Anti-Inflammatory Effects of Compounds from Cudrania tricuspidata in HaCaT Human Keratinocytes.

The root bark of Cudrania tricuspidata has been reported to have anti-sclerotic, anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, and cytotoxic activities. In the present study, the effect of 16 compounds from C. tricuspidata on tumor necrosis factor-α+interferon-γ-treated HaCaT cells were investigated. Among these 16 compounds, 11 decreased IL-6 production and 15 decreased IL-8 production. The six most effective compounds, namely, steppogenin (2), cudraflavone C (6), macluraxanthone B (12), 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3- methoxyxanthone (13), cudraflavanone B (4), and cudratricusxanthone L (14), were selected for further experiments. These six compounds decreased the expression levels of chemokines, such as regulated on activation, normal T cell expressed and secreted (RANTES) and thymus and activation-regulated chemokine (TARC), and downregulated the protein expression levels of intercellular adhesion molecule-1. Compounds 2, 6, 12, 4, and 14 inhibited nuclear factor-kappa B p65 translocation to the nucleus; however, compound 13 showed no significant effects. In addition, extracellular signal regulatory kinase-1/2 phosphorylation was only inhibited by compound 14, whereas p38 phosphorylation was inhibited by compounds 13 and 4. Taken together, the compounds from C. tricuspidata showed potential to be further developed as therapeutic agents to suppress inflammation in skin cells.

Anti-Neuroinflammatory and Anti-Inflammatory Activities of Phenylheptatriyne Isolated from the Flowers of Coreopsis lanceolata L. via NF-κB Inhibition and HO-1 Expression in BV2 and RAW264.7 Cells.

Aging is associated with immune disregulation and oxidative stress which lead to inflammation and neurodegenerative diseases. We have tried to identify the anti-neuroinflammatory and anti-inflammatory components of Coreopsis lanceolata L. The dried flowers of C. lanceolata were extracted with 70% EtOH, and the obtained extract was divided into CH2Cl2, EtOAc, n-BuOH, and H2O fractions. The CH2Cl2 fraction was separated using silica gel and C-18 column chromatography to yield phenylheptatriyne (1), 2'-hydroxy-3,4,4'-trimethoxychalcone (2), and 4',7-dimethoxyflavanone (3). Additionally, the EtOAc fraction was subjected to silica gel, C-18, and Sephadex LH-20 column chromatography to yield 8-methoxybutin (4) and leptosidin (5). All the compounds isolated from C. lanceolata inhibited the production of nitric oxide (NO) in LPS-induced BV2 and RAW264.7 cells. In addition, phenylheptatriyne and 4',7-dimethoxyflavanone reduced the secretion of inflammatory cytokines, tumor necrosis factor alpha (TNF-α), and interleukin (IL)-6. Among them, phenylheptatriyne was significantly downregulated in the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequently, phenylheptatriyne also effectively inhibited nuclear factor-kappa B (NF-κB) activation in LPS-stimulated BV2 and RAW264.7 cells. Based on these results, the anti-neuroinflammatory effect of phenylheptatriyne isolated from C. lanceolata was confirmed, which may exert a therapeutic effect in treatment of neuroinflammation-related diseases.

Comparison of anti-inflammatory effects of Mecasin and its constituents on lipopolysaccharide-stimulated BV2 cells.

Mecasin, a traditional medicine, contains nine herbal constituents: Curcuma longa, Salvia miltio rhiza, Gastrodia elata, Chaenomeles sinensis, Polygala tenuifolia, Paeonia japonica, Glycyrrhiza uralensis, Atractylodes japonica and processed Aconitum carmichaeli. Several biological effects of mecasin have been described both in vivo and in vitro. Previous studies have demonstrated that mecasin has anti-inflammatory effects. The purpose of the present study was to determine anti-inflammatory effects of mecasin and its natural product constituents on lipopolysaccharide (LPS)-stimulated BV2 cells by measuring nitrite and nitric oxide contents. Nitrite production levels in LPS-stimulated BV2 cells incubated with mecasin and each individual constituent of mecasin were measured. The results suggested that C. longa, P. tenuifolia and P. japonica inhibited nitrite production in a pattern similar to that of mecasin. The effect of mecasin was likely a result of synergistic effects of its natural herb constituents.

