Diterpene and biflavone derivatives from Thuja koraiensis and their cytotoxicities against A549 cells

During the screening of the cytotoxicity of rare Korean endemic plants, the extract of Thuja koraiensis Nakai displayed potent cytotoxicity against the adenocarcinomic human alveolar basal epithelial A549 cell line. Through a series of separations via column chromatography, three undescribed abietanes, an undescribed labdane along with a labdane, and a biflavonoid were purified from methylene chloride (CH₂Cl₂) fraction possessing a potent cytotoxic effect. Extensive 1D and 2D NMR spectroscopic data analyses, in combination with quantum chemical calculations were conducted to establish the planar and absolute configurations of thujakoraienes A-C. The chemical structure of thujakoraiene D was elucidated by spectroscopic data analysis and competing enantioselective acylation. Thujakoraienes A and C along with 7,7″-di-O-methylamentoflavone, showed cytotoxic effects on A549 cells, with IC₅₀ values of 64.86, 47.97, and 16.14 μM, respectively. Finally, thujakoraiene C and 7,7″-di-O-methylamentoflavone were identified as potent cytotoxic compounds in A549 cells, followed by an additional cytotoxicity test in the normal human lung fibroblast MRC-5 cell line. This is the first study on the non-volatile chemicals in the extract of T. koraiensis and comparison of chemical profiles of T. orientalis and T. koraiensis.

Inhibitory Effects of Euscaphic Acid in the Atopic Dermatitis Model by Reducing Skin Inflammation and Intense Pruritus

Atopic dermatitis (AD) is a complex and multifactorial skin disease characterized by skin inflammation and intense pruritus. There are many commercially available treatments such as topical corticosteroids and immunosuppressants to treat of AD, but their effectiveness is limited, and frequent use of these treatments can cause serious side effects. Therefore, the development of new therapeutic agents is necessary for the treatment of AD. Hence, an alternative agent that was derived from natural products that are effective and safe for AD treatment was investigated using experimental models. The biological activity of euscaphic acid has anti-inflammatory, anticoagulant, and antioxidant effects. Despite the various biomedical properties of euscaphic acid, its therapeutic effects on AD have not been well studied. In this study, we investigated the effects of euscaphic acid on skin inflammation and pruritus in AD mouse model. The effects of euscaphic acid were investigated in activated human epidermal keratinocytes and leukemia T lymphoblast cell lines, and Dermatophagoides farina extract and 2,4-dinitrochlorobenzene-induced AD mouse model. Euscaphic acid ameliorated AD properties, such as the expression of inflammatory cytokines and activation of transcription factors. In addition, euscaphic acid reduced critical factors for pruritus such as immunoglobulin E hyperproduction, mast cell invasion, and interleukin-33 expression. Taken together, euscaphic acid could be a potent therapeutic agent for the treatment of AD.

The ameliorative effects of capsidiol isolated from elicited Capsicum annuum on mouse splenocyte immune responses and neuroinflammation

Capsidiol, is an anti-fungal phytoalexin produced by plants of Solanaceae. Capsidiol was examined in cultures of primary splenocytes (SPLCs) isolated from healthy C57BL/6 mice and from those with induced experimental autoimmune encephalomyelitis (EAE) as a mouse model for autoimmune neurodegenerative multiple sclerosis (MS). We also examined the impact of capsidiol in IFN-γ-stimulated mouse BV2 microglial cells. Capsidiol resulted in a significant reduction in the anti-CD3/CD28 (αCD3/CD28)-induced IFN-γ⁺ CD4⁺ (Th1) and IFN-γ⁺ CD8⁺ (Tc1) populations as well as in the production of cytokines (IFN-γ, IL-17A, IL-6, IL-2, TNF-α, and IP-10). Specifically, the CD4⁺ and CD8⁺ populations (T-bet⁺ IFN-γ^- , T-bet⁺ IFN-γ⁺ , and T-bet^- IFN-γ⁺ ) and cytokine production mediated by Th1/Tc1 polarization were diminished by 25 μM capsidiol. MOG_35-55 restimulation of SPLCs from EAE mice resulted in an increase in antigen-specific T cells, including Th1, IL-17A⁺ CD4⁺ (Th17), and IL-17A⁺ CD8⁺ (Tc17) populations. By contrast, capsidiol resulted in a decrease in the proportions of Th17 and Tc17 cells; MOG_35-55 -specific cytokine production was also diminished by capsidiol. Capsidiol treatment resulted in diminished levels of IFN-γ-induced nitric oxide and IL-6; expression of iNOS and COX-2 were suppressed by 50 μM capsidiol in IFN-γ-stimulated BV2 cells. This is the first report of capsidiol-mediated immunomodulatory and antineuroinflammatory activities that may serve to prevent neurodegeneration.

