kyoungtae lee - Academia.edu (original) (raw)

Papers by kyoungtae lee

Biomolecules, 2019

Hibiscus syriacus L. exhibited promising potential as a new source of food and colorants containi... more Hibiscus syriacus L. exhibited promising potential as a new source of food and colorants containing various anthocyanins. However, the function of anthocyanins from H. syriacus L. has not been investigated. In the current study, we evaluated whether anthocyanins from the H. syriacus L. varieties Pulsae and Paektanshim (PS and PTS) inhibit melanin biogenesis. B16F10 cells and zebrafish larvae were exposed to PS and PTS in the presence or absence of α-melanocyte-stimulating hormone (α-MSH), and melanin contents accompanied by its regulating genes and proteins were analyzed. PS and PTS moderately downregulated mushroom tyrosinase activity in vitro, but significantly decreased extracellular and intracellular melanin production in B16F10 cells, and inhibited α-MSH-induced expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. PS and PTS also attenuated pigmentation in α-MSH-stimulated zebrafish larvae. Furthermore, PS and PTS activated the phosphorylation of ...

Journal of Korean Forest Society, 2014

Life sciences, Jan 26, 2015

The aim of this study was to prove the neuroprotective effect of 5,7-Dihydroxychromone (DHC) thro... more The aim of this study was to prove the neuroprotective effect of 5,7-Dihydroxychromone (DHC) through the Nrf2/ARE signaling pathway. To elucidate the mechanism, we investigated whether 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y cells could be attenuated by DHC via activating the Nrf2/ARE signal and whether DHC could down-regulate 6-OHDA-induced excessive ROS generation MAIN METHODS: To evaluate the neuroprotective effect of DHC against 6-OHDA-induced apoptosis, FACS analysis was performed using PI staining. The inhibitory effect of DHC against 6-OHDA-induced ROS generation was evaluated by DCFH-DA staining assay. Additionally, translocation of Nrf2 to the nucleus and increased Nrf2/ARE binding activity, which subsequently resulted in the up-regulation of the Nrf2-dependent antioxidant gene expressions including HO-1, NQO1, and GCLc, were evaluated by Western blotting and EMSA. Pre-treatment of DHC, one of the constituents of Cudrania tricuspidata, significantly prot...

It is known not only that antifungal compounds such as sparassol, methyl orsellinate (ScI) and me... more It is known not only that antifungal compounds such as sparassol, methyl orsellinate (ScI) and methyl-dihydroxy-methoxy-methylbenzoate (ScII) were produced during submerged culture from Sparassis crispa, but also that ScI and ScII were appeared higher antifungal activity than sparassol. The aim of this study, antifungal compounds of Sparassis latifolia were purified from mycelial culture media and identified by using NMR and ESI-MS. Based on HPLC analysis, methyl orsellinate and sparassol were detected at 15 min and 31 min of retention time, respectively. The compounds derived from S. latifolia were classified into four production patterns according to their strains. The strains originated from host plant Larix kaempferi and Pinus koraiensis showed different patterns of compound production, whereas the strains originated from host plant P. densiflora and Abies holophylla showed almost same patterns. There was no correlation between mycelial biomass and compound production. KFRI 645 ...

Eritadenine, a potent compound of hypocholesterolemic activity, was investigated in relation to i... more Eritadenine, a potent compound of hypocholesterolemic activity, was investigated in relation to its content in domestic cultivars and wild types of shiitake (Lentinula edodes). Eighteens strains of shiitake were tested for the quantification of eritadenine by LC-MS/MS analysis. Among the strains, wild type-40 was highest as the content was 3.912 mg/g. Also, Soohyangko was 3.352mg/g, Sanlim No. 9 3.008mg/g, Chunbaegko 2.832 mg/g, Gaeulhyang and KFRI 675 both 2.792 mg/g as high-content strains. Soohyangko and Chunbaegko are applied strains for registration in 2010. Soohyangko is high-temperature type with concentrated fruiting, and 90% of production occurs in the first year, thus, recovery of cost is very fast. Chunbaegko is mid-temperature type with concentrated flushing, and produces "hwago", the best quality, in spring. Wild type-40 is excellent in productivity and is prepared for registration. Wild type-40 could be used as parent strain to make new strain with high erita...

Cellular immunology, 2014

α-Viniferin is an oligostilbene of trimeric resveratrol and has anticancer activity; however, the... more α-Viniferin is an oligostilbene of trimeric resveratrol and has anticancer activity; however, the molecular mechanism underlying the anti-inflammatory effects of α-viniferin has not been completely elucidated thus far. Therefore, we determined the mechanism by which α-viniferin regulates lipopolysaccharide (LPS)-induced expression of proinflammatory mediators in BV2 microglial cells. Treatment with α-viniferin isolated from Clematis mandshurica decreased LPS-induced production of nitric oxide (NO) and prostaglandin E2 (PGE2). α-Viniferin also downregulated the LPS-induced expression of proinflammatory genes such as iNOS and COX-2 by suppressing the activity of nuclear factor kappa B (NF-κB) via dephosphorylation of Akt/PI3K. Treatment with a specific NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), indirectly showed that NF-κB is a crucial transcription factor for expression of these genes in the early stage of inflammation. Additionally, our results indicated that α-viniferin s...

