scholarly journals How Does Pyridoxamine Inhibit the Formation of Advanced Glycation End Products? The Role of Its Primary Antioxidant Activity

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 344 ◽  
Author(s):  
Rafael Ramis ◽  
Joaquín Ortega-Castro ◽  
Carmen Caballero ◽  
Rodrigo Casasnovas ◽  
Antonia Cerrillo ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Advanced Glycation End Products ◽  
Rate Constants ◽  
Protein Glycation ◽  
Diffusion Limit ◽  
Advanced Glycation ◽  
Hydrogen Atoms ◽  
Glycation End Products ◽  
End Products ◽  
Primary Antioxidant

Pyridoxamine, one of the natural forms of vitamin B6, is known to be an effective inhibitor of the formation of advanced glycation end products (AGEs), which are closely related to various human diseases. Pyridoxamine forms stable complexes with metal ions that catalyze the oxidative reactions taking place in the advanced stages of the protein glycation cascade. It also reacts with reactive carbonyl compounds generated as byproducts of protein glycation, thereby preventing further protein damage. We applied Density Functional Theory to study the primary antioxidant activity of pyridoxamine towards three oxygen-centered radicals (•OOH, •OOCH3 and •OCH3) to find out whether this activity may also play a crucial role in the context of protein glycation inhibition. Our results show that, at physiological pH, pyridoxamine can trap the •OCH3 radical, in both aqueous and lipidic media, with rate constants in the diffusion limit (>1.0 × 108 M - 1 s - 1 ). The quickest pathways involve the transfer of the hydrogen atoms from the protonated pyridine nitrogen, the protonated amino group or the phenolic group. Its reactivity towards •OOH and •OOCH3 is smaller, but pyridoxamine can still scavenge them with moderate rate constants in aqueous media. Since reactive oxygen species are also involved in the formation of AGEs, these results highlight that the antioxidant capacity of pyridoxamine is also relevant to explain its inhibitory role on the glycation process.

scholarly journals Advanced Glycation End Products and Oxidative Stress in a Hyperglycaemic Environment

2021 ◽  
Author(s):  
Akio Nakamura ◽  
Ritsuko Kawahrada
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Advanced Glycation End Products ◽  
Reactive Oxygen ◽  
Protein Glycation ◽  
Oxygen Species ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products ◽  
And Oxidative Stress

Protein glycation is the random, nonenzymatic reaction of sugar and protein induced by diabetes and ageing; this process is quite different from glycosylation mediated by the enzymatic reactions catalysed by glycosyltransferases. Schiff bases form advanced glycation end products (AGEs) via intermediates, such as Amadori compounds. Although these AGEs form various molecular species, only a few of their structures have been determined. AGEs bind to different AGE receptors on the cell membrane and transmit signals to the cell. Signal transduction via the receptor of AGEs produces reactive oxygen species in cells, and oxidative stress is responsible for the onset of diabetic complications. This chapter introduces the molecular mechanisms of disease onset due to oxidative stress, including reactive oxygen species, caused by AGEs generated by protein glycation in a hyperglycaemic environment.

Inhibition of advanced glycation end products by Punica granatum Linn. leaves and its antioxidant activity

2018 ◽  
Vol 18 (2) ◽  
pp. 97-105
Author(s):  
Snehal Nitin Mestry ◽  
Nitin Bhanudas Gawali ◽  
Malvika Sunil Gursahani ◽  
Sarayu Arvind Pai ◽  
Jayesh Bachu Dhodi ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Advanced Glycation End Products ◽  
Punica Granatum ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products

scholarly journals Advanced glycation end products (AGEs), protein aggregation and their cross talk: new insight in tumorigenesis

Glycobiology ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 2-18
Author(s):  
Ejazul Haque ◽  
Mohd Kamil ◽  
Adria Hasan ◽  
Safia Irfan ◽  
Saba Sheikh ◽  
...  
Keyword(s):  
Protein Aggregation ◽  
Advanced Glycation End Products ◽  
Cross Talk ◽  
Structural Changes ◽  
Current Knowledge ◽  
Normal Function ◽  
Protein Glycation ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products

Abstract Protein glycation and protein aggregation are two distinct phenomena being observed in cancer cells as factors promoting cancer cell viability. Protein aggregation is an abnormal interaction between proteins caused as a result of structural changes in them after any mutation or environmental assault. Protein aggregation is usually associated with neurodegenerative diseases like Alzheimer’s and Parkinson’s, but of late, research findings have shown its association with the development of different cancers like lung, breast and ovarian cancer. On the contrary, protein glycation is a cascade of irreversible nonenzymatic reaction of reducing sugar with the amino group of the protein resulting in the modification of protein structure and formation of advanced glycation end products (AGEs). These AGEs are reported to obstruct the normal function of proteins. Lately, it has been reported that protein aggregation occurs as a result of AGEs. This aggregation of protein promotes the transformation of healthy cells to neoplasia leading to tumorigenesis. In this review, we underline the current knowledge of protein aggregation and glycation along with the cross talk between the two, which may eventually lead to the development of cancer.

