Sun Yeou Kim

Publications of Sun Yeou Kim

• Royal Jelly Increases Collagen Production in Rat Skin After Ovariectomy.

  Authors: Hye Min Park, Min Hyoung Cho, Yunhi Cho, Sun Yeou Kim

  Journal of medicinal food. 04/2012;

  Abstract Royal jelly (RJ) is a honeybee product that contains proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. RJ has been reported to have antitumor, antibacterial, andAbstract Royal jelly (RJ) is a honeybee product that contains proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. RJ has been reported to have antitumor, antibacterial, and wound-healing activities. We previously reported that RJ enhanced the migration of human dermal fibroblasts and altered the levels of cholesterol and sphinganine in an in vitro wound-healing model in addition to regulating skin photoaging following exposure to ultraviolet-B radiation. We established an animal model of skin aging in the context of estrogen deficiency and assessed the antiaging effects of RJ on skin. To establish an in vivo model of skin aging, bilateral ovariectomies were performed in 12-week-old virgin female Sprague-Dawley rats. Induction of osteoporosis was confirmed through two-dimensional images of the trabecular bone in the left femoral necks using microcomputed tomography. The protective effects of RJ ovariectomy-induced skin aging were examined by determining the protein expression of type I procollagen and matrix metalloproteinase (MMP)-1. The collagen content and epidermal thickness of skin tissue were measured by staining techniques. There was a significant difference in weight between sham-operated and ovariectomized groups. Food efficiency ratio did not differ significantly among the groups. The level of procollagen type I protein was increased in the dorsal skin of ovariectomized rats fed with a dietary supplement containing 1% RJ extract, but the level of MMP-1 was not altered. In particular, the amount of collagen recovered was close to the normal level. RJ may protect against skin aging by enhancing collagen production in rats with ovariectomy-induced estrogen deficiency.

• 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.

• Neuroprotective iridoid glycosides from Cornus officinalis fruits against glutamate-induced toxicity in HT22 hippocampal cells.

  Authors: Eun Ju Jeong, Tae Bum Kim, Heejung Yang, So Young Kang, Sun Yeou Kim, Sang Hyun Sung, Young Choong Kim

  Phytomedicine : international journal of phytotherapy and phytopharmacology. 02/2012; 19(3-4):317-21.

  The methanolic extract of the fruits of Cornus officinalis S et Z. (Cornaceae) showed the significant neuroprotective activity against glutamate-induced toxicity in HT22 hippocampal cells. ChemicalThe methanolic extract of the fruits of Cornus officinalis S et Z. (Cornaceae) showed the significant neuroprotective activity against glutamate-induced toxicity in HT22 hippocampal cells. Chemical profile of n-BuOH fraction of the methanolic extract of C. officinalis fruits, which showed the most potent activity, was established using HPLC-diode array detector-electrospray-MS (HPLC-DAD-ESI-MS). Through bioactivity-guided isolation, five iridoid glycosides including one new compound, 7-O-butylmorroniside (1), loganin (2), morroniside (3), 7R-O-methylmorroniside (4), 7S-O-methylmorroniside (5) were isolated from the n-BuOH fraction. The protective activities of the isolated compounds, themselves, were not statistically significant. However, the hydrolyzed products of compounds 1, 4 and 5 significantly protected glutamate-injured HT22 cells up to 78±2.2%, 60±3.2% and 59±2.5% of non-treated control, respectively.

• Lonicera japonica THUNB. protects 6-hydroxydopamine-induced neurotoxicity by inhibiting activation of MAPKs, PI3K/Akt, and NF-κB in SH-SY5Y cells.

  Authors: Seung-Hwan Kwon, Sa-Ik Hong, Yang-Hee Jung, Min-Jung Kim, Sun-Yeou Kim, Hyoung-Chun Kim, Seok-Yong Lee, Choon-Gon Jang

  Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 12/2011; 50(3-4):797-807.