International immunopharmacology, 2015

Microglia are main immune cells to exacerbate neural disorders in persistent overactivating. Ther... more Microglia are main immune cells to exacerbate neural disorders in persistent overactivating. Therefore, it is a good strategy to regulate microglia for the treatment of neural disorders. In the present study, we isolated and characterized a novel compound, 5-O-isoferuloyl-2-deoxy-D-ribono-γ-lacton (5-DRL) from Clematis mandshurica, and evaluated its anti-inflammatory effect in lipopolysaccharide (LPS)-treated BV2 microglial cells. 5-DRL inhibited the expression of LPS-stimulated proinflammatory mediators such as nitric oxide (NO) and prostaglandin E2 (PGE2), as well as their regulatory genes inducible NO syntheses (iNOS) and cyclooxygenase-2 (COX-2). 5-DRL also downregulated the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) through suppression of the nuclear translocation of the NF-κB subunits, p65 and p50. Consistent with the inhibition of iNOS and COX-2 via NF-κB activity with 5-DRL, an inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), also led to the suppres...

Nutrition Research, 2014

Microglia are important macrophages to defend against pathogens in the central nervous system (CN... more Microglia are important macrophages to defend against pathogens in the central nervous system (CNS); however, persistent or acute inflammation of microglia lead to CNS disorders via neuronal cell death. Therefore, we theorized that a good strategy for the treatment of CNS disorders would be to target inflammatory mediators from microglia in disease. Consequently, we investigated whether isobutyrylshikonin (IBS) attenuates the production of proinflammatory mediators, such as nitric oxide (NO) and prostaglandin E2, in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Treatment with IBS inhibited the secretion of NO and prostaglandin E2 (as well as the expression of their key regulatory genes), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2). Isobutyrylshikonin also suppressed LPS-induced DNA-binding activity of nuclear transcription factor-κB (NF-κB), by inhibiting the nuclear translocation of p50 and p65 in addition to blocking the phosphorylation and degradation of IκBα. Pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor, showed the down-regulation of LPS-induced iNOS and COX-2 messenger RNA by suppressing NF-κB activity. This indirectly suggests that IBS-mediated NF-κB inhibition is the main signaling pathway involved in the inhibition of iNOS and COX-2 expression. In addition, IBS attenuated LPS-induced phosphorylation of PI3K and Akt, which are upstream molecules of NF-κB, in LPS-stimulated BV2 microglial cells. The functional aspects of the PI3K/Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor that attenuated LPS-induced iNOS and COX-2 expression by suppressing NF-κB activity. These data suggest that an IBS-mediated anti-inflammatory effect may be involved in suppressing the PI3K/Akt-mediated NF-κB signaling pathway.

Neurochemistry International, 2014

D-glucopyranosyl-3-indolecarbonate (RG3I) is a chemical constituent isolated from the commonly us... more D-glucopyranosyl-3-indolecarbonate (RG3I) is a chemical constituent isolated from the commonly used Asian traditional medicinal plant, Clematis mandshurica; however, no studies have been reported on its anti-inflammatory properties. In the present study, we found that RG3I attenuates the lipopolysaccharide (LPS)-induced DNA-binding activity of nuclear factor-jB (NF-jB) via the dephosphorylation of PI3K/Akt in BV2 microglial cells, leading to a suppression of nitric oxide (NO) and prostaglandin E 2 (PGE 2) production, along with that of their regulatory genes, inducible NO synthase (iNOS) and cyclooxygenase-2 (Cox-2). Further, the PI3K/Akt inhibitor, LY294002 diminished the expression of LPS-stimulated iNOS and COX-2 genes by suppressing NF-jB activity. Moreover, RG3I significantly inhibited LPS-induced reactive oxygen species (ROS) generation similar to the ROS inhibitors, N-acetylcysteine (NAC) and glutathione (GSH). Notably, NAC and GSH abolished the LPS-induced expression of iNOS and Cox-2 in BV2 microglial cells by inhibiting NF-jB activity. Taken together, our data indicate that RG3I suppresses the production of proinflammatory mediators such as NO and PGE 2 as well as their regulatory genes in LPS-stimulated BV2 microglial cells by inhibiting the PI3K/Akt-and ROS-dependent NF-jB signaling pathway, suggesting that RG3I may be a good candidate to regulate LPS-induced inflammatory response.

