Eunjung Moon

Publications of Eunjung Moon

• Acacetin Attenuates Neuroinflammation via Regulation the Response to LPS Stimuli In Vitro and In Vivo.

  Authors: Sang Keun Ha, Eunjung Moon, Pyeongjae Lee, Jong Hoon Ryu, Myung Sook Oh, Sun Yeou Kim

  Neurochemical research. 03/2012;

  Under normal conditions in the brain, microglia play roles in homeostasis regulation and defense against injury. However, over-activated microglia secrete proinflammatory and cytotoxic factors thatUnder normal conditions in the brain, microglia play roles in homeostasis regulation and defense against injury. However, over-activated microglia secrete proinflammatory and cytotoxic factors that can induce progressive brain disorders, including Alzheimer's disease, Parkinson's disease and ischemia. Therefore, regulation of microglial activation contributes to the suppression of neuronal diseases via neuroinflammatory regulation. In this study, we investigated the effects of acacetin (5,7-dihydroxy-4'-methoxyflavone), which is derived from Robinia pseudoacacia, on neuroinflammation in lipopolysaccharide (LPS)-stimulated BV-2 cells and in animal models of neuroinflammation and ischemia. Acacetin significantly inhibited the release of nitric oxide (NO) and prostaglandin E(2) and the expression of inducible NO synthase and cyclooxygenase-2 in LPS-stimulated BV-2 cells. The compound also reduced proinflammatory cytokines, tumor necrosis factor-α and interleukin-1β, and inhibited the activation of nuclear factor-κB and p38 mitogen-activated protein kinase. In an LPS-induced neuroinflammation mouse model, acacetin significantly suppressed microglial activation. Moreover, acacetin reduced neuronal cell death in an animal model of ischemia. These results suggest that acacetin may act as a potential therapeutic agent for brain diseases involving neuroinflammation.

• 6-Shogaol, a ginger product, modulates neuroinflammation: A new approach to neuroprotection.

  Authors: Sang Keun Ha, Eunjung Moon, Mi Sun Ju, Dong Hyun Kim, Jong Hoon Ryu, Myung Sook Oh, Sun Yeou Kim

  Neuropharmacology. 03/2012;

  Inflammatory processes in the central nervous system play an important role in a number of neurodegenerative diseases mediated by microglial activation, which results in neuronal cell death.Inflammatory processes in the central nervous system play an important role in a number of neurodegenerative diseases mediated by microglial activation, which results in neuronal cell death. Microglia act in immune surveillance and host defense while resting. When activated, they can be deleterious to neurons, even resulting in neurodegeneration. Therefore, the inhibition of microglial activation is considered a useful strategy in searching for neuroprotective agents. In this study, we investigated the effects of 6-shogaol, a pungent agent from Zingiber officinale Roscoe, on microglia activation in BV-2 and primary microglial cell cultures. 6-Shogaol significantly inhibited the release of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) induced by lipopolysaccharide (LPS). The effect was better than that of 6-gingerol, wogonin, or N-monomethyl-l-arginine, agents previously reported to inhibit nitric oxide. 6-Shogaol exerted its anti-inflammatory effects by inhibiting the production of prostaglandin E(2) (PGE(2)) and proinflammatory cytokines, such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), and by downregulating cyclooxygenase-2 (COX-2), p38 mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF-κB) expression. In addition, 6-shogaol suppressed the microglial activation induced by LPS both in primary cortical neuron-glia culture and in an in vivo neuroinflammatory model. Moreover, 6-shogaol showed significant neuroprotective effects in vivo in transient global ischemia via the inhibition of microglia. These results suggest that 6-shogaol is an effective therapeutic agent for treating neurodegenerative diseases.

• Bioactive lignans from the rhizomes of Acorus gramineus.

  Authors: Ki Hyun Kim, Ho Kyung Kim, Sang Un Choi, Eunjung Moon, Sun Yeou Kim, Kang Ro Lee

  Journal of natural products. 09/2011; 74(10):2187-92.

  As a part of our ongoing search for bioactive constituents from natural Korean sources, the investigation of rhizomes of Acorus gramineus afforded five new lignans, named ligraminols A-E (1-5),As a part of our ongoing search for bioactive constituents from natural Korean sources, the investigation of rhizomes of Acorus gramineus afforded five new lignans, named ligraminols A-E (1-5), together with seven known ones (6-12). The structures of 1-5 were determined by a combination of 1D and 2D NMR, HRMS, CD, and enzymatic hydrolysis. Compounds 1-12 were tested for their antiproliferative activities toward a panel of human-derived normal and cancer cell lines. Moreover, compounds 1-12 were evaluated for their inhibitory activities on nitric oxide production in an activated murine microglial cell line.