Characterization of red ginseng-drug interaction by CYP3A activity increased in high dose administration in mice

Ginseng (Panax ginseng Meyer) is a popular traditional herbal medicine used worldwide. Patients often take ginseng preparations with other medicines where the ginseng dose could exceed the recommended dose during long-term administration. However, ginseng-drug interactions at high doses of ginseng are poorly understood. This study showed the possibility of herb-drug interactions between the Korean red ginseng (KRG) extract and cytochrome P450 (CYP) substrates in higher administration in mice. The CYP activities were determined in vivo after oral administration of KRG extract doses of 0.5, 1.0, and 2.0 g/kg for 2 or 4 weeks by monitoring the concentration of five CYP substrates/metabolites in the blood. The area under the curve for OH-midazolam/midazolam catalysed by CYP3A was increased significantly by the administration of 2.0 g/kg KRG extract for 2 and 4 weeks. CYP3A-catalysed midazolam 1'-hydroxylation also increased significantly in a dose- and time-dependent manner in the S9 fraction of mouse liver which was not related to induction by transcription. Whereas CYP2D-catalysed dextromethorphan O-deethylation decreased in a dose- and time-dependent manner in vivo. In conclusion, interactions were observed between KRG extract and CYP2D and CYP3A substrates at subchronic-high doses of KRG administration in mice.

Polyozellin alleviates atopic dermatitis-like inflammatory and pruritic responses in activated keratinocytes and mast cells

Polyozellus multiplex is an edible mushroom that offers beneficial pharmacological effects against intestinal inflammation and cancer. Previous studies have demonstrated that polyozellin, a major component of P. multiplex, has therapeutic activities against inflammation, cancer, and oxidative stress-related disorders. This study aimed to determine the pharmacological effects of polyozellin on inflammatory and pruritic responses, the major symptoms of atopic dermatitis (AD), and to define its underlying mechanism of action. Our results showed that polyozellin inhibited the expression of inflammatory cytokines and chemokines through blockade of signal transducer and activator of transcription 1 and nuclear factor-κB in activated keratinocytes, the major cells involved in AD progression. Based on the histological and immunological analyses, oral treatment with polyozellin attenuated the Dermatophagoides farinae extract (DFE)/2,4-dinitrochlorobenzene (DNCB)-induced atopic inflammatory symptoms in the skin. Pruritus is an unpleasant sensation for AD patients that causes scratching behavior and ultimately exacerbates the severity of AD. To find a possible explanation for the anti-pruritic effects of polyozellin, we investigated its effects on mast cells and mast cell-derived histamines. Oral treatment with polyozellin reduced the DFE/DNCB-induced tissue infiltration of mast cells, the serum histamine levels, and the histaminergic scratching behaviors. Additionally, polyozellin decreased the immunoglobulin E-stimulated degranulation of mast cells. Taken together, the findings of this study provide us with novel insights into the potential pharmacological targets of polyozellin for treating AD by inhibiting the inflammatory and pruritic responses.

1,7-Bis(4-hydroxyphenyl)-4-hepten-3-one from Betula platyphylla induces apoptosis by suppressing autophagy flux and activating the p38 pathway in lung cancer cells

Betula platyphylla (BP) is frequently administered in the treatment of various human diseases, including cancers. This study was undertaken to investigate the pharmacological function of the active components in BP and the underlying mechanism of its chemotherapeutic effects in human lung cancer cells. We observed that BP extracts and 1,7-bis(4-hydroxyphenyl)-4-hepten-3-one (BE1), one of the components of BP, effectively decreased the cell viability of several lung cancer cell lines. BE1-treated cells exhibited apoptosis induction and cell cycle arrest at the G2/M phase. Further examination demonstrated that BE1 treatment resulted in suppression of autophagy, as evidenced by increased protein expression levels of both LC3 II and p62/SQSTM1. Interestingly, the pharmacological induction of autophagy with rapamycin remarkably reduced the BE1-induced apoptosis, indicating that apoptosis induced by BE1 was associated with autophagy inhibition. Our data also demonstrated that BE1 exposure activated the p38 pathway resulting in regulation of the pro-apoptotic activity. Taken together, we believe that BE1 is a potential anticancer agent for human lung cancer, which exerts its effect by enhancing apoptosis via regulating autophagy and the p38 pathway.

Avenanthramide C from germinated oats exhibits anti-allergic inflammatory effects in mast cells

Mast cells play a crucial role in allergic diseases via the release of inflammatory mediators, particularly histamine and pro-inflammatory cytokines. Avenanthramide (Avn) C, a polyphenol found mainly in oats, is known to exhibit various biological properties. In this study, we aimed to evaluate the effectiveness of Avn C from germinated oats against mast cell-mediated allergic inflammation. For the in vitro study, RBL-2H3, mouse bone marrow-derived mast cells and rat peritoneal mast cells were used. Avn C (1–100 nM) inhibited the immunoglobulin (Ig)E-stimulated mast cells degranulation by suppressing phosphorylation of phosphoinositide 3-kinase and phospholipase Cγ1 and decreasing intracellular calcium levels. It inhibited IgE-stimulated secretion of inflammatory cytokines via suppression of FcεRI-mediated signaling proteins Lyn, Syk, Akt, and nuclear factor-κB. To verify the effects of Avn C in vivo, ovalbumin-induced active systemic anaphylaxis (ASA) and IgE-mediated passive cutaneous anaphylaxis (PCA) models were used. Oral administration of Avn C dose-dependently attenuated the ASA reactions, as evidenced by the inhibition of hypothermia and reduction of elevated serum histamine, IgE, and interleukin-4 levels. Avn C also inhibited the PCA reactions, such as ear swelling and plasma extravasation. Our results suggested that Avn C from germinated oats might be a possible therapeutic candidate for mast cell-mediated allergic inflammation.

