• 약학회지
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• 제50권1호
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• pp.58-63
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• 2006

The antioxidant enzyme (AOE) system plays an important role in the defense against oxidative stress damage. To determine whether myricetin or myricetin/taurine can exert antioxidative effects not only by modulating the AOE system directly but also by scavenging free radical, we investigated the influence of the myricetin and taurine on cell viability ROS level, activities of different antioxidant enzyme, and the expression of different antioxidant enzyme. As results, the cell viability showed inhibition of the proliferation with treatment of 'myricetin' or 'myricetin with taruine', respectively, with dose-dependent manner. Compared to control, the treatment of 'myricetin' decreased activities and gene expressions of superoxide dismutase (SOD), and glutathione peroxidase (GPx). However, combined treatment of 'myricetin with taurine' increased activities and gene expressions of the SOD, GPx, and catalase (CAT). In addition, the combined treatment of 'myricetin with taurine' somewhat decreased ROS levels, compared to the treatment of 'myricetin'. In conclusion, our study provides that the combined treatment of different antioxidants can enhance antioxidant effects.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.37-45
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• 2022

The fungal cell wall and membrane are the principal targets of antifungals. Herein, we report that myricetin exerts antifungal activity against Candida albicans by damaging the cell wall integrity and notably enhancing the membrane permeability. In the presence of sorbitol, an osmotic protectant, the minimum inhibitory concentration (MIC) of myricetin against C. albicans increased from 20 to 40 and 80 ㎍/ml in 24 and 72 h, respectively, demonstrating that myricetin disturbs the cell wall integrity of C. albicans. Fluorescence microscopic images showed the presence of propidium iodide-stained C. albicans cells, indicating the myricetin-induced initial damage of the cell membrane. The effects of myricetin on the membrane permeability of C. albicans cells were assessed using crystal violet-uptake and intracellular material-leakage assays. The percentage uptakes of crystal violet for myricetin-treated C. albicans cells at 1×, 2×, and 4× the MIC of myricetin were 36.5, 60.6, and 79.4%, respectively, while those for DMSO-treated C. albicans cells were 28.2, 28.9, and 29.7%, respectively. Additionally, myricetin-treated C. albicans cells showed notable DNA and protein leakage, compared with the DMSO-treated controls. Furthermore, treatment of C. albicans cells with 1× the MIC of myricetin showed a 17.2 and 28.0% reduction in the binding of the lipophilic probes diphenylhexatriene and Nile red, respectively, indicating that myricetin alters the lipid components or order in the C. albicans cell membrane, leading to increased membrane permeability. Therefore, these data will provide insights into the pharmacological worth of myricetin as a prospective antifungal for treating C. albicans infections.

• 동의생리병리학회지
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• 제24권1호
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• pp.74-79
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• 2010

Osteoclasts are bone-resorbing giant cells that differentiate from hematopoietic cells of the monocyte/macrophages. Excessive osteoclast differentiation leads to gradual loss of bone mass causing fracture of the skeleton. The aim of this study was to develop a drug candidates for the treatment of osteoporosis. RANKL-induced osteoclast differentiation was dose-dependently inhibited by myricetin. Myricetin inhibited the expression of c-Fos, NFATc1, and TRAP in BMMs treated with RANKL. Myricetin disrupted the structure of actin ring and suppressed osteoclastic bone resorption. Also, myricetin induced apoptosis in mature osteoclasts. Myricetin inhibited the phosphorylation of ERK in mature osteoclasts treated with M-CSF. The activation of caspase-9 and caspase-3 was increased by myricetin treatment. Our results suggest that myricetin may be an effective agent to prevent bone diseases such as osteoporosis.

• 약학회지
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• 제49권1호
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• pp.86-91
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• 2005

Flavonoids are class of polyphenolic compounds widely distributed in the plant kingdom, which display a variety of biological activities, including antiviral, antithrombotic, antiinflammatory, antihistaminic, antioxidant and free-radica 1 scavenging abilities. The antioxidant enzyme (AOE) system plays an important role in the defense against oxidative stress insults. To determine whether flavonoid, myricetin can exert antioxidative effects not only directly by modulating the AOE system but also scavenging free radical, we investigated the influence of the flavonoid myricetin on cell viability, different antioxidant enzyme activities, ROS level and the expression of different antioxidant emzyme in B16F10 murine melanoma cells. Myricetin in a concentration range from 6.25 to $50\;{\mu}M$ decreased superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities, but catalase (CAT) activity was increased. In the myricetin-treated group, ROS levels were decreased dose-dependently. Antioxidant enzyme expression was measured by RT-PCR. Myricetin treatment of B16F10 cells increased catalase expression. Expression levels of copper zinc superoxide dismutase (CuZn SOD) were not affected by exposure of myricetin. Manganese superoxide dismutase (Mn SOD) and GPx expression levels decreased slightly after myricetin treatment. In conclusion, the antioxidant capacity of myricetin was due to CAT and free-radical scavenging.

