• BMB Reports
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• v.44 no.10
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• pp.692-697
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• 2011

To investigate the pathways of oxidoreductases in plants, 2 key components in thioredox systems i.e. thioredoxin h (Trx h) and NADPH-dependent thioredoxin reductase (NTR) genes were first isolated from tomatoes (Solanum lycopersicum). Subsequently, the coding sequences of Trx h and NTR were inserted into pET expression vectors, and overexpressed in Escherichia coli. In the UV-Visible spectra of the purified proteins, tomato Trx h was shown to have a characteristic 'shoulder' at ~290 nm, while the NTR protein had the 3 typical peaks unique to flavoenzymes. The activities of both proteins were demonstrated by following insulin reduction, as well as DTNB reduction. Moreover, both NADPH and NADH could serve as substrates in the NTR reduction system, but the catalytic efficiency of NTR with NADPH was 2500-fold higher than with NADH. Additionally, our results reveal that the tomato Trx system might be involved in oxidative stress, but not in cold damage.

• 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.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.354-358
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• 2014

Aldose reductase (AR) has been demonstrated to play important role in the development of the diabetic complications such as diabetic retinopathy, diabetic neuropathy and diabetic nephropathy. To discover novel treatments for diabetic complications from natural sources, 69 Korean herbal medicines have been investigated for inhibitory activities on AR. Among them, 7 herbal medicines, Eleutherococcus sessiliflorus (stems), Artemisia japonica (whole plants), Wisteria floribunda (leaves), Eurya japonica (stems, twigs and leaves, leaves), Ampelopsis brevipedunculata (stems) exhibited a significant inhibitory activity compared with 3,3-tetramethyleneglutaric acid as positive control.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.359-365
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• 2014

Aldose reductase (AR) is the key enzyme of the polyol pathway in the development of the diabetic complications. Sixty seven Chinese herbal medicines have been investigated for inhibitory activities on AR. Among them, 7 herbal medicines, Buddleja crispa (twigs and leaves), Taiwania flousiana (twigs and leaves), Sloanea hemsleyana (fruits), Euphorbia nemetocypha (whole plants), Photinia glomerata (twigs and leaves), Vitex yunnanensis (twigs and leaves) exhibited a significant inhibitory activity against AR. Particularly, S. hemsleyana and V. yunnanensis showed 1.2-4.5 times more potent inhibitory activity than the positive control, 3,3-tetramethyleneglutaric acid (TMG).

• Journal of the Korean Applied Science and Technology
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• v.4 no.2
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• pp.35-42
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• 1987

인삼, 들깨 기름, 칼슘 및 마그네슘이 함유되어 있는 식이로 사육한 토끼의 혈장 콜레스테롤과 HMG-CoA reductase의 활성을 조사하였다. 간에 포함되어 있는 HMG-CoA reductase의 활성은 인삼과 들깨 기름 및 마그네슘 첨가 식이군에 있어서 증가되었으며 혈장 콜레스테롤의 농도는 감소되었다. 혈장 LDL-콜레스테롤은 대조군보다 감소하였으나 HDL-콜레스테롤은 증가되었다. 또한 베타 글로블린의 분포도 인삼과 마그네슘 및 들깨 기름을 첨가 급여한 실험군에 있어서 가장 낮았으며, ${\alpha}$-2-글로블린은 대조군에 비하여 가장 높은 값을 보였다. 전해질은 $K^+$은 인삼 첨가로 감소 되었으나 $Na^+$은 증가되었다. 혈장 마그네슘의 농도는 인삼의 첨가로 변화가 없었지만 칼슘과 들깨 기름 및 인삼 첨가식이로 마그네슘의 농도가 더 증가되었다. 혈장 칼슘의 농도는 마그네슘과 인삼을 첨가한 식이군에 있어서 감소하였다.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.29-33
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• 2017

The methanol extract of Rhododendron mucronulatum for. albiflorum (RMFA) stems inhibited aldose reductase (AR) activity. The RMFA fractions obtained by stepwise extraction with solvents of different polarity were tested for AR inhibition in vitro using the lens of a rat. Among them, the ethyl acetate (EtOAc) fraction inhibited AR more than the other fractions. Quercetin (1) from the EtOAc fraction showed a high AR inhibition with $IC_{50}$ of $2.11{\mu}M$. The stems of RMFA contained the highest amount (5.12 mg/g extract) of quercetin. Our results suggest that RMFA, which contained quercetin, could be a useful material for the development of supplementary functional foods.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.221-224
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• 1997

Effects of melatonin on hepatic glutathione-peroxidase (GSH-Px) and glutathione-reductase (GSH-reductase) activities were studied in Sprague-Dawley (SD) rats administered i.p. (10 mg/kg body weight) with melatonin during 15 days. The activity of cytosolic GSH-reductase in the liver was not changed by melatonin. However, melatonin injection increased significantly the activity of liver cytosolic GSH-Px activity compared with those in saline-treated rats. At the same time, plasma GSH-Px was also increased significantly in melatonin-treated rats. Since GSH-Px, a major antioxidative enzyme, removes $H_2O_2$ and lipid peroxides which are formed during lipid peroxidation from cellular membrane, such elevation of heptatic GSH-Px activity may contribute to the improvement of antioxidative effects under oxidative damage in the liver.

• BMB Reports
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• v.41 no.1
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• pp.79-85
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• 2008

The source of nitric oxide (NO) in plants is unclear and it has been reported NO can be produced by nitric oxide synthase (NOS) like enzymes and by nitrate reductase (NR). Here we used wild-type, Atnos1 mutant and nia1, nia2 NR-deficient mutant plants of Arabidopsis thaliana to investigate the potential source of NO production in response to Verticillium dahliae toxins (VD-toxins). The results revealed that NO production is much higher in wild-type and Atnos1 mutant than in nia1, nia2 NR-deficient mutants. The NR inhibitor had a significant effect on VD-toxins-induced NO production; whereas NOS inhibitor had a slight effect. NR activity was significantly implicated in NO production. The results indicated that as NO was induced in response to VD-toxins in Arabidopsis, the major source was the NR pathway. The production of NOS-system appeared to be secondary.

• 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.

• Plant Resources
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• v.4 no.3
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• pp.181-188
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• 2001

We tried to introduce two forsythia genes related in lignan biosynthesis, dirigent protein and pinoresinol/lariciresinol (Ph) reductase, into potatoes for accumulation of lignans in transgenic potatoes. We made binary vectors overexpressing dirigent protein gene and P/L reductase gene driven by a CaMV35S promoter and transformed into potatoes via Agrobacterium mediated transformation. And in order to control the metabolic flux of lignan biosynthesis pathway, we tried to inhibit chalcone synthase genes of potatoes by antisense inhibition technique also. We tried to use PCR screening method for selection of transgenic plants of different vectors. We tried to determine and compare lignan contents from different transgenic potato lines.