Ethanol extract of Glycyrrhizae Radix modulates the responses of antigen-specific splenocytes in experimental autoimmune encephalomyelitis

BACKGROUND

Multiple sclerosis (MS) is an autoimmune disorder resulting in paralysis, and the responses of reactive T cells against self-antigens are hallmarks. Glycyrrhizae Radix (GR) has been used for detoxification and reducing inflammation. However, very few reports have described the effects of GR on MS.

PURPOSE

The immunomodulatory effects of GR extract on autoimmune responses were evaluated through in vitro, ex vivo, and in vivo assays using primary mouse splenocytes (SPLC), mouse microglia BV2 cell line, and a mouse model of experimental autoimmune encephalomyelitis (EAE).

STUDY DESIGN

Ethanol extract of GR was used in vitro with primary SPLC in the condition of anti-CD3/CD28 stimulation and interferon (IFN)-γ-producing CD4+ (TH1)/CD8+ (TC1) polarization as well as IFN-γ-stimulated BV2 cells. For EAE induction, female C57BL/6 mice were immunized with 200 μg of myelin oligodendrocyte glycoprotein (MOG)35-55 without pertussis toxin. EAE SPLC (ex vivo) and EAE mice (in vivo) were treated with GR extract to evaluate the changes in antigen-specific responses. SPLC media containing antigen-specific responses were used to stimulate BV2 cells.

RESULTS

GR extract effectively modulated the responses of reactive splenic T cells through the reduction in IFN-γ+ T cell populations, the expressions of cell adhesion molecules (CAMs), and secretions of cytokines containing IFN-γ and a chemokine IFN-γ-induced protein 10 (IP-10) in vitro. In addition, GR extract significantly decreased nitric oxide production and secretion of tumor necrosis factor (TNF)-α and IP-10 in IFN-γ-stimulated BV2 cells. The antigen-specific TH1 and TC1 populations were decreased following administration of 100 mg/kg of GR extract, whereas CD8+IL-17A+ (TC17) population was increased on day 36 after EAE induction. Moreover, IFN-γ, which showed the highest secretion among examined cytokines, and IP-10 decreased on day 36. SPLC media derived from 100 mg/kg GR extract-administered EAE mice revealed the ameliorative effects on BV2 cell stimulation.

CONCLUSION

This is the first report on the immunomodulatory effects of GR extract on antigen-specific SPLC responses in EAE. These results could be helpful for the discovery of drug candidates for MS by focusing on IFN-γ-related autoimmune responses.

Simultaneous Determination of Five Cytochrome P450 Probe Substrates and Their Metabolites and Organic Anion Transporting Polypeptide Probe Substrate in Human Plasma Using Liquid Chromatography-Tandem Mass Spectrometry

A rapid and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of organic anion transporting polypeptide 1B1 (OATP1B1) and cytochrome P450 (P450) probe substrates and their phase I metabolites in human plasma was developed. The OATP1B1 (pitavastatin) and five P450 probe substrates, caffeine (CYP1A2), losartan (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), and midazolam (CYP3A) and their metabolites were extracted from human plasma (50 µL) using methanol. Analytes were separated on a C18 column followed by selected reaction monitoring detection using MS/MS. All analytes were separated simultaneously within a 9 min run time. The developed method was fully validated over the expected clinical concentration range for all analytes tested. The intra- and inter-day precisions for all analytes were lower than 11.3% and 8.82%, respectively, and accuracy was 88.5–117.3% and 96.1–109.2%, respectively. The lower limit of quantitation was 0.05 ng/mL for dextromethorphan, dextrorphan, midazolam, and 1′-hydroxymidazolam; 0.5 ng/mL for losartan, EXP-3174, omeprazole, 5′-hydroxyomeprazole, and pitavastatin; and 5 ng/mL for caffeine and paraxanthine. The method was successfully used in a pharmacokinetic study in healthy subjects after oral doses of five P450 and OATP1B1 probes. This analytical method provides a simple, sensitive, and accurate tool for the determination of OATP1B1 and five major P450 activities in vivo drug interaction studies.

Isolation, Synthesis, and Antisepsis Effects of a C-Methylcoumarinochromone Isolated from Abronia nana Cell Culture

Only a few isoflavones have been isolated from plants of the genus Abronia. The biological properties of compounds isolated from Abronia species have not been well established, and their antisepsis effects have not been reported yet. In the present study, a new C-methylcoumarinochromone, was isolated from Abronia nana suspension cultures. Its structure was deduced as 9,11-dihydroxy-10-methylcoumarinochromone (boeravinone Y, 1) by spectroscopic data analysis and verified by chemical synthesis. The potential inhibitory effects of 1 against high mobility group box 1 (HMGB1)-mediated septic responses were investigated. Results showed that 1 effectively inhibited lipopolysaccharide-induced release of HMGB1 and suppressed HMGB1-mediated septic responses, in terms of reduction of hyperpermeability, leukocyte adhesion and migration, and cell adhesion molecule expression. In addition, 1 increased the phagocytic activity of macrophages and exhibited bacterial clearance effects in the peritoneal fluid and blood of mice with cecal ligation and puncture-induced sepsis. Collectively, these results suggested that 1 might have potential therapeutic activity against various severe vascular inflammatory diseases via inhibition of the HMGB1 signaling pathway.

