• Restorative Dentistry and Endodontics
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• 제48권2호
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• pp.13.1-13.11
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• 2023

Objectives: Natural extracts have been investigated as a biomimetic strategy to mechanically strengthen the collagen network and control the biodegradation of extracellular matrix. This study evaluated the effect of epigallocatechin-3-gallate (EGCG) on abfraction lesions prior to the composite resin. Materials and Methods: The sample consisted of 30 patients (aged between 28 and 60 years) with abfraction lesions located in 2 homologous premolars. The teeth were randomly assigned according to dentin treatment: 0.02% EGCG solution or distilled water (control). After enamel acid etching, the solutions were applied immediately for 1 minute. The teeth were restored with Universal Adhesive (3M) and Filtek Z350 XT (3M). Analyzes were done by 2 independent examiners using modified USPHS (retention, secondary caries, marginal adaptation, and postoperative sensitivity) and photographic (color, marginal pigmentation, and anatomical form) criteria at baseline (7 days) and final (18 months). The data analysis used Friedman and Wilcoxon signed-rank tests (α = 0.05). Results: At baseline, all restorations were evaluated as alpha for all criteria. After 18 months, restorations were evaluated as alpha for secondary caries, color, and marginal pigmentation. There was significant difference between baseline and 18 months (p = 0.009) for marginal adaptation and postoperative sensitivity (p = 0.029), but no significant difference were verified between treatments (p = 0.433). The EGCG group had a restoration retention rate of 93.3%, while the control group had 96.7%. Conclusions: The application of EGCG solution on abfraction lesions did not significantly influence the survival of the restorations based on clinical and photographic criteria.

• 대한의용생체공학회:의공학회지
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• 제34권3호
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• pp.111-116
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• 2013

Finite element analysis(FEA) has been extensively applied in the analyses of biomechanical properties of stents. Geometrically, a closed-cell stent is an assembly of a number of repeated unit cells and exhibits periodicity in both longitudinal and circumferential directions. This study concentrates on various parameters of the FEA models for the analysis of drug-eluting biodegradable polymeric stents for application to the treatment of coronary artery disease. In order to determine the mechanical characteristics of biodegradable polymeric stents, FEA was used to model two different types of stents: tubular stents(TS) and helicoidal stents(HS). For this modeling, epigallocatechin-3-O-gallate (EGCG)-eluting poly[(L-lactide-co-${\varepsilon}$-caprolactone), PLCL] (E-PLCL) was chosen as drug-eluting stent materials. E-PLCL was prepared by blending PLCL with 5% EGCG as previously described. In addition, the effects of EGCG blending on the mechanical properties of PLCL were investigated for both types of stent models. EGCG did not affect tensile strength at break, but significantly increased elastic modulus of PLCL. It is suggested that FEA is a cost-effective method to improve the design of drug-eluting biodegradable polymeric stents.

• 한국식품과학회지
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• 제35권5호
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• pp.959-967
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• 2003

한국산 배를 60% acetone으로 추출하여 Sephadex LH-20 gel column chromatography, MCI-CHP 20 gel column chromatography, Bondapack $C_{18}$ gel column chromatography을 이용하여 TLC와 HPLC로 순도를 검증한 후 4종의 polyphenol 화합물을 분리, 정제하였다. Compound A와 B는 Sepadex LH-20 gel column chromatography에서 증류수상에서 용출되었고 compound C는 40% methanol상에서 용출됨을 보아 compound B와 compound C는 흡착성이 강한 polyphenol 화합물이라 추정되었다. 분리, 정제한 4종의 compound를 NMR, FAM-mass 및 FT-IR를 이용하여 화학구조를 결정한 결과 compound A는 (+)-catechin, compound B는 (+)-gallocatechin, compound C는 (-)-epigallocatechin이고 compound D는 procyanidin B-3-3-o-gallate로 밝혀졌다.

• International Journal of Oral Biology
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• 제45권4호
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• pp.179-189
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• 2020

Green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is a potent antioxidant with protective effects against neurotoxicity. However, it is currently unclear whether EGCG protects neuronal cells against radiation-induced damage. Therefore, the objective of this study was to investigate the effects of EGCG on ultraviolet (UV)-induced oxidative stress and apoptosis in PC12 cells. The effects of UV irradiation included apoptotic cell death, which was associated with DNA fragmentation, reactive oxygen species (ROS) production, enhanced caspase-3 and caspase-9 activity, and poly (ADP-ribose) polymerase cleavage. UV irradiation also increased the Bax/Bcl-2 ratio and mitochondrial pathway-associated cytochrome c expression. However, pretreatment with EGCG before UV exposure markedly decreased UV-induced DNA fragmentation and ROS production. Furthermore, the UV irradiation-induced increase in Bax/Bcl-2 ratio, cytochrome c upregulation, and caspase-3 and caspase-9 activation were each ameliorated by EGCG pretreatment. Additionally, EGCG suppressed UV-induced phosphorylation of p38 and rescued UV-downregulated phosphorylation of ERK. Taken together, these results suggest that EGCG prevents UV irradiation-induced apoptosis in PC12 cells by scavenging ROS and inhibiting the mitochondrial pathways known to play a crucial role in apoptosis. In addition, EGCG inhibits UV-induced apoptosis via JNK inactivation and ERK activation in PC12 cells. Thus, EGCG represents a potential neuroprotective agent that could be applied to prevent neuronal cell death induced by UV irradiation.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
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• pp.74-79
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• 2004

