• Korean Journal of Pharmacognosy
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• v.47 no.4
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• pp.312-318
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• 2016

Advanced glycation end products (AGEs) such as $N^{\varepsilon}$-(carboxy-methyl)lysine (CML) have been implicated in the development of diabetic nephropathy. The aim of this study was to investigate the inhibitory effects of ethanolic extract of Aster koraiensis (AKE) on AGEs formation and AGEs-collagen cross-linking in vitro and CMLs formation in streptozotocin (STZ)-induced diabetic rats. AKE significantly inhibited AGEs formation ($IC_{50}$ value of $18.74{\mu}g/mL$) and AGEs-collagen cross-linking ($IC_{50}$ value of 0.274 mg/mL) in vitro than the well-known glycation inhibitor aminoguanidine ($IC_{50}$ value of $72.12{\mu}g/mL$ and 1.99 mg/mL, respectively). AKE (100 mg/kg per day) was given to diabetic rats for 9 weeks. In STZ-induced diabetic rats, severe hyperglycemia was developed, and urinary CMLs and plasma CMLs were markedly increased. Immunohistochemical stain revealed that CMLs were accumulated within renal glomerulus in STZ-induced diabetic rats. However, AKE significantly reduced urinary CMLs and plasma CMLs in diabetic rats. CMLs accumulation was inhibited by AKE treatment in the renal glomerulus. These results suggest that AKE had an inhibitory effect of AGE accumulation in the glomeruli of diabetic rat and could be an inhibitor of AGE-induced protein cross-linking. The oral administration of AKE may significantly help to prevent the progression of diabetic nephropathy in patients with diabetes.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.382-387
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• 2009

Enhanced formation and accumulation of advanced glycation end products (AGEs) have been implicated as a major pathogenesis process leading to diabetic complications, normal aging, atherosclerosis and Alzheimer's disease. In our ongoing project to discover novel treatments for diabetic complications from natural sources, we have investigated on the inhibitory activity of 67 ethanol extracts from 57 Korean herbal medicines against the formation of AGEs in vitro. Of these, 22 extracts were found to have a significant AGEs inhibitory activity ($IC_{50}$<50 ${\mu}g$/ml) compared with aminoguanidine ($IC_{50}$=75.98 ${\mu}g$/ml). Particularly, 6 extracts from 3 herbal medicines, Castanea crenata (flower, leaf, bark-twig), Acer tatarium subsp. ginnala (fruit) and Sapium japonicum (leaf, twig) showed (approximately 8-17 fold) stronger inhibitory activity than that of aminoguanidine.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.3
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• pp.273-280
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• 2012

Scutellaria baicalensis Georgi, which has been known to be able to clear away heat and remove dampness, was used for febrile disease. It is now clear that Advanced glycation end products (AGEs) play major roles in the pathogenesis of diabetic complications such as atherosclerosis. In this study, we examined whether Scutellaria baicalensis Georgi suppress the AGE mediated inflammatory responses in the THP-1 cells. AGE treatment increased the gene expression of pro-inflammatory cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$), monocyte chemotactic protein-1 (MCP-1) and cyclooxygenase-2 (COX-2). Reverse transcriptase-polymerase chain reaction and Western blot analysis revealed that S. baicalensis had inhibitory effects on the expression of pro-inflammatory genes and protein levels in AGE-treated THP-1 cells. S. baicalensis had also reduced the production of ROS in the AGE-treated THP-1 cells. These results suggest that S. baicalensis has inhibitory effects for the development of diabetic vascular complication.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.249-254
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• 2008

An 80% EtOH extract and the solvent fractions of the seeds of Cornus officinalis were evaluated for their inhibitory activities against advanced glycation end products (AGEs) formation and AGEs-induced protein cross-linking in vitro. In vitro assay for AGEs-bovine serum albumin (BSA) formation showed that the 80% EtOH extract, n-hexane, EtOAc, n-BuOH and water fractions significantly inhibited AGEs formation with observed $IC_{50}$ values of 1.13, 17.64, 1.52, 1.24 and $3.27{\mu}g/ml$, respectively. In indirect AGEs-ELISA assay, the 800% EtOH extract, EtOAc and n-BuOH fractions exhibited more potent inhibitory activity on AGEs-BSA formation than aminoguanidine, a well know AGEs inhibitor. Furthermore, the 80% EtOH extract and all the solvent fractions inhibited concentration-dependently AGE-BSA cross-linking to collagen. The 80% EtOH extract, EtOAc, n-BuOH and water fractions also had a breaking activity against preformed AGE-BSA cross-linking concentration dependently. Thus these results suggest that the 80% EtOH extract and fractions of the seeds of C. officinalis could be an inhibitor as well as breaker of AGE-BSA cross-linking.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.338-344
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• 2012