Laccase Fermentation of Clove Extract Increases Content of Dehydrodieugenol, Which Has Neuroprotective Activity against Glutamate Toxicity in HT22 Cells

Enzyme fermentation is a type of food processing technique generally used to improve the biological activities of food and herbal medicines. In this study, a Syzygii Flos (clove) extract was fermented using laccase derived from Trametes versicolor (LTV). The fermented clove extract showed greater neuroprotective effects against glutamate toxicity on HT22 than the non-fermented extract did. HPLC analysis revealed that the eugenol (1) and dehydrodieugenol (2) contents had decreased and increased, respectively, after fermentation. The content of 2 peaked at 1 h after fermentation to 103.50 ± 8.20 mg/g_ex (not detected at zero time), while that of 1 decreased to 79.54 ± 4.77 mg/g_ex (185.41 ± 10.16 mg/g_ex at zero time). Compound 2 demonstrated promising HT22 neuroprotective properties with inhibition of Ca²⁺ influx, the overproduction of intracellular reactive oxygen species, and lipid peroxidation. In addition, LTV showed the best fermentation efficacy compared with laccases derived from Pleurotus ostreatus and Rhus vernicifera.

β-Secretase inhibition by C-methylisoflavones from Abronia nana

The methanol extract of Abronia nana suspension cultures were subjected to column chromatography to identify potential inhibitors of β-secretase, which is a major factor in Alzheimer's disease development. Two new C-methylisoflavones boeravinone T (1) and U (4) were isolated with three knowns boeravinone B (2), J (3) and X (5). The half-maximal inhibitory concentration (IC₅₀) values of compounds 1-5 were 18.29, 8.57, 7.87, 12.02 and 5.30 μM, respectively. The most potent 5, non-competitively inhibited β-secretase [inhibition constant (K_i) = 3.79 μM]. Compounds 1-5 did not inhibit other proteases such as chymotrypsin, trypsin and elastase at concentrations up to 1 mM, indicating that they were relatively specific inhibitors of β-secretase. A free hydroxyl group at C-3 position of the C-methylisoflavone skeleton appeared to be responsible for the stronger inhibitory activity against β-secretase.

Protective Effect of Isoliquiritigenin against Ethanol-Induced Hepatic Steatosis by Regulating the SIRT1-AMPK Pathway

Ethanol-induced fat accumulation, the earliest and most common response of the liver to ethanol exposure, may be involved in the pathogenesis of liver diseases. Isoliquiritigenin (ISL), an important constituent of Glycyrrhizae Radix, is a chalcone derivative that exhibits antioxidant, anti-inflammatory, and phytoestrogenic activities. However, the effect of ISL treatment on lipid accumulation in hepatocytes and alcoholic hepatitis remains unclear. Therefore, we evaluated the effect and underlying mechanism of ISL on ethanol-induced hepatic steatosis by treating AML-12 cells with 200 mM ethanol and/or ISL (0~50 μM) for 72 hr. Lipid accumulation was assayed by oil red O staining, and the expression of sirtuin1 (SIRT1), sterol regulatory element-binding protein-1c (SREBP-1c), AMP-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor alpha (PPARα) was studied by western blotting. Our results indicated that ISL treatment upregulated SIRT1 expression and downregulated SREBP-1c expression in ethanol-treated cells. Similarly, oil red O staining revealed a decrease in ethanol-induced fat accumulation upon co-treatment of ethanol-treated cells with 10, 20, and 50 μM of ISL. These findings suggest that ISL can reduce ethanol induced-hepatic lipogenesis by activating the SIRT1-AMPK pathway and thus improve lipid metabolism in alcoholic fatty livers.

The Glycosidase Treatment of Gentianae Scabrae Radix Converts Trifloroside into Deglucosyltrifloroside with an Enhancement of Antioxidative Effects

Herbal medicines were subjected to enzyme reaction by using a commercial glycosidase AMG-300L, and were evaluated for enhancement of their antioxidative activities. The methanolic extract of Gentianae Scabrae Radix (GSR) showed the most dramatic changes after enzyme reaction, as seen in the high-performance liquid chromatography profiles and an increase in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect. Trifloroside (1, TF) was identified as being significantly decreased by enzyme reaction, whereas deglucosyltrifloroside (2, DTF) increased. The optimal reaction time to induce DTF was 24 h at 30°C. The content increased from 1.00 ± 0.29 mg/g of extract (g_ex) to 2.80 ± 0.85 mg/g_ex after 24 h of enzyme reaction. DTF showed better antioxidative effect than TF in the DPPH, Trolox equivalent antioxidant capacity, and reactive oxygen species (ROS) in HT22 cell assays. In addition, when HT22 cells were stressed by 5 mM glutamate, 50 μM of DTF significantly inhibited the glutamate-induced lactate dehydrogenase leakage, Ca²⁺ influx, lipid peroxidation, and intracellular ROS production. These data demonstrated that the enzyme-treated GSR and its increased level of antioxidant DTF could be useful as a starting point in the discovery of functional foods to prevent various oxidative stresses, especially neurodegenerative disorders.

