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Bimetallic Pt-based catalysts have been extensively investigated to enhance the performance of direct methanol fuel cells (DMFCs) because CO, a by-product, reduces the activity of the pure Pt catalysts. Herein, we synthesized Pt-Pb hexagonal nanoplates as a model catalyst for the methanol oxidation reaction (MOR) and further controlled the Pt and Pb distributions on the surface of the nanoplates through acetic acid (HAc) treatment. As a result, we obtained Pt-Pb nanoplates and HAc-treated Pt-Pb nanoplates with homogeneous and heterogeneous distributions of the Pt-Pb alloy surfaces, respectively. We showed that the MOR activity and stability of the Pt-Pb nanoplates improved compared to those of the HAc-treated Pt-Pb nanoplates, mainly due to the enhanced CO tolerance and the modified electronic structure of Pt under the influence of the oxophilic Pb.

Colletotrichum acutatum is a species complex responsible for anthracnose disease in a wide range of host plants. Strain C. acutatum KC05, which was previously isolated from an infected pepper in Gangwon Province of South Korea, was reidentified as C. scovillei using combined sequence analyses of multiple genes. As a prerequisite for understanding the pathogenic development of the pepper anthracnose pathogen, we optimized the transformation system of C. scovillei KC05. Protoplast generation from young hyphae of KC05 was optimal in an enzymatic digestion using a combined treatment of 2% lysing enzyme and 0.8% driselase in 1 M NH4Cl for 3 h incubation. Prolonged incubation for more than 3 h decreased protoplast yields. Protoplast growth of KC05 was completely inhibited for 4 days on regeneration media containing 200 µg/ml hygromycin B, indicating the viability of this antibiotic as a selection marker. To evaluate transformation efficiency, we tested polyethylene glycol-mediated protoplast transformation of KC05 using 19 different loci found throughout 10 (of 27) scaffolds, covering approximately 84.1% of the entire genome. PCR screening showed that the average transformation efficiency was about 17.1% per 100 colonies. Southern blot analyses revealed that at least one transformant per locus had single copy integration of PCR-screened positive transformants. Our results provide valuable information for a functional genomics approach to the pepper anthracnose pathogen C. scovillei.

This study was conducted to compare the volatile flavor compounds of Artemisia annua L. after extraction by simultaneous steam distillation extraction (SDE) and solid-phase micro extraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. Via SDE and SPME processes, 79 (1,254.00 mg/kg) and 39 (488.74 mg/kg) compounds were identified respectively. The compounds extracted by SDE included 27 alcohols, 13 aldehydes, 22 hydrocarbons, 3 esters, 12 ketones, 1 oxide and 1 N-containing compound, on the other hand, using the SPME method, 7 alcohols, 5 aldehydes, 1 ester, 18 hydrocarbons, 7 ketones, and 1 oxide were extracted. The major volatile flavor compounds of Artemisia annua L. isolated by the two methods were caryophyllene oxide, β-caryophyllene, camphor, β-selinene, γ-muurolene, 1,8-cineol, (E)-pinocarveol and pinocarvone. The sesquiterpene named caryophyllene oxide was the most abundant volatile flavor compound with relative contents of 234.16 mg/kg and 195.44 mg/kg obtained by the SDE and SPME methods, respectively. Among the identified volatiles, sabinene, β-pinene, α-terpinene, γ-terpinene, yomogi alcohol, myrtenol, (Z)-nerolidol, p-cymen-8-ol and eugenol were detected by the SDE method only while (E)-anethole and α-cubebene were detected by the SPME method only. This study confirmed that the composition and contents of the volatile flavor compounds vary between different extraction methods. More volatile flavor compounds were identified using the SDE method than the SPME method.

