• ALGAE
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• v.19 no.4
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• pp.349-352
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• 2004

We examined MeOH extracts of the marine plants from Korea for their inhibitory activities on rat lens aldose reductase in vitro. Among the MeOH extracts tested, the extracts of Enteromorpha prolifera, Ecklonia cava, Pelvetia siliquosa and Salicornia herbacea exhibited a rat lens aldose reductase inhibition (IC$_{50}$: 3.04, 8.84, 11.42 and 4.99 $\mu$g-ml$^{-1}$, respectively) in vitro.

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.314-317
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• 2003

Inhibitory effects of the whole extract and isolated compounds from the leaves of Vaccinium koreanum (Ericaceae) on rat lens aldose reductase (RLAR) and on platelet aggregation were investigated for the prevention or the treatment of chronic diabetic complications. Arbutin, isolated from n-butanol fraction of methanol extract, exhibited a potent inhibitory effects on rat platelet aggregation induced by ADP $(IC_{50}=0.12\;{\mu}M)$ and collagen $(IC_{50}=0.039\;{\mu}M)$ and showed same inhibitory activities with positive control, tetramethylene glutaric acid, on RLAR.

• Natural Product Sciences
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• v.9 no.1
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• pp.34-37
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• 2003

We examined methanol extracts prepared from the Korean plants for their inhibitory effects on rat lens aldose reductase (RLAR) activity in vitro. Among 41 plant extracts, the extracts of Lagerstroemia indica, Punica granatum, Eurya japonica, Liquidambar styraciflua, and Vitis coignetiae exhibited highest inhibitory potency, even more potent than tetramethylene glutaric acid (TMG), known as one of typical aldose reductase inhibitors $(IC_{50}\;value,\;0.51\;{\mu}g/ml)$. Especially, the extract of Lagerstroemia indica (Lythraceae), exhibited the most inhibitory potency $(IC_{50}\;value,\;0.069\;{\mu}/ml)$ on RLAR.

• Archives of Pharmacal Research
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• v.11 no.4
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• pp.308-311
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• 1988

Nine coumarin dervatives were examined for thier inhibitory effects on bovine lens aldose reductase activity (bovine-LAR). More than 50% inhibition of BLAR activities was observed in the cases of treatments with decursin, decursinol, esculin, isoimperatorin, oxypeucedanine and isobergapten at the concentration of $10^{-4}$M. Especially, BLAR activity was completely inhibited by the treatment of decursin and decursinol at this concentration. At $10^{-5}$ M, only three coumarins-decursin, decursinol and isoimperatorin, were found to have still relatively higher inhibitory effect.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.344-349
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• 2005

Aldose reductase catalyzes the conversion of glucose into sorbitol. Inhibiting this enzyme in diabetes mellitus can delay or prevent pathogenic process. Aldose reductase inhibitor was screened from Korean fermented soybean pastes (Doen-jang) and purified via sequential processes of ethanol extraction, HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, and crystallization. Aldose reductase inhibitor was identified as genistein with molecular weight of 270 Da and molecular formula of $C_{15}H_{10}O_5$ based on UV spectrometry, $^1H$ and $^{13}C\;NMRs$, and mass spectrometry. Genistein inhibited aldose reductase of pig lens with $IC_{50}$ level of $20\;{\mu}M$. Because genistein was effective against aldose reductase of animal source, it may be a potential therapeutic agent for diabetic complications.

• Korean Journal of Pharmacognosy
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• v.32 no.3 s.126
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• pp.248-252
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• 2001

The present study was undertaken to elucidate the hypoglycemic effect and inhibitory effect of Cudrania tricuspidata root bark on aldose reductase activity. C. tricuspidata MeOH ext. 1,000 mg/kg showed a significant blood glucose lowering effect on alloxan-induced hyperglycemic rats and increasing body weight. C. tricuspidata MeOH ext. showed a potent inhibitory effect on bovine lens aldose reductase.

• Natural Product Sciences
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• v.16 no.4
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• pp.285-290
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• 2010

The inhibition of rat lens aldose reductase (AR) in vitro using methanol extracts from Korean folk plants was investigated. Among them, the extracts of Saussurea grandifolia and Rumex crispus showed highest inhibition of AR. $IC_{50}$ values of the extracts from S. grandifolia and R. crispus were demonstrated 0.07 and 0.05 mg/ml, respectively. Korean folk plants such as S. grandifolia and R. crispus has a possibility of new natural resources for the inhibition of AR.

• Natural Product Sciences
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• v.19 no.4
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• pp.275-280
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• 2013

Aldose reductase (AR) has been shown to play an important role in the development of diabetic complications. To search for AR inhibitors from Chinese plants, the ethanol extracts of Chinese plants was tested against an inhibition of rat lens AR in vitro. Among Chinese plants tested, Cissus assamica var. pilosissima and Syzygium oblatum showed highest inhibition of AR ($IC_{50}$ values, 0.71 and 0.79 ${\mu}g/ml$, respectively). Cissus assamica var. pilosissima and Syzygium oblatum showed more potent inhibitory activity against AR than the positive control, TMG. Consequently, C. assamica var. pilosissima and S. oblatum have a possibility of new natural resources for the development of AR inhibitor for the prevention of diabetic complications.

• Natural Product Sciences
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• v.16 no.1
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• pp.54-57
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• 2010

Effects of the species Scrophularia takesimensis, S. kakudensis, S. boreali-koreana, and S. buergeriana on rat lens aldose reductase inhibition have been investigated. Among them, the extracts of S. kakudensis and S. boreali-koreana were exhibited good inhibitory potencies compared with those of S. takesimensis and S. buergeriana. The $IC_{50}$ values of the aerial part extracts from S. kakudensis and S. boreali-koreana were demonstrated 0.46 and 0.35 mg/ml, respectively.

• Journal of the Korean Wood Science and Technology
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• v.38 no.2
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• pp.159-164
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• 2010

Nine compounds, caffeic acid, naringenin, apigenin, luteolin, kaempferol, verbascoside, isoverbascoside, isocampneoside II, and cistanoside F, were isolated from the EtOAc and n-BuOH fractions of P. coreana bark. The structures of these compounds (1-9) were elucidated by spectroscopic methods and literature data. All the isolates were subjected to in vitro bioassay to evaluate their inhibitory activity against rat lens aldose reductase. Among these, compounds 6 and 8 indicated the significant inhibitory activity on rat lens aldose reductase with $IC_{50}$ values of 2.67 and 5.59 ${\mu}M$, respectively. Especially, The inhibition activity of acteoside was 3.9 times better than that of quercetin as a positive control (10.6 ${\mu}M$). These results suggested that phenylethanoid glycosides are likely to be the potential compounds for the prevention and/or treatment of diabetic complications.