Oleuropein isolated from Fraxinus rhynchophylla inhibits glutamate-induced neuronal cell death by attenuating mitochondrial dysfunction

Glutamate-induced neurotoxicity is related to excessive oxidative stress accumulation and results in the increase of neuronal cell death. In addition, glutamate has been reported to lead to neurodegenerative diseases, including Parkinson's and Alzheimer's diseases.It is well known that Fraxinus rhynchophylla contains a significant level of oleuropein (Ole), which exerts various pharmacological effects. However, the mechanism of neuroprotective effects of Ole is still poorly defined. In this study, we aimed to investigate whether Ole prevents glutamate-induced toxicity in HT-22 hippocampal neuronal cells. The exposure of the glutamate treatment caused neuronal cell death through an alteration of Bax/Bcl-2 expression and translocation of mitochondrial apoptosis-inducing factor (AIF) to the cytoplasm of HT-22 cells. In addition, glutamate induced an increase in dephosphorylation of dynamin-related protein 1 (Drp1), mitochondrial fragmentation, and mitochondrial dysfunction. The pretreatment of Ole decreased Bax expression, increased Bcl-2 expression, and inhibited the translocation of mitochondrial AIF to the cytoplasm. Furthermore, Ole amended a glutamate-induced mitochondrial dynamic imbalance and reduced the number of cells with fragmented mitochondria, regulating the phosphorylation of Drp1 at amino acid residue serine 637. In conclusion, our results show that Ole has a preventive effect against glutamate-induced toxicity in HT-22 hippocampal neuronal cells. Therefore, these data imply that Ole may be an efficient approach for the treatment of neurodegenerative diseases.

Anti-inflammatory effect of oleuropein on microglia through regulation of Drp1-dependent mitochondrial fission

Oleuropein is a primary phenolic compound found in olive leaf and Fraxinus rhynchophylla. Here, we investigated the impact of oleuropein on LPS-induced BV-2 microglial cells. Oleuropein suppressed the LPS-induced increase in pro-inflammatory mediators, such as nitric oxide, and pro-inflammatory cytokines, via inhibition of ERK/p38/NF-κB activation and reactive oxygen species (ROS) generation. Furthermore, it suppressed LPS-induced excessive mitochondrial fission, which regulates mitochondrial ROS generation and pro-inflammatory response by diminishing Drp1 dephosphorylation. Collectively, we demonstrated that oleuropein suppresses pro-inflammatory response of microglia by inhibiting Drp1-dependent mitochondrial fission. Our findings suggest a potential role of oleuropein in microglial inflammation-mediated neurodegenerative disorders.

Identification of acetylshikonin as the novel CYP2J2 inhibitor with anti-cancer activity in HepG2 cells

BACKGROUND

Acetylshikonin is one of the biologically active compounds derived from the root of Lithospermum erythrorhizon, a medicinal plant with anti-cancer and anti-inflammation activity. Although there have been a few previous reports demonstrating that acetylshikonin exerts anti-cancer activity in vitro and in vivo, it is still not clear what is the exact molecular target protein of acetylshikonin in cancer cells.

PURPOSE

The purpose of this study is to evaluate the inhibitory effect of acetylshikonin against CYP2J2 enzyme which is predominantly expressed in human tumor tissues and carcinoma cell lines.

STUDY DESIGN

The inhibitory effect of acetylshikonin on the activities of CYP2J2-mediated metabolism were investigated using human liver microsomes (HLMs), and its cytotoxicity against human hepatoma HepG2 cells was also evaluated.

METHOD

Astemizole, a representative CYP2J2 probe substrate, was incubated in HLMs in the presence or absence of acetylshikonin. After incubation, the samples were analyzed by liquid chromatography and triple quadrupole mass spectrometry. The anti-cancer activity of acetylshikonin was evaluated on human hepatocellular carcinoma HepG2 cells. WST-1, cell counting, and colony formation assays were further adopted for the estimation of the growth rate of HepG2 cells treated with acetylshikonin.

RESULTS

Acetylshikonin inhibited CYP2J2-mediated astemizole O-demethylation activity (K_i = 2.1µM) in a noncompetitive manner. The noncompetitive inhibitory effect of acetylshikonin on CYP2J2 enzyme was also demonstrated using this 3D structure, which showed different binding location of astemizole and acetylshikonin in CYP2J2 model. It showed cytotoxic effects against human hepatoma HepG2 cells (IC₅₀ = 2μM). In addition, acetylshikonin treatment inhibited growth of human hepatocellular carcinoma HepG2 cells leading to apoptosis accompanied with p53, bax, and caspase3 activation as well as bcl2 down-regulation.

CONCLUSION

Taken together, our present study elucidates acetylshikonin displays the inhibitory effects against CYP2J2 in HLMs and anti-cancer activity in human hepatocellular carcinoma HepG2 cells.

β-Secretase (BACE1) inhibitory and neuroprotective effects of p-terphenyls from Polyozellus multiplex

Polyozellin, thelephoric acid, and polyozellic acid might be useful in the development of lead compounds for the prevention of neurodegenerative disorders, especially Alzheimer's disease (AD).

Enhanced anti-oxidative effect of fermented Korean mistletoe is originated from an increase in the contents of caffeic acid and lyoniresinol

The crude enzyme extract derived from Aspergillus kawachii increased the anti-oxidants, caffeic acid and lyoniresinol, in Korean mistletoe.