Liver International, 2013

A key factor in the development of type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) ... more A key factor in the development of type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) is hepatic steatosis. Incubation of human hepatic cells with free fatty acids (FFAs) causes accumulation of neutral lipids in lipid droplets (LDs) and serves as a model for hepatic steatosis. Ginsenosides, active constituents of ginsengs, have demonstrated beneficial effects in various pharmacological areas, including diabetes, however their effect on lipid accumulation in hepatocytes remains unclear. Here, we examine the effect of compound K (ComK), an active metabolite of ginsenosides, on the regulation of LD formation and on the expression of proteins involved in lipid homeostasis in hepatocytes. HuH7 cells were pretreated with ComK, followed by lipid loading with FFA. LDs were visualized using Oil Red O staining and immunohistochemistry for the LD-related protein PLIN2. Triglyceride levels were determined in isolated LDs. The expression of proteins involved in lipid homeostasis was examined by Western blotting. Treatment with ComK significantly decreased LD formation in FFA-loaded HuH7 cells and increased phosphorylation levels of AMPK, and its substrate ACC. ComK also increased protein expression of peroxisome proliferator-activated receptor-α (PPAR-α) and acyl-CoA oxidase (ACOX1) together with elevated activity of a PPAR-α response element reporter construct. These effects were inhibited by the PPAR-α antagonist MK886. ComK reduced LD formation and TG accumulation in FFA-loaded hepatocytes, in part by up-regulating AMPK activity and PPAR-α related pathways. These results suggest that ComK may have efficacy for the treatment of hepatic steatosis and associated diseases.

International Immunopharmacology, 2014

Little is known about whether trans-isoferulic acid (TIA) regulates the production of lipopolysac... more Little is known about whether trans-isoferulic acid (TIA) regulates the production of lipopolysaccharide (LPS)induced proinflammatory mediators. Therefore, we examined the effect of TIA isolated from Clematis mandshurica on LPS-induced nitric oxide (NO) and prostaglandin E 2 (PGE 2) production in BV2 microglial cells. We found that TIA inhibited the production of LPS-induced NO and PGE 2 without accompanying cytotoxicity in BV2 microglial cells. TIA also downregulated the expression levels of specific regulatory genes such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) by suppressing LPS-induced NF-κB activity via dephosphorylation of PI3K/Akt. In addition, we demonstrated that a specific NF-κB inhibitor PDTC and a selective PI3K/Akt inhibitor, LY294002 effectively attenuated the expression of LPS-stimulated iNOS and COX-2 mRNA, while LY294002 suppressed LPS-induced NF-κB activity, suggesting that TIA attenuates the expression of these proinflammatory genes by suppressing PI3K/Akt-mediated NF-κB activity. Our results showed that TIA suppressed NO and PGE 2 production through the induction of nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent heme oxygenase-1 (HO-1). Taken together, our data indicate that TIA suppresses the production of proinflammatory mediators such as NO and PGE 2 , as well as their regulatory genes, in LPS-stimulated BV2 microglial cells, by inhibiting PI3K/Akt-dependent NF-κB activity and enhancing Nrf2-mediated HO-1 expression.

Food and Chemical Toxicology, 2014

In the present study, we investigated whether β-hydroxyisovalerylshikonin (β-HIVS) affects the pr... more In the present study, we investigated whether β-hydroxyisovalerylshikonin (β-HIVS) affects the production of proinflammatory mediators such as nitric oxide (NO) and prostaglandin E2 (PGE2) in BV2 microglial cells. Our data showed that β-HIVS inhibited secretion of NO and PGE2 and downregulated expression of their main regulatory genes, inducible NO synthesis (iNOS) and cyclooxygenase-2 (COX-2). β-HIVS also reduced the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) by suppressing nuclear translocation of the NF-κB subunits and inhibiting the degradation and phosphorylation of IκBα. Furthermore, an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), attenuated LPS-stimulated iNOS and COX-2 expression, suggesting that NF-κB inhibition is a main effector in the expression of iNOS and COX-2. We also found that LPS-induced NF-κB activation is regulated through inhibition of PI3K/Akt phosphorylation in response to β-HIVS. Additionally, β-HIVS caused the induction of heme oxygenase-1 (HO-1) via upregulation of nuclear factor-erythroid 2-related factor 2 (Nrf2), both of which are involved in the secretion of proinflammatory mediators such as NO and PGE2. Taken together, our data indicate that β-HIVS diminishes the proinflammatory mediators NO and PGE2 and the expression of their regulatory genes, iNOS and COX-2, in LPS-stimulated BV2 microglial cells by inhibiting PI3K/Akt-dependent NF-κB activation and inducing Nrf2-mediated HO-1 expression.