  In this study, we investigated the neuroprotective effects of Lonicera japonica THUNB. extract (LJ) on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y cells. We found that LJIn this study, we investigated the neuroprotective effects of Lonicera japonica THUNB. extract (LJ) on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y cells. We found that LJ significantly increased cell viability decrease, lactate dehydrogenase release (LDH), morphological changes, nuclear condensation, fragmentation, and reactive oxygen species (ROS) production induced by 6-OHDA in SH-SY5Y cells. The cytoprotection afforded by pretreatment with LJ was associated with increases of the glutathione (GSH) level, superoxide dismutase (SOD) activity, and catalase (CAT) activity in 6-OHDA-induced SH-SY5Y cells. In addition, LJ strikingly inhibited 6-OHDA-induced mitochondrial dysfunctions including reduction of mitochondria membrane potential (MMP) and activation of cleaved poly-ADP-ribose polymerase (PARP), cleaved caspase-3, cleaved caspase-9, increased Bax, as well as decreased Bcl-2 and Bcl-xL. Additionally, LJ dramatically attenuated 6-OHDA-induced phosphorylation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), and phosphoinositide 3-kinase (PI3K)/Akt. Meanwhile, LJ counteracted nuclear factor-κB (NF-κB) activation by blocking its translocation to the nucleus. These findings suggest that LJ has a potent anti-parkinsonism; this effect was mediated, at least in part, by inhibition of neurotoxicity, apoptotic cascade events, and oxidative stress via activation of MAPKs, PI3K/Akt, and NF-κB.

• 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.

• Royal jelly protects against ultraviolet B-induced photoaging in human skin fibroblasts via enhancing collagen production.

  Authors: Hye Min Park, Eunson Hwang, Kwang Gill Lee, Sang-Mi Han, Yunhi Cho, Sun Yeou Kim

  Journal of medicinal food. 09/2011; 14(9):899-906.

  Royal jelly (RJ) is a honeybee product containing proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. As its principal unsaturated fatty acid, RJ contains 10-hydroxy-2-decenoicRoyal jelly (RJ) is a honeybee product containing proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. As its principal unsaturated fatty acid, RJ contains 10-hydroxy-2-decenoic acid (10-HDA), which may have antitumor and antibacterial activity and a capacity to stimulate collagen production. RJ has attracted interest in various parts of the world for its pharmacological properties. However, the effects of RJ on ultraviolet (UV)-induced photoaging of the skin have not been reported. In this study we measured the 10-HDA content of RJ by high-performance liquid chromatography and tested the effects of RJ on UVB-induced skin photoaging in normal human dermal fibroblasts. The effects of RJ and 10-HDA on UVB-induced photoaging were tested by measuring procollagen type I, transforming growth factor (TGF)-β1, and matrix metalloproteinase (MMP)-1 after UVB irradiation. The RJ contained about 0.211% 10-HDA. The UVB-irradiated human skin fibroblasts treated with RJ and 10-HDA had increased procollagen type I and TGF-β1 productions, but the level of MMP-1 was not changed. Thus RJ may potentially protect the skin from UVB-induced photoaging by enhancing collagen production.

• Coprismycins A and B, neuroprotective phenylpyridines from the dung beetle-associated bacterium, Streptomyces sp.

  Authors: Seong-Hwan Kim, Hyeonseok Ko, Hea-Son Bang, Seon-Hui Park, Dong-Gyu Kim, Hak Cheol Kwon, Sun Yeou Kim, Jongheon Shin, Dong-Chan Oh

  Bioorganic & medicinal chemistry letters. 08/2011; 21(19):5715-8.

  Two new phenylpyridines, named coprismycins A and B (1 and 2), and previously reported dipyridines (3-6) were isolated from a culture of Streptomyces sp. associated with the dung beetle, CoprisTwo new phenylpyridines, named coprismycins A and B (1 and 2), and previously reported dipyridines (3-6) were isolated from a culture of Streptomyces sp. associated with the dung beetle, Copris tripartitus. The structures of the coprismycins (1 and 2) were elucidated by the analysis of 1D and 2D NMR spectra and mass, UV, and IR spectra. Coprismycins A-B (1 and 2) and dipyridines (5 and 6) displayed comparable neuroprotective effects against MPP(+) (1-methyl-4-phenylpyrimidium)-induced neurotoxicity in neuroblastoma SH-SY5Y cells.

• Gami-Chunghyuldan ameliorates memory impairment and neurodegeneration induced by intrahippocampal Aβ 1-42 oligomer injection.

  Authors: Jin Gyu Choi, Minho Moon, Hyo Geun Kim, Inhee Mook-Jung, Sun Yong Chung, Tong Ho Kang, Sun Yeou Kim, Eunjoo H Lee, Myung Sook Oh

  Neurobiology of learning and memory. 06/2011; 96(2):306-14.