Pex7 is a shuttling receptor that imports matrix proteins with a type 2 peroxisomal targeting signal (PTS2) to peroxisomes. The Pex7-mediated PTS2 protein import contributes to crucial metabolic processes such as the fatty acid β-oxidation and glucose metabolism in a number of fungi, but cellular roles of Pex7 between the import of PTS2 target proteins and metabolic processes have not been fully understood. In this study, we investigated the functional roles of CsPex7, a homolog of the yeast Pex7, by targeted gene deletion in the pepper anthracnose fungus Colletotrichum scovillei. CsPex7 was required for carbon source utilization, scavenging of reactive oxygen species, conidial production, and disease development in C. scovillei. The expression of fluorescently tagged PTS2 signal of hexokinases and 3-ketoacyl-CoA thiolases showed that peroxisomal localization of the hexokinase CsGlk1 PTS2 is dependent on CsPex7, but those of the 3-ketoacyl-CoA thiolases are independent on CsPex7. In addition, GFP-tagged CsPex7 proteins were intensely localized to the peroxisomes on glucose-containing media, indicating a role of CsPex7 in glucose utilization. Collectively, these findings indicate that CsPex7 selectively recognizes specific PTS2 signal for import of PTS2-containing proteins to peroxisomes, thereby mediating peroxisomal targeting efficiency of PTS2-containing proteins in C. scovillei. On pepper fruits, the ΔCspex7 mutant exhibited significantly reduced virulence, in which excessive accumulation of hydrogen peroxide was observed in the pepper cells. We think the reduced virulence results from the abnormality in hydrogen peroxide metabolism of the ΔCspex7 mutant. Our findings provide insight into the cellular roles of CsPex7 in PTS2 protein import system.

Ginseng root rot caused by Cylindrocarpon destructans is the most destructive disease of ginseng. Six different fungicides (thiophanate-methyl, benomyl, prochloraz, mancozeb, azoxystrobin, and iprodione) were selected to evaluate the inhibitory effect on the mycelial growth and conidial germination of C. destructans isolates. Benomyl and prochloraz were found to be the most effective fungicides in inhibiting mycelial growth of all tested isolates, showing 64.7% to 100% inhibition at a concentration of 10 µg/mL, whereas thiophanate-methyl was the least effective fungicide, showing less than 50% inhibition even at a higher concentration of 100 µg/mL. The tested fungicides exhibited less than 20% inhibition of conidium germination at concentrations of 0.01, 0.1, and 1 µg/mL. However, the inhibition effect of mancozeb on condium germination of C. destructans was significantly increased to 92% to 99% at a higher concentration of 100 µg/mL, while the others still showed no higher than 30% inhibition.

Recently, air pollution is increasing sharply in Korea, caused by fine particulate matter. Nitrogen oxides (NOx) are particulate matter precursors that significantly contribute to air pollution. They are transmitted into the atmosphere by a large amount, especially in high-volume traffic areas. This pollutant is particularly harmful. Therefore, there are increasing efforts focused on NOx removal from the air. As the photocatalytic reaction of titanium dioxide (TiO2) is the mechanism that eliminates NOx, the ultraviolet (UV) rays in sunlight and TiO2 in existing concrete structure need to be contacted for reaction process. Generally, TiO2 concrete is produced by mixing the concrete binder with TiO2. However, a significant amount of TiO2 in the concrete cannot be exposed to air pollutants or UV. Additionally, this technique may not be applicable to existing structures. Therefore, an alternative method that utilizes surface penetration agents is used to add TiO2 to the concrete surface of the structures. This proposed method may not only be economical but also applicable to various types of structures. The applicability of the TiO2 penetration application method to existing concrete road structures for reducing NOx is the purpose of this study. The penetration depth of TiO2 particles was measured using scanning electron microscopy (SEM) combined with energy dispersive analysis of X-rays (EDAX). Additionally, the NOx removal efficiency was evaluated using the NOx analyzing system. The results of this study showed that the TiO2 penetration method was advantageous in removing NOx effectively and securing economic feasibility.

Botrytis cinerea is a necrotrophic pathogen causing a major problem in the export and post-harvest of strawberries. Inappropriate use of fungicides leads to resistance among fungal pathogens. Therefore, it is necessary to evaluate the sensitivity of B. cinerea to various classes of fungicide and to determine the effectiveness of different concentrations of commonly used fungicides. We thus evaluated the effectiveness of six classes of fungicide in inhibiting the growth and development of this pathogen, namely, fludioxonil, iprodione, pyrimethanil, tebuconazole, fenpyrazamine, and boscalid. Fludioxonil was the most effective (EC50 < 0.1 μg/ml), and pyrimethanil was the least effective (EC50 = 50 μg/ml), at inhibiting the mycelial growth of B. cinerea. Fenpyrazamine and pyrimethanil showed relatively low effectiveness in inhibiting the germination and conidial production of B. cinerea. Our results are useful for the management of B. cinerea and as a basis for monitoring the sensitivity of B. cinerea strains to fungicides.

