Effect of glycation inhibitors on aging and age-related diseases

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), β-amyloid (βA), 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, ↓βA, ↓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.

The antiglycation potential of H1 receptor antagonists - in vitro studies in bovine serum albumin model and in silico molecular docking analyses

The H1 receptor belongs to the family of rhodopsin-like G-protein-coupled receptors activated by the biogenic amine histamine. H1 receptor antagonists are widely used in the treatment of allergies. However, these drugs could have a much broader spectrum of activity, including hypoglycemic effects, which can broaden the spectrum of their use. The aim of the study was to evaluate the antiglycation potential of twelve H1 receptor antagonists (diphenhydramine, antazoline, promethazine, ketotifen, clemastine, pheniramine, cetirizine, levocetirizine, bilastine, fexofenadine, desloratadine, and loratadine). Bovine serum albumin (BSA) was glycated with sugars (glucose, fructose, galactose, and ribose) and aldehydes (glyoxal and methylglyoxal) in the presence of H1 blockers. The tested substances did not induce a significant decrease in the content of albumin glycation end-products, and the inhibition rate of glycoxidation was not influenced by the chemical structure or generation of H1 blockers. None of the tested H1 receptor antagonists exhibited strong antiglycation activity. Antiglycemic potential of H1 blockers could be attributed to their antioxidant and anti-inflammatory activity, as well as their effects on carbohydrate metabolism/metabolic balance at the systemic level.

Inhibition by pesticides of the DJ-1/Park7 protein related to Parkinson disease

Parkinson's disease is a severe neurodegenerative disease. Several environmental contaminants such as pesticides have been suspected to favor the appearance of this pathology. The protein DJ-1 (or Park7) protects against the development of Parkinson's disease. Thus, the possible inhibitory effects of about a hundred pesticides on human DJ-1 have been studied. We identified fifteen of them as strong inhibitors of DJ-1 with IC50 values between 0.02 and 30 µM. Thiocarbamates are particularly good inhibitors, as shown by thiram that acts as an irreversible inhibitor of an esterase activity of DJ-1 with an IC50 value of 0.02 µM. Thiram was also found as a good inhibitor of the protective activity of DJ-1 against glycation. Such inhibitory effects could be one of the various biological effects of these pesticides that may explain their involvement in the development of Parkinson's disease.

Antiglycoxidative properties of amantadine – a systematic review and comprehensive in vitro study

An important drug used in the treatment of Parkinson’s disease is amantadine. We are the first to perform a comprehensive study based on various glycation and oxidation factors, determining the impact of amantadine on protein glycoxidation. Sugars (glucose, fructose, galactose) and aldehydes (glyoxal, methylglyoxal) were used as glycation agents, and chloramine T was used as an oxidant. Glycoxidation biomarkers in albumin treated with amantadine were generally not different from the control group (glycation/oxidation factors), indicating that the drug did not affect oxidation and glycation processes. Molecular docking analysis did not reveal strong binding sites of amantadine on the bovine serum albumin structure. Although amantadine poorly scavenged hydroxyl radical and hydrogen peroxide, it had significantly lower antioxidant and antiglycation effect than all protein oxidation and glycation inhibitors. In some cases, amantadine even demonstrated glycoxidant, proglycation, and prooxidant properties. In summary, amantadine exhibited weak antioxidant properties and a lack of antiglycation activity.

Advanced glycation end products and their related signaling cascades in adult survivors of childhood Hodgkin lymphoma: A possible role in the onset of late complications

Hodgkin lymphoma (HL) is today one of the most curable pediatric cancers. Despite survival rates now exceeding 90%, survivors of pediatric HL are still at higher risk to develop late effects of cancer therapy. Premature aging has been proposed as a paradigm to explain the onset of long-term complications in these subjects. High levels of advanced glycation end products (AGEs), together with chronic inflammation and oxidative unbalance, have been shown to be among the main factors contributing to aging. The present study aims to evaluate glycoxydation, inflammatory status, and oxidative stress in plasma and peripheral blood mononuclear cells (PBMC) obtained from 20 adult survivors of pediatric HL and 40 age- and sex-matched healthy controls. After the isolation of PBMC and the collection of plasma, we performed the analyses of gene expression by qRT-PCR and measured inflammatory and oxidative-stress markers. AGEs plasma levels, expressed as Nϵ-carboxymethyl-lysine and methylglyoxal hydroimidazolone, were markedly higher in HL survivors than in healthy subjects. HL survivors also showed a condition of higher oxidative stress, as demonstrated by an increased expression of NADPH oxidase on PBMC. Antioxidant defenses, evaluated in terms of alpha-tocopherol, GSSG/GSH ratio and catalase plasma levels, were strongly impaired in survivors. This pro-oxidative condition led to the over-expression of both NLRP3 and NFkB genes in PBMC and, consequently, to increased plasma levels of interleukin(IL)-1β and IL-6. Finally, the expression of the receptors for AGEs in PBMC confirmed the dysregulated AGE pathways. Data show AGEs accumulation in survivors of pediatric HL. The consequent activation of the receptor for AGEs leads to the persistent activation of intracellular signaling toward inflammation. These results suggest that the co-existence of AGEs accumulation, unbalanced oxidative status, and inflammation could play a role in the onset of late complications in HL survivors.