In vitro inhibition of protein glycation and advanced glycation end products formation by hydroethanolic extract and two fractions of Simaba trichilioides roots

2018 ◽  
Vol 34 (16) ◽  
pp. 2389-2393
Author(s):  
Bruno Pereira Motta ◽  
Anderson Kiyoshi Kaga ◽  
Juliana Oriel Oliveira ◽  
Maiara Destro Inacio ◽  
Cledson Ferreira da Silva ◽  
...  
Keyword(s):  
Advanced Glycation End Products ◽  
Protein Glycation ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products ◽  
In Vitro Inhibition ◽  
Hydroethanolic Extract

scholarly journals Improved Methods for the Rapid Formation and Prevention of Advanced Glycation End Products (AGEs) In Vitro by Coupling to the Hypoxanthine/Xanthine Oxidase Assay System

Biomedicines ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 88 ◽  
Author(s):  
Samuel Marques ◽  
Teresa Trevisan ◽  
Carlos Maia ◽  
Andrea Breuer ◽  
Robert Owen
Keyword(s):  
Xanthine Oxidase ◽  
Advanced Glycation End Products ◽  
High Capacity ◽  
Protein Glycation ◽  
Advanced Glycation ◽  
Leaf Extracts ◽  
Reactive Carbonyl Species ◽  
Glycation End Products ◽  
End Products

Advanced glycation end products (AGEs) represent a set of molecules that contribute directly to the initiation and aggravation of diseases associated with ageing. AGEs are produced by the reaction between reducing sugars (or α-dicarbonyl compounds), proteins, and amino acid residues. Previous in vitro methods using non-enzymatic procedures described in the literature require an incubation period of 1–3 weeks to generate AGEs. In this study, the reaction time for the formation of AGEs (48 and 3 h) was significantly reduced by adaptation of methods previously described in the literature and coupling them to the free radical generation system termed hypoxanthine/xanthine oxidase assay. The incorporation of this assay into the experimental system accelerated the production of AGEs as a result of the formation of reactive oxygen species (ROS), as shown by increased fluorescence. The capacity of different classes of chemical compounds (aminoguanidine, chlorogenic acid, rutin, and methanol extracts of Hancornia speciosa Gomes) to inhibit protein glycation by acting as scavenging agents of α-dicarbonyl species was evaluated. Aminoguanidine and, especially, rutin identified in the leaf extracts of H. speciosa Gomes showed a high capacity to act as scavengers of reactive carbonyl species RCS-trapping, resulting in the inhibition of AGEs formation.

scholarly journals 3′-O-β-d-glucopyranosyl-α,4,2′,4′,6′-pentahydroxy-dihydrochalcone, from Bark of Eysenhardtia polystachya Prevents Diabetic Nephropathy via Inhibiting Protein Glycation in STZ-Nicotinamide Induced Diabetic Mice

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1214 ◽  
Author(s):  
Rosa Pérez Gutierrez ◽  
Abraham García Campoy ◽  
Silvia Paredes Carrera ◽  
Alethia Muñiz Ramirez ◽  
José Mota Flores ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Advanced Glycation End Products ◽  
Renal Damage ◽  
Histological Analysis ◽  
Protein Glycation ◽  
Diabetic Patients ◽  
Diabetic Mice ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products

Previous studies have shown that accumulation of advanced glycation end products (AGEs) can be the cause of diabetic nephropathy (DN) in diabetic patients. Dihydrochalcone 3′-O-β-d-glucopyranosyl α,4,2′,4′,6′-pentahydroxy–dihydrochalcone (1) is a powerful antiglycation compound previously isolated from Eysenhardtia polystachya. The aim was to investigate whether (1) was able to protect against diabetic nephropathy in streptozotocin (STZ)-induced diabetic mice, which displayed renal dysfunction markers such as body weight, creatinine, uric acid, serum urea, total urinary protein, and urea nitrogen in the blood (BUN). In addition, pathological changes were evaluated including glycated hemoglobin (HbA1c), advanced glycation end products (AGEs) in the kidney, as well as in circulation level and pro-inflammatory markers ICAM-1 levels in diabetic mice. After 5 weeks, these elevated markers of dihydrochalcone treatment (25, 50 and 100 mg/kg) were significantly (p < 0.05) attenuated. In addition, they ameliorate the indices of renal inflammation as indicated by ICAM-1 markers. The kidney and circulatory AGEs levels in diabetic mice were significantly (p < 0.05) attenuated by (1) treatment. Histological analysis of kidney tissues showed an important recovery in its structure compared with the diabetic group. It was found that the compound (1) attenuated the renal damage in diabetic mice by inhibiting AGEs formation.

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