Chemistry of Natural Compounds, 2010

Fatsia japonica Decne. (Araliaceae) is used in eastern folk medicine [1]. Various class of compou... more Fatsia japonica Decne. (Araliaceae) is used in eastern folk medicine [1]. Various class of compounds such as triterpene saponins [2-5], squalene, fatty acids and their methyl esters [6], anthocynanins [7], and sterols [6] and their glycosides [8] have been isolated from this plant. Shade air-dried and powdered roots (16.3 kg) and mature fruits (425.0 g) of F. japonica were extracted with 95% ethanol. Dried EtOH extracts of roots (752.2 g) and fruits (58.9 g) were dissolved in water and fractionated with n-hexane, dichloromethane, and ethyl acetate. The dichloromethane-soluble fraction (139.0 g) of F. japonica root produced some precipitate, which was filtered to give two fractions, FRD-1 (precipitate) and FRD-2 (filtrate). FRD-1 on a silica gel column (CHCl 3-MeOH 7:1) gave compound 1 (415 mg). On the other hand, fraction FRD-2 on a Sephadex LH-20 column (MeOH) gave four fractions, FRD-2-1 to FRD-2-4. Fraction FRD-2-2 (20 g) on a silica gel column (CHCl 3-MeOH 20:1) gave 15 fractions, FRD-2-2-1 to FRD-2-2-15. Separate column chromatography of FRD-2-2-6, FRD-2-2-9, and FRD-2-2-10 on Sephadex LH-20 columns using acetone as an eluent yielded compounds 4 (90 mg), 3 (350 mg), and 7 (50 mg), respectively. The EtOAcsoluble fraction of F. japonica fruit (6 g) was chromatographed on a Sephadex LH-20 column using MeOH as eluent to give five fractions, FFE-I to FFE-V. Fraction FFE-I was further chromatographed on a silica gel column using CHCl 3-MeOH (7:1, v/v) as eluent to yield nine fractions, FFE-I to FFE-IX. Separate preparative TLC of fractions FFE-I-II and FFE-I-VIII in CHCl 3-MeOH (5:1, v/v) and fractions FFE-I-IV in a solvent system of CHCl 3-MeOH-H 2 O (15:6:0.6, v/v/v) gave compounds 1 (40 mg), 5 (20 mg), and 2 (190 mg), respectively. The shade air-dried and powdered wood (4.7 kg) of F. japonica was extracted with acetone. The dried acetone extract of wood was dissolved in water and fractionated with n-hexane, dichloromethane, and ethyl acetate. The EtOAc-soluble fraction of F. japonica wood (2.12 g) on a Sephadex column (MeOH-EtOH, 1:1, v/v) gave four fractions. Fraction 3 (114.5 mg) was further purified on a silica column using benzene-MeOH (5:1, v/v) as eluent to give compound 6 (64.2 mg).

Biochemical and Biophysical Research Communications, 2012

Endoplasmic reticulum (ER) stress has been implicated in the pathology of type 2 diabetes mellitu... more Endoplasmic reticulum (ER) stress has been implicated in the pathology of type 2 diabetes mellitus (T2DM). Although SIRT1 has a therapeutic effect on T2DM, the mechanisms by which SIRT1 ameliorates insulin resistance (IR) remain unclear. In this study, we investigated the impact of SIRT1 on palmitateinduced ER stress in HepG2 cells and its underlying signal pathway. Treatment with resveratrol, a SIRT1 activator significantly inhibited palmitate-induced ER stress, leading to the protection against palmitateinduced ER stress and insulin resistance. Resveratrol and SIRT1 overexpression induced the expression of oxygen-regulated protein (ORP) 150 in HepG2 cells. Forkhead box O1 (FOXO1) was involved in the regulation of ORP150 expression because suppression of FOXO1 inhibited the induction of ORP150 by SIRT1. Our results indicate a novel mechanism by which SIRT1 regulates ER stress by overexpression of ORP150, and suggest that SIRT1 ameliorates palmitate-induced insulin resistance in HepG2 cells via regulation of ER stress.

Archives of Pharmacal Research, 2008

The chromatographic separation of MeOH extract from the Quercus salicina Blume Stem led to the is... more The chromatographic separation of MeOH extract from the Quercus salicina Blume Stem led to the isolation of five phenolic compounds. Using spectroscopic methods, the structures of these compounds were determined as D-threo-guaiacylglycerol 8-O-beta-D-(6'-O-galloyl)glucopyranoside (1), 9-methoxy-D-threo-guaiacylglycerol 8-O-beta-D-(6'-O-galloyl)glucopyranoside (2), 6''-O-galloyl salidroside (3), methyl gallate (4), quercetin (5). We measured radical scavenging activity with the DPPH method and the anti-lipid peroxidative efficacy on human LDL with TBARS assay, with the result that all these compounds exhibited the antioxidative activity.

Archives of Pharmacal Research, 2011

Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabet... more Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabetic treatments. The aim of this study was to determine whether Rb2, a type of ginsenoside, regulates hepatic gluconeogenesis through AMP-activated protein kinase (AMPK) and the orphan nuclear receptor small heterodimer partner (SHP) in hyperlipidemic conditions used as an in vitro model of type 2 diabetes. Considering these results, we concluded that Rb2 may inhibit palmitate-induced gluconeogenesis via AMPK-induced SHP by relieving ER stress, a cause of gluconeogenesis.