Biological Aspects of Inflamm-Aging in Childhood Cancer Survivors

Anti-cancer treatments improve survival in children with cancer. A total of 80% of children treated for childhood cancer achieve 5-year survival, becoming long-term survivors. However, they undergo several chronic late effects related to treatments. In childhood cancer survivors a chronic low-grade inflammation, known as inflamm-aging, is responsible for frailty, a condition characterized by vital organ failure and by premature aging processes. Inflamm-aging is closely related to chemotherapy and radiotherapy, which induce inflammation, accumulation of senescent cells, DNA mutations, and the production of reactive oxygen species. All these conditions are responsible for the onset of secondary diseases, such as osteoporosis, cardiovascular diseases, obesity, and infertility. Considering that the pathobiology of frailty among childhood cancer survivors is still unknown, investigations are needed to better understand frailty's biological and molecular processes and to identify inflamm-aging key biomarkers in order to facilitate the screening of comorbidities and to clarify whether treatments, normally used to modulate inflamm-aging, may be beneficial. This review offers an overview of the possible biological mechanisms involved in the development of inflamm-aging, focusing our attention on immune system alteration, oxidative stress, cellular senescence, and therapeutic strategies.

High-Frequency Ultrasound Assessment of Skin and Oral Mucosa in Metabolic Syndrome Patients-A Cross-Sectional Study

Background: Exogenous factors (such as sun exposure, smoking habits, and diet) and endogenous (inflammatory status, general diseases) have a direct influence on skin and soft tissue characteristics. The study’s objective was to assess the impact of metabolic syndrome (MS) on characteristics of skin layers in sun-exposed and non-exposed maxillofacial tissues evaluated by high-frequency ultrasound (HFU), as a potential diagnosis and monitoring tool for the aging process. Material and methods: The present study included 102 subjects (24 with MS; 78 without MS). Anthropometric parameters and disease history were recorded, and blood samples were harvested in order to assess biochemical parameters of MS. Sun-exposed skin (zygomatic region) and non-exposed oral mucosa of the lower lip were assessed using HFU (DUB^® cutis, Taberna Pro Medicum) with a 22 MHz probe. Results: Patients with cardiac disease had significantly lower values for epidermis density (p = 0.002). Gender was independently linked to the aged dermis depth (p < 0.001), aged dermis no. of px (pixels) (p < 0.001), dermis depth (p < 0.001), dermis no. of px (p < 0.001), and subcutaneous tissue density (p < 0.001). Patients with MS had thinner epidermis (p = 0.008) and thinner aged dermis (p = 0.037) when compared to non-MS subjects. Conclusion: Patients with MS had thinner epidermis and a lower epidermis number of pixels in sun-exposed skin. Women had lower epidermis density and thicker dermis in sun-exposed skin. Our study showed that HFU, as a non-invasive investigation approach, is useful to diagnose and monitor the aging process in skin and oral mucosa, correlated with skin phenotype pathological conditions.

Flavonoids derived from buckwheat hull can break advanced glycation end-products and improve diabetic nephropathy

Diabetic nephropathy (DN) is the most important complication in patients with diabetes. The accumulation of advanced glycation end-products (AGEs) is the main reason for the development of DN. In this study, we investigated the mechanism of buckwheat hull flavonoids to break AGEs in vitro by measuring fluorescence analysis, three-dimensional fluorescence, protein molecular weight, free amino groups, and the sulfhydryl group content. Proteomics analysis was used to determine the effect of total buckwheat hull flavonoids (TBHF) intervention on protein differential expression in the kidney of db/db mice. The results showed that buckwheat hull flavonoids were potent in breaking AGEs in vitro, and they protected mice kidneys by regulating the renal AGE-RAGE pathway. This study lays a strong experimental and theoretical foundation for the development of new lysing agents to break AGEs. The findings should make an important contribution to the field of flavonoids in improving the application of diabetic nephropathy in the diet.

An essay on the nominal vs. real definitions of aging

In the current literature, the definitions of aging range from relying on certain sets of distinctive features at the molecular, organismal, populational and/or even evolutional levels/scales to declaring it a treatable disease and, moreover, to treating aging as a mental construct rather than a natural phenomenon. One reason of such a mess may be that it is common in the natural sciences to disregard philosophy of science where several categories of definitions are recognized, among which the nominal are less, and the so-called real ones are more appropriate in scientific contexts. E.g., water is, by its nominal definition, a liquid having certain observable features and, by its real definition, a specific combination (or a product of interaction) of hydrogen and oxygen atoms. Noteworthy, the real definition is senseless for people ignorant of atoms. Likewise, the nominal definition of aging as a set of observable features should be supplemented, if not replaced, with its real definition. The latter is suggested here to imply that aging is the product of chemical interactions between the rapidly turning-over free metabolites and the slowly turning-over metabolites incorporated in macromolecules involved in metabolic control. The phenomenon defined in this way emerged concomitantly with metabolic pathways controlled by enzymes coded for by information-storing macromolecules and is inevitable wherever such conditions coincide. Aging research, thus, is concerned with the elucidation of the pathways and mechanisms that link aging defined as above to its hallmarks and manifestations, including those comprised by its nominal definitions. Esoteric as it may seem, defining aging is important for deciding whether aging is what should be declared as the target of interventions aimed at increasing human life and health spans.