Dojuksan is a traditional herbal medicine used in Korea and China to treat urinary diseases. In the present study, we aimed to examine the anti-inflammatory effects of an ethanol solvent extract of Dojuksan and a fraction (by bioassay-guided fractionation) derived from this extract, and to elucidate the specific mechanisms involved. The Dojuksan 30% ethanol extract (DEE) had a more significant and potent anti-inflammatory effect than the Dojuksan water extract (DWE). DEE markedly inhibited the production of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), as well as nuclear factor-κB (NF-κB) binding activity. We found that the anti-inflammatory effects of DEE were mediated by the induction of nuclear factor E2-related factor 2 (Nrf2)-dependent heme oxygenase-1 (HO-1). To further explore the anti-inflammatory effects of DEE, we generated 6 different fractions of DEE. Of these, DEE-5 decreased the production of NO more significantly than the other fractions. DEE-5 also significantly decreased the expression of iNOS and COX-2, and the production of NO, PGE2, TNF-α and IL-1β. In addition, DEE-5 also significantly increased HO-1 levels; HO-1 significanlty contributed to the inhibitory effects of DEE-5 on the production of pro-inflammatory mediators. In this study, we determined whether the choice of extraction solvent affects the biological activity of Dojuksan, a traditional herbal formula. Our findings demonstrate that DEE and a fraction derived from this extract exerts anti-inflammatory effects through Nrf2‑dependent HO-1 expression, and that DEE may thus have greater potential therapeutic application than DWE.

Maize is a socioeconomically important crop in many countries. Recently, a high incidence of stalk rot disease has been reported in several maize fields in Gangwon province. In this report, we show that maize stalk rot is associated with the fungal pathogens Fusarium subglutinans and F. temperatum. Since no fungicides are available to control these pathogens on maize plants, we selected six fungicides (tebuconazole, difenoconazole, fluquinconazole, azoxystrobin, prochloraz and kresoxim-methyl) and examined their effectiveness against the two pathogens. The in vitro antifungal effects of the six fungicides on mycelial growth and colony formation were investigated. Based on the inhibition of mycelial growth, the most toxic fungicide was tebuconazole with 50% effective concentrations (EC50) of 3,000 μg/ml for both pathogens. Based on the inhibition of colony formation by the two pathogens, kresoxim-methyl was the most toxic fungicide with complete inhibition of colony formation at concentrations of 0.1 and 0.01 μg/ml for F. subglutinans and F. temperatum, respectively, whereas azoxystrobin was the least toxic fungicide with complete inhibition of colony formation at concentrations >3,000 μg/ml for both pathogens.

Sulfuretin is one of the major flavonoid components in Rhus verniciflua Stokes (Anacardiaceae) isolates. In this study, we investigated the protective effects of sulfuretin against tert-butyl hydroperoxide (t-BHP)-induced oxidative injury. The results indicated that the addition of sulfuretin before t-BHP treatment significantly inhibited cytotoxicity and reactive oxygen species (ROS) production in human liver-derived HepG2 cells. Sulfuretin up-regulated the activity of the antioxidant enzyme heme oxygenase (HO)-1 via nuclear factor E2-related factor 2 (Nrf2) translocation into the nucleus and increased the promoter activity of the antioxidant response element (ARE). Moreover, sulfuretin exposure enhanced the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (ERK1/2), which are members of the mitogen-activated protein kinase (MAPK) family. Furthermore, cell treatment with a JNK inhibitor (SP600125) and ERK inhibitor (PD98059) reduced sulfuretin-induced HO-1 expression and decreased its protective effects. Taken together, these results suggest that the protective effect of sulfuretin against t-BHP-induced oxidative damage in human liver-derived HepG2 cells is attributable to its ability to scavenge ROS and up-regulate the activity of HO-1 through the Nrf2/ARE and JNK/ERK signaling pathways. Therefore, sulfuretin could be advantageous as a bioactive source for the prevention of oxidative injury.

