factor-κB (NF-κB). Discussion: The results of our study confirm the antiglycoxidant properties of verapamil. The drug's action is comparable to recognized substances protecting against oxidative and glycation modifications. Verapamil may be particularly helpful in patients with cardiovascular disease and concomitant diabetes. Studies in animal models and humans are needed to confirm verapamil's antiglycative/antidiabetic activity.

Association of Ischemia-Modified Albumin (IMA) in Saliva, Serum, and Urine with Diagnosis of Chronic Kidney Disease (CKD) in Children: A Case-Control Study.

BACKGROUND Ischemia-modified albumin (IMA) is a secreted biomarker for ischemic oxidative stress. This case-control study aimed to evaluate the association of ischemia-modified albumin (IMA) in saliva, serum, and urine with diagnosis of chronic kidney disease (CKD) in 24 children. MATERIAL AND METHODS The study involved 24 children with CKD. CKD was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) diagnostic criteria. The control group consisted of 24 healthy children who were matched for age and gender to the experimental group. The concentration of IMA was determined by the colorimetric method in non-stimulated whole saliva (NWS), stimulated whole saliva (SWS), serum, and urine of children with CKD. The Mann-Whitney U test was used for inter-group comparisons. RESULTS IMA levels were significantly higher in NWS (P=0.0082) and SWS (P=0.0014) of children with CKD than in the control group. The concentration of IMA in NWS was correlated with standard indicators of kidney function, including the estimated glomerular filtration rate (r=-0.798, P≤0.0001), stage of CKD (r=0.814, P≤0.0001), and serum creatinine (r=0.711, P≤0.0001) and urea levels (r=0.738, P≤0.0001). CONCLUSIONS Salivary IMA concentration depends on renal function in children. Salivary IMA discriminates children with end-stage kidney disease from children with mild and moderate CKD and healthy children with high sensitivity and specificity. Further research is required, including assessment of the diagnostic usefulness and validation of the biomarker in a clinical diagnostic study.

[The human zona pellucida: New genetic findings]. / La zone pellucide - Aspects génétiques et infertilité.

The Zona Pellucida (ZP) is an ovarian specialized extracellular coat surrounding the oocyte. In human, ZP is composed of four glycoproteins: ZP1, ZP2, ZP3 and ZP4. It regulates sperm binding to the oocyte during fertilization. After fertilization, ZP prevents polyspermia and is important for the protection of the developing embryo and oviductal transport avoiding ectopic implantation. According to the development of sequencing techniques, many mutations have been described in infertile patients. The aim of this review is to synthesize mutations in genes encoding ZP glycoproteins described in humans and their effects on female fertility.

Title: La zone pellucide - Aspects génétiques et infertilité. Abstract: La zone pellucide (ZP) est une matrice extracellulaire spécifique enveloppant l'ovocyte. Elle régule la liaison des spermatozoïdes à l'ovocyte lors de la fécondation. Après la fécondation, la zone pellucide prévient la polyspermie en modifiant sa conformation. La zone pellucide est importante pour la protection de l'embryon pré-implantatoire en développement lors de son trajet oviductal en évitant l'implantation ectopique. Suite au développement des techniques génétiques et du séquençage du génome, de nombreuses mutations ont été récemment décrites chez des patientes infertiles. Après avoir présenté la structure et les fonctions des glycoprotéines ZP constituant la zone pellucide, nous discutons dans cette revue de l'impact des mutations mises en évidence dans les gènes codant ces glycoprotéines sur la fertilité féminine.