Pigment epithelium-derived factor inhibits advanced glycation end product-induced proliferation, VEGF and MMP-9 expression in breast cancer cells via interaction with laminin receptor

Pigment epithelium-derived factor (PEDF) is one of the adipocytokines with multifaceted functions, which may serve a role in the development of various types of cardiometabolic disorders. Advanced glycation end products (AGEs) have been shown to contribute to numerous aging-associated disorders, such as cancer. However, it remains unclear whether and how PEDF exerts antitumor effects in AGE-exposed human breast cancer MCF-7 cells, and therefore this was explored in the present study. NADPH oxidase activity was measured with luciferase assay, while gene and protein expression levels were evaluated with quantitative PCR and western blot analysis, respectively. AGEs significantly increased NADPH oxidase-driven superoxide generation, cytochrome b-245 β chain (gp91phox) and receptor for AGE (RAGE) mRNA expression, proliferation, mRNA and protein expression levels of vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-9 mRNA expression in MCF-7 cells, all of which were dose-dependently inhibited by PEDF. Neutralizing antibody against laminin receptor (LR-Ab) significantly blocked these beneficial effects of PEDF in AGE-exposed MCF-7 cells. Furthermore, as in AGE-treated cells, PEDF dose-dependently inhibited the NADPH oxidase-driven superoxide generation, gp91phox, RAGE and MMP-9 mRNA expression, proliferation, mRNA and protein expression levels of VEGF in non-treated control MCF-7 cells, and these effects were also reversed by LR-Ab. LR levels were not affected by the treatment with AGEs, PEDF or LR-Ab. The present study suggested that PEDF may exert antitumor effects in AGE-exposed breast cancer cells by suppressing NADPH oxidase-induced ROS generation and VEGF and MMP-9 expression via interaction with LR. Since PEDF expression is decreased in breast cancer tissues, pharmacological upregulation or restoration of PEDF may inhibit the growth and metastasis of breast cancer.

Exome-Wide Association Study Identifies FN3KRP and PGP as New Candidate Longevity Genes

Despite enormous research efforts, the genetic component of longevity has remained largely elusive. The investigation of common variants, mainly located in intronic or regulatory regions, has yielded only little new information on the heritability of the phenotype. Here, we performed a chip-based exome-wide association study investigating 62 488 common and rare coding variants in 1248 German long-lived individuals, including 599 centenarians and 6941 younger controls (age < 60 years). In a single-variant analysis, we observed an exome-wide significant association between rs1046896 in the gene fructosamine-3-kinase-related-protein (FN3KRP) and longevity. Noteworthy, we found the longevity allele C of rs1046896 to be associated with an increased FN3KRP expression in whole blood; a database look-up confirmed this effect for various other human tissues. A gene-based analysis, in which potential cumulative effects of common and rare variants were considered, yielded the gene phosphoglycolate phosphatase (PGP) as another potential longevity gene, though no single variant in PGP reached the discovery p-value (1 × 10E−04). Furthermore, we validated the previously reported longevity locus cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1). Replication of our results in a French longevity cohort was only successful for rs1063192 in CDKN2B-AS1. In conclusion, we identified 2 new potential candidate longevity genes, FN3KRP and PGP which may influence the phenotype through their role in metabolic processes, that is, the reverse glycation of proteins (FN3KRP) and the control of glycerol-3-phosphate levels (PGP).

Allysine and α-Aminoadipic Acid as Markers of the Glyco-Oxidative Damage to Human Serum Albumin under Pathological Glucose Concentrations

Understanding the molecular basis of the disease is of the utmost scientific interest as it contributes to the development of targeted strategies of prevention, diagnosis, and therapy. Protein carbonylation is a typical feature of glyco-oxidative stress and takes place in health disorders such as diabetes. Allysine as well as its oxidation product, the α-amino adipic acid (α-AA) have been found to be markers of diabetes risk whereas little is known about the chemistry involved in its formation under hyperglycemic conditions. To provide insight into this issue, human serum albumin was incubated in the presence of FeCl3 (25 μM) and increasing glucose concentrations for 32 h at 37 °C. These concentrations were selected to simulate (i) physiological fasting plasma concentration (4 mM), (ii) pathological pre-diabetes fasting plasma concentration (8 mM), and pathological diabetes fasting plasma concentration (12 mM) of glucose. While both allysine and α-AA were found to increase with increasing glucose concentrations, the carboxylic acid was only detected at pathological glucose concentrations and appeared to be a more reliable indicator of glyco-oxidative stress. The underlying chemical mechanisms of lysine glycation as well as of the depletion of tryptophan and formation of fluorescent and colored advanced glycation products are discussed.