• International Journal of Oral Biology
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• 제41권4호
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• pp.163-173
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• 2016

Flavonoid myricetin, usually found in tea and medicinal plants, has antioxidant and anti-inflammatory effects. Our objectives in this study were to verify the effects of myricetin on periodontal ligament fibroblasts (PDLFs) under inflammatory conditions and to observe its effects on osteoclast generation and on cytokine expression in RAW264.7 cells. To determine the effects of myricetin on PDLFs, we examined the expression and activity of proteolytic enzymes, including MMP-1, MMP-2, and MMP-8, which all play an important role in chronic periodontitis. We observed the effects of myricetin on intracellular signal transduction to verify the molecular mechanism involved. By measuring the formation of TRAP-positive multinucleated cells and the expression and activity of MMP-8, we were able to assess the effects of myricetin on osteoclast generation. In addition, by measuring the secretion of IL-6 and NO, we could evaluate the effects of myricetin on inflammatory mediators. We found that Myricetin had no effect on the viability of the PDLFs in the presence of inflammation, but it did decrease both the expression of MMP-1 and MMP-8 and the enzyme activity of MMP-2 and MMP-8 in these fibroblasts. Myricetin also decreased the lipopolysaccharide-stimulated phosphorylation of JNK, p38 signaling, IKKB, AKT, and p65RelA in the PDLFs. In the RAW264.7 cells, myricetin inhibited both the expression and the activity of MMP-8. Furthermore, Myricetin not only suppressed the generation of LPS-stimulated osteoclasts, but it also slightly inhibited LPS-stimulated degradation of IkB and decreased the release of LPS-induced IL-6 and NO. These findings suggest that myricetin alleviates the tissue-destructive processes that occur during periodontal inflammation.

• 동의생리병리학회지
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• 제18권3호
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• pp.830-836
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• 2004

The unique biochemical pathways in melanocytes responsible for melanogenesis provide us with a rational mechanism-based means for developing both pharmacological regulators of pigmentation and cytotoxic chemotherapeutic drugs for melanoma, Myricetin is a polyphenolic antioxidant and a component from Biotae Semen, Biotae orientalis Folium. Therefore, the present study was conducted to evaluate the effects of myricetin on the melanogenesis in human melanoma (HM₃KO) cells. The cells were treated for 5 days with myricetin at several concentrations (10 - 100 μg/ml). Treatment with myricetin dose-dependently suppressed cell growth in HM₃KO cells, But melanin formation was markedly increased by myricetin as a dose dependent manner. Myricetin did not affect to tyrosinase activity, which is a key enzyme for melanogenesis, but significantly increased the level of tyrosinase protein expression, These results suggest that myricetin stimulate melanin synthesis of human melanoma cells through the modification of tyrosinase protein expression.

• 생약학회지
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• 제35권4호통권139호
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• pp.357-363
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• 2004

Flavonoids are class of polyphenolic compounds widely distributed in the plant kingdom, which display a variety of biological activities, including antiviral, antithrombotic, antiiflammatory, antihistaminic, antioxidant and free-radical scavenging abilities. To determined flavonoid, myricetin in the presence of other antioxidants - vitamin C and vitamin E - can exert antioxidative properties not only directly by modulating the AOE system but also scavenging free radical, we investigated cell viability, antioxidant enzyme activities and ROS level in B16F10 murine melanoma cell. B16F10 cells were exposed to medium containing myricetin in the presence or absence of vitamin C or vitamin E for a period of 24 hr. Cell viability was measured by MTT assay. In co-treating myricetin with other antioxidants, CAT activities were increased, compared with control, but SOD and GPx activities were decreased, compared with each antioxidant treated groups . In the group of myricetin or myricetin present with other antioxidants, ROS levels were decreased dose-dependently. Especially, myricetin present of other antioxidants were decreased compared with myricetin.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1505-1509
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• 2008