Archives of Pharmacal Research, 2011

Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabet... more Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabetic treatments. The aim of this study was to determine whether Rb2, a type of ginsenoside, regulates hepatic gluconeogenesis through AMP-activated protein kinase (AMPK) and the orphan nuclear receptor small heterodimer partner (SHP) in hyperlipidemic conditions used as an in vitro model of type 2 diabetes. Considering

Biomolecules, 2019

Hibiscus syriacus L. exhibited promising potential as a new source of food and colorants containi... more Hibiscus syriacus L. exhibited promising potential as a new source of food and colorants containing various anthocyanins. However, the function of anthocyanins from H. syriacus L. has not been investigated. In the current study, we evaluated whether anthocyanins from the H. syriacus L. varieties Pulsae and Paektanshim (PS and PTS) inhibit melanin biogenesis. B16F10 cells and zebrafish larvae were exposed to PS and PTS in the presence or absence of α-melanocyte-stimulating hormone (α-MSH), and melanin contents accompanied by its regulating genes and proteins were analyzed. PS and PTS moderately downregulated mushroom tyrosinase activity in vitro, but significantly decreased extracellular and intracellular melanin production in B16F10 cells, and inhibited α-MSH-induced expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. PS and PTS also attenuated pigmentation in α-MSH-stimulated zebrafish larvae. Furthermore, PS and PTS activated the phosphorylation of ...

Journal of Korean Forest Society, 2014

Life sciences, Jan 26, 2015

The aim of this study was to prove the neuroprotective effect of 5,7-Dihydroxychromone (DHC) thro... more The aim of this study was to prove the neuroprotective effect of 5,7-Dihydroxychromone (DHC) through the Nrf2/ARE signaling pathway. To elucidate the mechanism, we investigated whether 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y cells could be attenuated by DHC via activating the Nrf2/ARE signal and whether DHC could down-regulate 6-OHDA-induced excessive ROS generation MAIN METHODS: To evaluate the neuroprotective effect of DHC against 6-OHDA-induced apoptosis, FACS analysis was performed using PI staining. The inhibitory effect of DHC against 6-OHDA-induced ROS generation was evaluated by DCFH-DA staining assay. Additionally, translocation of Nrf2 to the nucleus and increased Nrf2/ARE binding activity, which subsequently resulted in the up-regulation of the Nrf2-dependent antioxidant gene expressions including HO-1, NQO1, and GCLc, were evaluated by Western blotting and EMSA. Pre-treatment of DHC, one of the constituents of Cudrania tricuspidata, significantly prot...

It is known not only that antifungal compounds such as sparassol, methyl orsellinate (ScI) and me... more It is known not only that antifungal compounds such as sparassol, methyl orsellinate (ScI) and methyl-dihydroxy-methoxy-methylbenzoate (ScII) were produced during submerged culture from Sparassis crispa, but also that ScI and ScII were appeared higher antifungal activity than sparassol. The aim of this study, antifungal compounds of Sparassis latifolia were purified from mycelial culture media and identified by using NMR and ESI-MS. Based on HPLC analysis, methyl orsellinate and sparassol were detected at 15 min and 31 min of retention time, respectively. The compounds derived from S. latifolia were classified into four production patterns according to their strains. The strains originated from host plant Larix kaempferi and Pinus koraiensis showed different patterns of compound production, whereas the strains originated from host plant P. densiflora and Abies holophylla showed almost same patterns. There was no correlation between mycelial biomass and compound production. KFRI 645 ...

Eritadenine, a potent compound of hypocholesterolemic activity, was investigated in relation to i... more Eritadenine, a potent compound of hypocholesterolemic activity, was investigated in relation to its content in domestic cultivars and wild types of shiitake (Lentinula edodes). Eighteens strains of shiitake were tested for the quantification of eritadenine by LC-MS/MS analysis. Among the strains, wild type-40 was highest as the content was 3.912 mg/g. Also, Soohyangko was 3.352mg/g, Sanlim No. 9 3.008mg/g, Chunbaegko 2.832 mg/g, Gaeulhyang and KFRI 675 both 2.792 mg/g as high-content strains. Soohyangko and Chunbaegko are applied strains for registration in 2010. Soohyangko is high-temperature type with concentrated fruiting, and 90% of production occurs in the first year, thus, recovery of cost is very fast. Chunbaegko is mid-temperature type with concentrated flushing, and produces "hwago", the best quality, in spring. Wild type-40 is excellent in productivity and is prepared for registration. Wild type-40 could be used as parent strain to make new strain with high erita...

Cellular immunology, 2014

α-Viniferin is an oligostilbene of trimeric resveratrol and has anticancer activity; however, the... more α-Viniferin is an oligostilbene of trimeric resveratrol and has anticancer activity; however, the molecular mechanism underlying the anti-inflammatory effects of α-viniferin has not been completely elucidated thus far. Therefore, we determined the mechanism by which α-viniferin regulates lipopolysaccharide (LPS)-induced expression of proinflammatory mediators in BV2 microglial cells. Treatment with α-viniferin isolated from Clematis mandshurica decreased LPS-induced production of nitric oxide (NO) and prostaglandin E2 (PGE2). α-Viniferin also downregulated the LPS-induced expression of proinflammatory genes such as iNOS and COX-2 by suppressing the activity of nuclear factor kappa B (NF-κB) via dephosphorylation of Akt/PI3K. Treatment with a specific NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), indirectly showed that NF-κB is a crucial transcription factor for expression of these genes in the early stage of inflammation. Additionally, our results indicated that α-viniferin s...