Pleiotropic Properties of Valsartan: Do They Result from the Antiglycooxidant Activity? Literature Review and In Vitro Study

Valsartan belongs to angiotensin II type 1 (AT1) receptor blockers (ARB) used in cardiovascular diseases like heart failure and hypertension. Except for its AT1-antagonism, another mechanism of drug action has been suggested in recent research. One of the supposed actions refers to the positive impact on redox balance and reducing protein glycation. Our study is aimed at assessing the antiglycooxidant properties of valsartan in an in vitro model of oxidized bovine serum albumin (BSA). Glucose, fructose, ribose, glyoxal (GO), methylglyoxal (MGO), and chloramine T were used as glycation or oxidation agents. Protein oxidation products (total thiols, protein carbonyls (PC), and advanced oxidation protein products (AOPP)), glycooxidation products (tryptophan, kynurenine, N-formylkynurenine, and dityrosine), glycation products (amyloid-β structure, fructosamine, and advanced glycation end products (AGE)), and albumin antioxidant activity (total antioxidant capacity (TAC), DPPH assay, and ferric reducing antioxidant power (FRAP)) were measured in each sample. In the presence of valsartan, concentrations of protein oxidation and glycation products were significantly lower comparing to control. Moreover, albumin antioxidant activity was significantly higher in those samples. The drug's action was comparable to renowned antiglycation agents and antioxidants, e.g., aminoguanidine, metformin, Trolox, N-acetylcysteine, or alpha-lipoic acid. The conducted experiment proves that valsartan can ameliorate protein glycation and oxidation in vitro in various conditions. Available animal and clinical studies uphold this statement, but further research is needed to confirm it, as reduction of protein oxidation and glycation may prevent cardiovascular disease development.

COVID-19: A Challenge to Physiology of Aging

The death toll of the current COVID-19 pandemic is strongly biased toward the elderly. COVID-19 case fatality rate (CFR) increases with age exponentially, its doubling time being about 7 years, irrespective of countries and epidemic stages. The same age-dependent mortality pattern known as the Gompertz law is featured by the total mortality and its main constituents attributed to cardiovascular, metabolic, neurological, and oncological diseases. Among patients dying of COVID-19, most have at least one of these conditions, whereas none is found in most of those who pass it successfully. Thus, gerontology is indispensable in dealing with the pandemic, which becomes a benchmark for validating the gerontological concepts and advances. The two basic alternative gerontological concepts imply that either aging results from the accumulation of stochastic damage, or is programmed. Based on these different grounds, several putative anti-aging drugs have been proposed as adjuvant means for COVID-19 prevention and/or treatment. These proposals are reviewed in the context of attributing the molecular targets of these drugs to the signaling pathways between the sensors of resource availability and the molecular mechanisms that allocate resources to storage, growth and reproduction or to self-maintenance and repair. Each of the drugs appears to reproduce only a part of the physiological responses to reduced resource availability caused by either dietary calories restriction or physical activity promotion, which are the most robust means of mitigating the adverse manifestations of aging. In the pathophysiological terms, the conditions of the endothelium, which worsen as age increases and may be significantly improved by the physical activity, is a common limiting factor for the abilities to withstand both physical stresses and challenges imposed by COVID-19. However, the current anti-epidemic measures promote sedentary indoor lifestyles, at odds with the most efficient behavioral interventions known to decrease the vulnerability to both the severe forms of COVID-19 and the prevalent aging-associated diseases. To achieve a proper balance in public health approaches to COVID-19, gerontologists should be involved in crosstalk between virologists, therapists, epidemiologists, and policy makers. The present publication suggests a conceptual background for that.

Sodium 4-phenylbutyrate inhibits protein glycation

The production and accumulation of advanced glycation end-products (AGEs) are hypothesized to have a causal role in the development of the complications associated with aging and lifestyle-related diseases, such as diabetes, atherosclerosis and hyperlipidemia. Therefore, it is important to reduce the production and accumulation of AGEs. In the present study, the ability of sodium 4-phenylbutyrate (PBA) on inhibition of glycation was assessed. In vitro, PBA inhibited the glycation of albumin and collagen by up to 42.1 and 36.9%, respectively. Furthermore, when spontaneously diabetic KK mice were administered PBA (20 mg/day) or vehicle orally, glycosuria developed rapidly in the control mice, but after 6 weeks, only one treated mouse was glycosuric. In addition, the weight gain and HbA1c levels were significantly lower in the treated mice compared with the untreated mice (weight gain, 36.0 g vs. 39.4 g, P<0.01; HbA1C level, 3.96 vs. 4.78%, P<0.01; respectively). These results suggested that PBA also inhibited glycation in vivo. Further studies are required to determine whether PBA may be effective for the therapy or prevention of aging or lifestyle-related diseases caused by the accumulation of AGEs. The method of administration and the side-effects of PBA have already been established as PBA is already used clinically. Therefore, the repurposing of PBA for reducing AGE levels may be a potential option to reduce complications associated with aging.