• New triterpenoids from the tubers of Corydalis ternata: structural elucidation and bioactivity evaluation.

  Authors: Ki Hyun Kim, Il Kyun Lee, Sang Un Choi, Jei Hyun Lee, Eunjung Moon, Sun Yeou Kim, Kang Ro Lee

  Planta medica. 02/2011; 77(13):1555-8.

  Two new triterpene glycosides, coryternic acid 3-O-β-D-glucuronopyranoside (1) and coryternic acid 3-O-β-D-glucuronopyranoside-6'-O-methyl ester (2), were isolated from a MeOH extract of the tubersTwo new triterpene glycosides, coryternic acid 3-O-β-D-glucuronopyranoside (1) and coryternic acid 3-O-β-D-glucuronopyranoside-6'-O-methyl ester (2), were isolated from a MeOH extract of the tubers of Corydalis ternata. Acidic hydrolysis of 1 and 2 yielded a new triterpene as their aglycone, coryternic acid (3). The structures of these new compounds were determined through spectral analysis, including extensive 2D-NMR data. In this study we reported that triterpenoids were first isolated from the genus Corydalis. Compound 2 exhibited significant cytotoxicity against the A549, SK-OV-3, SK-MEL-2, and HCT-15 cell lines (IC50 = 15.16, 17.07, 13.32, and 11.95 µM, respectively) and significantly reduced NO production in lipopolysaccharide (LPS)-activated microglia/BV-2 cells with an IC50 value of 16.2 µM without cell toxicity.

• Furostanol saponins from the rhizomes of Dioscorea japonica and their effects on NGF induction.

  Authors: Ki Hyun Kim, Min Ah Kim, Eunjung Moon, Sun Yeou Kim, Sang Zin Choi, Mi Won Son, Kang Ro Lee

  Bioorganic & medicinal chemistry letters. 02/2011; 21(7):2075-8.

  The rhizome of Dioscorea japonica is a food and medicinal source known as 'San Yak' in Korea. Two new furostanol saponins, coreajaponins A (1) and B (2), together with 10 known compounds (3-12) wereThe rhizome of Dioscorea japonica is a food and medicinal source known as 'San Yak' in Korea. Two new furostanol saponins, coreajaponins A (1) and B (2), together with 10 known compounds (3-12) were isolated from the rhizomes of D. japonica. Their structures were determined by spectroscopic methods, including 1D and 2D NMR techniques, HRMS, and chemical methods. Nerve growth factor (NGF), a crucial factor for neuronal survival and differentiation, can potentially improve neurodegenerative diseases and diabetic polyneuropathy. We evaluated the effects of isolates (1-12) on NGF induction in a C6 rat glioma cell line. Coreajaponin B (2) upregulated NGF content without significant cell toxicity, as did 6, 8, 9, and 11.

• Biological evaluation of phenolic constituents from the trunk of Berberis koreana.

  Authors: Ki Hyun Kim, Eunjung Moon, Sang Un Choi, Sun Yeou Kim, Kang Ro Lee

  Bioorganic & medicinal chemistry letters. 02/2011; 21(8):2270-3.

  A bioassay-guided fractionation and chemical investigation of the trunk of Berberis koreana resulted in the isolation and identification of a new sesquilignan, named berbikonol (1), along withA bioassay-guided fractionation and chemical investigation of the trunk of Berberis koreana resulted in the isolation and identification of a new sesquilignan, named berbikonol (1), along with fourteen known lignan derivatives (2-15) and a new phenolic compound, named berfussinol (16), together with five known ones (17-21). The structures of these new compounds were elucidated on the basis of 1D and 2D NMR spectroscopic data analysis as well as circular dichroism (CD) spectroscopy studies. Compounds 1-5, 7-8, 11, and 14 showed significant cytotoxicity against the XF498 cell line with IC(50) values of 7.14-19.32 μM. In addition, compounds 3-8 and 15 strongly reduced nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells, a microglial cell line.

• Diosgenin from Dioscorea nipponica ameliorates diabetic neuropathy by inducing nerve growth factor.

  Authors: Tong Ho Kang, Eunjung Moon, Bin Na Hong, Sang Zin Choi, Miwon Son, Ji-Ho Park, Sun Yeou Kim

  Biological & pharmaceutical bulletin. 01/2011; 34(9):1493-8.