International immunopharmacology, 2015

Microglia are main immune cells to exacerbate neural disorders in persistent overactivating. Ther... more Microglia are main immune cells to exacerbate neural disorders in persistent overactivating. Therefore, it is a good strategy to regulate microglia for the treatment of neural disorders. In the present study, we isolated and characterized a novel compound, 5-O-isoferuloyl-2-deoxy-D-ribono-γ-lacton (5-DRL) from Clematis mandshurica, and evaluated its anti-inflammatory effect in lipopolysaccharide (LPS)-treated BV2 microglial cells. 5-DRL inhibited the expression of LPS-stimulated proinflammatory mediators such as nitric oxide (NO) and prostaglandin E2 (PGE2), as well as their regulatory genes inducible NO syntheses (iNOS) and cyclooxygenase-2 (COX-2). 5-DRL also downregulated the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) through suppression of the nuclear translocation of the NF-κB subunits, p65 and p50. Consistent with the inhibition of iNOS and COX-2 via NF-κB activity with 5-DRL, an inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), also led to the suppres...

Nutrition Research, 2014

Microglia are important macrophages to defend against pathogens in the central nervous system (CN... more Microglia are important macrophages to defend against pathogens in the central nervous system (CNS); however, persistent or acute inflammation of microglia lead to CNS disorders via neuronal cell death. Therefore, we theorized that a good strategy for the treatment of CNS disorders would be to target inflammatory mediators from microglia in disease. Consequently, we investigated whether isobutyrylshikonin (IBS) attenuates the production of proinflammatory mediators, such as nitric oxide (NO) and prostaglandin E2, in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Treatment with IBS inhibited the secretion of NO and prostaglandin E2 (as well as the expression of their key regulatory genes), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2). Isobutyrylshikonin also suppressed LPS-induced DNA-binding activity of nuclear transcription factor-κB (NF-κB), by inhibiting the nuclear translocation of p50 and p65 in addition to blocking the phosphorylation and degradation of IκBα. Pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor, showed the down-regulation of LPS-induced iNOS and COX-2 messenger RNA by suppressing NF-κB activity. This indirectly suggests that IBS-mediated NF-κB inhibition is the main signaling pathway involved in the inhibition of iNOS and COX-2 expression. In addition, IBS attenuated LPS-induced phosphorylation of PI3K and Akt, which are upstream molecules of NF-κB, in LPS-stimulated BV2 microglial cells. The functional aspects of the PI3K/Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor that attenuated LPS-induced iNOS and COX-2 expression by suppressing NF-κB activity. These data suggest that an IBS-mediated anti-inflammatory effect may be involved in suppressing the PI3K/Akt-mediated NF-κB signaling pathway.

Neurochemistry International, 2014

D-glucopyranosyl-3-indolecarbonate (RG3I) is a chemical constituent isolated from the commonly us... more D-glucopyranosyl-3-indolecarbonate (RG3I) is a chemical constituent isolated from the commonly used Asian traditional medicinal plant, Clematis mandshurica; however, no studies have been reported on its anti-inflammatory properties. In the present study, we found that RG3I attenuates the lipopolysaccharide (LPS)-induced DNA-binding activity of nuclear factor-jB (NF-jB) via the dephosphorylation of PI3K/Akt in BV2 microglial cells, leading to a suppression of nitric oxide (NO) and prostaglandin E 2 (PGE 2) production, along with that of their regulatory genes, inducible NO synthase (iNOS) and cyclooxygenase-2 (Cox-2). Further, the PI3K/Akt inhibitor, LY294002 diminished the expression of LPS-stimulated iNOS and COX-2 genes by suppressing NF-jB activity. Moreover, RG3I significantly inhibited LPS-induced reactive oxygen species (ROS) generation similar to the ROS inhibitors, N-acetylcysteine (NAC) and glutathione (GSH). Notably, NAC and GSH abolished the LPS-induced expression of iNOS and Cox-2 in BV2 microglial cells by inhibiting NF-jB activity. Taken together, our data indicate that RG3I suppresses the production of proinflammatory mediators such as NO and PGE 2 as well as their regulatory genes in LPS-stimulated BV2 microglial cells by inhibiting the PI3K/Akt-and ROS-dependent NF-jB signaling pathway, suggesting that RG3I may be a good candidate to regulate LPS-induced inflammatory response.

