• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.874-879
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• 2008

Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be reduced by treatment with depigmenting agents. The methanol extract of Lespedeza cyrtobotrya $M_{IQ}$ showed inhibitory activity against mushroom tyrosinase. The active compound was purified from the methanol extract of L. cyrtobotrya, followed by several chromatographic methods, and identified as dalbergioidin (DBG) by spectroscopic methods. The results showed that DBG exhibited tyrosinase inhibitory activity with an $IC_{50}$ of $20\;{\mu}M$. The kinetic analysis of tyrosinase inhibition revealed that DBG acted as a noncompetitive inhibitor. In addition, DBG showed a melanin biosynthesis inhibition zone in the culture plate of Streptomyces bikiniensis that has commonly been used as an indicator organism. Furthermore, $27\;{\mu}M$ DBG decreased more than 50% of melanin contents on the pigmentation using the immortalized mouse melanocyte, melan-a cell.

• Korean Journal of Pharmacognosy
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• v.42 no.3
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• pp.223-228
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• 2011

Chaenomeles sinensis Koehne (Rosaceae) is a deciduous tree and is distributed in China, Korea and Japan. In previous studies on the fruits of C. sinensis, some triterpenoid compouds such as oleanolic acid, tormentic acid were reported. In an ongoing investigation into biologically active compounds from natural products, the methanol extract of the stems of C. sinensis was investigated. By means of the repeated column chromatography using silica gel, Sephadex LH-20, LiChroprep RP-18, betulin (1), tormentic acid (2), 1-${\beta}$-D-glucopyranosyl-3,4,5-trimethoxybenzene (3), lyoniresinol-2a-O-${\alpha}$-L-rhamnopyranoside (4) were isolated. The chemical structures of compounds 1-4 were determined by the basis of physico-chemical properties and spectroscopic methods such as 1D and 2D NMR. For the isolated compounds (1-4), the inhibitory activity of IL-6 production in TNF-${\alpha}$ stimulated MG-63 cell was examined. Among the isolates, betulin (1), 1-${\beta}$-D-glucopyranosyl-3,4,5-trimethoxybenzene (3), lyoniresinol-2a-O-${\alpha}$-L-rhamnopyranoside (4) showed inhibitory effects on IL-6 production in TNF-${\alpha}$ stimulated MG-63 cell.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1781-1789
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• 2018

In this study, whey proteins were fermented with 34 lactic acid bacteria for 48 h at $37^{\circ}C$ and their ability to inhibit angiotensin 1-converting enzyme (ACE) activity were compared. All the lactic acid bacteria displayed varying proteolytic abilities in whey. Their fermentates also displayed varying abilities to inhibit ACE in vitro. Seven fermentates showed strong ACE inhibitory abilities between $84.70{\pm}0.67$ and $52.40{\pm}2.1%$ with $IC_{50}$ values between $19.78{\pm}1.73$ and $2.13{\pm}0.7mg/ml$. Pediococcus acidilactici SDL1414 showed the strongest ACE inhibitory activity of $84.7{\pm}0.67%$ ($IC_{50}=19.78{\pm}1.73{\mu}g/ml$). Mass spectrometry revealed that more than half (57.7%) of the low molecular weight peptides (< 7 kDa) in the P. acidilactici SDL1414 fermented samples were ACE inhibitory peptides. Our results show that P. acidilactici SDL1414 could be used as a starter culture in the dairy industry to develop antihypertensive functional foods for hypertension management.