  Diabetic neuropathy is characterized by axonal degeneration, demyelination, and atrophy in association with failed axonal regeneration, remyelination, and synaptogenesis. Recent reports suggest thatDiabetic neuropathy is characterized by axonal degeneration, demyelination, and atrophy in association with failed axonal regeneration, remyelination, and synaptogenesis. Recent reports suggest that reduced levels of nerve growth factor (NGF) may play a significant role in the pathogenesis of diabetic polyneuropathy. In this study, we investigated the regulation of NGF by steroid diosgenin (DG) in a diabetic neuropathy rodent model. We found that DG, the primary spirostane-type steroid in several Dioscorea species, increased NGF levels in the sciatic nerve of diabetic rats. Additionally, DG increased neurite outgrowth in PC12 cells and enhanced nerve conduction velocities in the diabetic neuropathy mouse model. DG-treated diabetic mice showed reduced disarrangement of the myelin sheath and increased area of myelinated axons by electron microscope studies and exhibited improvement in the damaged axons. Our data further suggest that DG increased the nerve conduction velocity through induction of NGF. Thus, our findings indicate that DG, a major sapogenin obtained from Dioscorea nipponica, reverses functional and ultrastructural changes and induces neural regeneration in a diabetic neuropathy model.

• Chrysin suppresses LPS-stimulated proinflammatory responses by blocking NF-κB and JNK activations in microglia cells.

  Authors: Sang Keun Ha, Eunjung Moon, Sun Yeou Kim

  Neuroscience letters. 11/2010; 485(3):143-7.

  Neuroinflammation mediated by microglia has been implicated in neurodegenerative diseases. Suppression of microglial activation may therefore contribute to neuronal cell survival. Chrysin is presentNeuroinflammation mediated by microglia has been implicated in neurodegenerative diseases. Suppression of microglial activation may therefore contribute to neuronal cell survival. Chrysin is present in honey and propolis and in low concentrations in fruits, vegetables, and certain beverages. It has been reported that chrysin has potent anti-inflammation, anti-cancer, and anti-oxidation properties. In the present study, we investigated the effects of chrysin on the production of proinflammatory mediators in lipopolysaccharide (LPS)-stimulated microglia. Chrysin significantly inhibited the release of nitric oxide (NO) and proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). The expressions of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) were also significantly inhibited by chrysin. Furthermore, chrysin inhibited the activations of c-Jun N-terminal kinase (JNK) and nuclear factor-κB (NF-κB), which are signaling molecules involved in neuroinflammation. These results suggest that chrysin may act as a potential therapeutic agent for various neurodegenerative diseases involving neuroinflammation.

• Anti-neuroinflammatory activity of 1,5-benzodiazepine derivatives.

  Authors: Sang Keun Ha, Donthabhaktuni Shobha, Eunjung Moon, Murugulla A Chari, Kagga Mukkanti, Sung-Hoon Kim, Kwang-Hyun Ahn, Sun Yeou Kim

  Bioorganic & medicinal chemistry letters. 07/2010; 20(13):3969-71.

  A series of 2,3-dihydro-1,5-benzodiazepines were synthesized and evaluated for anti-inflammatory effects in microglia cells. Among the 1,5-benzodiazepines tested, compound 3e strongly inhibitedA series of 2,3-dihydro-1,5-benzodiazepines were synthesized and evaluated for anti-inflammatory effects in microglia cells. Among the 1,5-benzodiazepines tested, compound 3e strongly inhibited LPS-induced nitric oxide (NO) production, with an IC(50) value of 7.0microM in the microglia cells. Also, compound 3e significantly inhibited the enzymatic activity of inducible NO synthase (iNOS) without changes in iNOS protein expression or NO scavenging activity. This result suggests that compound 3e showed anti-neuroinflammatory effects by suppressing iNOS enzyme activity.

• Lignans from the tuber-barks of Colocasia antiquorum var. esculenta and their antimelanogenic Activity.

  Authors: Ki Hyun Kim, Eunjung Moon, Sun Yeou Kim, Kang Ro Lee

  Journal of agricultural and food chemistry. 04/2010; 58(8):4779-85.