In Korea and China, the heartwood of Dalbergia odorifera T. Chen is an important traditional medicine used to treat blood disorders, ischemia, swelling, and epigastric pain. In this study, we investigated the inhibitory effects of latifolin, a major neoflavonoid component isolated from the MeOH extract of D. odorifera, on the inflammatory reaction of thioglycollate-elicited peritoneal macrophages exposed to lipopolysaccharide, with a particular focus on heme oxygenase-1 (HO-1) expression and nuclear factor-κB (NF-κB) signaling. Latifolin significantly inhibited the protein and mRNA expression of inducible nitric oxide synthase and COX-2, reduced NO, prostaglandins E2, tumor necrosis factor-α, and interleukin-1β production in primary murine peritoneal macrophages exposed to lipopolysaccharide. Latifolin also suppressed inhibitor κB-α levels, NF-κB nuclear translocation, and NF-κB DNA-binding activity. Furthermore, latifolin upregulated HO-1 expression via nuclear transcription factor-E2-related factor 2 (Nrf2) nuclear translocation. In addition, using inhibitor tin protoporphyrin IX (SnPP), an inhibitor of HO-1, it was verified that the inhibitory effects of latifolin on the proinflammatory mediators and NF-κB DNA-binding activity were associated with the HO-1 expression. These results suggested that the latifolin-mediated up-regulation of HO-1 expression played a critical role in anti-inflammatory effects in macrophages. This study therefore identified potent therapeutic effects of latifolin, which warrants further investigation as a potential treatment for inflammatory diseases.

The root of Polygala tenuifolia Willd. (Polygalaceae) is well known for its use in the treatment of neurasthenia, amnesia, and inflammation. In this study, we isolated phenyl propanoid type metabolite tenuifoliside A, one of the phenylpropanoids from P. tenuifolia, and investigated its anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 and murine peritoneal macrophages. The results showed that tenuifoliside A inhibited the production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), prostaglandin E2 (PG E2), and cyclooxygenase (COX)-2. In addition, tenuifoliside A suppressed the production of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β. We also evaluated the effects of tenuifoliside A on the activation of nuclear factor-kappaB (NF-κB). Tenuifoliside A inhibited the translocation of the NF-κB subunit p65 into the nucleus by interrupting the phosphorylation and degradation of inhibitor kappa B (IκB)-α in LPS-stimulated murine peritoneal macrophages. Moreover, we confirmed that the suppression of the inflammatory process by tenuifoliside A was mediated through the mitogen-activated protein kinases (MAPKs) pathway based on the fact that tenuifoliside A significantly decreased p-c-Jun N-terminal kinase (p-JNK) protein expression in LPS-stimulated murine peritoneal macrophages. Taken together, the anti-inflammatory effects of tenuifoliside A were mediated by the inhibition of the NF-κB and MAPK pathways. This study is the first report on the anti-inflammatory effects of tenuifoliside A, and the strong anti-inflammatory effects of tenuifoliside A provide potential compound to be developed as therapeutic for inflammatory diseases.

In this study, we isolated a new sulfonic acid derivative, (Z)-4-methylundeca-1,9-diene-6-sulfonic acid (1), from the sea urchin collected from the Sea of Okhotsk. We established the structure of this new compound by analysis of NMR and HRMS data, along with comparison of the data with those of the related compounds reported in the literature. In addition, we investigated its anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages. Compound 1 inhibited the production of NO, iNOS, PGE2, and COX-2, and it also suppressed the production of pro-inflammatory cytokines, such as TNF-α and IL-1β. It inhibited the translocation of the NF-κB subunit p65 into the nucleus by interrupting the phosphorylation and degradation of IκB-α. In addition, compound 1 significantly decreased the phosphorylation of JNK and p38 in LPS-stimulated RAW264.7 macrophages, suggesting that suppression of the inflammation process by compound 1 was mediated through the MAPK pathway. Taken together, this study showed that the anti-inflammatory effects of a new sulfonic acid derivative, (Z)-4-methylundeca-1,9-diene-6-sulfonic acid were mediated through the inhibition of NF-κB and JNK/p38 MAPK signaling pathways.

