• Journal of Life Science
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• 제24권1호
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• pp.92-97
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• 2014

Cordycepin, an active component originally isolated from the traditional medicine Cordyceps militaris, is a derivative of the nucleoside adenosine, which has been shown to possess a number of pharmacological properties, including antioxidant and anti-inflammatory activities, immunological stimulation, and antitumor effects. This study was conducted on cultured human prostate carcinoma LNCap cells to elucidate the possible mechanisms by which cordycepin exerts its anticancer activity, which, until now, has remained poorly understood. Cordycepin treatment of LNCap cells resulted in dose-dependent inhibition of cell growth and the induction of apoptotic cell death as detected by an MTT assay, cleavage of poly ADP-ribose polymerase, and annexin V-FITC staining. Flow cytometric analysis revealed that cordycepin resulted in G2/M arrest in cell cycle progression and downregulation of cyclin B1 and cyclin A expression in a concentration-dependent manner. Moreover, the incubation of cells with cordycepin caused a striking induction in the expression of the cyclin-dependent kinase (CDK) inhibitor p21Waf1/Cip1 without affecting the expression of the tumor suppressor p53. It also resulted in a significant increase in the binding of CDK2 and CDC2 to p21. These findings suggest that cordycepin-induced G2/M arrest and apoptosis in human prostate carcinoma cells is mediated through p53-independent upregulation of the CDK inhibitor p21.

• Journal of Life Science
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• 제24권7호
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• pp.769-776
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• 2014

Anisomycin, also known as flagecidin, is an antibiotic produced by Streptomyces griseolus that inhibits protein synthesis by binding to the ribosomal 28S subunit. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a protein that induces apoptotic cell death. TRAIL primarily causes apoptosis in tumor cells by binding to death receptors. Many human cancer cell lines are refractory to TRAIL-induced cell death. In this study, we investigated whether anisomycin could enhance TRAIL-mediated apoptosis in TRAIL-resistant human hepatocarcinoma Hep3B cells. Treatment with anisomycin and TRAIL alone did not reduce cell viability in Hep3B cells. However, in the presence of TRAIL, the anisomycin concentration dependently reduced the cell viability. Our results indicate that anisomycin sensitizes Hep3B cells to TRAIL-mediated apoptosis and that this occurs, at least partly, via caspase activation. Interestingly, Bid knockdown by small interfering RNA significantly reduced the induction of apoptosis in combination with anisomycin and TRAIL, indicating that anisomycin effectively acts to lower the threshold at which TRAIL-mediated truncated Bid triggers the mitochondrial-mediated apoptosis program in Hep3B cells. Therefore, the use of TRAIL in combination with anisomycin might provide an effective therapeutic strategy for the safe treatment of some TRAIL-resistant cancer cells.

• Journal of Life Science
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• 제27권10호
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• pp.1130-1136
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• 2017

Traditionally, the larvae of Allomyrina dichotoma (AD), a species of the rhinoceros beetle, have been widely used for their antidiabetic, antihepatofibrotic, antineoplastic, and antiobesity effects. The United Nations' Food and Agriculture Organization has reported on the possibility of using edible insects in human dietary supplements in the future. However, despite the growing interest in insect-based bio-active products, the biological activities of these products have rarely been studied. Previously, we reported that AD larvae inhibit the in vitro differentiation of adipocytes via transcription factor downregulation. In this study, our objective was to evaluate the effects of a hot-water extract of AD larvae on allergy and inflammation. To investigate the inhibitory effect of the extract on allergic reactions, we measured the levels of ${\beta}-hexosaminidase$, tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), interleukin-4 (IL-4), and cyclooxygenase-2 (COX-2) after activation of RBL-2H3 cells using Compound 48/80. In addition, the inhibitory effect of the extract on inflammation was determined using Raw 264.7 cells after lipopolysaccharide (LPS) stimulation. The extract significantly inhibited the ${\beta}-hexosaminidase$, $TNF-{\alpha}$, IL-4, and COX-2 levels in RBL-2H3 cells. Furthermore, it effectively inhibited the inflammatory cytokine IL-6, nitric oxide, and inducible nitric oxide synthase expression in LPS-stimulated Raw 264.7 cells. These results suggest that AD larval extract can be potentially developed as an antiallergic and anti-inflammatory therapeutic agent.

• Journal of Life Science
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• 제27권11호
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• pp.1357-1368
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• 2017

The purpose of this study was to investigate the anti-obesity and anti-inflammation effect of the cheonggukjang (a soybean paste fermented for only a few days) in diet induced obesity mice. Weight gain was significantly decreased in the mice fed cheonggukjang compared High Fat Diets (HFD). The HFD plus cheonggukjang (CGJ) were also effective in improving the lipid metabolism. The levels of plasma triglyceride, cholesterol, ALT, AST, leptin, glucose, and insulin were significantly lower in CGJ than HFD group (p<0.05). The adiponectin level of CGJ group was significantly increased compared to the HFD group (p<0.05). In the CGJ group, the mRNA expression of adipogenic genes in the liver and adipose tissues, which are transcription factors crucial for adipogenesis, were significantly suppressed (p<0.05). The number of $CD11b^+F4/80^+$ T cells, $Gr-1^{int}CD11b^{high}$ cells, and $Gr-1^{int}CD11b^{high}$ cells were significantly higher in HFD group than CGJ group (p<0.05). The size of adipocyte was significantly reduced in CGJ group compared to HFD group. In addition, the contents of liver lipid droplets were significantly downregulated in the CGJ mice than HFD mice (p<0.05). Collectively, these data suggest the novel function of cheonggukjang in modulating adipogenesis through an immune function-alteration involving downregulation of adipogenic transcription factors and macrophage activation.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.219-228
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• 2015

