• 생약학회지
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• 제45권4호
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• pp.366-375
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• 2014

Aldose reductase (AR) has been indicated the critical enzyme of the polyol pathway in the development of the diabetic complications. In this study, 119 Vietnamese herbal medicines have been investigated for inhibitory activities on AR. Among them, 7 herbal medicines, Synedrella nodiflora (stems and leaves), Combretum sundaicum (stems and leaves), Argyreia acuta (stems and leaves), Platea latifolia (whole plants), Linociera sangda (whole plants), Rhaphiolepis indica (whole plants), Harrisonia perforata (stems and leaves) and 2 fractions from Harrisonia perforata (stems and leaves) with EtOAc and BuOH, exhibited a significant inhibitory activity against AR. Particularly, S. nodiflora, A. acuta and H. perforata (stems and leaves) showed 1.0-1.8 times more potent inhibitory activity than the positive control, 3,3-tetramethyleneglutaric acid (TMG).

• Natural Product Sciences
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• 제17권3호
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• pp.230-233
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• 2011

To evaluate the potential of naturally occurring aldose reductase (AR) inhibitors from food material, MeOH extract and stepwise polarity fractions from tartary buckwheat and two common Korean buckwheat cultivars, yangjul-maemil and daesan-maemil, were tested on AR inhibition in rat lens in vitro. The EtOAc fraction from tartary buckwheat exhibited good AR inhibitory activity ($IC_{50}$ value, $8.19\;{\mu}g$/ml). A portion of the EtOAc fraction from tartary buckwheat led to the isolation of rutin by MeOH recrystalization. Rutin exhibited good AR inhibitory activity ($IC_{50}$ value, $9.28\;{\mu}M$). These results suggest that tartary buckwheat could be a useful food material in the development of a novel AR inhibitory agent against diabetic complications.

• 생약학회지
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• 제40권4호
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• pp.394-399
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• 2009

Aldose reductase (AR) is a critical enzyme in the development of the diabetic complications. AR, the first enzyme in the polyol pathway, catalyzes the reduction of the aldehyde form of glucose to sorbitol with concomitant conversion of NADPH to $NADP^+$. None of aldose reductase inhibitor (ARI) has achieved worldwide use because of limited efficacy or undesirable side effects. Therefore, evaluating natural sources for ARI potential may lead to the development of safer and more effective agents against diabetic complications. Forty eight Chinese herbal medicines have been investigated for inhibitory activities on AR. Among them, seven herbal medicines, Buddleja officinalis (whole plant), Lonicera japonica (leaf and flower), Polygonum aviculare (aerial part), Polygonum aviculare (whole plant), Salvia miltiorrhiza (root), Schisandra chinensis (stem), and Zanthoxylum armatum (leaf and stem) exhibited a significant inhibitory activity against AR. Particularly, L. japonica and P. aviculare showed two times more potent inhibitory activity than the positive control, 3,3-tetramethyleneglutaric acid (TMG).

• Journal of Applied Biological Chemistry
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• 제51권1호
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• pp.13-16
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• 2008

Five anthraquinones, emodin (1), ${\omega}$-hydroxyemodin (2), chrysophanol-8-O-${\beta}$-D-glucoside (3), emodin-8-O-${\beta}$-D-glucoside (4), and physcion-8-O-${\beta}$-D-glucoside (5), and five flavonoids, kaempferol-3-O-${\beta}$-D-glucoside (6), quercetin (7), quercitrin (8), isoquercitrin (9), and (+)-catechin (10), were isolated from the EtOAc-soluble extract of the fruits of Rumex japonicus. The structures of 1-10 were identified by spectroscopic methods including NMR studies. This is the first report on the isolation of compounds 3-5 from this plant. The isolates were subjected to in vitro bioassays to evaluate their inhibitory activities on the rat lens aldose reductase (RLAR), among which two anthraquinones (1 and 4), and five flavonols (5-9) showed significant activities on RLAR.

• Archives of Pharmacal Research
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• 제17권5호
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• pp.331-336
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• 1994

The ether extract from the roots of angelica clahurica was found to inhibit bovine lens aldose reductase (BLAR0 activity in vitro by 100% at 100.mu.g/ml. Systematic fractionation of the ether soluble fraction and subsequent active frctions monitorede by bioassy led to isolation of four furanocoumarins, isoimperatorin (I0, imperatorin (II), ter-O-methyl byakangelicin (III) and byakangelicin (IV), among which compound III and IV were identified as potential AR inhibitors, their $IC_{50}$ values being $2.8{\mu}M{\;}and{\;}6.2{\mu}M$, respectively. Galactosemic cataract formation tors, in rats treated with 40 g/kg/day of galactose was blocked almost completely throughout the exeprimental periods up to 44 days by i.p. administrations of byakangelicin (IV) at 50 mg/kg/day. In coincidence with the inhibitory action on cataract formation, the galactitol accumulation in rats treated with byakangelicin (IV) was found to be markedly prevented by approximately 80.5% compared to those of the contro. These results indicate that byakangelicin (IV), as a main principle of this plant, possesses high potential for a clinically useful drug of the future which prevents and/or improves sugar cataract as well as diabetic complications.