In the course of studies on bioactive metabolites from marine fungi, a new 10-membered lactone, named penicillinolide A (1) was isolated from the organic extract of Penicillium sp. SF-5292 as a potential anti-inflammatory compound. The structure of penicillinolide A (1) was mainly determined by analysis of NMR and MS data and Mosher's method. Penicillinolide A (1) inhibited the production of NO and PGE(2) due to inhibition of the expression of iNOS and COX-2. Penicillinolide A (1) also reduced TNF-alpha, IL-1 beta and IL-6 production, and these anti-inflammatory effects were shown to be correlated with the suppression of the phosphorylation and degradation of I kappa B-alpha, NF-kappa B nuclear translocation, and NF-kappa B DNA binding activity. In addition, using inhibitor tin protoporphyrin (SnPP), a competitive inhibitor of HO activity, it was verified that the inhibitory effects of compound 1 on the production of pro-inflammatory mediators and NF-kappa B DNA binding activity were partially associated with HO-1 expression through Nrf2 nuclear translocation.

Rhus verniciflua Stokes is a plant that is native to East Asian countries, such as Korea, China, and Japan. Butein, a plant polyphenol, is one of the major active components of R. verniciflua. Reactive oxygen species (ROS), produced via dental adhesive bleaching agents and pulpal disease, can cause oxidative stress. Here, we found that butein possesses cytoprotective effects on hydrogen peroxide (H2O2)-induced dental cell death. H2O2 is a representative ROS and causes cell death through necrosis in human dental pulp (HDP) cells. H2O2-induced cytotoxicity and production of ROS were blocked in the presence of butein, and these effects were dose dependent. Butein also increased heme oxygenase-1 (HO-1) protein expression and HO activity. In addition, butein-dependent HO-1 expression was required for the inhibition of H2O2-induced cell death and ROS generation. Furthermore, butein treatment caused nuclear accumulation of nuclear factor-E2-related factor 2 (Nrf2) and increased the promoter activity of antioxidant response elements (AREs). Treatment of HDP cells with a c-Jun NH2-terminal kinase (JNK) inhibitor also reduced butein-induced HO-1 expression, and butein treatment led to increased JNK phosphorylation. These results indicate that butein may be used to prevent functional dental cell death and thus may be useful as a pulpal disease agent.

Diospyros kaki Thunb. is widely distributed in East Asian countries, its leaves being mainly used for making tea. In this study, coussaric acid (CA) and betulinic acid (BA), both triterpenoid compounds, were obtained from D. kaki leaf extracts through bioassay-guided isolation. CA and BA showed anti-inflammatory effects via inhibition of the nuclear factor-κB (NF-κB) pathway, providing important information on their anti-inflammatory mechanism. Furthermore, they markedly inhibited nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages, and suppressed tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) levels. Furthermore, they decreased protein expression of inducible nitric oxide synthase and cyclooxygenase-2. Pre-treatment with CA and BA inhibited LPS-induced NF-κB. We further examined the effects of CA and BA on heme oxygenase (HO)-1 expression in RAW 264.7 macrophages: BA induced HO-1 protein expression in a dose-dependent manner, while CA had no effect. We also investigated whether BA treatment induced nuclear translocation of Nrf2. BA inhibited LPS-induced NF-κB-binding activity, as well as pro-inflammatory mediator and cytokine production (e.g., NO, PGE₂, TNF-α, IL-1β, IL-6), by partial reversal of this effect by SnPP, an inhibitor of HO-1. These findings further elucidate the anti-inflammatory mechanism of CA and BA isolated from D. kaki.

One of the earliest plant responses to pathogens is the induced accumulation of reactive oxygen species (ROS). The superoxide ion is an important intermediate in the generation of ROS having a key regulatory function during plant–microbe interactions and is an important component in fungal development. The superoxide dismutase (SOD) family contributes to frontline defense via detoxification of reactive superoxide radical anions. Sclerotinia sclerotiorum (Lib.) de Bary is a necrotrophic fungal pathogen with a broad host range. S. sclerotiorum produces the non-specific phytotoxin and key pathogenicity factor, oxalic acid (OA). We have identified an S. sclerotiorum SOD (Sssod1) with high similarity to CuZnSODs. Sssod1 contains an open reading frame of 908 bp in length and is predicted to encode a protein of 155 amino acids that harbors the entire hallmark motifs associated with SOD function. Treatment with the CuZnSOD inhibitor diethyldithiocarbamate (DETC) resulted in delayed hyphal growth and sclerotial development in a dose-dependent manner. Mutants generated carrying an Sssod1 deletion (ΔSssod1) exhibited morphological defects similar to those observed with the inhibitor treatment. Moreover, ΔSssod1 was more sensitive than wild-type to menadione, a redox cycling agent. Expression of Sssod1 was induced following treatment with oxidizing agents and during interaction with plant host tissue the ΔSssod1 mutant was significantly reduced in virulence on both tomato and tobacco plants compared to wild-type. Interestingly, pathogenicity of the superoxide dismutase mutant was mostly restored following supplementation with oxalate. We also observed that ΔSssod1 was reduced in oxalate production by half. In accordance with reduced virulence, ΔSssod1 induced a host oxidative burst in adjacent uninfected cells, a phenotype indicative of active pathogen recognition by the host. Intriguingly, during wild-type infection, host ROS production was significantly reduced. These results suggest that wild-type Sclerotinia suppresses host defense responses during infection.