Little is known about the effect of epigallocatechin-3 gallate (ESCG), a major constituent of green tea, on the expression of cyclooxygenase (COX)-2. Here, we studied the role of phospholipase D (PLD) isozymes in EGCG-induced COX-2 expression. Stimulation of human astrocytoma cells (U87) with EGCG induced formation of phosphatidylbutanol, a specific product of PLD activity, and synthesis of COX-2protein and its product, prostaglandin $E_2$ ($PGE_2$). Pretreatment of cells with 1-butanol, but not 3-butanol, suppressed EGCG-induced COX-2 expression and $PGE_2$ synthesis. Furthermore, evidence that PLD was involved in EGCG-induced COX-2 expression w3s provided by the observations that COX-2 expression was stimulated by over-expression of PLD1 or PLD2 isozymes and treatment with phosphatidic acid(PA), and that prevention of PA dephosphorylation by 1-propranolol significantly potentiated COX-2expression Induced by EGCG. EGCG induced activation of p38 mitogen-activated protein kinase (p38MAPK), and specific Inhibition of p38 MAPK dramatically abolished EGCG-Induced PLD activation, COX-2 expression, and $PGE_2$ formation. Moreover, protein kinase C (PKC) inhibition suppressed EGCG-induced p38 MAPK activation, COX-2 expression, and $PGE_2$ accumulation. The same pathways as those obtained in the astrocytoma cells were active in primary rat astrocytes, suggesting the relevance of the findings. Collectively, our results demonstrate for the first time that PLD isozymes mediate EGCG-induced COX-2 expression through PKC and p38 in immortalized astroglial line and normal astrocyte cells.

• Preventive Nutrition and Food Science
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• 제11권3호
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• pp.191-197
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• 2006

Matrix metalloproteinase-2 (MMP-2) is a key enzyme involved in tumor invasiveness. The plant of Magnolia officinalis Rehd. et Wils. is often included as an ingredient in various herbal remedies recommended for cancer theraphies in Korea. Various extracts prepared from stems of M. officinalis were tested for cytotoxic activity on human hepatocellular carcinoma cell line, SK-Hep cells using the XTT assay method. Then, the inhibitory effect was examined on MMP-2 activity using gelatin zymography. Methanol (MeOH) extract of M. officinalis caused the strongest inhibition of the MMP-2 activity, as measured by gelatin zymography method for enzyme activity. $IC_{50}$ values of fractions on MMP-2 activity were in a range of $4.9{\sim}11.3\;{\mu}g/mL$. Among each fraction, butanol and ethylacetate (EtOAc) fractions showed the strong inhibitory activities ($IC_{50}=10.7\;and\;4.9\;{\mu}g/mL$, respectively). When the M. officinalis's constituents such as magnolol, honokiol, (-)-epigallocatechin gallate (EGCG) and ovovatol were examined for inhibitory effects on MMP-2 activity, EGCG showed strong inhibitory activity. However, MeOH extract of M. officinalis was dose-dependently inhibited to MMP-2 activity. The MeOH extract, hexane and EtOAc fractions $(IC_{50}\;of\;>200\;{\mu}g/mL)$ exhibited weak cytotoxicity activity, while butanol $(IC_{50}=80\;{\mu}g/mL)$ and chloroform fractions $(IC_{50}=90\;{\mu}g/mL)$ exhibited relatively strong cytotoxic activity. From these results, M. officinalis could be suitable for cancer treatment and chemopreventive drugs.

• 미생물학회지
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• 제52권3호
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• pp.260-268
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• 2016

본 연구의 목적은 시중에 판매되고 있는 쌈장에서 용혈성을 가지는 Bacillus cereus MH-2를 분리하여, EGCG 노출에 따른 MH-2 균주의 세포 반응과 프로테옴 분석을 위해 수행되었다. 다양한 농도의 EGCG에 노출된 MH-2 균주는 노출시간이 증가함에 따라 생존률은 점차 감소함을 보였다. MH-2 균주의 alginate 생성량은 EGCG의 농도가 증가함에 따라 감소하였으며, 특정 EGCG 농도에서 노출시간이 진행됨에 따라 그 생성량은 증가하는 것으로 나타났다. SDS-PAGE 및 anti-DnaK와 anti-GroEL의 단일항체를 이용한 Western blot 통한 분석으로, 두 가지 스트레스 충격단백질인 70 kDa의 DnaK와 60 kDa의 GroEL의 발현은 대수생장기의 배양에서 EGCG의 농도에 비례하여 감소하는 것을 확인하였다. EGCG에 노출된 세균의 세포 외부형태 변화를 주사전자현미경을 이용하여 관찰한 결과, 세포 표면의 돌출부 생성과 함께 세포의 뭉그러짐이 관찰되었다. EGCG에 노출된 Bacillus cereus MH-2 배양의 수용성 단백질 부분에 대한 2-DE에서 20개의 단백질 스팟이 EGCG 노출에 의해 크게 변화하는 것이 확인되었다. 장독소(hemolysin BL lytic component L1, hemolysin BL-binding protein), chaperon (DnaK, GroEL), 세포방어요소(peptidase M4 family proteins), 에너지 및 물질대사 등에 수반되는 이들 단백질은 MALDI-TOF를 사용한 peptide mass fingerprinting에 의해 동정되었다. 이들 결과는 B. cereus MH-2에 대한 EGCG-유도 스트레스와 세포독성의 기작을 이해하는데 중요한 단서를 제공할 것이다.