  Soluble oligomeric forms of amyloid beta (AβO) are regarded as a main cause of synaptic and cognitive dysfunction in Alzheimer's disease (AD) and have been a primary target in the development of drugSoluble oligomeric forms of amyloid beta (AβO) are regarded as a main cause of synaptic and cognitive dysfunction in Alzheimer's disease (AD) and have been a primary target in the development of drug treatments for AD. The present study utilized a mouse model of AD induced by intrahippocampal injection of AβO (10 μM) to investigate the effects of Gami-Chunghyuldan (GCD), a standardized multi-herbal medicinal formula, on the presentation of memory deficits and neurohistological pathogenesis. GCD (10 and 50mg/kg/day, 5 days, p.o.) improved AβO-induced memory impairment as well as reduced neuronal cell death, astrogliosis, and microgliosis in the hippocampus. In addition, GCD prevented AβO-triggered synaptic disruption and cholinergic fiber loss. These results suggest that GCD may be useful in the prevention and treatment of AD.

• Neurotrophic activity of DA-9801, a mixture extract of Dioscorea japonica Thunb. and Dioscorea nipponica Makino, in vitro.

  Authors: Namho Kim, Soo-Hyun Kim, Yu-Jin Kim, Jeong-Ki Kim, Min-Kyung Nam, Hyangshuk Rhim, Sungjoo Kim Yoon, Sang-Zin Choi, Miwon Son, Sun-Yeou Kim, Hyo-Jeong Kuh

  Journal of ethnopharmacology. 05/2011; 137(1):312-9.

  Dioscorea japonica Thunb. has been traditionally used to treat polyuria and diabetes in Korea. We previously report the effects of Dioscorea japonica Thunb. extract on glucose control, NGF induction,Dioscorea japonica Thunb. has been traditionally used to treat polyuria and diabetes in Korea. We previously report the effects of Dioscorea japonica Thunb. extract on glucose control, NGF induction, and neuroprotection in a rodent diabetic model. Since the most potent fraction, DA-9801, was identified from a mixture of Dioscorea japonica Thunb. (DJ) and Dioscorea nipponica Makino (DN) following bioactivity-guided fractionation, here, we investigated the potential mechanism of the extract activity against diabetic peripheral neuropathy (DPN). A 1:3 mixture of DJ and DN was extracted with ethanol (DA-9801) and further fractionated into an ethylacetate-soluble fraction (DA-9801E). Effects of these extracts on neurite outgrowth were measured in PC-12 cells and DRG neurons. Effects on cell viability and TrkA phosphorylation were evaluated in PC-12 cells. NGF induction effect was determined in primary Schwann cells as well as IMS32 cells (immortalized Schwann cells). No cytotoxicity was observed in PC-12 cells at the concentration below 500 μg/ml of either DA-9801 or DA-9801E. DA-9801 and DA-9801E at 100 μg/ml and 10 μg/ml, respectively, showed a significant effect on neurite outgrowth in PC-12 cells and DRG neurons in the presence of or absence a low concentration of NGF (2 ng/ml). The Trk-A phosphorylation effect of DA9801 was confirmed in PC-12 cells. An NGF induction effect of these extracts was not detected in either IMS-32 cells, or primary Schwann cells. The NGF agonistic activity of DA-9801 and DA-9801E was demonstrated, which may contribute to their neuroprotective effect against DPN. Studies of the detailed mechanism of these extracts as well as identification of the active components are warranted for the development of an anti-DPN drug from DJ and DN.

• The chemical constituents of Piper kadsura and their cytotoxic and anti-neuroinflammtaory activities.

  Authors: Ki Hyun Kim, Jung Wook Choi, Sang Un Choi, Sang Keun Ha, Sun Yeou Kim, Hee-Juhn Park, Kang Ro Lee

  Journal of enzyme inhibition and medicinal chemistry. 04/2011; 26(2):254-60.

