• Natural Product Sciences
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• 제19권4호
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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.

• 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.

• Archives of Pharmacal Research
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• 제11권4호
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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.

• Natural Product Sciences
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• 제16권1호
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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.

• 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.

• Journal of Applied Biological Chemistry
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• 제61권2호
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• pp.135-139
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• 2018

The inhibition of aldose reductase (AR) has been shown to prevent the progression of the many complications associated with diabetic hyperglycemia. Several compounds purified from various plant sources have exhibited potent inhibition against AR. In this study, the inhibitory effects of the methanol extracts of the flowers of Synurus excelsus and Weigela subsessilis on AR were determined in vitro. Scopolin and scopoletin are coumarins isolated from the flowers of S. excelsus and W. subsessilis; and quercetin is a known AR inhibitor present in many flowers. To determine and quantify their presence in both plants, HPLC-UV analysis of all three compounds was performed. S. excelsus and W. subsessilis showed potent inhibition against AR having $IC_{50}$ values of 0.17 and $0.14{\mu}g/mL$, respectively. The concentration of scopolin in S. excelsus and W. subsessilis were 34.71 and 174.14 mg/g extract, respectively. Scopoletin was detected in S. excelsus at 3.41 mg/g extract, whereas quercetin was not detected in both plants. This study shows that S. excelsus and W. subsessilis exhibited promising AR inhibitory effects and are both sources of coumarins.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.62-62
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• 2018

Inhibition of aldose reductase (AR) has been shown to prevent the onset and progression of many diabetic complications wherein several AR inhibitors were isolated from plants abundant in polyphenolic compounds. Lespedeza cuneata (Fabaceae), a perennial plant indigenous in East Asian countries, is shown to be abundant in these polyphenolic substances such as flavonoids and tannins. However, there are no studies to date regarding its effects on AR. In this study, the inhibitory activity of the methanol extract and stepwise polarity fractions of Lespedeza cuneata on AR was investigated. The bioactive compounds purified from L. cuneata by repeated column chromatography were also tested for AR inhibition. Results show that the ethyl acetate and n-butanol fractions of L. cuneata exhibited potent inhibition against AR with $IC_{50}$ values of 0.57 and $0.49{\mu}g/mL$, respectively. Further analysis led to the isolation of acacetin (1), afzelin (2), astragalin (3), kaempferol (4), and scutellarein 7-O-glucoside (5). The AR inhibitory effects these five compounds were also determined in which compounds 2, 3, and 5 showed potent AR inhibitory effects with $IC_{50}$ values of 2.20, 1.91, and $12.87{\mu}M$, respectively. Quantitative analysis of astragalin (3) by HPLC-UV was also performed in the leaves and roots of L. cuneata (0.626 and 0.671 mg/g, respectively). This study reports that the flavonoids isolated from L. cuneata show promising AR inhibitory activities which can be further developed as natural therapies for treating and managing diabetic complications.

• Advances in Traditional Medicine
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• 제9권3호
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• pp.245-251
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• 2009

Aldose reductase (AR) has been reported to play an important role in sugar-induced cataract. In the present study, the AR inhibitory activity of Enicostemma hyssopifolium (EH), Gymnema sylvestre, Eclipta alba, and Tinospora cordifolia (TC) were studied along with their effect on sugar-induced cataractogenic changes in sheep lenses in vitro. AR inhibitory activity of the aqueous extracts of plants and their anticataract potentials were evaluated in vitro in sheep lenses, considering the activity of normal sheep lenses as 100%. The concentration of the plant extract that showed maximum activity was selected to further study its effect on galactose-induced polyol accumulation in vitro. The $IC_50$ values of EH and TC were calculated to be 102 and 85 ${\mu}g$/ml, respectively. EH showed a significant inhibition (61.3%) in polyol accumulation followed by TC (53.1%). EH and TC possesses a significant anticataract activity in vitro and its anticataract potential could be related with its AR inhibitory effect.

• Archives of Pharmacal Research
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• 제29권6호
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• pp.479-483
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• 2006

Eight compounds were isolated from the fruiting bodies of Ganoderma applanatum, and were identified as 2-methoxyfatty acids (1), 5-dihydroergosterol (2), ergosterol peroxide (3) $3{\beta},7{\beta},20,23{\zeta}-tetrahydroxy-11,15-dioxolanosta-8-en-26-oic$ acid (4), $7{\beta},20,23{\zeta}-trihydroxy-3,11,15-trioxolanosta-8-en-26-oic$ acid (5), cerevisterol (6), $7{\beta},23{\zeta}-dihydroxy-3,11,15-trioxolanosta-8,20E(22)-dien-26-oic$ acid (7), and $7{\beta}-hydroxy-3,11,15,23-tetraoxolanosta-8,20E(22)-dien-26-oic$ acid methyl ester (8) by spectral analysis. All compounds were isolated for the first time from this fruiting bodies, and their effect on rat lens aldose reductase (RLAR) activity was tested. Among these eight compounds, ergosterol peroxide (3) was found to exhibit potent RLAR inhibition, its $IC_{50}$ value being $15.4\;{\mu}g/mL$.

• The Korean Journal of Physiology and Pharmacology
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• 제5권3호
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• pp.271-278
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• 2001

Oxidative stress and methylglyoxal (MG), a reactive dicarbonyl metabolites produced by enzymatic and non-enzymatic reaction of normal metabolism, induced aldose reductase (AR) expression in rat aortic smooth muscle cells (SMC). AR expression was induced in a time-dependent manner and reached at a maximum of 4.5-fold in 12 h of MG treatment. This effect of MG was completely abolished by cyclohemide and actinomycin D treatment suggesting AR was synthesized by de novo pathway. Pretreatment of the SMC with N-acetyl-L-cysteine significantly down-regulated the MG-induced AR mRNA. Furthermore, DL-Buthionine-(S,R)-sulfoximine, a reagent which depletes intracellular glutathione levels, increased the levels of MG-induced AR mRNA. These results indicated that MG induces AR mRNA by increasing the intracellular peroxide levels. Aminoguanidine, a scanvenger of dicarbonyl, significantly down-regulated the MG-induced AR mRNA. In addition, the inhibition of AR activities with statil, an AR inhibitor, enhanced the cytotoxic effect of MG on SMC under normal glucose, suggesting a protective role of AR against MG-induced cell damages. These results imply that the induction of AR by MG may contribute to an important cellular detoxification of reactive aldehyde compounds generated under oxidative stress in extrahepatic tissues.