Liver International, 2013

A key factor in the development of type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) ... more A key factor in the development of type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) is hepatic steatosis. Incubation of human hepatic cells with free fatty acids (FFAs) causes accumulation of neutral lipids in lipid droplets (LDs) and serves as a model for hepatic steatosis. Ginsenosides, active constituents of ginsengs, have demonstrated beneficial effects in various pharmacological areas, including diabetes, however their effect on lipid accumulation in hepatocytes remains unclear. Here, we examine the effect of compound K (ComK), an active metabolite of ginsenosides, on the regulation of LD formation and on the expression of proteins involved in lipid homeostasis in hepatocytes. HuH7 cells were pretreated with ComK, followed by lipid loading with FFA. LDs were visualized using Oil Red O staining and immunohistochemistry for the LD-related protein PLIN2. Triglyceride levels were determined in isolated LDs. The expression of proteins involved in lipid homeostasis was examined by Western blotting. Treatment with ComK significantly decreased LD formation in FFA-loaded HuH7 cells and increased phosphorylation levels of AMPK, and its substrate ACC. ComK also increased protein expression of peroxisome proliferator-activated receptor-α (PPAR-α) and acyl-CoA oxidase (ACOX1) together with elevated activity of a PPAR-α response element reporter construct. These effects were inhibited by the PPAR-α antagonist MK886. ComK reduced LD formation and TG accumulation in FFA-loaded hepatocytes, in part by up-regulating AMPK activity and PPAR-α related pathways. These results suggest that ComK may have efficacy for the treatment of hepatic steatosis and associated diseases.

International Immunopharmacology, 2014

Little is known about whether trans-isoferulic acid (TIA) regulates the production of lipopolysac... more Little is known about whether trans-isoferulic acid (TIA) regulates the production of lipopolysaccharide (LPS)induced proinflammatory mediators. Therefore, we examined the effect of TIA isolated from Clematis mandshurica on LPS-induced nitric oxide (NO) and prostaglandin E 2 (PGE 2) production in BV2 microglial cells. We found that TIA inhibited the production of LPS-induced NO and PGE 2 without accompanying cytotoxicity in BV2 microglial cells. TIA also downregulated the expression levels of specific regulatory genes such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) by suppressing LPS-induced NF-κB activity via dephosphorylation of PI3K/Akt. In addition, we demonstrated that a specific NF-κB inhibitor PDTC and a selective PI3K/Akt inhibitor, LY294002 effectively attenuated the expression of LPS-stimulated iNOS and COX-2 mRNA, while LY294002 suppressed LPS-induced NF-κB activity, suggesting that TIA attenuates the expression of these proinflammatory genes by suppressing PI3K/Akt-mediated NF-κB activity. Our results showed that TIA suppressed NO and PGE 2 production through the induction of nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent heme oxygenase-1 (HO-1). Taken together, our data indicate that TIA suppresses the production of proinflammatory mediators such as NO and PGE 2 , as well as their regulatory genes, in LPS-stimulated BV2 microglial cells, by inhibiting PI3K/Akt-dependent NF-κB activity and enhancing Nrf2-mediated HO-1 expression.

Food and Chemical Toxicology, 2014

In the present study, we investigated whether β-hydroxyisovalerylshikonin (β-HIVS) affects the pr... more In the present study, we investigated whether β-hydroxyisovalerylshikonin (β-HIVS) affects the production of proinflammatory mediators such as nitric oxide (NO) and prostaglandin E2 (PGE2) in BV2 microglial cells. Our data showed that β-HIVS inhibited secretion of NO and PGE2 and downregulated expression of their main regulatory genes, inducible NO synthesis (iNOS) and cyclooxygenase-2 (COX-2). β-HIVS also reduced the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) by suppressing nuclear translocation of the NF-κB subunits and inhibiting the degradation and phosphorylation of IκBα. Furthermore, an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), attenuated LPS-stimulated iNOS and COX-2 expression, suggesting that NF-κB inhibition is a main effector in the expression of iNOS and COX-2. We also found that LPS-induced NF-κB activation is regulated through inhibition of PI3K/Akt phosphorylation in response to β-HIVS. Additionally, β-HIVS caused the induction of heme oxygenase-1 (HO-1) via upregulation of nuclear factor-erythroid 2-related factor 2 (Nrf2), both of which are involved in the secretion of proinflammatory mediators such as NO and PGE2. Taken together, our data indicate that β-HIVS diminishes the proinflammatory mediators NO and PGE2 and the expression of their regulatory genes, iNOS and COX-2, in LPS-stimulated BV2 microglial cells by inhibiting PI3K/Akt-dependent NF-κB activation and inducing Nrf2-mediated HO-1 expression.