Neuroprotective and Anti-Inflammatory Effects of Kuwanon C from Cudrania tricuspidata Are Mediated by Heme Oxygenase-1 in HT22 Hippocampal Cells, RAW264.7 Macrophage, and BV2 Microglia.

Heme oxygenase (HO)-1 is a detoxifying phase II enzyme that plays a role in both inflammatory and oxidative stress responses. Curdrania tricuspidata is widespread throughout East Asia and is used as a therapeutic agent in traditional medicine. We investigated whether treatment with sixteen flavonoid or xanthone compounds from C. tricuspidata could induce HO-1 expression in HT22 hippocampal cells, RAW264.7 macrophage, and BV2 microglia. In these compounds, kuwanon C showed the most remarkable HO-1 expression effects. In addition, treatment with kuwanon C reduced cytoplasmic nuclear erythroid 2-related factor (Nrf2) expression and increased Nrf2 expression in the nucleus. Significant inhibition of glutamate-induced oxidative injury and induction of reactive oxygen species (ROS) occurred when HT22 hippocampal cells were pretreated with kuwanon C. The levels of inflammatory mediator and cytokine, which increased following lipopolysaccharide (LPS) stimulation, were suppressed in RAW264.7 macrophage and BV2 microglia after kuwanon C pretreatment. Kuwanon C also attenuated p65 DNA binding and translocation into the nucleus in LPS-induced RAW264.7 and BV2 cells. The anti-inflammatory, anti-neuroinflammatory, and neuroprotective effects of kuwanon C were reversed when co-treatment with HO-1 inhibitor of tin protoporphyrin-IX (SnPP). These results suggest that the neuroprotective and anti-inflammatory effects of kuwanon C are regulated by HO-1 expression.

Standardized microwave extract of Sappan Lignum exerts anti­inflammatory effects through inhibition of NF­κB activation via regulation of heme oxygenase­1 expression.

The extract of Sappan Lignum, the heartwood of Caesalpinia sappan L., has been used in medicine to improve blood circulation. Recently, the application of microwave extraction methods has been a major focus of research into the extraction of components from natural sources. In this experiment, we compared the anti­inflammatory effects of Sappan Lignum prepared by heat­70% EtOH extraction (CSE­H­70E) and microwave­70% EtOH extraction (CSE­MW­70E). High­performance liquid chromatography analysis was used to identify the compounds in these extracts. The heat­70% EtOH and microwave­70% EtOH extracts of Sappan Lignum had different chromatograms. CSE­MW­70E significantly inhibited the protein expression of iNOS and COX­2, PGE2, TNF­α, and reduced NO and IL­1ß production in macrophages exposed to LPS, whereas, only high concentrations of CSE­H­70E (20 µg/ml) resulted in any effects. Furthermore, CSE­MW­70E upregulated heme oxygenase­1 (HO­1) expression. In addition, the use of tin protoporphyrin, an inhibitor of HO­1, confirmed the inhibitory effects of CSE­MW­70E on pro­inflammatory mediators. These results suggested that the CSE­MW­70E­mediated upregulation of HO­1 played an important role in the anti­inflammatory effects of macrophages. Therefore, these findings showed that microwave extraction can be utilized to improve the extraction efficiency and biological activity of Sappan Lignum.

Nardosinone-Type Sesquiterpenes from the Hexane Fraction of Nardostachys jatamansi Attenuate NF-κB and MAPK Signaling Pathways in Lipopolysaccharide-Stimulated BV2 Microglial Cells.