Comparative molecular simulations were performed to establish molecular interaction and inhibitory effect of flavonoid myricetin on formation of amyloid fibris. For computational comparison, the conformational stability of myricetin with amyloid $\beta$ -peptide (A$\beta$ ) and $\beta$ -amyloid fibrils (fA$\beta$) were traced with multiple molecular dynamics simulations (MD) using the CHARMM program from Monte Carlo docked structures. Simulations showed that the inhibition by myricetin involves binding of the flavonoid to fA$\beta$ rather than A$\beta$ . Even in MD simulations over 5 ns at 300 K, myricetin/fA$\beta$ complex remained stable in compact conformation for multiple trajectories. In contrast, myricetin/A$\beta$ complex mostly turned into the dissociated conformation during the MD simulations at 300 K. These multiple MD simulations provide a theoretical basis for the higher inhibitory effect of myricetin on fibrillogenesis of fA$\beta$ relative to A$\beta$ . Significant binding between myricetin and fA$\beta$ observed from the computational simulations clearly reflects the previous experimental results in which only fA$\beta$ had bound to the myricetin molecules.

• Nutrition Research and Practice
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• 제8권5호
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• pp.544-549
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• 2014

BACKGROUND/OBJECTIVES: Obesity-associated insulin resistance is a strong risk factor for type 2 diabetes mellitus. The aim of this study was to investigate the effect of myricetin on adiposity, insulin resistance, and inflammatory markers in mice with diet-induced insulin resistance. MATERIALS/METHODS: Five-week-old male C57BL/6J mice were fed a basal diet, a high-fat, high-sucrose (HFHS) diet, or the HFHS diet containing 0.06% myricetin or 0.12% myricetin for 12 weeks after a 1-week adaptation, and body weight and food intake were monitored. After sacrifice, serum lipid profiles, glucose, insulin, adipocyte-derived hormones, and proinflammatory cytokines were measured. The homeostasis model assessment for insulin resistance (HOMA-IR) was determined. RESULTS: Myricetin given at 0.12% of the total diet significantly reduced body weight, weight gain, and epidydimal white adipose tissue weight, and improved hypertriglyceridemia and hypercholesterolemia without a significant influence on food intake in mice fed the HFHS diet. Serum glucose and insulin levels, as well as HOMA-IR values, decreased significantly by 0.12% myricetin supplementation in mice fed the HFHS diet. Myricetin given at 0.12% of the total diet significantly reduced serum levels of leptin, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) in mice fed the HFHS diet. CONCLUSIONS: These findings suggest that myricetin may have a protective effect against diet-induced obesity and insulin resistance in mice fed HFHS diet, and that alleviation of insulin resistance could partly occur by improving obesity and reducing serum proinflammatory cytokine levels.

• 생명과학회지
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• 제30권12호
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• pp.1101-1108
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• 2020

타타리메밀은 rutin, quercetin, kaempferol, myricetin 등의 플라보노이드를 함유하고 있는 곡물이다. 또한, 이러한 생리활성 물질은 곡물을 발아시키고 싹으로 재배하였을 경우 증가하는 경향을 가지게 된다. 이에 본 연구에서는 반응표면분석법을 활용하여 재배한 타타리메밀싹으로부터 생리활성 물질인 플라보노이드, rutin, quercetin, myricetin의 추출 함량이 최대로 되는 최적추출조건을 도출하였다. Box-Behnken design에 따라 함량에 영향을 끼칠 수 있는 독립변수로 추출온도(X1, 50~70℃), 추출시간(X2, 5~9 hr), 에탄올의 농도(X3, 60~90%)를 설정하였고, 종속변수로는 rutin, quercetin, myricetin 각각의 함량을 사용하였다. 각각의 함량에 대한 모델식의 R2은 0.95 이상으로 유의성을 가져 적합하다고 판단되었다. 적합성 결여 test에서의 p-value가 모두 0.1 이상을 나타내어 유의성이 기각되었고, 이는 모델이 추출조건을 잘 설명할 수 있음을 나타내었다. 최적화된 추출 방법은 추출온도 51.03℃에서 6.62시간 동안 69.16%의 에탄올을 이용하여 추출하는 것이었다. 최적 조건에서의 예측된 rutin, quercetin, myricetin의 함량은 각각 808.467, 193.296, 37.361 ㎍/ml이었다. 예상된 모델을 검증하기 위하여 최적화된 추출조건을 이용하여 10회 추출을 진행한 결과, rutin, quercetin, myricetin 함량이 각각 802.84±8.49 ㎍/ml, 193.76±2.80 ㎍/ml, 34.84±0.43 ㎍/ml으로 측정되었다 rutin과 quercetin는 예측치와 실험치가 유의적 차이를 보이지 않았지만, myricetin의 경우에는 예상된 값에 조금 미치지 못하는 값이 측정되었다.