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, 62 herbal medicines from China and Vietnam have been investigated with an in vitro evaluation system using AGEs formation inhibitory activity. Of these, 5 herbal medicines ($IC_{50}$ < $5{\mu}g/ml$) were found to have significant AGEs formation inhibitory activity. Particularly, herbal medicines Albizia odoratissima (twigs and leaves), Rhododendron spinuliferum (twigs and leaves), Dioscorea cirrhosa (stems and leaves), Illicium verum (stems and leaves) and Aglaia perviridis (stems and leaves), showed more potent inhibitory activity (approximately 16-26 fold) than the positive control aminoguanidine ($IC_{50}=76.47{\mu}g/ml$).

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1305-1313
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• 2009

Saengjihwangeum-ja (SJHEJ) was recorded in DongEuiBoGam as being able to be used for treatment of Sogal whose concept had been applied to Diabetes Mellitus (DM). Modification of proteins by long term circulation of glucose leads to the formation of advanced glycation end product(AGE). Recent immunological studies demonstrated that ligation of AGE play an important role in the development of diabetic complications including atherosclerosis, which includes activation, adhesion, and migration of monocytes. Also, AGE and Maillard reaction product(MRP) could augment monocyte inflammatory responses via ligation of AGE receptor. In this study, the effects of SJHEJ extracts on the expression of inflammatory response-related genes such as tumor necrosis factor-$\alpha$, monocyte chemoattractant protein-1, interferon-g-inducible protein-10, and cyclooxygenase-2 in the human monocyte cell line, THP-1 cells. Reverse transcriptase-polymerase chain reaction revealed that SJHEJ had inhibitory effects on the expression of the TNF-a, MCP-1, IP-10, COX2, IL-1b genes in MRP-induced THP-1 cells. Treatment with SJHEJ had reduced reactive oxygen production in THP-1 cells stimulated by MRP. These inhibitory effects might be exerted via prevention of oxidative stress in activated monocytes. In addition, radical scavenging activity of SJHEJ was increased. These results suggest that SJHEJ has a beneficial effects for improve diabetic vascular complication.

• Journal of Marine Bioscience and Biotechnology
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• v.13 no.2
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• pp.94-103
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• 2021

Here, we evaluated the anti-glycation effects and renal protective properties of 70% (v/v) ethanolic extract of Colpomenia sinuosa (CSE) against AGEs -induced oxidative stress and apoptosis at different concentrations (1, 5, and 20 ㎍/mL). At 20 ㎍/mL, CSE showed that anti-glycation activities via the inhibition of AGE formation (51.1%), inhibition of AGEs-protein cross-linking (61.7%), and breaking of AGEs-protein cross-links (33.3%), were significantly (###p < 0.001 vs. non-treated group) lower than the nontreated group. Methylglyoxal (MGO) significantly (***p < 0.001) reduced cell viability (24.4%) and increased reactive oxygen species (ROS) level (642.3%), MGO accumulation (119.4 ㎍/mL), and apoptosis (55.0%) in mesangial cells compared to the nontreated group. Pretreatment with CSE significantly (###p < 0.001) increased cell viability (57.8%) and decreased intracellular ROS (96.5%), MGO accumulation (80.0 ㎍/mL), and apoptosis (22.6%) at 20 ㎍/mL. Additionally, we confirmed intracellular AGEs reduction by CSE pretreatment. Consequently, our results suggest that CSE is a good source of natural therapeutics for managing diabetic complications by the antiglycation effect and renal protective activity against MGO-induced oxidative stress.