This study was performed to evaluate the antioxidant and antimicrobial activities from the methanol extracts of the root and stem of Hippophae rhamnoides and their further partitioned fractions including hexane, ethyl acetate, butanol, and water. Antioxidant activities of the plant parts were measured by l,l-dephenyl-2-picryl-hydrazyl (DPPH), superoxide dismutase (SOD)-like activity, and ferric thiocyanate (FTC) assays, and compared to standard antioxidants of butylated hydroxyl anisole, butylated hydroxyl toluene, a-tocopherol, and ascorbic acid. Antimicrobial activity of the plant extracts and fractions were evaluated by determining the minimum inhibitory concentration values. DPPH assay showed that the overall strong antioxidant activities from the methanol extracts and fractions. The values of SOD-like activities in hexane fractions of the root and stem were close to the measurement of a reference, ascorbic acid at 1,000 ppm. The methanol extract of the root in FTC assay showed a remarkable antioxidant and free radical scavenging activity. The extracts and fractions of the root and stem showed better antimicrobial activity than compared antimicrobial agents, (+)-catechin, ketoconazol, and mycostantin. This study indicates that the plant root and stem contain a variety of compounds contributing to antioxidant and antimicrobial activity, which could be used for food additives and the development of useful natural compounds.

Two benzaldehyde derivatives, flavoglaucin (1) and isotetrahydro-auroglaucin (2), were isolated from the marine fungus Eurotium sp. SF-5989 through bioassay- and 1H NMR-guided investigation. In this study, we evaluated the anti-inflammatory effects of these compounds in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We demonstrated that compounds 1 and 2 markedly inhibited LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production by suppressing inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression without affecting cell viability. We also demonstrated that the compounds reduced the secretion of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Furthermore, compounds 1 and 2 inhibited LPS-induced nuclear factor-κB (NF-κB) activation by suppressing phosphorylation of IkappaB (IκB). These results indicated that the anti-inflammatory effects of these benzaldehyde derivatives in LPS-stimulated RAW264.7 macrophages were due to the inactivation of the NF-κB pathway. In addition, compounds 1 and 2 induced heme oxygenase-1 (HO-1) expression through the nuclear transcription factor-E2–related factor 2 (Nrf2) translocation. The inhibitory effects of compounds 1 and 2 on the production of pro-inflammatory mediators and on NF-κB binding activity were reversed by HO-1 inhibitor tin protoporphyrin (SnPP). Thus, the anti-inflammatory effects of compounds 1 and 2 also correlated with their ability of inducing HO-1 expression.

In the course of a search for anti-neuroinflammatory metabolites from marine fungi, aurantiamide acetate (1) was isolated from marine-derived Aspergillus sp. as an anti-neuroinflammatory component. Compound 1 dose-dependently inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in BV2 microglial cells. It also attenuated inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and other pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). In a further study designed to elucidate the mechanism of its anti-neuroinflammatory effect, compound 1 was shown to block the activation of nuclear factor-kappa B (NF-κB) in lipopolysaccharide (LPS)-induced BV2 microglial cells by inhibiting the phosphorylation of the inhibitor kappa B-α (IκB)-α. In addition, compound 1 decreased the phosphorylation levels of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases (MAPKs). These results suggest that compound 1 has an anti-neuroinflammatory effect on LPS stimulation through its inhibition of the NF-κB, JNK and p38 pathways.