Excessive microglial activation and subsequent neuroinflammation lead to synaptic loss and dysfunction as well as neuronal cell death, which are involved in the pathogenesis and progression of several neurodegenerative diseases. Thus, the regulation of microglial activation has been evaluated as effective therapeutic strategies. Although dieckol (DEK), one of the phlorotannins isolated from marine brown alga Ecklonia cava, has been previously reported to inhibit microglial activation, the molecular mechanism is still unclear. Therefore, we investigated here molecular mechanism of DEK via extracellular signal-regulated kinase (ERK), Akt and nicotinamide adenine dinuclelotide phosphate (NADPH) oxidase-mediated pathways. In addition, the neuroprotective mechanism of DEK was investigated in microglia-mediated neurotoxicity models such as neuron-microglia co-culture and microglial conditioned media system. Our results demonstrated that treatment of anti-oxidant DEK potently suppressed phosphorylation of ERK in lipopolysaccharide (LPS, $1{\mu}g/ml$)-stimulated BV-2 microglia. In addition, DEK markedly attenuated Akt phosphorylation and increased expression of $gp91^{phox}$, which is the catalytic component of NADPH oxidase complex responsible for microglial reactive oxygen species (ROS) generation. Finally, DEK significantly attenuated neuronal cell death that is induced by treatment of microglial conditioned media containing neurotoxic secretary molecules. These neuroprotective effects of DEK were also confirmed in a neuron-microglia co-culture system using enhanced green fluorescent protein (EGFP)-transfected B35 neuroblastoma cell line. Taken together, these results suggest that DEK suppresses excessive microglial activation and microglia-mediated neuronal cell death via downregulation of ERK, Akt and NADPH oxidase-mediated pathways.

• Korean Journal of Plant Resources
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• 제33권6호
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• pp.604-614
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• 2020

Chronological aging and photoaging affect appearance, causing wrinkles, pigmentation, texture changes, and loss of elasticity in the skin. Phragmites communis is a tall perennial herb used for its high nutritional value and for medicinal purposes, such as relief from fever and vomiting and facilitation of diuresis. In this study, we investigated the effects of ethanol extract of P. communis rhizome (PCE) on skin aging. The total flavonoid and total phenolic content in PCE were 2.92 ± 0.007 ㎍ of quercetin equivalents (QE) and 231.8 ± 0.001 ㎍ of gallic acid equivalents (GAE) per 100 mg of dried extract (n = 3). The half-maximal inhibitory concentration (IC50) values of PCE for 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and hydrogen peroxide scavenging activities were 0.96 and 0.97 mg/mL, respectively. PCE showed inhibitory effects on tyrosinase when L-tyrosine (IC50 = 1.25 mg/mL) and L-3,4-dihydroxyphenylalanine (IC50 = 0.92 mg/mL) were used as substrates. PCE treatment up to 200 ㎍/mL for 24 h did not cause any significant cytotoxicity in B16F10 melanocytes, human dermal fibroblasts (HDFs), and HaCaT keratinocytes. In B16F10 melanocytes, PCE (25 and 50 ㎍ /mL) inhibited melanin production and cellular tyrosinase activity after challenge with α-melanocyte-stimulating hormone (α-MSH; p < 0.05). In HDFs, PCE suppressed the mRNA expression of matrix metalloproteinase-1 (MMP-1) and reduced the activity of elastase (p < 0.05). In addition, ultraviolet B (UVB)-mediated downregulation of hyaluronic acid synthase-2 gene expression in HaCaT keratinocytes was also effectively suppressed by PCE treatment. Overall, our results showed that PCE has potential anti-skin aging activity associated with the suppression of hyperpigmentation, wrinkle formation, and reduction in dryness. PCE is a promising candidate for the development of an anti-skin aging cosmetic ingredient.

