Three Novel Monoterpenoid Glycosides From Fruits Of Eleutherococcus Henryi.

The phytochemical investigation on the fruits of Eleutherococcus henryi (Araliaceae) resulted in the discovery of three novel monoterpene glycosides, eleuhenryiside A (1), eleuhenryiside B (2), and eleuhenryiside C (3), as well as a known lignan, (-)-kobusin (4). Their chemical structures were elucidated by mass, 1 D- and 2 D-NMR spectroscopy. The chemical structures of new compounds 1-3 were determined to be (2E,6R)-6-hydroxy-2,6-dimethyl-2,7-octadien-1-yl-(6'-O-acetyl)-O-ß-glucopyranoside, (2Z,6R)-6-hydroxy-2,6-dimethyl-2,7-octadien-1-yl-(6'-O-acetyl)-O-ß-glucopyranoside, and (-)-(4 R)-4,7-dihydroxy-1-menthene 7-O-ß-glucopyranoside, respectively. The anti-neuroinflammatory and anti-inflammatory activities of these compounds were evaluated with LPS-stimulated BV2 microglia and RAW264.7 macrophage, respectively. The results showed that new compounds 1 and 3 have inhibitory effects of NO production with IC50 values of 32.50 ± 1.60 and 3.54 ± 0.20 µM in LPS-stimulated BV2 microglia. Also, (-)-kobusin (4) has abilities to inhibit NO production with the IC50 values of 14.25 ± 2.69 and 36.35 ± 6.27 µM in BV2 and RAW264.7 cells, respectively, which indicated that it may possess the potential anti-neuroinflammatory and anti-inflammatory activities.

Anti-neuroinflammatory effects of tryptanthrin from Polygonum tinctorium Lour. in lipopolysaccharide-stimulated BV2 microglial cells.

This study was conducted to isolate the anti-neuroinflammatory component(s) in the 80% EtOH extract of P. tinctoria, and to investigate underlying molecular mechanism of the anti-neuroinflammatory component(s) in LPS-induced BV2 microglial cells. To isolate the active component(s) in the extract, various chromatographic methods were employed, and the structures of the isolated secondary metabolites were determined mainly by analysis of spectroscopic data such as NMR and MS data. Tryptanthrin (1), isolated from P. tinctoria extract, significantly inhibited the protein expression of iNOS and COX-2, and reduced the levels of their products (NO and PGE2) in LPS-stimulated BV2 microglial cells. Tryptanthrin (1) also downregulated the production of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-1ß. These anti-neuroinflammatory effects of tryptanthrin (1) was elucidated to be correlated with inactivating NF-κB pathway by interrupting the phosphorylation and degradation of the inhibitor of κB-α protein, and inhibiting the DNA binding activity of NF-κB. In addition, tryptanthrin (1) suppressed the activation of p38 MAPK pathway. Furthermore, tryptanthrin (1) inhibited the TLR4 and MyD88 protein expression in LPS-stimulated BV2 microglial cells. Taken together, it was suggested that tryptanthrin (1) have anti-neuroinflammatory effect by regulating TLR4-MyD88-mediated several inflammatory pathways including p38 and NF-κB pathways in LPS-induced BV2 microglial cells.

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.

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.

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.

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.

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.