Four nardosinone-type sesquiterpenes, nardosinone, isonardosinone, kanshone E, and kanshone B, were isolated from the hexane fraction of Nardostachys jatamansi (Valerianaceae) methanol extract. The structures of these compounds were mainly established by analyzing the data obtained from nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). In this study, we investigated their anti-neuroinflammatory effects in lipopolysaccharide (LPS)-induced BV2 microglial cells. The results showed that nardosinone-type sesquiterpenes inhibited the production of pro-inflammatory mediators, such as nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-induced BV2 microglial cells. These inhibitory effects were correlated with the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, these sesquiterpenes also attenuated the mRNA expression of pro-inflammatory cytokines including interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α) in LPS-induced BV2 microglial cells. During the evaluation of the signaling pathways involved in these anti-neuroinflammatory effects, western blot analysis and DNA-binding activity assay revealed that the suppression of inflammatory reaction by these sesquiterpenes was mediated by the inactivation of nuclear factor-kappa B (NF-κB) pathway. These sesquiterpenes also suppressed the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) signaling pathways in LPS-stimulated BV2 microglial cells. Taken together, these four nardosinone-type sesquiterpenes inhibited NF-κB- and MAPK-mediated inflammatory pathways, demonstrating their potential role in the treatment of neuroinflammation conditions.

Anti-neuroinflammatory effects of cudraflavanone A isolated from the chloroform fraction of Cudrania tricuspidata root bark.

CONTEXT: Cudrania tricuspidata Bureau (Moraceae) is an important source of traditional Korean and Chinese medicines used to treat neuritis and inflammation. OBJECTIVE: The anti-neuroinflammatory effects of cudraflavanone A isolated from a chloroform fraction of C. tricuspidata were investigated in LPS-induced BV2 cells. MATERIALS AND METHODS: Cudraflavanone A was isolated from the root of C. tricuspidata, and its structure was determined by MS and NMR data. Cytotoxicity of the compound was examined by MTT assay, indicating no cytotoxicity at 5-40 µM of cudraflavanone A. NO concentration was measured by the Griess reaction, and the levels of PGE2, cytokines and COX-2 enzyme activity were measured by each ELISA kit. The mRNA levels of cytokines were analysed by quantitative-PCR. The expression of iNOS, COX-2, HO-1, NF-κB, MAPKs and Nrf2 was detected by Western blot. RESULTS: Cudraflavanone A had no major effect on cell viability at 40 µM indicating 91.5% viability. It reduced the production of NO (IC50 = 22.2 µM), PGE2 (IC50 = 20.6 µM), IL-1ß (IC50 = 24.7 µM) and TNF-α (IC50 = 33.0 µM) in LPS-stimulated BV2 cells. It also suppressed iNOS protein, IL-1ß and TNF-α mRNA expression. These effects were associated with the inactivation of NF-κB, JNK and p38 MAPK pathways. This compound mediated its anti-neuroinflammatory effects by inducing HO-1 protein expression via increased nuclear translocation of Nrf2. DISCUSSION AND CONCLUSIONS: The present study suggests a potent effect of cudraflavanone A to prevent neuroinflammatory diseases. Further investigation is necessary to elucidate specific molecular mechanism of cudraflavanone A.

Pueraria lobate Inhibits RANKL-Mediated Osteoclastogenesis Via Downregulation of CREB/PGC1ß/c-Fos/NFATc1 Signaling.

Puerariae radix, the dried root of Pueraria lobate Ohwi, is known to prevent bone loss in ovariectomized mice; however, the precise molecular mechanisms are not understood. In this study, we investigated the effects and underlying mechanisms of action of Puerariae radix extract (PRE) on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. PRE dose-dependently inhibited osteoclast differentiation and formation, decreased the bone-resorbing activity of osteoclasts, and downregulated the expression of osteoclast differentiation marker genes. The expression of osteoclastogenic factors produced by PRE-treated osteoblasts such as RANKL, macrophage colony-stimulating factor (M-CSF), and osteoprotegerin (OPG) was comparable to that of untreated (control) cells. However, the formation of osteoclasts via bone marrow cell and calvaria-derived osteoblast co-cultures was suppressed by PRE treatment. Therefore, the inhibitory effects of PRE on osteoclastogenesis clearly targeted osteoclasts, but not osteoblasts. PRE treatment considerably reduced RANKL-induced mitogen-activated protein kinases (MAPKs) activity, especially c-Jun N-terminal kinase, in osteoclast precursor cells. In addition, PRE markedly suppressed cAMP response element-binding protein (CREB) activation and the induction of peroxisome proliferator-activated receptor gamma coactivator 1ß (PGC1ß), which stimulate osteoclastogenesis - an effect that was not observed for puerarin and 17-ß estradiol. Finally, PRE treatment significantly repressed the expression of c-Fos and the nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), which is a master transcription factor for osteoclastogenesis in vitro and in vivo. Overall, these results strongly suggest that PRE is an effective inhibitor of RANKL-induced osteoclastogenesis and may be a potent therapeutic agent for bone-related diseases such as osteoporosis, rheumatoid arthritis, and periodontitis.