  The n-hexane and CHCl₃ soluble fractions of the MeOH extract of the aerial parts of Piper kadsura were found to potently inhibit nitric oxide (NO) production in LPS-activated BV-2 cells, a microglialThe n-hexane and CHCl₃ soluble fractions of the MeOH extract of the aerial parts of Piper kadsura were found to potently inhibit nitric oxide (NO) production in LPS-activated BV-2 cells, a microglial cell line. From the active fractions, a new stereoisomer of guaiane sesquiterpene, 1α,5β-guai-4(15)-ene-6β,10β-diol, kadsuguain A (1) and a new cyclohexadienone, kadsuketanone A (2), together with twelve known compounds (3-14) were isolated. The structures of these compounds were elucidated by extensive NMR spectral studies. The absolute configuration of 2 was determined by circular dichroism (CD) spectra. Compounds 2, 6, and 11-14 significantly inhibited both nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in the LPS-activated microglia cells. In addition, compounds 4, 6, and 11-14 exhibited cytotoxicity against the A549, SK-OV-3, SK-MEL-2, and HCT15 human tumour cells.

• Inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells by lignans isolated from Euonymus alatus leaves and twigs.

  Authors: Eun Ju Jeong, Jung Hee Cho, Sang Hyun Sung, Sun Yeou Kim, Young Choong Kim

  Bioorganic & medicinal chemistry letters. 03/2011; 21(8):2283-6.

  The 80% methanolic extract of Euonymus alatus leaves and twigs afforded three new lignans, (-)-threo-4,9,4',9'-tetrahydroxy-3,7,3',5'-tetramethoxy-8-O-8'-neolignan (1),The 80% methanolic extract of Euonymus alatus leaves and twigs afforded three new lignans, (-)-threo-4,9,4',9'-tetrahydroxy-3,7,3',5'-tetramethoxy-8-O-8'-neolignan (1), (-)-threo-4,9,4',9'-tetrahydroxy-3,5,7,3'-tetramethoxy-8-O-8'-neolignan (2), (7R,8R,7'R)-(+)-lyoniresinol (3), together with seventeen known lignans (4-20). The structures of 1-20 were elucidated by extensive 1D and 2D spectroscopic methods including (1)H NMR, (13)C NMR, (1)H-(1)H COSY, HMQC, HMBC and NOESY. All the isolated compounds except for dilignans (19 and 20) significantly inhibited nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells.

• 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.

• Cistanches Herba enhances learning and memory by inducing nerve growth factor.

  Authors: Jin Gyu Choi, Minho Moon, Hyun Uk Jeong, Min Cheol Kim, Sun Yeou Kim, Myung Sook Oh

  Behavioural brain research. 01/2011; 216(2):652-8.

  Nerve growth factor (NGF) has potent biological activities such as preventing neuronal death, promoting neurite outgrowth, supporting synapse formation, and enhancing memory function. NGF andNerve growth factor (NGF) has potent biological activities such as preventing neuronal death, promoting neurite outgrowth, supporting synapse formation, and enhancing memory function. NGF and NGF-like molecules can potentially be used to treat neurodegenerative disorders, such as dementia. This study investigated the effects of Cistanches Herba, a widely used medicinal herb, on NGF regulation and its neuronal actions, including neurite outgrowth, synapse formation, and learning and memory enhancement. Cistanches Herba extract (CHE; 250 μg/ml) increased NGF induction in C6 cells and led to neurite extension in PC12 cells. It also stimulated NGF secretion in the cortex and hippocampus of the mouse brain at 5 and 20mg/kg/day (3 days, p.o.). Furthermore, CHE increased neuronal cell differentiation, neurite length, and synapse formation in the mouse hippocampus. CHE significantly enhanced learning and memory, as demonstrated by passive avoidance test and novel object recognition test. These results suggest that CHE is useful for improving memory function via its action in upregulating NGF.

• Bioactive phenolic constituents from the seeds of Pharbitis nil.

  Authors: Ki Hyun Kim, Sang Keun Ha, Sang Un Choi, Sun Yeou Kim, Kang Ro Lee

  Chemical & pharmaceutical bulletin. 01/2011; 59(11):1425-9.

  Two new lignans, termed pharsyringaresinol (1) and pharbilignoside (2), a new phenylethanoid glycoside, termed pharbiniloside (3), and 22 known compounds, were isolated from the ethanol extract ofTwo new lignans, termed pharsyringaresinol (1) and pharbilignoside (2), a new phenylethanoid glycoside, termed pharbiniloside (3), and 22 known compounds, were isolated from the ethanol extract of the seeds of Pharbitis nil. The structures of the new compounds (1-3) were determined on the basis of spectroscopic analyses, including 2D-NMR and circular dichroism (CD) spectroscopy studies. Among the isolates, compounds 2, 11, 12, and 24 exhibited significant cytotoxicity against human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15) with IC(50) values ranging from 8.07 to 28.30 µM. In addition, compounds 11, 12 and 24 potently inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells, a microglia cells with IC(50) values ranging from 14.7 to 19.9 µM.