  Colocasia antiquorum var. esculenta , a variant of C. antiquorum , commonly known as "Imperial Taro", is an edible vegetable in many tropical and subtropical regions of the world. This study with theColocasia antiquorum var. esculenta , a variant of C. antiquorum , commonly known as "Imperial Taro", is an edible vegetable in many tropical and subtropical regions of the world. This study with the aim of evaluating the potential of C. antiquorum var. esculenta as a functional food with a depigmenting effect resulted in the identification of a new sesquilignan, named colocasinol A (1), and a new acyclic phenylpropane lignanamide, named cis-grossamide K (2), together with 10 known compounds (3-12). The identification and structural elucidation of these compounds were based on 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data analysis as well as high-resolution fast atom bombardment mass spectrometry (FABMS) and electron impact mass spectrometry (EIMS). Quantitation of the melanin contents and cell viability in murine melanocyte melan-a cells was used to assess the antimelanogenic activities of the isolated compounds. Among them, cis-grossamide K (2), isoamericanol A (3), americanol A (4), 2-hydroxy-3,2'-dimethoxy-4'-(2,3-epoxy-1-hydroxypropyl)-5-(3-hydroxy-1-propenyl)biphenyl (5), and (-)-pinoresinol (6) showed inhibitory effects on melanin production. Compounds 2, 5, and 6 exerted a particularly strong antimelanogenic activity on the cells without high cell toxicity (IC(50) = 54.24, 53.49, and 56.26 microM, and LD(50) = 163.60, 110.23, and >500 microM, respectively).

• Extract of Punica granatum inhibits skin photoaging induced by UVB irradiation.

  Authors: Hye Min Park, Eunjung Moon, Ae-Jung Kim, Mi Hyun Kim, Sanghee Lee, Jung Bok Lee, Yong Kon Park, Hyuk-Sang Jung, Yoon-Bum Kim, Sun Yeou Kim

  International journal of dermatology. 03/2010; 49(3):276-82.

  Punica granatum (pomegranate) is kind of a fruit consumed fresh or in beverage. It has been widely used in traditional medicine in various parts of the world. In this study, we examined the efficacyPunica granatum (pomegranate) is kind of a fruit consumed fresh or in beverage. It has been widely used in traditional medicine in various parts of the world. In this study, we examined the efficacy of a Punica granatum (PG) extract in protecting skin against UVB-induced damage using cultured human skin fibroblasts. A Korean red PG sample was used, and its effects classified according to if the PG source originated from the rind, seed and fruit. The polyphenol content of PG, which is known to prevent other adverse cutaneous effects of UV irradiation, was measured by GC-MS. The protective effects of PG on UVB-induced skin photoaging were examined by determining the level of procollagen type I and MMP-1 after UVB irradiation. Based on the GC-MS quantitative analysis, catechin, quercetin, kaempferol, and equol were the predominant compounds detected in PG. In the changes of expression of procollagen type I and MMP-1 in UV irradiated human skin fibroblasts treated PG, especially extract prepared from rind, the synthesis of collagen was increased and the expression of MMP-1 was decreased. The major polyphenols in PG, particularly catechin, play a significant role in its photoprotective effects on UVB-induced skin damage.

• Inhibitory effects of 1,3-thiazine derivatives on melanogenesis.

  Authors: Sang Keun Ha, Mamoru Koketsu, Minjae Lee, Eunjung Moon, Sung-Hoon Kim, Tae-Jin Yoon, Sun Yeou Kim

  The Journal of pharmacy and pharmacology. 12/2009; 61(12):1657-63.

  OBJECTIVES: The aim of this study was to identify a novel skin-depigmenting agent from synthetic 1,3-thiazine derivatives. METHODS: We investigated the inhibitory effects of six kinds of 1,3-thiazineOBJECTIVES: The aim of this study was to identify a novel skin-depigmenting agent from synthetic 1,3-thiazine derivatives. METHODS: We investigated the inhibitory effects of six kinds of 1,3-thiazine derivative on melanogenesis by examining their effects on tyrosinase activity and melanin biosynthesis in melan-a cells and the zebrafish model. KEY FINDINGS: Of the six compounds, 4-hydroxy-2,6-dimethyl-5,6-dihydro-4H-1,3-thiazine (TZ-6) had the strongest anti-melanogenic effects in cultured melan-a cells (30.4% inhibition at 100 microm). In addition, TZ-6 exhibited an inhibitory effect on mushroom and cellular tyrosinase. Based on the results of Western blotting, TZ-6 reduced the expression of tyrosinase at 100 microm. Additionally, TZ-6 reduced body pigmentation and inhibited tyrosinase activity in the zebrafish model. CONCLUSIONS: The results have provided useful information for the development of a skin whitening agent.