Taraxacum coreanum protects against glutamate-induced neurotoxicity through heme oxygenase-1 expression in mouse hippocampal HT22 cells.

Taraxacum coreanum Nakai is a dandelion that is native to Korea, and is widely used as an edible and medicinal herb. The present study revealed the neuroprotective effect of this plant against glutamate-induced oxidative stress in HT22 murine hippocampal neuronal cells. Ethanolic extracts from the aerial (TCAE) and the root parts (TCRE) of T. coreanum were prepared. Both extracts were demonstrated, by high performance liquid chromatography, to contain caffeic acid and ferulic acid as representative constituents. TCAE and TCRE significantly increased cell viability against glutamate-induced oxidative stress in mouse hippocampal HT22 cells. Western blot analysis revealed that treatment of HT22 cells with the extracts induced increased expression of the enzyme heme oxygenase-1 (HO-1), compared with untreated cells, in a concentration-dependent manner. Increased HO-1 enzymatic activity, compared with untreated cells, was also demonstrated following treatment with TCAE and TCRE. In addition, western blot analysis of the nuclear fractions of both TCAE and TCRE-treated HT22 cells revealed increased levels of nuclear factor erythroid 2 like 2 (Nrf2) compared with untreated cells, and decreased Nrf2 levels in the cytoplasmic fraction compared with untreated cells. The present study suggested that the neuroprotective effect of T. coreanum is associated with induction of HO-1 expression and Nrf2 translocation to the nucleus. Therefore, T. coreanum exhibits a promising function in prevention of neurodegeneration. Further studies will be required for the isolation and the full characterization of its active substances.

Anti-inflammatory coumarins from Paramignya trimera.

CONTEXT: Paramignya trimera (Oliv.) Burkill (Rutaceae) has been used to treat liver diseases and cancer. However, the anti-inflammatory effects of this medicinal plant and its components have not been elucidated. OBJECTIVE: This study investigated chemical constituents of the P. trimera stems and evaluated anti-inflammatory effects of isolated compounds. MATERIALS AND METHODS: Cytotoxicity of isolated compounds (5-40 µM) toward BV2 cells was tested using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) for 24 h. Inhibitory effects of isolated compounds (5-40 µM) on nitrite and PGE2 concentrations were determined using Griess reaction and PGE2 ELISA kit, respectively (pretreated with the compounds for 3 h and then stimulated for 18 h with LPS). Inhibitory effects of compounds (5-40 µM) on iNOS and COX-2 protein expression were evaluated by Western blot analysis (pretreated with the compounds for 3 h and then stimulated for 24 h with LPS). RESULTS: Seven coumarins were isolated and identified as: ostruthin (1), ninhvanin (2), 8-geranyl-7-hydroxycoumarin (3), 6-(6',7'-dihydroxy-3',7'-dimethylocta-2'-enyl)-7-hydroxycoumarin (4), 6-(7-hydroperoxy-3,7-dimethylocta-2,5-dienyl)-7-hydroxycoumarin (5), 6-(2-hydroxyethyl)-2,2-dimethyl-2H-1-benzopyran (6), and luvangetin (7). Compounds 1-4 and 7 inhibited NO and PGE2 production in LPS-stimulated BV2 cells, with IC50 values ranging from 9.8 to 46.8 and from 9.4 to 52.8 µM, respectively. Ostruthin (1) and ninhvanin (2) were shown to suppress LPS-induced iNOS and COX-2 protein expression. DISCUSSION AND CONCLUSION: The present study provides a scientific rationale for the use of P. trimera in the prevention and treatment of neuroinflammatory diseases. Ostruthin and ninhvanin might have potential therapeutic effects and should be considered for further development as new anti-neuroinflammatory agents.