• KSBB Journal
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• 제28권1호
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• pp.1-6
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• 2013

Curcumin has diverse anticancer activities that lead to tumor growth inhibition of cancer cells and induction of apoptosis. Curcumin is involved in the regulation of multiple genes via transcription factors including NF-${\kappa}B$, STATs, AP1, and SP. Notch signaling plays critical roles in maintaining the balance between cell proliferation, differentiation and apoptosis, and thereby may contribute to the development of various cancers involving breast cancer. This study was to investigate the effects of curcumin on Notch1 gene expression and to explore the underlying mechanism. Here, we found that curcumin decreased the levels of Notch1 mRNA and protein in MDA-MB-231 human breast cancer cells, along with the downregulation of Sp family genes (Sp1, Sp2, Sp3, and Sp4). The repressive effect of curcumin on Notch1 gene transcription was confirmed by performing Notch1 promoter-driven reporter assay and three Sp-binding sites were identified on Notch1 promoter that may act as curcumin-respose elements. Moreover, treatment with mitramycin A, a specific Sp inhibitor, decreased the levels of Notch1 mRNA and protein in human breast cancer cells. Taken together, our results indicate that Notch1 gene expression is downregulated by curcumin, at least in part, through the suppression of Sp family, which may lead to apoptosis in human breast cancer cells.

• Animal cells and systems
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• 제14권4호
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• pp.275-282
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• 2010

Chunghyul-dan (CHD) is a combinatorial drug known to exert anti-inflammatory effects in endothelial cells. In this study, we employed global transcriptional profiling using cDNA microarrays to identify molecular mechanisms responsible for the anti-inflammatory activity of CHD in endothelial cells. An analysis of the microarray data revealed that transcript levels of monocyte chemotactic protein-1 (MCP-1), vascular cell-adhesion molecule-1 (VCAM-1) and activated leukocyte cell-adhesion molecule were dramatically altered in CHD-treated endothelial cells. These changes in gene expression were confirmed by RT-PCR, Western blotting and ELISA. Chronic CHD treatment also appeared to decrease MCP-1 secretion, probably as a result of decreased MCP-1 expression. In addition, we determined that chronic CHD treatment inhibited lipopolysaccharide-stimulated adhesion of THP-1 leukocytes to endothelial cells. The inhibitory effect of CHD on LPS-stimulated adhesion resulted from downregulation of VCAM-1 expression. Transmigration of THP-1 leukocytes through endothelial cells was also inhibited by chronic CHD treatment. In conclusion, CHD controls a variety of inflammatory activities by regulating MCP-1 and VCAM-1 gene expression.

• Journal of the Society of Cosmetic Scientists of Korea
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• 제39권2호
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• pp.159-166
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• 2013

In order to develop new skin whitening agents, we prepared the EtOAc layer (AJE) after enzyme treatment of 75% EtOH extract of the Alnus Japonica Steud. We measured their tyrosinase inhibitory activity in vitro and melanin synthesis inhibitory activity in B16-F1 melanoma cells. They did not show inhibitory activity against mushroom tyrosinase but showed melanin synthesis inhibitory activity in a dose-dependent manner. In a melanin synthesis inhibition assay, AJE suppressed melanin production up to 52% at a concentration of $40{\mu}g/mL$. To elucidate the mechanism of the inhibitory effects of AJE on melanogenesis, we measured expression of melanogenesis-related proteins by the western blot assay. As a result, AJE suppressed the expression of tyrosinase related protein 1 (TRP-1) and microphthalmia associated transcription factor (MITF). Moreover, AJE increased the expression of phosphorylated extracellular signal-regulated kinase (p-ERK). These results conclude that ERK activation by AJE reduces melanin synthesis via MITF downregulation and is subsequent to the inhibition of TRP-1 expression. Therefore, we suggest that AJE could be used as active ingredients for skin whitening.

• Journal of Ginseng Research
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• 제41권3호
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• pp.330-338
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• 2017

Background: Ginsenoside Rh2 (G-Rh2) is a ginseng saponin that is widely investigated because of its remarkable antitumor activity. However, the molecular mechanism by which (20S) G-Rh2 triggers its functions and how target animals avoid its cytotoxic action remains largely unknown. Methods: Phage display was used to screen the human targets of (20S) G-Rh2. Fluorescence spectroscopy and UV-visible absorption spectroscopy were used to confirm the interaction of candidate target proteins and (20S) G-Rh2. Molecular docking was utilized to calculate the estimated free energy of binding and to structurally visualize their interactions. MTT assay and immunoblotting were used to assess whether human serum albumin (HSA), bovine serum albumin (BSA), and bovine serum can reduce the cytotoxic activity of (20S) G-Rh2 in HepG2 cells. Results: In phage display, (20S) G-Rh2-beads and (20R) G-Rh2-beads were combined with numerous kinds of phages, and a total of 111 different human complementary DNAs (cDNA) were identified, including HSA which had the highest rate. The binding constant and number of binding site in the interaction between (20S)-Rh2 and HSA were $3.5{\times}10^5M^{-1}$ and 1, and those in the interaction between (20S) G-Rh2 and BSA were $1.4{\times}10^5M^{-1}$ and 1. The quenching mechanism is static quenching. HSA, BSA and bovine serum significantly reduced the proapoptotic effect of (20S) G-Rh2. Conclusion: HSA and BSA interact with (20S) G-Rh2. Serum inhibited the activity of (20S) G-Rh2 mainly due to the interaction between (20S) G-Rh2 and serum albumin (SA). This study proposes that HSA may enhance (20S) G-Rh2 water solubility, and thus might be used as nanoparticles in the (20S) G-Rh2 delivery process.