• 한국염색가공학회지
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• 제28권1호
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• pp.1-13
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• 2016

Natural colorant extracts were obtained by extraction from tumeric root, gardenia seeds, mugwort and green tea using water, methanol, ethanol and acetone as extractants at room temperature for 3 hours under shaking condition(180rpm) with liquor ratio(solid:solvent; 1:100). The main pigment components of tumeric root, gardenia seeds, mugwort and green tea are known to be curcumin, crocin, chlorophyll b and epigallocatechin gallate, respectively. The effects of the kind of extractant and pH on the color characteristics of natural colorant extracts were investigated. The solubility parameters of pigment components were determined to find adequate extractant. The solubility parameters of curcumin, crocin, chlorophyll b and epigallocatechin gallate were found to be 27.85, 29.40, 19.48 and $37.97(J/cm^3)^{1/2}$. As expected, solvents that have a solubility parameter similar to that of pigment component were generally found to be effective to obtain pigment extracts having high visible absorbance(A). The extract(pigment/solvent) with high visible absorbance was generally found to have low $L^*$(lightness) and high Chroma($C^*$, purity).

• The Korean Journal of Physiology and Pharmacology
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• 제19권6호
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• pp.491-497
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• 2015

Traumatic brain injury (TBI) is a major cause of mortality and long-term disability, which can decrease quality of life. In spite of numerous studies suggesting that Epigallocatechin-3- gallate (EGCG) has been used as a therapeutic agent for a broad range of disorders, the effect of EGCG on TBI remains unknown. In this study, a weight drop model was established to evaluate the therapeutic potential of EGCG on TBI. Rats were administered with 100 mg/kg EGCG or PBS intraperitoneally. At different times following trauma, rats were sacrificed for analysis. It was found that EGCG (100 mg/kg, i.p.) treatment significantly reduced brain water content and vascular permeability at 12, 24, 48, 72 hour after TBI. Real-time PCR results revealed that EGCG inhibited TBI-induced IL-$1{\beta}$ and TNF-${\alpha}$ mRNA expression. Importantly, CD68 mRNA expression decreasing in the brain suggested that EGCG inhibited microglia activation. Western blotting and immunohistochemistry results showed that administering of EGCG significantly inhibited the levels of aquaporin-4 (AQP4) and glial fibrillary acidic protein (GFAP) expression. TBI-induced oxidative stress was remarkably impaired by EGCG treatment, which elevated the activities of SOD and GSH-PX. Conversely, EGCG significantly reduced the contents of MDA after TBI. In addition, EGCG decreased TBI-induced NADPH oxidase activation through inhibition of $p47^{phox}$ translocation from cytoplasm to plasma membrane. These data demonstrate that EGCG treatment may be an effective therapeutic strategy for TBI and the underlying mechanism involves inhibition of oxidative stress.

• Molecular & Cellular Toxicology
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• 제3권2호
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• pp.127-131
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• 2007

Chronic treatment with olanzapine (OLZ), an atypical antipsychotic drug, is associated with the adverse effects of weight gain, hyperglycemia and/or hypertriglyceridemia. Green tea or epigallocatechin gallate (EGCG), one of the most abundant green tea polyphenols, significantly reduces or prevents an increase in glucose levels, lipid markers and/or body weight. We hypothesized that combined treatment with OLZ and green tea extract (GTE) or EGCG may prevent body weight gain and increase of the lipid markers. ICR male mice weighing an average of 30.51 g (n=32) at the beginning of the experiment were used. OLZ, OLZ+GTE and OLZ+EGCG were administered for 27 d in the drinking water, and then the levels of fasting glucose, nitric oxide (NO), and a typical lipid marker triglyceride (TG) were determined in plasma. The body weight and food intake were also compared. The chronic treatment of OLZ increased the average body weight compared with that of controls. In the presence of GTE or EGCG, the OLZ-induced increase in body weight was significantly prevented. Furthermore, in the OLZ group, the plasma levels of glucose, NO and TG were significantly increased, whereas GTE or EGCG prevented these increases. These results implicate that OLZ may induce systematic inflammatory reaction, and suggest that GTE or EGCG can protect against OLZinduced weight gain, hyperglycemia and hypertriglyceridemia.