• The Korean Journal of Physiology and Pharmacology
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• v.18 no.1
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• pp.1-14
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• 2014

During long standing hyperglycaemic state in diabetes mellitus, glucose forms covalent adducts with the plasma proteins through a non-enzymatic process known as glycation. Protein glycation and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic complications like retinopathy, nephropathy, neuropathy, cardiomyopathy along with some other diseases such as rheumatoid arthritis, osteoporosis and aging. Glycation of proteins interferes with their normal functions by disrupting molecular conformation, altering enzymatic activity, and interfering with receptor functioning. AGEs form intra- and extracellular cross linking not only with proteins, but with some other endogenous key molecules including lipids and nucleic acids to contribute in the development of diabetic complications. Recent studies suggest that AGEs interact with plasma membrane localized receptors for AGEs (RAGE) to alter intracellular signaling, gene expression, release of pro-inflammatory molecules and free radicals. The present review discusses the glycation of plasma proteins such as albumin, fibrinogen, globulins and collagen to form different types of AGEs. Furthermore, the role of AGEs in the pathogenesis of diabetic complications including retinopathy, cataract, neuropathy, nephropathy and cardiomyopathy is also discussed.

• Natural Product Sciences
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• v.14 no.3
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• pp.192-195
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• 2008

Three known compounds, puerarol (1), pueroside B (2), and ononin (3), were isolated from an EtOAc-soluble fraction of the roots of Pueraria lobata. The isolates (1 - 3) were subjected to an in vitro bioassay to evaluate their inhibitory activity on the formation of advanced glycation end products (AGEs). Puerarol (1) exhibited a remarkable inhibitory activity on AGEs formation with $IC_{50}$ value of $2.05{\pm}0.32{\mu}M$ as compared with positive control, aminoguanidine ($IC_{50}$ value : $905.32{\pm}7.58{\mu}M$).

• Korean Journal of Pharmacognosy
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• v.37 no.1 s.144
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• pp.48-52
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• 2006

Advanced glycation end products (AGEs) are largely involved in the pathogenesis of diabetic complications. As part of our ongoing project directed toward the discovery of preventive and/or delay agents for diabetic complications from natural sources, 92 Korean traditional herbal medicines have been investigated with an in vitro evaluation system using AGEs inhibitory activity. Of these, 17 herbal medicines exhibited a significant inhibitory activity against AGEs formation. Particularly, 9 herbal medicines, i.e., Cinnamomi Cortex, Artemisiae Argyi Herba, Ammoni Tsao-ko Fructus, Menthae Herba, Amomi Semen, Polygoni Avicularis Herba, Lycopi Herba, Salviae Radix, and Nelumbinis Semen showed more potent inhibitory activity (2-4 fold) than the positive control aminoguanidine.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.587-590
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• 2006

Three naphthopyrone glucosides, cassiaside (1), $rubrofusarin-6-O-{\beta}-D-gentiobioside$ (2), and $toralactone-9-O-{\beta}-D-gentiobioside$ (3), were isolated from the BuOH-soluble extract of the seeds of Cassia tora as active constituents, using an in vitro bioassay based on the inhibition of advanced glycation end products (AGEs) to monitor chromatographic fractionation. The structures of 1-3 were determined by spectroscopic data interpretation, particularly by extensive 1D and 2D NMR studies. All the isolates (1-3) were evaluated for the inhibitory activity on AGEs formation in vitro.

• Journal of Nutrition and Health
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• v.49 no.4
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• pp.233-240
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• 2016

Purpose: Diabetic complications are a major concern to manage progression of diabetes. Production of advanced glycation end products (AGEs) due to high blood glucose is one of the mechanisms leading to diabetic complications. Multiple pharmacologic AGE inhibitory agents are currently under development, but clinical applications are still limited due to safety issues. Thus, it is necessary to identify a safe anti-glycation agent. It is known that burdock roots have antioxidant, anti-inflammatory, and anti-cancer activities. The objective of the present study was to investigate the inhibitory role of burdock roots on the formation of high glucose-induced glycation of bovine serum albumin (BSA). Methods: In this study, glycation of BSA by glucose, galactose, or fructose at $37^{\circ}C$ for 3 weeks was assessed based on levels of ${\alpha}$-dicarbonyl compounds (early-stage glycation products), fructosamine (intermediate products of glycation), and fluorescent AGEs (late-stage glycation products). In order to compare the inhibitory actions of burdock root extract in AGE formation, aminoguanidine (AG), a pharmacological AGE inhibitor, was used as a positive control. Results: BSA glycation by glucose, fructose, and galatose was dose- and time-dependently produced. Burdock root extract at a concentration of 4 mg/mL almost completely inhibited glucose-induced BSA glycation. The results demonstrate that burdock root extract inhibited AGE formation with an $IC_{50}$ value of 1.534 mg/mL, and inhibitory activity was found to be more effective than the standard anti-glycation agent aminoguanidine. This study identified a novel function of burdock root as a potential anti-glycation agent. Conclusion: Our findings suggest that burdock root could be beneficial for preventing diabetic complications.