In the course of a bioassay-guided study of metabolites from the marine fungus Eurotium sp. SF-5989, two diketopiperazine type indole alkaloids, neoechinulins A and B, were isolated. In this study, we investigated the anti-inflammatory effects of neoechinulins A (1) and B (2) on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Neoechinulin A (1) markedly suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose dependent manner ranging from 12.5 µM to 100 µM without affecting the cell viability. On the other hand, neoechinulin B (2) affected the cell viability at 25 µM although the compound displayed similar inhibitory effect of NO production to neoechinulin A (1) at lower doses. Furthermore, neoechinulin A (1) decreased the secretion of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). We also confirmed that neoechinulin A (1) blocked the activation of nuclear factor-kappaB (NF-κB) in LPS-stimulated RAW264.7 macrophages by inhibiting the phosphorylation and degradation of inhibitor kappa B (IκB)-α. Moreover, neoechinulin A (1) decreased p38 mitogen-activated protein kinase (MAPK) phosphorylation. Therefore, these data showed that the anti-inflammatory effects of neoechinulin A (1) in LPS-stimulated RAW264.7 macrophages were due to the inhibition of the NF-κB and p38 MAPK pathways, suggesting that neoechinulin A (1) might be a potential therapeutic agent for the treatment of various inflammatory diseases.

The heartwood of Dalbergia odorifera T. Chen (Leguminosae) is an important source of traditional Korean and Chinese medicines. 9-Hydroxy-6,7-dimethoxydalbergiquinol (HDDQ), a compound isolated from D. odorifera, has various biological activities. The aim of this study was to determine the efficacy of HDDQ in modulating the regulation of anti-inflammatory activity through the upregulation of heme oxygenase (HO)-1 in BV2 microglia. HDDQ inhibited the protein expression of inducible nitric oxide synthase (iNOS), iNOS-derived nitric oxide (NO), and the production of cyclooxygenase (COX)-2 and COX-2-derived prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-stimulated mouse BV2 microglia. HDDQ also reduced tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) production, and suppressed the phosphorylation and degradation of IκB-α and the nuclear translocation of p65 in mouse BV2 microglia in response to LPS. Furthermore, HDDQ upregulated HO-1 expression via nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) in mouse BV2 microglia. Using tin protoporphyrin (SnPP), an HO activity inhibitor, we verified that the inhibitory effects of HDDQ on the proinflammatory mediators NO, PGE2, TNF-α, and IL-1β, and nuclear factor kappa B (NF-κB) DNA-binding activity are associated with the induction of HO-1 expression. Our data suggest that HDDQ has therapeutic potential against neurodegenerative diseases caused by neuroinflammation.

Protein tyrosine phosphatase 1B (PTP1B) plays a major role in the negative regulation of insulin signaling, and is thus considered as an attractive therapeutic target for the treatment of diabetes. Bioassay-guided investigation of the methylethylketone extract of marine-derived fungus Penicillium sp. JF-55 cultures afforded a new PTP1B inhibitory styrylpyrone-type metabolite named penstyrylpyrone (1), and two known metabolites, anhydrofulvic acid (2) and citromycetin (3). Compounds 1 and 2 inhibited PTP1B activity in a dose-dependent manner, and kinetic analyses of PTP1B inhibition suggested that these compounds inhibited PTP1B activity in a competitive manner. In an effort to gain more biological potential of the isolated compounds, the anti-inflammatory effects of compounds 1-3 were also evaluated. Among the tested compounds, only compound 1 inhibited the production of NO and PGE(2), due to the inhibition of the expression of iNOS and COX-2. Penstyrylpyrone (1) also reduced TNF-alpha and IL-1 beta production, and these anti-inflammatory effects were shown to be correlated with the suppression of the phosphorylation and degradation of I kappa B-alpha, NF-kappa B nuclear translocation, and NF-kappa B DNA binding activity. In addition, using inhibitor tin protoporphyrin (SnPP), an inhibitor of HO-1, it was verified that the inhibitory effects of penstyrylpyrone (1) on the pro-inflammatory mediators and NF-kappa B DNA binding activity were associated with the HO-1 expression. Therefore, these results suggest that penstyrylpyrone (1) suppresses PTP1B activity, as well as the production of pro-inflammatory mediators via NF-kappa B pathway, through expression of anti-inflammatory HO-1.