• The Korea Journal of Herbology
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• v.32 no.3
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• pp.63-69
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• 2017

Objectives : Advanced glycation end product (AGEs) is combine formation of glucose and protein. AGEs and reactive oxygen species are potential therapeutic targets for the various disease such as diabetic complications, renal injury, skin damage. The aim of this study was investigated the AGEs inhibitory activity and antioxidant activity of water extracts from 40 Korean medicines and 5 heating-processed Korean medicines. Methods: AGEs formation inhibitory activities of Korean medicines measured using bovine serum albumin (BSA), glucose, and fructose. Then, five effective Korean medicines were selected and heated with 30% ethanol. The AGEs inhibitory activities of heated Korean medicine were measured compared with not-heated Korean medicines. The antioxidant activities were evaluated through radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals. Furthermore, we examined total phenol and flavonoids contents. Results: Scutellariae Radix, Corni Fructus, Persimmon Fruit, Paeoniae Radix, Mori Folium respectively reduced AGEs production. Morever, heating-processed Scutellariae Radix has AGEs inhibitory activities better than not-processed Scutellariae Radix. Heating- processed Scutellariae Radix scavenged DPPH and ABTS effectively and $IC_{50}$ of DPPH and ABTS radical scavenging activity of Heat processed Scutellariae Radix were $15.47{\pm}0.26{\mu}g/m{\ell}$ and $12.07{\pm}1.23{\mu}g/m{\ell}$. It caused heat processing methods of Scutellariae Radix up regulated total phenol and flavonoids contents ($26.68{\pm}0.01$ to $46.15{\pm}0.10$, $20.30{\pm}0.38$ to $64.20{\pm}0.52$). Conclusion: It has AGEs inhibitory activities that 20 kind of medicinal plants of 40 medicinal plants. Especially, heat processed Scutellariae Radix has excellent AGEs inhibitory activities and antioxidant effect.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.95-100
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• 2018

Objectives : Ligustri Fructus has been used since ancient times as a medicinal usages in folk medicines against antitumor purpose. Many biological active constituents have been identified from this biomass such as several terpenoids and lignans. In current study, the properties of antioxidant and anti-diabetic complications using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)($ABTS^+$) radicals scavenging, and advanced glycation end products (AGEs) inhibition assays were evaluated by different extraction methods of Ligustri Fructus. Methods : In present continuing research for development of bioactive natural ingredients, antioxidant and AGEs formation inhibitory capacities of Ligustri Fructus extracts using different organic solvents were prepared and the biological potentials were investigated using in vitro bioassays. Antioxidant properties were evaluated employing radical scavenging assays using DPPH and $ABTS^+$ radicals. In addition, the anti-diabetic complications effects of Ligustri Fructus extracts were tested via AGEs formation inhibitory assay. The total phenolic contents were determined using a spectrophotometric method. Results : All the tested extracts exhibited dose-dependent radical scavenging and AGEs formation inhibitory activities. Among the tested samples, hot water extract of Ligustri Fructus was showed the most potent activity with $IC_{50}$ value of $494.8{\pm}6.7{\mu}g/m{\ell}$ against DPPH radical scavenging assay. Also, $ABTS^+$ radical scavenging activity of hot water extract was higher than those of other extracts. In addition, AGEs formation inhibitory effects of each extacts and total phenolic contents were evaluated. Conclusions : These results suggested that Ligustri Fructus can be considered as a new effective source of natural antioxidant and anti-diabetic complications resources.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.517-527
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• 2018

The current study investigated in vitro anti-diabetic and neuroprotective effects of the ethyl acetate fraction in Actinidia arguta sprouts (EFAS), on $H_2O_2$ and high glucose-induced cytotoxicity in human neuroblastoma MC-IXC cells. EFAS had high total phenolic and total flavonoid contents. An assessment of 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of EFAS, as well as its potential for inhibiting malondialdehyde production, indicated that EFAS may possess significant antioxidant properties. EFAS exerted inhibitory effects on ${\alpha}-glucosidase$ via glycemic regulation which forms advanced glycation end products. In addition, EFAS exhibited significant acetylcholinesterase inhibitory effects. Moreover, EFAS displayed protective effects against $H_2O_2$ and high glucose-induced cell death, and inhibited the generation of reactive oxygen species in MC-IXC cells. Finally, the main physiological compound of EFAS was identified via high performance liquid chromatography as a rutin.