• YAKHAK HOEJI
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• v.48 no.5
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• pp.291-296
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• 2004

Sparganium stoloniferum Buch.-Ham. (Sparganiaceae) is a perennial herb which has been used as treatments for menstrual disorder, galactagogue and endometriosis in folk remedies. The Sparganii Rhizoma processed, heated with vinegar, used to different purpose compared with origin in medicine. In order to estimate the different effects between processed (PSR) and unprocessed (USR) Sparganii Rhizoma, extraction and systemic fractionation of the rhizomes were archived. Inhibitory effects of the extracts as well as the fractions of PSR and USR on rat lens aldose reductase and on rat platelet aggregation were investigated for the prevention or the treatment of chronic diabetic complications. Their antioxidant effects, measured using lipid peroxidation of liver tissue and radical scavenging activities on 1,1-diphenyl-picrylhydrazyl in vitro, were evaluated. The most of biological activities tested except rat platelet aggregation, fractions from PSR were shown to exhibit stronger activities than those from USR. It seems that caused by changing of the chemical components by heating process in conditioned with acetic acid. Compounds isolated were shown to significant inhibitory activity on rat lens aldose reductase. Inhibitory activity of compounds isolated on rat lens aldose reductase have been tested in vitro. $IC_{50}$/ (6.31 $\mu$M) of cerebroside I (V) was nearly equal to that (6.32 $\mu$M) of a reference compound, tetrametbylene glutaric acid (TMG).

• Korean Journal of Pharmacognosy
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• v.50 no.1
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• pp.25-31
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• 2019

The zebrafish (Danio rerio) is an established model organism for several pathophysiological conditions which are related to human diseases. In this study, we tested the preventive effect of eight herbal extracts, which show the inhibitory effect of advanced glycation end products (AGEs) or aldose reductase (AR) in our previous study, on high glucose (HG)-induced retinal vessel dilation in larval zebrafish and analyzed the change of hyaloid vasculature. HG-induced zebrafish hyaloid vasculatures were significantly increased in the thickness compared to untreated zebrafish (P<0.001, n=6~10). Eight herbal extracts were found to have significant retinal vessel dilation on the inhibitory activity. Particularly, Brandisia hancei (twigs and fruits), Castanopsis orthacantha (leaves and twigs), Litsea japonica (leaves and twigs), Spenceria ramalana (whole plant), and Synedrella nodiflora (leaves and stems) showed potent inhibitory activity against retinal vessel dilation in HG-induced larval zebrafish.

• Natural Product Sciences
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• v.25 no.1
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• pp.76-80
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• 2019

Bioactivity-guided fractionation of MeOH extract of the dried fruits of Amomum tsao-ko led to isolation of nine compounds (1 - 9). Their structures were elucidated by spectroscopic methods including extensive 1D and 2D-NMR, as alpinetin (1), naringenin-5-O-methyl ether (2), naringenin (3), hesperetin (4), 2',4',6'-trihydroxy-4-methoxy chalcone (5), tsaokoin (6), boesenbergin B (7), 4-hydroxyboesenbergin B (8), and tsaokoarylone (9). Of these, compound 8 was isolated from a natural source for the first time, which was previously reported as a synthetic product. The isolated compounds (1 - 9) were tested for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Among them, three chalcone derivatives (compounds 5, 7, and 8) and a diarylheptanoid (compound 9) exhibited significant inhibitory activity on the NO production with $IC_{50}$ values ranging from 10.9 to $22.5{\mu}M$.

• Natural Product Sciences
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• v.27 no.1
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• pp.28-35
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• 2021

The aim of this study was to anatomize the therapeutic potential of alaternin (=7-hydroxyemodin) against inflammation, advanced glycation end products (AGEs) formation, tyrosinase, and two cyclin-dependent kinases (CDKs), CDK2 and CDK4, and compare its potency with emodin. Alaternin showed lower cytotoxicity and higher dose-dependent inhibition against lipopolysaccharide (LPS) induced nitric oxide (NO) production with half maximal inhibitory concentration (IC50) of 18.68 µM. Similarly, alaternin efficaciously inhibited biotransformation of fluorescent AGEs and amyloid cross-β structure on the bovine serum albumin (BSA)-glucose-fructose system, five times more than emodin. Interestingly, alaternin also showed selective activity against CDK4 at 170 µM, whereas emodin inhibited both CDK2 and CDK4 at a concentration of 17 and 380 µM respectively. In addition, alaternin showed dose-dependent inhibitory activity against mushroom tyrosinase with inhibition percentage of 35.84 % at 400 µM. Altogether, alaternin with pronounced inhibition against inflammatory mediator (NO), glycated products formation, and targeted inhibition towards CDK4 receptor can be taken as an important candidate to target multiple diseases.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1576-1582
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• 2021