• Neurite outgrowth induced by spicatoside A, a steroidal saponin, via the tyrosine kinase A receptor pathway.

  Authors: Jinyoung Hur, Pyeongjae Lee, Eunjung Moon, Insug Kang, Sung-Hoon Kim, Myung Sook Oh, Sun Yeou Kim

  European journal of pharmacology. 09/2009;

  Although nerve growth factor (NGF) therapy is an available option for the treatment of Alzheimer's disease, several limitations exist in its medical application. In the present study, we examined theAlthough nerve growth factor (NGF) therapy is an available option for the treatment of Alzheimer's disease, several limitations exist in its medical application. In the present study, we examined the neurotrophic effects of spicatoside A isolated from Liriope platyphylla on PC12 cells as well as the mechanisms involved in this process. Spicatoside A (10mug/mL) induced neurite outgrowth similar to NGF (50ng/mL). Furthermore, spicatoside A, a steroidal saponin, activated extracellular signal-regulated kinase 1/2 (ERK 1/2) and Phosphatidylinositol 3-kinase (PI 3-kinase/Akt) via tyrosine receptor kinase A (TrkA), which is responsible for the induction of the neuritic process. The effects of NGF and spicatoside A on neurite outgrowth disappeared in TrkA knockdown PC12 cells by siRNA. In conclusion, neuritogenic effects resulting from spicatoside A may be involved in TrkA activation.

• The multi-herbal medicine Gongjin-dan enhances memory and learning tasks via NGF regulation.

  Authors: Eunjung Moon, Youngjin Her, Jung Bok Lee, Ji-Ho Park, Eunjoo H Lee, Sung-Hoon Kim, Myung Sook Oh, Choon-Gon Jang, Sun Yeou Kim

  Neuroscience letters. 09/2009;

  Nerve growth factor (NGF) decreases degeneration of cholinergic neurons, improves memory loss, and increases long-term potentiation and learning tasks. Therefore, NGF mimetics or NGF inducers may beNerve growth factor (NGF) decreases degeneration of cholinergic neurons, improves memory loss, and increases long-term potentiation and learning tasks. Therefore, NGF mimetics or NGF inducers may be important targets for the treatment of various neurodegenerative disorders. Traditionally, Gongjin-dan (GJD) has been used clinically for the treatment of central nervous system disorders. In this study, we examined the effects of GJD on NGF mimetic activity in PC12 cells and the induction of NGF secretion in primary astrocytes. Moreover, we also measured neuron survival by MAP-2 staining in an immobilization stress rat model and induction of long-term potentiation by the MEA system in rat hippocampus slices treated with dexamethasone. The behavioral syndrome by novel object test was also performed in mice. GJD increased neurite outgrowth in PC12 cells and NGF secretion in primary astrocytes. Also, it reduced neuronal cell death and increased long-term potentiation in the rat hippocampus. Moreover, the number of entries, the time spent and the distance moved in the center area of the test region by the mice was increased by oral administration of GJD in comparison with the distance moved over the total area. These data suggest that administration of GJD may improve memory and learning tasks via NGF regulation, and that it may have a potential for multiple function neuroprotection via NGF regulation.

• Neurite outgrowth induced by spicatoside A, a steroidal saponin, via the tyrosine kinase A receptor pathway

  Authors: Jinyoung Hur, Pyeongjae Lee, Eunjung Moon, Insug Kang, Sung-Hoon Kim, Myung Sook Oh, Sun Yeou Kim

  European Journal of Pharmacology.

  Although nerve growth factor (NGF) therapy is an available option for the treatment of Alzheimer's disease, several limitations exist in its medical application. In the present study, we examined theAlthough nerve growth factor (NGF) therapy is an available option for the treatment of Alzheimer's disease, several limitations exist in its medical application. In the present study, we examined the neurotrophic effects of spicatoside A isolated from Liriope platyphylla on PC12 cells as well as the mechanisms involved in this process. Spicatoside A (10 μg/mL) induced neurite outgrowth similar to NGF (50 ng/mL). Furthermore, spicatoside A, a steroidal saponin, activated extracellular signal-regulated kinase 1/2 (ERK 1/2) and phosphatidylinositol 3-kinase (PI 3-kinase/Akt) via tyrosine receptor kinase A (TrkA), which is responsible for the induction of the neuritic process. The effects of NGF and spicatoside A on neurite outgrowth disappeared in TrkA knockdown PC12 cells by siRNA. In conclusion, neuritogenic effects resulting from spicatoside A may be involved in TrkA activation.