The herbal extract KCHO-1 exerts a neuroprotective effect by ameliorating oxidative stress via heme oxygenase-1 upregulation.

KCHO-1 is a novel product comprised of 30% ethanol extracts obtained from nine medical herbs, which are commonly used in traditional Korean and Chinese medicine. The nine herbs include Curcuma longa, Salvia miltiorrhiza, Gastrodia elata, Chaenomeles sinensis, Polygala tenuifolia, Paeonia japonica, Glycyrrhiza uralensis, Atractylodes japonica and processed Aconitum carmichaeli. Recent studies have reported the beneficial effects of these herbs. The present study aimed to investigate the direct neuroprotective effects of KCHO­1 on HT22 mouse hippocampal cells, and to determine the possible underlying mechanisms. KCHO­1 significantly suppressed glutamate­ and hydrogen peroxide (H2O2)­induced cell damage, and reactive oxygen species generation. In addition, KCHO­1 increased the mRNA and protein expression levels of heme oxygenase (HO)­1. Tin protoporphyrin, which is an inhibitor of HO activity, partially suppressed the effects of KCHO­1. Furthermore, KCHO­1 significantly upregulated nuclear factor erythroid­derived 2­related factor­2 (Nrf2) nuclear translocation. Extracellular signal­regulated kinase (ERK) activation also appeared to be associated with KCHO­1­induced HO­1 expression, since the ERK inhibitor PD98059 suppressed HO­1 expression and prevented KCHO­1­induced cytoprotection. The results of the present study suggested that KCHO­1 may effectively prevent glutamate­ or H2O2­induced oxidative damage via Nrf2/ERK mitogen­activated protein kinase­dependent HO­1 expression. These data suggest that KCHO­1 may be useful for the treatment of neurodegenerative diseases.

Steroidal Glucosides from the Rhizomes of Tacca chantrieri and Their Inhibitory Activities of NO Production in BV2 Cells.

Two new steroidal glucosides, chantriolides D and E (1 and 2), along with four known compounds, chantriolide A (3), chantriolide B (4), chantriolide C (5), and (25S)-spirost-5-en-3-ol 3-O-α-L-rhamnopyranosyl-(1-->2)-O-[α-L-rhamnopyranosyl-(1-->3)]-ß-D-glucopyranoside (6) were isolated from the rhizomes of Tacca chantrieri. Their structures were determined by 1D and 2D NMR spectroscopic and HR-ESI-MS data, as well as by comparison with reported data. Compounds 1 and 2 were found to show strong inhibitory NO effect in BV2 cells, with IC50 values of 12.45 and 59.03 µM, respectively.

Prenylated Flavonoids from Cudrania tricuspidata Suppress Lipopolysaccharide-Induced Neuroinflammatory Activities in BV2 Microglial Cells.

In Korea and China, Cudrania tricuspidata Bureau (Moraceae) is an important traditional medicinal plant used to treat lumbago, hemoptysis, and contusions. The C. tricuspidata methanol extract suppressed both production of NO and PGE2 in BV2 microglial cells. Cudraflavanone D (1), isolated from this extract, remarkably suppressed the protein expression of inducible NO synthase and cyclooxygenase-2, and decreased the levels of NO and PGE2 in BV2 microglial cells exposed to lipopolysaccharide. Cudraflavanone D (1) also decreased IL-6, TNF-α, IL-12, and IL-1ß production, blocked nuclear translocation of NF-κB heterodimers (p50 and p65) by interrupting the degradation and phosphorylation of inhibitor of IκB-α, and inhibited NF-κB binding. In addition, cudraflavanone D (1) suppressed the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK pathways. This study indicated that cudraflavanone D (1) can be a potential drug candidate for the cure of neuroinflammation.

A fraction from Dojuksan 30% ethanol extract exerts its anti-inflammatory effects through Nrf2-dependent heme oxygenase-1 expression.

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-1ß (IL-1ß), 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-1ß. 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 Nrf2­dependent HO-1 expression, and that DEE may thus have greater potential therapeutic application than DWE.