Sauchinone, a biologically active lignan isolated from the roots of Saururus chinensis (LOUR.) BAILL. (Saururaceae), is reported to exert a variety of biological activities, such as hepatoprotective, anti-inflammatory actions and inhibitory effects on bone resorption. In this study, we investigated the effect of sauchinone in suppressing cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, leading to a reduction in COX-2-derived prostaglandin E(2) (PGE(2)) and iNOS-derived nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated RAW264.7 macrophages. Present study also demonstrates the effects of sauchinone in inducing heme oxygenase-1 (HO-1) expression and an increase in heme oxygenase (HO) activity in RAW264.7 macrophages. The effects of sauchinone on LPS-induced PGE(2), NO, tumor necrosis factor-α (TNF-α) and interlukine-1β (IL-1β) production were partially reversed by the HO-1 inhibitor Tin protoporphyrin was also seen in this study. In addition, we found that treatment with extracellular signal-regulated kinase (ERK) inhibitor (PD98059) reduced sauchinone-induced HO-1 expression. Sauchinone also increased ERK phosphorylation. These results suggest that sauchinone inhibits pro-inflammatory mediators through expression of anti-inflammatory HO-1 via ERK pathway.

The full-length cDNA of LebZIP2 (Lycopersicon esculentum bZIP2) encodes a protein of 164 amino acids and contains a N-terminal basic-region leucine zipper domain. Analysis of the deduced tomato LebZIP2 amino acid sequence revealed that it shares 85% sequence identity with both tobacco bZIP and pepper CcbZIP. LebZIP2 mRNA is expressed at a high level exclusively in flowers. Presently, LebZIP2 was strongly increased also following NaCl and mannitol treatments. No significant LebZIP2 expression was evident following cold treatment. Transient LebZIP2 overexpression resulted in increased NbNOA1 and NbNR transcript levels in Nicotiana benthamiana leaves. Our results indicate that LebZIP2 might play roles as an abiotic stress-signaling pathway and as a transcriptional regulator of the NbNOA1 or NbNR genes.

Accumulating evidence supports the idea that necrotrophic plant pathogens interact with their hosts by controlling cell death. Sclerotinia sclerotiorum is a necrotrophic ascomycete fungus with a broad host range (>400 species). Previously, we established that oxalic acid (OA) is an important pathogenicity determinant of this fungus. In this report, we describe a mechanism by which oxalate contributes to the pathogenic success of this fungus; namely, that OA induces a programmed cell death (PCD) response in plant tissue that is required for disease development. This response exhibits features associated with mammalian apoptosis, including DNA laddering and TUNEL reactive cells. Fungal mutants deficient in OA production are nonpathogenic, and apoptotic-like characteristics are not observed following plant inoculation. The induction of PCD by OA is independent of the pH-reducing abilities of this organic acid, which is required for sclerotial development. Moreover, oxalate also induces increased reactive oxygen species (ROS) levels in the plant, which correlate to PCD. When ROS induction is inhibited, apoptotic-like cell death induced by OA does not occur. Taken together, we show that Sclerotinia spp.-secreted OA is an elicitor of PCD in plants and is responsible for induction of apoptotic-like features in the plant during disease development. This PCD is essential for fungal pathogenicity and involves ROS. Thus, OA appears to function by triggering in the plant pathways responsible for PCD. Further, OA secretion by Sclerotinia spp. is not directly toxic but, more subtly, may function as a signaling molecule.

The oomycete genus Phytophthora includes many important plant pathogens for which extensive genome data exist, but lacking is an inducible expression system to study contributions of their genes to growth and pathogenicity. Here the adaptation of the reverse tetracycline transactivator (rtTA) system to P. infestans is described. Vectors were developed containing rtTA expressed from an oomycete promoter, and beta-glucuronidase (GUS) controlled by TetR binding sites fused to a minimal oomycete promoter. Transformants were obtained in which GUS was expressed in a dose-dependent manner by the rtTA inducer doxycycline, indicating that the gene switch functions in P. infestans. However, toxicity of rtTA hindered the isolation of transformants if expressed on the same plasmid as the nptII selection marker. Better results were obtained by cotransforming those genes on separate plasmids, with 92% of transformants acquiring both DNAs although only 4% expressed rtTA at detectable levels. Low levels of reporter activity were measured in such transformants, suggesting that rtTA activated transcription weakly. Also, significant variation in the sensitivity of isolates to doxycycline and tetracycline was observed. These results are useful both in terms of developing tools for functional genomics and understanding the fate of DNA during Phytophthora transformation.