A New Insight into Meloxicam: Assessment of Antioxidant and Anti-Glycating Activity in In Vitro Studies

Meloxicam is a non-steroidal anti-inflammatory drug, which has a preferential inhibitory effect to cyclooxyganase-2 (COX-2). Although the drug inhibits prostaglandin synthesis, the exact mechanism of meloxicam is still unknown. This is the first study to assess the effect of meloxicam on protein glyco-oxidation as well as antioxidant activity. For this purpose, we used an in vitro model of oxidized bovine serum albumin (BSA). Glucose, fructose, ribose, glyoxal and methylglyoxal were used as glycating agents, while chloramine T was used as an oxidant. We evaluated the antioxidant properties of albumin (2,2-di-phenyl-1-picrylhydrazyl radical scavenging capacity, total antioxidant capacity and ferric reducing antioxidant power), the intensity of protein glycation (Amadori products, advanced glycation end products) and glyco-oxidation (dityrosine, kynurenine, N-formylkynurenine, tryptophan and amyloid-β) as well as the content of protein oxidation products (advanced oxidation protein products, carbonyl groups and thiol groups). We have demonstrated that meloxicam enhances the antioxidant properties of albumin and prevents the protein oxidation and glycation under the influence of various factors such as sugars, aldehydes and oxidants. Importantly, the antioxidant and anti-glycating activity is similar to that of routinely used antioxidants such as captopril, Trolox, reduced glutathione and lipoic acid as well as protein glycation inhibitors (aminoguanidine). Pleiotropic action of meloxicam may increase the effectiveness of anti-inflammatory treatment in diseases with oxidative stress etiology.

Advanced Glycation End Product Inhibition by Alkaloids from Ocotea paranapiacabensis for the Prevention of Skin Aging

A bioassay-guided study aiming at identifying inhibitors of the glycation process on the leaves of Ocotea paranapiacabensis afforded four benzylisoquinoline alkaloids (1-4), with 1 and 2 identified as new naturals products, while 3 and 4 were previously described in the literature, with 3 being identified as magnocurarine. Purification was performed by column chromatography and high-performance liquid chromatography. The structures of the isolated compounds were elucidated by spectroscopic methods including UV, NMR, and HRMS. The process of skin aging has been recently associated with advanced glycation end products (AGEs), and strategies inhibiting their formation have been addressed by pharmaceutical companies for the development of novel antiaging compounds. Alkaloids 1-4 were evaluated for their potential to inhibit AGE formation and showed inhibition of 62.9%, 83.3%, 26.1%, and 98.2% (150 μM), respectively. The antiaging potential of compounds 1 and 4 were evaluated with a reconstructed human skin model in vitro, and results showed a decrease in dermis contraction (8.7% and 4.2% respectively for 1 and 4) when compared to the glycated control (57.4%). Additionally, absorption, distribution, metabolism, and excretion (ADME) and toxicity properties were predicted using in silico methods, and the results were considered significantly promising for alkaloids 1 and 4 to continue the development of these alkaloids with skincare properties.

Advanced glycation end products and chronic inflammation in adult survivors of childhood leukemia treated with hematopoietic stem cell transplantation

BACKGROUND

Among survivors of pediatric acute lymphoblastic leukemia (ALL), those who received hematopoietic stem cell transplantation (HSCT) conditioned with total-body irradiation (TBI) show the highest risk of late complications, including cardiovascular (CV) disease. Advanced glycation end products (AGEs) have been associated with CV disease in diabetes mellitus and other clinical conditions. This study explores AGEs plasma levels, inflammatory status, and lipid profile in survivors of pediatric ALL who received HSCT conditioned with TBI.

PROCEDURE

Inclusion criteria were (a) previous diagnosis of ALL at age < 18 years, treated with HSCT conditioned with TBI; (b) age > 18 at the time of the study enrollment; (c) off-therapy for at least five years. Radiotherapy other than TBI, preexisting heart disease, glucose metabolism impairment, body mass index > 25, active graft versus host disease (GvHD), smoking, or treatment with cholesterol lowering medications were exclusion criteria. Eighteen survivors and 30 age-matched healthy controls were enrolled.

RESULTS

AGEs plasma levels were markedly higher in ALL survivors than in healthy subjects (2.15 ± 2.21 vs 0.29 ± 0.15 pg/mL, P < 0.01). Survivors also showed higher levels of high-sensitivity C-reactive protein (2.32 ± 1.70 vs 0.88 ± 1.09 mg/dL, P < 0.05), IL-1β (7.04 ± 1.52 vs 4.64 ± 2.02 pg/mL, P < 0.001), IL17 (37.44 ± 3.51 vs 25.19 ± 6.34 pg/mL, P < 0.001), an increased glutathione/reduced glutathione ratio (0.085 ± 0.07 vs 0.041 ± 0.036, P < 0.05) and slight alterations in their lipid profile.