Bacterial β-glucuronidase in the intestine is involved in the conversion of 7-ethyl-10-hydroxycamptochecin glucuronide (derived from irinotecan) to 7-ethyl-10-hydroxycamptothecin, which causes intestinal bleeding and diarrhea (side effects of anti-cancer drugs). Twelve compounds (1-12) from Polygala tenuifolia were evaluated in terms of β-glucuronidase inhibition in vitro. 4-O-Benzoyl-3'-O-(O-methylsinapoyl) sucrose (C3) was highly inhibitory at low concentrations. C3 (an uncompetitive inhibitor) exhibited a k_i value of 13.4 μM; inhibitory activity increased as the substrate concentration rose. Molecular simulation revealed that C3 bound principally to the Gln158-Tyr160 enzyme loop. Thus, C3 will serve as a lead compound for development of new β-glucuronidase inhibitors.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.303-309
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• 2020

The purpose of this study was to identify the changes in the components of unfermented Gongjin-dan (GD) and fermented Gongjin-dan (FGD) and to confirm whether GD or FGD has an inhibitory effect on viral neuraminidase (NA) activity. A major component of FGD was isolated and identified as nodakenetin, which is the aglycone of nodakenin. After fermentation, the nodakenetin content in FGD was approximately 10-fold higher than that in GD. Then, we examined the viral NA-inhibitory activity of GD, FGD, nodakenin, and nodakenetin. At a concentration of 500 ㎍/ml, FGD inhibited viral NA activity by 92% compared to the DMSO-treated control, while GD barely inhibited viral NA activity. In addition, 250 ㎍/ml of nodakenetin inhibited viral NA activity by 68% compared to the control, while nodakenin inhibited viral NA activity by only 4% at the same concentration as nodakenetin. Collectively, these results suggest that FGD has a more remarkable viral NA-inhibitory activity than GD because the content of the anti-viral component nodakenetin was higher in FGD due to the hydrolysis of nodakenin by Lactobacillus plantarum KCTC 3104.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.429-438
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• 2014

This study was designed to investigate the effects on anti-oxidative activities and increasing extraction yield of Aralia elata Cortex by gamma irradiation. Electron spin resonance (ESR) analysis as physical techniques for irradiation identification of Aralia elata showed that a pair of peak appeared on a space of 6.0 mT at the left and right of symmetric unspecific central ESR spectrums, confirming that the plant was gamma-irradiated. The optimum extracting conditions for preparing gamma irradiated samples from Aralia elata Cortex were to extract with 50% ethanol for 15 hrs after 10 kGy irradiation. DPPH scavenging activity and ABTS radical cation inhibitory activity of the water and 50% ethanol extracts from non irradiated and irradiated Aralia elata Cortex was very high as over 80% and 98%, respectively, at tested low concentration of $50{\mu}g/mL$. Antioxidant protection factor (PF) as anti-oxidation indicator of lipophilic compounds showed a very high level of activity as 2.18~2.78 PF. As for TBARs, water and ethanol extracts showed high level. Increase of TBARs inhibitory activity of water extracts was not shown by gamma-ray irradiation but ethanol extracts showed slight increasement of TBARs inhibitory activity with 10 kGy gamma-ray irradiation. These results shown confirmed increasement of extraction yield for phenolic compounds and anti-oxidative activity from Aralia elata. Thus, the treatment of gamma-irradiation can be used a way to amplify a solubility for biological active compounds and anti-oxidative activity in plants.