Polyozellin, a key constituent of the edible mushroom Polyozellus multiplex, attenuates glutamate-induced mouse hippocampal neuronal HT22 cell death

Polyozellus multiplex (PM), a Korean edible mushroom, has biological activities such as chemoprevention of stomach cancer, inhibition of lipid peroxidation, and reduction of prolyl endopeptidase activity. However, there are little reports on the protective effects of PM or its constituents against glutamate-induced mouse hippocampal neuronal cell (HT22) death. In this study, polyozellin (PZ), a key constituent of PM, was applied to glutamate-treated HT22 cells to evaluate its neuroprotective mechanisms. PZ (25 μM) dramatically increased the HT22 cell viability when the cell death was induced by 5 mM glutamate for 12 h, which was mediated by inhibition of Ca(2+) influx, intracellular reactive oxygen species (ROS) production, and lipid peroxidation. PZ also regulated expression of Bid, Bcl-2, and apoptosis-inducing factor (AIF), as well as phosphorylation of mitogen-activated protein kinases (MAPKs). These data suggest that PM and its constituent PZ might be useful for prevention and treatment of neurodegenerative disorders.

Inhibitory effects of polyozellin from Polyozellus multiplex on HMGB1-mediated septic responses

AIM AND OBJECTIVE

The ubiquitous nuclear protein, high-mobility group box 1 (HMGB1), is released by activated macrophages and human umbilical vein endothelial cells (HUVECs) and functions as a late mediator of experimental sepsis. Polyozellin, which has been reported to have a variety of biological activities including antioxidant and anticancer activity, is the major active compound found in edible mushroom (Polyozellus multiplex). In this study, we investigated the antiseptic effects and underlying mechanisms of polyozellin against HMGB1-mediated septic responses in HUVECs and mice.

METHODS

The anti-inflammatory activities of polyozellin were determined by measuring permeability, human neutrophil adhesion and migration, and activation of proinflammatory proteins in HMGB1-activated HUVECs and mice.

RESULTS

According to the results, polyozellin effectively inhibited lipopolysaccharide (LPS)-induced release of HMGB1, and suppressed HMGB1-mediated septic responses, such as hyperpermeability, adhesion and migration of leukocytes, and expression of cell adhesion molecules. In addition, polyozellin suppressed the production of tumor necrosis factor-α and interleukin (IL)-6, and the activation of nuclear factor-κB and extracellular signal-regulated kinases 1/2 by HMGB1.

CONCLUSION

Collectively, these results indicate that P. multiplex containing polyozellin could be commercialized as functional food for preventing and treatment of various severe vascular inflammatory diseases via inhibition of the HMGB1 signaling pathway.

Kaempferol attenuates the glutamate-induced oxidative stress in mouse-derived hippocampal neuronal HT22 cells

It is thought that the neuronal cell loss caused by oxidative stress is the primary mechanism underlying the pathogenesis of several neurodegenerative disorders. Glutamate is an endogenous neurotransmitter, but at high concentrations it can act as a neurotoxicant by increasing the intracellular levels of reactive oxygen species (ROS). Therefore, the development of factors that can attenuate glutamate-induced oxidative stress in neuronal cells is a good strategy by which new drugs could be discovered that may treat or prevent neurodegenerative diseases. Here, the neuroprotective effects of kaempferol (KF) isolated from the stems of butterbur (Petasites japonicus) were examined in glutamate-treated hippocampal neuronal cells (HT22). The administration of KF (25 μM) resulted in a significant increase in cell viability (105.18 ± 7.48%) compared with the control (100.00 ± 3.05%), while glutamate (5 mM) reduced cell viability by 39.94 ± 1.61%. The glutamate-induced calcium (Ca(2+)) influx (1.93 ± 0.08-fold) was significantly reduced by 0.89 ± 0.02-fold following the administration of 25 μM KF. Additionally, when HT22 cells were stressed with excessive glutamate, there was a 3.70 ± 0.01-fold increase in intracellular ROS generation, even though this was effectively attenuated by KF (25 μM, 0.72 ± 0.01-fold). The protective effects of KF in HT22 cells were later confirmed using a lactate dehydrogenase (LDH) assay and a FITC-annexin V/propidium iodide double staining procedure. These findings also revealed that the neuroprotective effects of KF are a result of the regulation of the expression levels of proteins, such as Bcl-2, Bid, apoptosis-inducing factor (AIF), and mitogen-activated protein kinase (MAPK). This is the first report to investigate the neuroprotective influence of KF in glutamate-treated HT22 cells. These data demonstrate that KF may be a useful candidate for pharmacological therapies that can prevent and treat neurodegenerative diseases such as Alzheimer's disease (AD).

A Comparison of the In Vitro Inhibitory Effects of Thelephoric Acid and SKF-525A on Human Cytochrome P450 Activity

Thelephoric acid is an antioxidant produced by the hydrolysis of polyozellin, which is isolated from Polyozellus multiplex. In the present study, the inhibitory effects of polyozellin and thelephoric acid on 9 cytochrome P450 (CYP) family members (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4) were examined in pooled human liver microsomes (HLMs) using a cocktail probe assay. Polyozellin exhibited weak inhibitory effects on the activities of all 9 CYPs examined, whereas thelephoric acid exhibited dose- and time-dependent inhibition of all 9 CYP isoforms (IC50 values, 3.2-33.7 μM). Dixon plots of CYP inhibition indicated that thelephoric acid was a competitive inhibitor of CYP1A2 and CYP3A4. In contrast, thelephoric acid was a noncompetitive inhibitor of CYP2D6. Our findings indicate that thelephoric acid may be a novel, non-specific CYP inhibitor, suggesting that it could replace SKF-525A in inhibitory studies designed to investigate the effects of CYP enzymes on the metabolism of given compounds.