CONCLUSIONS

Our data show AGEs accumulation and chronic inflammation in ALL survivors who received HSCT conditioned with TBI. These alterations may contribute to the increased risk of CV disease reported in these subjects.

Understanding the links between cardiovascular disease and Parkinson's disease

Studies investigating the associations between genetic or environmental factors and Parkinson's disease (PD) have uncovered a number of factors shared with cardiovascular disease, either as risk factors or manifestations of cardiovascular disease itself. Older age, male sex, and possibly type 2 diabetes are examples. On the other hand, coffee consumption and physical activity are each associated with a lower risk of both PD and cardiovascular disease. This observation raises questions about the underlying pathophysiological links between cardiovascular disease and PD. There is evidence for common mechanisms in the areas of glucose metabolism, cellular stress, lipid metabolism, and inflammation. On the other hand, smoking and total/low-density lipoprotein cholesterol appear to have opposite associations with cardiovascular disease and PD. Thus, it is uncertain whether the treatment of cardiovascular risk factors will impact on the onset or progression of PD. The available data suggest that a nuanced approach is necessary to manage risk factors such as cholesterol levels once the associations are better understood. Ultimately, the choice of therapy may be tailored to a patient's comorbidity profile. This review presents the epidemiological evidence for both concordant and discordant associations between cardiovascular disease and PD, discusses the cellular and metabolic processes that may underlie these links, and explores the implications this has for patient care and future research. © 2019 International Parkinson and Movement Disorder Society.

Identification of a biomarker panel for improvement of prostate cancer diagnosis by volatile metabolic profiling of urine

BACKGROUND

The lack of sensitive and specific biomarkers for the early detection of prostate cancer (PCa) is a major hurdle to improve patient management.

METHODS

A metabolomics approach based on GC-MS was used to investigate the performance of volatile organic compounds (VOCs) in general and, more specifically, volatile carbonyl compounds (VCCs) present in urine as potential markers for PCa detection.

RESULTS

Results showed that PCa patients (n = 40) can be differentiated from cancer-free subjects (n = 42) based on their urinary volatile profile in both VOCs and VCCs models, unveiling significant differences in the levels of several metabolites. The models constructed were further validated using an external validation set (n = 18 PCa and n = 18 controls) to evaluate sensitivity, specificity and accuracy of the urinary volatile profile to discriminate PCa from controls. The VOCs model disclosed 78% sensitivity, 94% specificity and 86% accuracy, whereas the VCCs model achieved the same sensitivity, a specificity of 100% and an accuracy of 89%. Our findings unveil a panel of 6 volatile compounds significantly altered in PCa patients' urine samples that was able to identify PCa, with a sensitivity of 89%, specificity of 83%, and accuracy of 86%.

CONCLUSIONS

It is disclosed a biomarker panel with potential to be used as a non-invasive diagnostic tool for PCa.

Microbial ageing and longevity

Longevity reflects the ability to maintain homeostatic conditions necessary for life as an organism ages. A long-lived organism must contend not only with environmental hazards but also with internal entropy and macromolecular damage that result in the loss of fitness during ageing, a phenomenon known as senescence. Although central to many of the core concepts in biology, ageing and longevity have primarily been investigated in sexually reproducing, multicellular organisms. However, growing evidence suggests that microorganisms undergo senescence, and can also exhibit extreme longevity. In this Review, we integrate theoretical and empirical insights to establish a unified perspective on senescence and longevity. We discuss the evolutionary origins, genetic mechanisms and functional consequences of microbial ageing. In addition to having biomedical implications, insights into microbial ageing shed light on the role of ageing in the origin of life and the upper limits to longevity.

Inhibition of Advanced Glycation End-Product Formation by High Antioxidant-Leveled Spices Commonly Used in European Cuisine

Spices and herbs, as good sources of polyphenols, could be strong inhibitors of advanced glycation end-product (AGE) formation. The aim of this research was to measure the ability of various spices to inhibit AGEs and to study the correlation of AGE inhibition with total phenolic (TP) content and antioxidant capacity. Fourteen spices commonly used in European cuisine were extracted with a 50% ethanol solution, and their water and total phenolic contents and antioxidant capacities were examined. Antioxidant capacity was evaluated using three methods: (1) Measurement of the radical scavenging ability of 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and (2) 2,2-diphenyl-1-picrylhydrazyl (DPPH●); and (3) photochemiluminescence (PCL) assay. Antiglycation properties were studied in vivo using two model systems: Bovine serum albumin-glucose (BSA-glucose) and bovine serum albumin-methylglyoxal (BSA-MGO). The most potent glycation inhibitors, according to the BSA-MGO assay, were star anise (88%), cinnamon (85%), allspice (81%), and cloves (79%), whereas in the BSA-glucose measurement, oregano was noted to be a very effective inhibitor of the glycation process. The ability to inhibit glycation was highly correlated with TP values in the BSA-MGO and BSA-glucose assay (r = 0.84 and 0.76, respectively). Our research showed the high antiglycation ability of cinnamon, cloves, and allspice, and we suggest, for the first time, that anise could also be considered a good glycation inhibitor.

