• Archives of Pharmacal Research
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• 제27권12호
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• pp.1226-1232
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• 2004

Extracts from seventeen seaweeds were determined for tyrosinase inhibitory activity using mushroom tyrosinase with L-tyrosine as a substrate. Only one of them, Ecklonia stolonifera OKAMURA (Laminariaceae) belonging to brown algae, showed high tyrosinase inhibitory activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction from the methanolic extract of E. stolonifera, led us to the isolation of phloroglucinol derivatives [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds 1~5 were found to inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with $IC_{50}$ values of 92.8, 126, 33.2, 177, and 2.16 ${\mu}g$ /mL, respectively. It was compared with those of kojic acid and arbutin, well-known tyrosinase inhibitors, with $IC_{50}$ values of 6.32 and 112 ${\mu}g$ / mL, respectively. The inhibitory kinetics analyzed from Lineweaver-Burk plots, showed compounds 1 and 2 to be competitive inhibitors with $K_i$ of $2.3{\times}10^{-4}\;and\;3.1{times}10^{-4}$ M, and compounds 3~5 to be noncompetitive inhibitors with $K_i$ of $1.9{\times}10^{-5},\;1.4{\times}10^{-3}\;and\;1.5{\times}10^{-5}$ M, respectively. This work showed that phloroglucinol derivatives, natural compounds found in brown algae, could be involved in the control of pigmentation in plants and other organisms through inhibition of tyrosinase activity using L-tyrosine as a substrate.

• 한국약용작물학회지
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• 제23권3호
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• pp.245-252
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• 2015

This study was carried out to investigate the effects of Salvia plebeia R. Br. ethanolic extract with different aspects (stem/leaf and whole plant) on differentiation and lipid accumulation in 3T3-L1 preadipocytes. The morphological changes and the degrees of lipid accumulation in 3T3-L1 cells were measured by Oil Red O staining and intra-cellular triglyceride (TG) assay. The mRNA expressions of special peroxisome proliferation activated receptor- genes (PPAR), CCAAT/ enhancer-binding protein (C/$EBP{\alpha}$), fatty acid synthase (FAS) and lipoprotein lipase (LPL) were detected by reverse transcriptase polymerase chain reaction (RT-PCR). The 50% ethanolic extracts ($100{\mu}g/mL$) of stem and leaf (SALE) and 30% ethanolic extracts (100 g/mL) of whole plant (SAE) from Salvia plebeia R. Br. were significantly attenuated lipid accumulation during adipogenesis in 3T3-L1 cells. Ethyl acetate-soluble fractions ($50{\mu}g/mL$) significantly inhibited lipid droplet accumulation in 3T3-L1 cells. In addition, SALE induced down-regulation of specific adipogenic transcriptional factors (C/$EBP{\alpha}$ and $PPAR{\gamma}$) and target genes (FAS and LPL) during adipogenesis. Salvia plebeia R. Br. may be used as a safe and efficient natural substance to manage obesity.

• Journal of Applied Biological Chemistry
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• 제61권3호
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• pp.283-290
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• 2018

맥문동탕 열수추출물의 용매분획물을 이용하여 1-1-diphenyl-2-picryl-hydrazyl radical scavenge, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenge, elastase, tyrosinase 억제 효과를 검증하였고 그 결과 에틸아세테이트 분획물(MW-EA)에서 가장 우수한 저해활성을 보여주었다. 세포를 이용한 활성 검증에서는 MW-EA를 처리하였을 때 ROS 저해활성에서 34% ($100{\mu}g/mL$), MMPs 저해 50% ($100{\mu}g/mL$) 이상, 미백 활성에서는 tyrosinase를 25% ($50{\mu}g/mL$) 억제하는 것을 확인 하였다. 따라서 맥문동탕은 피부개선 소재로서 개발 가능성이 높다고 사료된다.