• 농업과학연구
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• 제39권2호
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• pp.169-175
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• 2012

To search for the aldose reductase (AR) inhibitors from Korean folk plants, the inhibition of rat lens AR in vitro using the methanol (MeOH) extracts from Korean folk plants was investigated. Among fifty four Korean folk plants tested, the MeOH extract of Cedrela sinensis showed highest inhibition of AR ($IC_{50}$ value, 2.52 ${\mu}g/ml$). The plant C. sinensis has a possibility of new natural resources for the development of AR inhibitor for the prevention of diabetic complications.

• 한국약용작물학회지
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• 제18권5호
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• pp.305-310
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• 2010

Taxifolin-3-O-$\beta$-D-xylopyranoside and quercetin-3-O-$\alpha$-L-rhamnopyranoside were isolated from an EtOAc-soluble extract of the leaves of Chamaecyparis obtuse. Quercetin-3-O-$\alpha$-L-rhamnopyranoside was found to possess a potent inhibitory activity of human recombinant aldose reductase in vitro, its $IC_{50}$ value being $11.5\;{\mu}M$. Kinetic analysis showed that quercetin-3-O-$\alpha$-L-rhamnopyranoside exhibited uncompetitive inhibition against DL-glyceraldehyde. Also, quercetin-3-O-$\alpha$-L-rhamnopyranoside suppresses sorbitol accumulation in rat lens under high glucose conditions, demonstrating the potential to prevent sorbitol accumulation in vivo. These results suggest that this compound may be a promising agent in the prevention or treatment of diabetic complications.

• Food Science and Biotechnology
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• 제18권1호
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• pp.190-196
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• 2009

The inhibition effects of an Alpinia officinarum (AO, Zingiberaceae) on the formation of advanced glycation end products, aldose reductase, and scavenging effect on 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical for the prevention and/or treatment of diabetic complications were investigated. The ethyl acetate fraction of AO was the most effective among all fractions. Through the tests with electron impact-mass spectrometry and nuclear magnetic resonance, two compounds (compound 1 and 2) finally obtained from the ethyl acetate fraction of AO were identified as galangin (1) and kaempferide (2), respectively. In addition, the compound 1 and 2 and the ethyl acetate fraction were compared for the prevention effect on advanced glycation end products, aldose reductase, and the scavenging effect on DPPH radical. The ethyl acetate fraction was significantly more effective than the 2 compounds for those preventive activities.

• 한국약용작물학회지
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• 제20권4호
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• pp.222-230
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• 2012

We evaluated the inhibitory effects of extracts and components of Geranium thunbergii on aldose reductase (AR) and galactitol formation in rat lenses with high levels of galactose as a part of our ongoing search of natural sources for therapeutic and preventive agents for diabetic complications. The inhibitory effects of water, methanol and ethanol extracts of G. thunbergii on rat lens AR (RLAR) were determined. Comparing inhibitory effects of various solvent extracts, ethanol extract showed RLAR inhibitory activity ($IC_{50}$ values, 5.24 and $6.39{\mu}g/m{\ell}$, respectively). The ethanol extract was fractionated to chloroform, ethyl acetate and water. Of these, the ethyl acetate fraction from ethanol extract of G. thunbergii exhibited RLAR inhibitory activity ($IC_{50}$ value, $2.64{\mu}g/m{\ell}$). In order to identify the bioactive components of ethyl acetate soluble fraction of ethanol extract from G. thunbergii, eight compounds, namely gallic acid (1), protocatechuic acid (2), p-hydroxybenzoic acid (3), brevifolin carboxylic acid (4), geraniin (5), ellagic acid (6), kaempferol-3-O-arabinofuranosyl-7-O-rhamnopyranoside (7), kaempferitrin (8) were isolated. The isolates were subjected to in vitro bioassays to evaluate their inhibitory activity on RLAR and galactitol formation in rat lenses. The ellagic tannins (5, 6) and flavonoid (7) exhibited strong inhibitory effects on RLAR. Also, these three compounds (5, 6 and 7) suppressed galactitol accumulation in rat lens under high galactose conditions, demonstrating the potential to prevent galactitol accumulation exo vivo. These results suggest that the extracts and components of G. thunbergii are a promising agent in the prevention or treatment of diabetic complications.

• Natural Product Sciences
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• 제17권2호
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• pp.130-134
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• 2011

The purpose of this study was to evaluate the therapeutic potential of naturally occurring aldose reductase (AR) inhibitors isolated from Korean native plants. The MeOH extract and stepwise polarity fractions of dandelions were tested on rat lens AR inhibition in vitro. Of these, the EtOAc fractions from the leaves of dandelions (Traxacum coreanum, T. officinale, and T. ohwianum) exhibited an AR inhibitory activity ($IC_{50}$ values, 2.37, 1.73 and 2.68 ${\mu}g/ml$, respectively). A chromatography of the EtOAc fraction from the leaves of T. coreanum led to the further isolation of two flavonoids identified as luteolin and luteolin 7-O-glucopyranoside. These compounds exhibited strong AR inhibitory activity, with $IC_{50}$ values of 0.15 and 1.05 ${\mu}M$, respectively. These results suggested that luteolin is a potent AR inhibitor within dandelions and that it could be a useful lead compound in the development of a novel AR inhibitory agent against diabetic complications.