Cecropia pachystachya Leaves Present Potential to Be Used as New Ingredient for Antiaging Dermocosmetics

Several biological activities have been reported for leaf extracts of Cecropia pachystachya species, including antioxidant and wound healing activities. This study aims to report, for the first time, the antiaging potential of the hydroethanolic (HE) and the ethanolic (EE) extracts obtained from the leaves of C. pachystachya using different in vitro assays. Both HE and EE presented relevant antioxidant capacity in different models, including phosphomolybdenum, 1,1-diphenyl-2-picryl-hydrazyl (DPPH), carotene/linoleic acid bleaching, and thiobarbituric acid reactive substances (TBARS) assays. Their ability to prevent the production of advanced glycation end products (AGEs) was also evaluated, and both extracts showed important activity, especially HE. The extracts also stimulated the fibroblasts proliferation in vitro, specialized cells that produce several mediators which maintain the skin integrity and youthfulness. Cytotoxicity of the extracts was not observed for this lineage or HEK-293, human embryonic kidney cells widely used to evaluate cytotoxicity of chemical compounds. HE also exhibited the ability to inhibit the collagenase (metalloproteinase MMP-2) and elastase activities. The total phenolic and flavonoids contents were also determined. HPLC analysis revealed the presence of the flavonoids orientin and iso-orientin, which were quantified to be used as chemical markers. The results suggested that the extracts of C. pachystachya leaves present the potential to be used in dermocosmetic formulations to prevent the skin aging process, which attracts the attention of pharmaceutical companies and researchers interested in the development of novel ingredients likely to be used as active principles in antiaging products.

Protein Interaction with Charged Macromolecules: From Model Polymers to Unfolded Proteins and Post-Translational Modifications

Interaction of proteins with charged macromolecules is involved in many processes in cells. Firstly, there are many naturally occurred charged polymers such as DNA and RNA, polyphosphates, sulfated glycosaminoglycans, etc., as well as pronouncedly charged proteins such as histones or actin. Electrostatic interactions are also important for "generic" proteins, which are not generally considered as polyanions or polycations. Finally, protein behavior can be altered due to post-translational modifications such as phosphorylation, sulfation, and glycation, which change a local charge of the protein region. Herein we review molecular modeling for the investigation of such interactions, from model polyanions and polycations to unfolded proteins. We will show that electrostatic interactions are ubiquitous, and molecular dynamics simulations provide an outstanding opportunity to look inside binding and reveal the contribution of electrostatic interactions. Since a molecular dynamics simulation is only a model, we will comprehensively consider its relationship with the experimental data.

Identification of differences in the formation of plasma glycated proteins between dogs and humans under diabetes-like glucose concentration conditions

Dogs have been proposed as a translational model and used for studying aging, diabetes, and diabetes-related complications in humans. However, no studies have ever compared the glycation of plasma proteins between dogs and humans under similar experimental conditions. Thus, the aim of this study was to fill this gap by comparing the plasma protein glycation patterns of dogs and humans in an ex-vivo system. Canine and human plasma samples were incubated with glucose at concentrations comparable to those observed in diabetic patients. The final glucose plasma concentration resulted in similar glucose:albumin ratios in both species. Glycated proteins were evaluated by measuring the content of fructosamine, protein carbonyls, and the formation of advanced glycation end-products (AGEs). The concentrations of fructosamine and protein carbonyls in canine and human plasma increased in a glucose concentration-dependent manner (P < 0.0001). Of note, the relative increment of fructosamine and protein carbonyl content and AGE formation was always higher in human than in dog plasma. Our results reveal that the plasma glycation processes in dogs and humans are not similar. These novel findings could contribute to improve our understating about canine and human diabetes as well as other condition associated in the glycation of proteins.

Serum levels of advanced glycation end-products (AGEs) and the decoy soluble receptor for AGEs (sRAGE) can identify non-alcoholic fatty liver disease in age-, sex- and BMI-matched normo-glycemic adults

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem affecting ~25% of the global population. While NAFLD pathogenesis is still unclear, multiple NAFLD parameters, including reduced insulin sensitivity, impaired glucose metabolism and increased oxidative stress are hypothesised to foster the formation of advanced glycation end-products (AGEs). Given the link of AGEs with end organ damage, there is scope to examine the role of the AGE/RAGE axis activation in liver injury and NAFLD.

METHODS

Age, sex and body mass index matched normo-glycemic NAFLD adults (n = 58) and healthy controls (n = 58) were enrolled in the study. AGEs were analysed by liquid chromatography-mass spectrometry (CML, CEL), fluorescence (pentosidine, AGE fluorescence), colorimetry (fructosamine) and ELISA (sRAGE). Their association with liver function, inflammation, fibrosis and stage of NAFLD was examined.