Chemistry of Natural Compounds, 2010

Fatsia japonica Decne. (Araliaceae) is used in eastern folk medicine [1]. Various class of compou... more Fatsia japonica Decne. (Araliaceae) is used in eastern folk medicine [1]. Various class of compounds such as triterpene saponins [2-5], squalene, fatty acids and their methyl esters [6], anthocynanins [7], and sterols [6] and their glycosides [8] have been isolated from this plant. Shade air-dried and powdered roots (16.3 kg) and mature fruits (425.0 g) of F. japonica were extracted with 95% ethanol. Dried EtOH extracts of roots (752.2 g) and fruits (58.9 g) were dissolved in water and fractionated with n-hexane, dichloromethane, and ethyl acetate. The dichloromethane-soluble fraction (139.0 g) of F. japonica root produced some precipitate, which was filtered to give two fractions, FRD-1 (precipitate) and FRD-2 (filtrate). FRD-1 on a silica gel column (CHCl 3-MeOH 7:1) gave compound 1 (415 mg). On the other hand, fraction FRD-2 on a Sephadex LH-20 column (MeOH) gave four fractions, FRD-2-1 to FRD-2-4. Fraction FRD-2-2 (20 g) on a silica gel column (CHCl 3-MeOH 20:1) gave 15 fractions, FRD-2-2-1 to FRD-2-2-15. Separate column chromatography of FRD-2-2-6, FRD-2-2-9, and FRD-2-2-10 on Sephadex LH-20 columns using acetone as an eluent yielded compounds 4 (90 mg), 3 (350 mg), and 7 (50 mg), respectively. The EtOAcsoluble fraction of F. japonica fruit (6 g) was chromatographed on a Sephadex LH-20 column using MeOH as eluent to give five fractions, FFE-I to FFE-V. Fraction FFE-I was further chromatographed on a silica gel column using CHCl 3-MeOH (7:1, v/v) as eluent to yield nine fractions, FFE-I to FFE-IX. Separate preparative TLC of fractions FFE-I-II and FFE-I-VIII in CHCl 3-MeOH (5:1, v/v) and fractions FFE-I-IV in a solvent system of CHCl 3-MeOH-H 2 O (15:6:0.6, v/v/v) gave compounds 1 (40 mg), 5 (20 mg), and 2 (190 mg), respectively. The shade air-dried and powdered wood (4.7 kg) of F. japonica was extracted with acetone. The dried acetone extract of wood was dissolved in water and fractionated with n-hexane, dichloromethane, and ethyl acetate. The EtOAc-soluble fraction of F. japonica wood (2.12 g) on a Sephadex column (MeOH-EtOH, 1:1, v/v) gave four fractions. Fraction 3 (114.5 mg) was further purified on a silica column using benzene-MeOH (5:1, v/v) as eluent to give compound 6 (64.2 mg).

Biochemical and Biophysical Research Communications, 2012

Endoplasmic reticulum (ER) stress has been implicated in the pathology of type 2 diabetes mellitu... more Endoplasmic reticulum (ER) stress has been implicated in the pathology of type 2 diabetes mellitus (T2DM). Although SIRT1 has a therapeutic effect on T2DM, the mechanisms by which SIRT1 ameliorates insulin resistance (IR) remain unclear. In this study, we investigated the impact of SIRT1 on palmitateinduced ER stress in HepG2 cells and its underlying signal pathway. Treatment with resveratrol, a SIRT1 activator significantly inhibited palmitate-induced ER stress, leading to the protection against palmitateinduced ER stress and insulin resistance. Resveratrol and SIRT1 overexpression induced the expression of oxygen-regulated protein (ORP) 150 in HepG2 cells. Forkhead box O1 (FOXO1) was involved in the regulation of ORP150 expression because suppression of FOXO1 inhibited the induction of ORP150 by SIRT1. Our results indicate a novel mechanism by which SIRT1 regulates ER stress by overexpression of ORP150, and suggest that SIRT1 ameliorates palmitate-induced insulin resistance in HepG2 cells via regulation of ER stress.

Archives of Pharmacal Research, 2008

The chromatographic separation of MeOH extract from the Quercus salicina Blume Stem led to the is... more The chromatographic separation of MeOH extract from the Quercus salicina Blume Stem led to the isolation of five phenolic compounds. Using spectroscopic methods, the structures of these compounds were determined as D-threo-guaiacylglycerol 8-O-beta-D-(6'-O-galloyl)glucopyranoside (1), 9-methoxy-D-threo-guaiacylglycerol 8-O-beta-D-(6'-O-galloyl)glucopyranoside (2), 6''-O-galloyl salidroside (3), methyl gallate (4), quercetin (5). We measured radical scavenging activity with the DPPH method and the anti-lipid peroxidative efficacy on human LDL with TBARS assay, with the result that all these compounds exhibited the antioxidative activity.

Archives of Pharmacal Research, 2011

Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabet... more Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabetic treatments. The aim of this study was to determine whether Rb2, a type of ginsenoside, regulates hepatic gluconeogenesis through AMP-activated protein kinase (AMPK) and the orphan nuclear receptor small heterodimer partner (SHP) in hyperlipidemic conditions used as an in vitro model of type 2 diabetes. Considering these results, we concluded that Rb2 may inhibit palmitate-induced gluconeogenesis via AMPK-induced SHP by relieving ER stress, a cause of gluconeogenesis.

Archives of Pharmacal Research, 2011

Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabet... more Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabetic treatments. The aim of this study was to determine whether Rb2, a type of ginsenoside, regulates hepatic gluconeogenesis through AMP-activated protein kinase (AMPK) and the orphan nuclear receptor small heterodimer partner (SHP) in hyperlipidemic conditions used as an in vitro model of type 2 diabetes. Considering