New ent-kauranes from the fruits of Annona glabra and their inhibitory nitric oxide production in LPS-stimulated RAW264.7 macrophages.

Three new ent-kaurane diterpenoids, 7ß,16α,17-trihydroxy-ent-kauran-19-oic acid (1), 7ß,17-dihydroxy-16α-ent-kauran-19-oic acid 19-O-ß-d-glucopyranoside ester (2), 7ß,17-dihydroxy-ent-kaur-15-en-19-oic acid 19-O-ß-d-glucopyranoside ester (3) along with five known compounds, paniculoside IV (4), 16α,17-dihydroxy-ent-kaurane (5), 16ß,17-dihydroxy-ent-kaurane (6), 16ß,17-dihydroxy-ent-kauran-19-al (7), and 16ß,17-dihydroxy-ent-kauran-19-oic acid (8) were isolated from the fruits of Annona glabra. Their chemical structures were elucidated by physical and chemical methods. All compounds were evaluated for inhibitory activity against nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages. As the results, compound 3 showed potent inhibitory LPS-stimulated NO production in RAW 264.7 macrophages with the IC50 value of 0.01±0.01µM; compounds 1 and 7 showed significant inhibitory NO production with the IC50 values of 0.39±0.12µM and 0.32±0.04µM, respectively.

The neoflavonoid latifolin isolated from MeOH extract of Dalbergia odorifera attenuates inflammatory responses by inhibiting NF-κB activation via Nrf2-mediated heme oxygenase-1 expression.

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-1ß 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.

Secondary metabolites isolated from Castilleja rubra exert anti-inflammatory effects through NF-κB inactivation on lipopolysaccharide-induced RAW264.7 macrophages.

8-Epiloganin (1), mussaenoside (2), and 5-O-caffeoylshikimic acid (3) have been isolated from Castilleja rubra, and the anti-inflammatory properties of these metabolites in a cell culture system were investigated. Compounds 1-3 suppressed not only the production of nitric oxide (NO) and prostaglandin E2, but also the expression of inducible NO synthase and cyclooxygenase-2 induced by lipopolysaccharide (LPS) in the RAW264.7 murine macrophage cell line. Compounds 1-3 also inhibited the release of pro-inflammatory cytokines induced by LPS, namely, tumor necrosis factor-α and interleukin-1ß. The underlying mechanism of the anti-inflammatory action of compounds 1-3 was associated with downregulation of nuclear factor-κB.

KCHO-1, a Novel Antineuroinflammatory Agent, Inhibits Lipopolysaccharide-Induced Neuroinflammatory Responses through Nrf2-Mediated Heme Oxygenase-1 Expression in Mouse BV2 Microglia Cells.

The brain is vulnerable to oxidative stress and inflammation that can occur as a result of aging or neurodegenerative diseases. Our work has sought to identify natural products that regulate heme oxygenase (HO)-1 and to determine their mechanism of action in neurodegenerative diseases. KCHO-1 is a novel herbal therapeutic containing 30% ethanol (EtOH) extracts from nine plants. In this study, we investigated the antineuroinflammatory effects of KCHO-1 in lipopolysaccharide- (LPS-) treated mouse BV2 microglia. KCHO-1 inhibited the protein expression of inducible nitric oxide synthase (iNOS), iNOS-derived nitric oxide (NO), cyclooxygenase- (COX-) 2, and COX-2-derived prostaglandin E2 (PGE2) in LPS-stimulated BV2 microglia. It also reduced tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 production. This effect was correlated with the suppression of inhibitor of nuclear factor kappa B-α (IκB-α) phosphorylation and degradation and nuclear factor kappa B (NF-κB) translocation and DNA binding. Additionally, KCHO-1 upregulated HO-1 expression by promoting nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) in mouse BV2 microglia. Tin protoporphyrin (SnPP), an HO activity inhibitor, was used to verify the inhibitory effects of KCHO-1 on proinflammatory mediators and proteins associated with HO-1 expression. Our data suggest that KCHO-1 has therapeutic potential in neurodegenerative diseases caused by neuroinflammation.