RESULTS

Early and advanced glycation end-products, except N^ε-carboxymethyl-L-lysine (CML), were 10-30% higher, sRAGE levels 1.7-fold lower, and glycation/sRAGE ratios 4-fold higher in the NAFLD cases compared to controls. While AGEs presented weak to moderate correlations with indices of liver function and damage (AST/ALT, HOMA-IR, TNF-α and TGF-β1), including sRAGE to characterize the AGEs/sRAGE axis strengthened the associations observed. High glycation/sRAGE ratios were associated with 1.3 to 14-fold likelihood of lower AST/ALT ratios. The sum of AGEs/sRAGE ratios accurately distinguished between healthy controls and NAFLD patients (area under the curve of 0.85). Elevated AGEs/sRAGE (>7.8 mmol/pmol) was associated with a 12-fold likelihood of the presence of NAFLD.

CONCLUSION

These findings strengthen the involvement of AGEs-RAGE axis in liver injury and the pathogenesis of NAFLD.

Activation of NLRP3 Inflammasome by Advanced Glycation End Products Promotes Pancreatic Islet Damage

Accumulation of advanced glycation end products (AGEs) contributes to ageing and age-related diseases, especially type 2 diabetes. The NLRP3 inflammasome, as a vital component of the innate immune system, is implicated in the pathogenesis of type 2 diabetes. However, the role of the NLRP3 inflammasome in AGE-induced pancreatic islet damage remains largely unclear. Results showed that administration of AGEs (120 mg/kg for 6 weeks) in C57BL/6J mice induced an abnormal response to glucose (as measured by glucose tolerance and insulin release), pancreatic β-cell ultrastructural lesion, and cell death. These effects were associated with an excessive superoxide anion level, significant increased protein expression levels for NADPH oxidase 2 (NOX2), thioredoxin-interacting protein (TXNIP), NLRP3, and cleaved IL-1β, enhanced caspase-1 activity, and a significant increase in the levels of TXNIP–NLRP3 protein interaction. Ablation of the NLRP3 inflammasome or treatment with antioxidant N-acetyl-cysteine (NAC) clearly ameliorated these effects. In conclusion, our results reveal a possible mechanism for AGE-induced pancreatic islet damage upon NLRP3 inflammasome activation.

The role of glycation in the pathogenesis of aging and its prevention through herbal products and physical exercise

[Purpose]

Advanced glycation end products (AGEs) are non-enzymatic modifications of proteins or lipids after exposure to sugars. In this review, the glycation process and AGEs are introduced, and the harmful effects of AGEs in the aging process are discussed.

[Methods]

Results from human and animal studies examining the mechanisms and effects of AGEs are considered. In addition, publications addressing means to attenuate glycation stress through AGE inhibitors or physical exercise are reviewed.

[Results]

AGEs form in hyperglycemic conditions and/or the natural process of aging. Numerous publications have demonstrated acceleration of the aging process by AGEs. Exogenous AGEs in dietary foods also trigger organ dysfunction and tissue aging. Various herbal supplements or regular physical exercise have beneficial effects on glycemic control and oxidative stress with a consequent reduction of AGE accumulation during aging.

[Conclusion]

The inhibition of AGE formation and accumulation in tissues can lead to an increase in lifespan.

Inhibitory Effect of Bunium Persicum Hydroalcoholic Extract on Glucose-Induced Albumin Glycation, Oxidation, and Aggregation In Vitro

BACKGROUND

Glucose-induced protein glycation has been implicated in the progression of diabetic complications and age-related diseases. The anti-glycation potential of polyphenol-rich plant extracts has been shown previously. Bunium Persicum has been demonstrated to possess a high level of polyphenols. The aim of current in vitro study was to determine the possible inhibitory effect of Bunium Persicum hydroalcoholic extract (BPE) on glucose-induced bovine serum albumin (BSA) glycation, oxidation, and aggregation.

METHODS

Folin-Ciocalteu assay was used to measure the content of total phenolic compounds of BPE. To test the in vitro effect of BPE on the formation of glycated BSA, thiol group oxidation, and protein aggregation of BSA, various concentrations of BPE were incubated with BSA and glucose at 37 °C for 72 hr. Glycation, thiol group oxidation, and aggregation of BSA were then measured using thiobarbituric acid, 2, 4-dinitrophenylhydrazine, and Congo red colorimetric methods, respectively. Data were analyzed using the SPSS software (version 16.0). One-way ANOVA followed by Tukey's post hoc test was used to compare group means. P<0.05 was accepted as the statistically significant difference between groups.

RESULTS

The results demonstrated that the content of total phenolics of BPE was 122.41 mg gallic acid equivalents per gram dried extract. BPE (10, 15, and 30 μg/ml) significantly inhibited the formation of GA in a concentration-dependent manner. BPE also significantly decreased the levels of thiol group oxidation and BSA aggregation.

CONCLUSION

The results showed that BPE has anti-glycation and antioxidant properties and might have therapeutic potentials in the prevention of glycation-mediated diabetic complications.