• 한국식품과학회지
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• 제33권2호
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• pp.271-277
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• 2001

항균 활성이 우수한 예덕나무의 75% 에탄올 추출물을 용매 분획 후 일정 수준의 농도로 액체 배지(tryptic soy broth)에 첨가하여 L. monocytogenes 5 균주를 배양시킨 결과 헥산분획물 20 ppm에서 72시간 동안 증식 저해 효과를 나타내었다. 항균 활성이 우수한 예덕나무 헥산 분획물을 silica gel column chromatography로 1회 분획하여 항균 활성이 우수한 획분 M34를 얻었으며 M34 획분은 50 ppm 수준의 농도에서 실험 균주 모두 증식을 저해했다. 획분 M34를 2회 연속 분리하여 소 획분 M34-4-4를 얻은 후 액체 배지에 첨가하여 L. monocytogenes 2 균주를 접종한 후 72시간 배양한 결과 50 ppm 수준의 농도에서 증식 저해 효과가 나타났으며, M34-4-4을 구조 동정한 결과 linolenic acid로 확인되었다.

• 한국식품영양과학회지
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• 제28권4호
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• pp.822-829
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• 1999

최근 식품 산업의 발달로 장기간 식품 보존을 위하여 합성 보존제의 사용이 크게 증가하고 있는 실정이다. 그러나, 인체에 대한 유해성이 문제로 대두되면서 이를 대체할 천연 보존제의 개발이 절실히 요고되고 있는 실정이다. 따라서 본 연구는 우리나라 야산에서 쉽게 구할 수 있는 구황 식물인 민들레를 메탄올과 여러 용매로 추출하여 식품부패 미생물에 대한 항균력을 실험하고 그 항균 활성 물질을 분석하여 다음과 같은 결론을 얻었다. 민들레의 메탄올 추출물은 $2000\mu\textrm{g}/ml$ 농도에서 s. aureus를 완전히 억제하였고, L. monocytogenes는 98.43% 억제하였다. 그리고 민들레의 ethylacetate 분획물은 $1000\mu\textrm{g}/disc$ 농도에서 5종의 모든 시험균주에 대하여 clear zone을 형성하여 가장 높은 항균력을 보였다. 민들레의 ethyl­-acetate 분획물을 silica gel column chromatography와 TLC를 통해 분리하여 얻은 fraction을 5가지 시험균주에 대한 항균 실험 결과 3번째 3rd fraction의 항균력이 가장 높아 $250\mu\textrm{g}/disc$ 농도에서 E. coli를 제외한 모든 균주에 대하여 14mm 이상의 clear zone을 나타내었다. 항균력을 보인 민들레의 ethylacetate 분획의 3번째 3rd fraction을 먼저 HPLC로 분리하여 얻은 peak II로부터 $^{l}H-NMR$ 및 GC-MS로 분석한 결과 benzoic acid로 동정 되었다.

• 한국자원식물학회지
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• 제30권1호
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• pp.22-28
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• 2017

회화나무는 한의학에서 간과 혈관계 질환의 치료에 사용되어온 약용 식물로, 그 꽃과 열매를 괴화와 괴각이라 한다. 괴화와 괴각은 메탄올 추출물로부터 에틸아세테이트 분획물을 얻어 시료로 사용하였고, B16 F10 세포를 이용하여 Western blot을 실행하였다. 미백효과를 확인하기 위해, tyrosinase, TRP-1, TRP-2, MITF 단백질을 확인하였다. 그 결과, 괴화와 괴각 추출물은 세포 생존율에는 영향이 미미하였으며, 모두tyrosinase, TRP-1, TRP-2, MITF 단백질의 발현 억제효과를 나타냈다. 또한 농도 의존적으로 억제효과를 보였으며, 이를 통해 전통적으로 사용되어 왔던 괴화와 괴각은 기능성 화장품의 원료와 같은 천연식물 유래 자원으로 상당한 가치를 나타냈다.

• 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.

• 약학회지
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• 제43권1호
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• pp.16-22
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• 1999