Protective effects of onion-derived quercetin on glutamate-mediated hippocampal neuronal cell death

Background:

Neurodegenerative diseases are characterized by progressive neuron degeneration in specific functional systems of the central or peripheral nervous system. This study investigated the protective effects of quercetin isolated from onion on neuronal cells and its protective mechanisms against glutamate-induced apoptosis in HT22 cells.

Materials and Methods:

HT22 cells were cultured to study the neuroprotective mechanism of quercetin against glutamate-mediated oxidative stress. The intracellular reactive oxygen species (ROS) level and mitochondrial membrane potential (ΔΨ_m) were measured. The protein expression of calpain, spectrin, Bcl-2, Bax, Bid, cytochrome c, and mitogen-activated protein kinases (MAPKs) was evaluated by Western blotting.

Results:

Quercetin had a protective effect by reducing both intracellular ROS overproduction and glutamate-mediated Ca²⁺ influx. These effects were due to the downregulation of several apoptosis-related biochemical markers. Calpain expression was reduced and spectrin cleavage was inhibited by quercetin in glutamate-exposed HT22 cells. Disruption of the mitochondrial membrane potential (ΔΨ_m), activation of the pro-apoptotic proteins Bid and Bax, and cytochrome c release in response to glutamate-induced oxidative stress were reduced. Quercetin also suppressed phosphorylation of MAPKs.

Conclusion:

This is the first report on the detailed mechanisms of the protective effect of quercetin on HT22 cells. Onion extract and quercetin may be useful for preventing or treating neurodegenerative disorders.

Rosmarinic acid down-regulates endothelial protein C receptor shedding in vitro and in vivo

The endothelial protein C receptor (EPCR) plays pivotal roles in coagulation and inflammation, however, its activity is markedly changed by ectodomain cleavage and release as the soluble protein (sEPCR). According to previous studies, there are approximately 100ng/ml sEPCR in human plasma and the levels increase in inflammatory diseases. EPCR can be shed from the cell surface, and this is mediated by tumor necrosis factor-α converting enzyme (TACE). We recently reported on the anti-inflammatory and barrier protective activities of rosmarinic acid (RA), an important component of the leaves of Perilla frutescens. However, little is known about the effects of RA on EPCR shedding. Here, we investigated this issue by monitoring the effects of RA on phorbol-12-myristate 13-acetate (PMA), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β, and on cecal ligation and puncture (CLP)-mediated EPCR shedding and underlying mechanisms. Data showed that treatment with RA resulted in potent inhibition of PMA, TNF-α, IL-induced EPCR shedding by suppression of TACE expression. In addition, RA reduced PMA-stimulated phosphorylation of p38, extracellular regulated kinases (ERK) 1/2, and c-Jun N-terminal kinase (JNK). These results suggest the potential for use of RA as an anti-sEPCR shedding reagent against PMA, TNF-α, IL-1β and CLP-mediated EPCR shedding.

Barrier protective effects of rosmarinic acid on HMGB1-induced inflammatory responses in vitro and in vivo

High mobility group box 1 (HMGB1) protein is a crucial cytokine that mediates response to infection, injury, and inflammation. Rosmarinic acid (RA) is an important component of the leaves of Perilla frutescens and has neuroprotective, anti-microbial, anti-oxidant, and anti-cancer effects but little is known of its effects on HMGB1-mediated inflammatory response. Here, we investigated this issue by monitoring the effects of RA on the lipopolysaccharide (LPS) or cecal ligation and puncture (CLP)-mediated release of HMGB1 and HMGB1-mediated modulation of inflammatory responses. RA potently inhibited the release of HMGB1 and down-regulated HMGB1-dependent inflammatory responses in human endothelial cells. RA also inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. Furthermore, RA reduced CLP-induced HMGB1 release and sepsis-related mortality. Given these results, RA should be viewed as a candidate therapeutic agent for the treatment of various inflammatory diseases via inhibition of the HMGB1 signaling pathway.

Identification of active compounds from Aurantii Immatri Pericarpium attenuating brain injury in a rat model of ischemia-reperfusion

Ischemic stroke is caused by brain injury due to prolonged ischemia by occlusion of cerebral arteries. In this study, we isolated active compounds from an ethanol extract of Aurantii Immatri Pericarpium (HY5356). We first showed by DNA fragmentation assay that HY5356 improved human hepatocellular carcinoma cells (HepG2) under hypoxic conditions by inhibiting apoptosis. When HY5356 was fractionated with dichloromethane (MC), ethyl acetate (EA) and n-butanol (BU), the MC fraction improved cell viability at the lowest concentration (100 μg/ml). Intraperitoneal injection of HY5356 (200 mg/kg) or the MC fraction (200 mg/kg) to rats prior to occlusion attenuated brain injury significantly in a rat model of ischemia-reperfusion. Adopting cell viability under hypoxic conditions as an activity screening system, we isolated nobiletin and tangeretin as active compounds. The results suggest that intake of Aurantii Immatri Pericarpium containing nobiletin and tangeretin as active compounds might be beneficial for preventing ischemic stroke.