• The neuroprotective effects of Lonicera japonica THUNB. against hydrogen peroxide-induced apoptosis via phosphorylation of MAPKs and PI3K/Akt in SH-SY5Y cells.

  Authors: Seung-Hwan Kwon, Sa-Ik Hong, Ji-Ah Kim, Yang-Hee Jung, Sun-Yeou Kim, Hyoung-Chun Kim, Seok-Yong Lee, Choon-Gon Jang

  Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 01/2011; 49(4):1011-9.

  We investigated the neuroprotective effects of Lonicera japonica THUNB. (Caprifoliaceae) (LJ) extract against hydrogen peroxide (H(2)O(2)), a toxin created by oxidative stress and implicated inWe investigated the neuroprotective effects of Lonicera japonica THUNB. (Caprifoliaceae) (LJ) extract against hydrogen peroxide (H(2)O(2)), a toxin created by oxidative stress and implicated in neurodegenerative diseases, in human SH-SY5Y neuroblastoma cells. We examined the effects of LJ against H(2)O(2)-induced cytotoxicity, apoptosis, the production of reactive oxygen species (ROS), the proteolysis of cleaved poly-ADP-ribose polymerase (PARP), and the expression of Bcl-2, Bcl-xL, and cleaved caspase-3. Moreover, we attempted to determine whether LJ suppressed the phosphorylation of Akt, c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and extracellular signal-regulated kinase 1/2 (ERK 1/2). We found that LJ improved cell viability, inhibited cytotoxicity and apoptosis, and attenuated elevations in ROS and nuclear condensation. In addition, LJ showed radical scavenging ability in 2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) assays. Western blot data revealed that LJ inhibited H(2)O(2)-induced up- and down-regulation of cleaved PARP, cleaved caspase-3, Bcl-2, and Bcl-xL. Furthermore, LJ significantly attenuated the H(2)O(2)-induced phosphorylation of Akt, JNK, p38 MAPK, and ERK1/2. These results demonstrate that LJ possesses potent neuroprotective activity. Its potential to treat neurodegenerative diseases warrants further research.

• 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.

• Polygalae radix inhibits toxin-induced neuronal death in the Parkinson's disease models.

  Authors: Jin Gyu Choi, Hyo Geun Kim, Min Cheol Kim, Woong Mo Yang, Youngbuhm Huh, Sun Yeou Kim, Myung Sook Oh

  Journal of ethnopharmacology. 12/2010; 134(2):414-21.

  Polygalae radix, the root of Polygala tenuifolia Willd, has commonly been used for the treatment of amnesia and anxiety in traditional Korean medicine. The aim of this study was to investigate itsPolygalae radix, the root of Polygala tenuifolia Willd, has commonly been used for the treatment of amnesia and anxiety in traditional Korean medicine. The aim of this study was to investigate its neuroprotective effects and possible mechanisms of action in models of Parkinson's disease. This study utilized a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, a reactive oxygen species (ROS) assay, a nitric oxide (NO) production assay, and a caspase-3 activity test as measures of cell viability in PC12 cells damaged by 6-hydroxydopamine (6-OHDA). The protective effects of PRE against 1-methyl-4-phenylpyridium (MPP(+))-induced neurotoxicity were assessed in rat primary dopaminergic neurons and in a mouse PD model in which PRE was administered (100mg/kg/day, 3 days, p.o.) before acute 1-mehtyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity. Finally, TH immunohistochemistry tests were conducted in the substantia nigra pars compacta (SNpc) and striatum (ST). PRE significantly inhibited 6-OHDA-induced cell damage at doses of 0.05-1μg/ml with a maximal effect at 0.1μg/ml. Caspase-3 activity and the production of ROS and NO were alleviated at 0.1μg/ml. Also at this dose, PRE protected mesencephalic dopaminergic neurons from MPP(+)-induced toxicity. In an in vivo mouse model of PD, PRE protected dopaminergic neurons and fibers from MPTP-induced toxicity in the SNpc and ST. These results demonstrate that PRE has protective effects on dopaminergic neurons via its anti-oxidant and anti-apoptotic activity.