Scutellaria baicalensis Georgi (Labiatae) has been extensively used in treatment of diarrhea, conjunctivitis, gastritis, enteritis and skin disease. As instructed in old description, the Scutellariae Radix should sometimes be processed before use. To 노디 light on the changes of chemical compositions by processing as well as processing method-activity relationships, Scutellariae Radix was heated at 16$0^{\circ}C$-20$0^{\circ}C$ for 30 min. in furnace or soaked with 20% EtOH (SPE) and boy's urine(SPU), respectively, which are one of processing methods and then heated at 17$0^{\circ}C$ for 30 min. To isolate the chemical components, Scutellariae Radix with/without processing were extracted with EtOH and EtOH extract was fractionated with ether, ethyl acetate and butanol to give respective fractions. Ether and EtOAc fractions obtained from the processed drug with urine (SPU) were subjected to chromatography to obtainsix components, oroxylin A, Wogonin, chrysin, baicalein, baicalein 7-O-$\beta$-D-glucopyranoside and $\beta$-sitosterol 3-O-$\beta$-D-glucopyranoside. All the isolated compounds were identified by means of physicochemical and spectroscopic methods (IR, $^1H-NMR,{\;}^13C-NMR$, Mass). By HPLC determination, the changes of the contents for each isolated components from SPE and SPU samples were observed. It was found that the content of nonglycosidic flavones such as oroxylin A, wogonin, chrysin and baicalein was increased markedly, whereas the content of baicalin and baicalein 7-O-$\beta$-D-glucopyranoside was significantly decreased in both samples as compared with those of Scutellariae Radix. When the sample was soaked with boy's urine, the total amount of nonglycosidic flavones was higher than that of processing with 20% EtOH.

• 대한임상독성학회지
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• 제15권2호
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• pp.107-115
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• 2017

Purpose: Glehnia littoralis has been used to treat ischemic stroke, phlegm, cough, systemic paralysis, antipyretics and neuralgia. The pharmacological mechanisms of Glehnia littoralis include calcium channel block, coumarin derivatives, anticoagulation, anti-convulsive effect, as well as anti-oxidant and anti-inflammatory effects. Alpha-amanitin (${\alpha}$-amanitin) is a major toxin from extremely poisonous Amanita fungi. Oxidative stress, which may contribute to severe hepatotoxicity was induced by ${\alpha}$-amanitin. The aim of this study was to investigate whether Glehnia littoralis ethyl acetate extract (GLEA) has the protective antioxidant effects on ${\alpha}$-amanitin -induced hepatotoxicity. Methods: Human hepatoma cell line HepG2 cells were pretreated in the presence or absence of GLEA (50, 100 and $200{\mu}g/ml$) for 4 hours, then exposed to $60{\mu}mol/L$ of${\alpha}$-amanitin for an additional 4 hours. Cell viability was evaluated using the MTT method. AST, ALT, and LDH production in a culture medium and intracellular MDA, GSH, and SOD levels were determined. Results: GLEA (50, 100 and $200{\mu}g/ml$) significantly increased the relative cell viability by 7.11, 9.87, and 14.39%, respectively, and reduced the level of ALT by 10.39%, 34.27%, and 52.14%, AST by 9.89%, 15.16%, and 32.84%, as well as LDH by 15.86%, 22.98%, and 24.32% in culture medium, respectively. GLEA could also remarkably decrease the level of MDA and increase the content of GSH and SOD in the HepG2 cells. Conclusion: In the in vitro model, Glehnia littoralis was effective in limiting hepatic injury after ${\alpha}$-amanitin poisoning. Its antioxidant effect is attenuated by antidotal therapy.

• Food Science and Biotechnology
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• 제18권3호
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• pp.766-770
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• 2009

Hot water extracts of Camellia japonica flower buds were found to have the higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the other solvent extracts. Five phenolic compounds were isolated and purified from the ethyl acetate soluble-neutral fraction of hot water extracts by Sephadex LH-20 column chromatography and octadecyl silane-high performance liquid chromatography using the guided assay of DPPH radical scavenging. Based on mass spectrometer and nuclear magnetic resonance, the isolated compounds were identified as p-hydroxybenzaldehyde (1), vanillin (2), dehydroxysynapyl alcohol (3), 7S,7'S,8R,8'R-icariol $A_2$ (4), and (-)-epicatechin (5). Four compounds (1-4) except for 5 were newly identified in this plant. Their DPPH radical scavenging activities as 50% scavenging concentration decreased in order to 5 $(20\;{\mu}M)>{\alpha}-tocopherol$ $(29\;{\mu}M)>4$ $(67\;{\mu}M)>3$ $(72\;{\mu}M)>1=2$ ($>250\;{\mu}M$). These results indicate that the antioxidant effect of the hot water extract of C. japonica flower buds may partially due to 5 isolated phenolic compounds.