Isoliquiritigenin isolated from Glycyrrhiza uralensis protects neuronal cells against glutamate-induced mitochondrial dysfunction

Glutamate-mediated excitotoxicity, which is associated with reactive oxygen species (ROS), is hypothesized to be a major contributor to pathological cell death in the mammalian central nervous system, and to be involved in many acute and chronic brain diseases. Here, we showed that isoliquiritigenin (ISL) isolated from Glycyrrhiza uralensis (Gu), one of the most frequently prescribed oriental herbal medicines, protected HT22 hippocampal neuronal cells from glutamate-induced oxidative stress. In addition, we clarified the molecular mechanisms by which it protects against glutamate-induced neuronal cell death. ISL reversed glutamate-induced ROS production and mitochondrial depolarization, as well as glutamate-induced changes in expression of the apoptotic regulators Bcl-2 and Bax. Pretreatment of HT22 cells with ISL suppresses the release of apoptosis-inducing factor from mitochondria into the cytosol. Taken together, our results suggest that ISL may protect against mitochondrial dysfunction by limiting glutamate-induced oxidative stress. In conclusion, our results demonstrated that ISL isolated from Gu has protective effects against glutamate-induced mitochondrial damage and hippocampal neuronal cell death. We expect ISL to be useful in the development of drugs to prevent or treat neurodegenerative diseases.

Conservative treatment of pediatric trigger thumb: follow-up for over 4 years

We analyzed the outcomes of our conservative treatment for pediatric trigger thumb. Since March 2004, we have used conservative treatment for all patients with pediatric trigger thumb. We prospectively analyzed 30 patients in whom 35 thumbs were affected (10 right, 15 left, 5 bilateral). The mean age at diagnosis was 28 (11-50) months. The treatment consisted of passive exercises performed by the children's mothers, 10-20 times daily. How reliably this was performed is unproven. Trigger thumb severity was graded as 0A (extension beyond 0°), 0B (extension to 0°), 1 (active extension with triggering), 2 (passive extension with triggering), and 3 (cannot extend either actively or passively i.e. locked). At diagnosis, six of the 35 thumbs (17%) were grade 1, 25 (71%) were grade 2, and four (11%) were grade 3. After a mean follow-up period of 63 (range, 49-73) months, 28 thumbs (80%) were grade 0A or 0B, 5 (14%) were grade 1 and 2 (6%) were grade 2. The bilateral cases and the patients who initially had grade 3 severity had significantly more unfavorable results than the other patients. This study suggests that conservative treatment for pediatric trigger thumb is a successful method, although cases that present with bilateral involvement or locking (grade 3) should be considered for early surgical release.

c-Ets1 inhibits the interaction of NF-κB and CREB, and downregulates IL-1β-induced MUC5AC overproduction during airway inflammation

Mucin hypersecretion is frequently observed in many inflammatory diseases of the human respiratory tract. As mucin hypersecretion refers to uncontrolled mucin expression and secretion during inflammation, studies examining the negative control mechanisms of mucin hypersecretion are vital in developing novel therapeutic medications. We hypothesized that the c-Ets1 induced by interleukin (IL)-1β would decrease MUC5AC overproduction by inhibiting the interaction of NF-κB with cAMP response element-binding protein (CREB) in vivo. Stimulation with IL-1β caused the direct binding of NF-κB and CREB to the MUC5AC promoter, thus increasing MUC5AC gene expression. However, IL-1β-induced MUC5AC messenger RNA levels were surprizingly downregulated by c-Ets1 (located -938 to -930). Interestingly, c-Ets1 also suppressed IL-1β-induced MUC5AC gene expression in vitro and in vivo by disrupting the interaction of NF-κB with CREB on the MUC5AC promoter. In addition, c-Ets1 also inhibited significant morphologic changes and inflammatory cell infiltration after IL-1β exposure in mouse lungs infected with either wild-type or shRNA-c-Ets1. Moreover, reactive oxygen species produced by NOX4 increased c-Ets1 gene expression and MUC5AC gene expression in alveolar macrophages from bronchoalveolar lavage fluid. These results suggest a molecular paradigm for the establishment of a novel mechanism underlying the negative regulation of mucin overproduction, thus enhancing our understanding of airway inflammation.

One-step production of a biologically active novel furan fatty acid from 7,10-dihydroxy-8(E)-octadecenoic acid

Furan fatty acids (F-acids) gain special attention because they are known to play important roles in biological systems including humans. Specifically, F-acids are known to have strong antioxidant activitis such as radical scavenging activity. Although widely distributed in most biological systems, F-acids are trace components and their biosynthesis is complicated and quite different by sources. On the basis of biochemical study, they are considered to be an essential nutritional factor for mammals and should be provided through the diet. Hence, several studies reported the chemical synthesis of F-acids using chemical catalysts. However, chemical synthesis required complicated multiple steps. In this study was developed a simple one-step synthesis of a novel F-acid, 7,10-epoxyoctadeca-7,9-dienoic acid (EODA), from a dihydroxyl fatty acid, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD), by heat treatment. The structure of EODA was confirmed by GC-MS, NMR, and FTIR analyses, and maximum production yield under the reaction conditions of 90 °C and 24 h reached 80%.