• Analytical Science and Technology
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• v.35 no.1
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• pp.8-14
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• 2022

Many studies have shown that advanced glycation end-products (AGEs) and glycation adducts are significantly linked to aging and disease. Particularly, the level of glycation in human milk is important because the AGE intake is closely related to AGE levels in infants. In this study, we used human milk samples obtained from four primiparae and four multiparae. We isolated proteins using acetone and trichloroacetic acid (TCA) precipitation. A total of 67 glycated proteins and 122 glycated peptides was quantified; among them, 19 glycated peptides were differentially expressed. We confirmed that the degree of glycation differed according to fertility. The study provides a foundation for using proteomics to evaluate the mother's milk quality and link between maternal health and human milk quality.

• Food Science and Preservation
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• v.24 no.4
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• pp.536-541
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• 2017

Hyperglycemia found in diabetes mellitus causes several physiological abnormalities including the formation of advanced glycation end products (AGEs) and oxidative stress. Accumulation of AGEs and elevation of oxidative stress plays major roles in the development of diabetic complications. Adiponectin secreted from adipocytes is known to improve insulin sensitivity and blood glucose level. Curcumin (CCM), a bioactive component of turmeric, has been reported as a potent antioxidant. Present work aimed to elucidate the roles of CCM in high glucose-induced protein glycation and intracellular events in mature adipocytes. The results demonstrated that CCM inhibited the formation of fluorescent AGEs by approximated 52% at 3 weeks of bovine serum albumin (BSA) glycation with glucose. Correspondingly, CCM decreased the levels of fructosamine and ${\alpha}-dicarbonyl$ compounds during BSA glycation with glucose. These data suggested that CCM might be a new promising anti-glycation agent. Also, CCM reduced high glucose-induced oxidative stress in a dose dependent manner, whereas CCM treatment time-dependently elevated the expression of adiponectin gene in 3T3-L1 adipocytes. The findings from this study suggested the possibility of therapeutic use of CCM for the prevention of diabetic complications and obesity-related diseases.

• Korean Journal of Pharmacognosy
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• v.37 no.4 s.147
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• pp.307-313
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• 2006

Reactive oxygen species (ROS) and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic nephropathy by hyperglycemia. To find natural agents improving diabetic nephropathy, 63 natural resources which used to the treatment of diabetes mellitus in a folk remedy were investigated with an in vitro system employing radical scavenging activity and inhibitory activity of AGEs formation. In results, the extracts of Aspalathus linearis, Rubus coreanus, Rosa rugosa, and Epimedium koreanum significantly inhibited the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical with $IC_{50}$ values less than $10{\mu}g/ml$. The extracts of Zea mays, Cucurbita moschata, Cudrania tricuspidata, and Aspalathus linearis effectively reduced the formation of AGEs compared with the positive control $N-acetyl-_L-cystenine$ (NAC) and aminoguanidine (AG). In addition, the extracts of Aspalathus linearis, Commelina communis, Cornus officinalis, and Lespodeza cuneata showed the all inhibitory activity against DPPH radical and AGEs formation. Also, these resources definitely showed the radical scavenging activity against peroxynitrite $(ONOO^-)$ and hydroxyl radical $({\cdot}OH)$ relating to high glucose-induced ROS production. Thus, these results suggest that some natural resources may regulate the initiation and progression of diabetic nephropathy through inhibition of ROS production and AGEs formation.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.260-267
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• 2015

Advanced glycation end products (AGEs) have been postulated to play a central role in the development of diabetic complications. A variety of different agents that inhibit AGEs have been under investigation. In this study, 111 herbal medicines from China have been investigated with an in vitro evaluation system using AGEs formation inhibitory activity. Of these, 9 herbal medicines (IC₅₀: <5 μg/ml) were found to have significant AGEs formation inhibitory activity. Particularly, herbal medicines Barleria cristata (leaves), Calotropis gigantea (stems), Ardisia virens (leaves), Dalbergia yunnanensis (leaves) Pittosporum runcatum (leaves), Ardisia japonica (leaves), Rhododendron racemosum (twigs), Oxyria sinensiss (aerial parts), Pyrrosia calvata (whole plants), showed more potent inhibitory activity (approximately 15-40 fold) than the positive control aminoguanidine (IC₅₀: 76.47 μg/ml).

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.250-259
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• 2015

Advanced glycation end products (AGEs) have been implicated in diabetic complications. In this study, the inhibitory effect on AGEs formation of 156 Korean herbal medicines has been evaluated. Among them, 15 Korean herbal medicines were showed to have significant effect (IC₅₀: <10 μg/ml) compared to positive reference, aminoguandine (IC₅₀: 76.47±4.81 μg/ml). Especially, four herbal medicines, Alnus firma (leaves, IC₅₀: 3.25±0.10 μg/ml), Juncus decipiens (whole plants, IC₅₀: 4.30±0.44 μg/ml), Smilax china (stems, IC₅₀: 3.55±0.21 μg/ml), and Vicia amoena (Aerial parts, IC₅₀: 4.25±0.06 μg/ml) showed more potent inhibitory activity approximately 8-24 fold) than the positive control aminoguanidine.