Esculentoside B inhibits inflammatory response through JNK and downstream NF-κB signaling pathway in LPS-triggered murine macrophage RAW 264.7 cells.

Natural compound esculentoside B (EsB), (2S,4aR,6aR,6aS,6bR,8aR,9R,10R,11S,12aR,14bS)-11-hydroxy-9-(hydroxymethyl)-2 methoxycarbonyl-2,6a,6b,9,12a-pentamethyl-10-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxy-1,3,4,5,6,6a,7,8,8a,10,11,12,13,14b-tetradecahydropicene-4a-carboxylic acid with molecular weight of 664.833, isolated from roots of Phytolacca acinosa Roxb has been widely used as a constituent of traditional Chinese medicine (TCM). However, the anti-inflammatory capacity of EsB has not been reported yet. Therefore, the objective of this study was to investigate anti-inflammatory activities of EsB in LPS-treated macrophage RAW 264.7 cells. EsB could inhibit nitric oxide (NO) production. EsB also suppressed gene and protein expression levels of inducible isoform of NO synthase (NOS) and cyclooxygenase-2 in a dose-dependent manner. In addition, EsB decreased gene expression and protein secretion levels of pro-inflammatory cytokines such as IL-1ß, TNF-α, and IL-6. EsB remarkably suppressed nuclear translocation of nuclear factor kappa-B (NF-κB) from cytosolic space. Phosphorylation of IκB was also inhibited by EsB. Moreover, EsB specifically down-regulated phospho-c-Jun N-terminal kinase (p-JNK), but not p-p38 or phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2). Taken together, these results suggest that EsB has inhibitory effect on inflammatory response by inactivating NF-κB and p-JNK. It could be used as a new modulatory drug for effective treatment of inflammation-related diseases.

Oldenlandia diffusa suppresses metastatic potential through inhibiting matrix metalloproteinase-9 and intercellular adhesion molecule-1 expression via p38 and ERK1/2 MAPK pathways and induces apoptosis in human breast cancer MCF-7 cells.

ETHNOPHARMACOLOGY RELEVANCE: Oldenlandia diffusa (OD) has long been known as an apoptotic inducer in breast tumors in ethnomedicine. AIM OF THE STUDY: To scientifically confirm the anti-breast cancer effects of water, methanol (MeOH) and butanol (BuOH) extracts of O. diffusa on cell apoptosis, matrix metalloproteinases (MMPs), intercellular adhesion molecule (ICAM)-1 and intracellular signaling in MCF-7 breast cancer cells. MATERIALS AND METHODS: MeOH extracts (MOD) and BuOH extracts (BOD) were prepared and examined for their ability to inhibit phorbol myristate acetate (PMA)-induced matrix metalloproteinase (MMP)-9 and intercellular adhesion molecule (ICAM)-1 expressions in MCF-7 human breast cancer cells. Additionally, transwell migration, invasion and transcriptional activity were assessed. Results of immunofluorescence confocal microscopy for translocation of NF-κB and p-ERK and p-p38 were also checked. Finally, apoptotic signals including processed caspase-8, caspase-7, poly ADP-ribose polymerase, Bax and Bcl-2 were examined. RESULTS: MOD and BOD specifically inhibited PMA-induced MMP-9 expression as well as invasive and migration potential via ICAM-1. The inhibitory activity was also based on the suppressed transcriptional activity in MCF-7 breast cancer cells. Results of immunofluorescence confocal microscopy showed that translocation of NF-κB decreased upon BOD and MOD treatments, with a decreased level of p-ERK and p-p38 phosphorylation. In addition, treatment of MCF-7 cells with MOD and BOD activated apoptosis-linked proteins including enzymatically active forms of processed caspase-8, caspase-7 and poly ADP-ribose polymerase, together with increased expression of mitochondrial apoptotic protein, Bax and decreased expression of Bcl-2. CONCLUSION: The results indicate that OD as an anti-metastatic agent suppresses the metastatic response by targeting p-ERK, p-38 and NF-κB, thus reducing the invasion capacity of MCF-7 breast cancer cells through inhibition of MMP-9 and ICAM-1 expression and plays an important role in the regulation of breast cancer cell apoptosis.

Progress in Studies on Rutaecarpine. II.--Synthesis and Structure-Biological Activity Relationships.

Rutaecarpine is a pentacyclic indolopyridoquinazolinone alkaloid found in Evodia rutaecarpa and other related herbs. It has a variety of intriguing biological properties, which continue to attract the academic and industrial interest. Studies on rutaecarpine have included isolation from new natural sources, development of new synthetic methods for its total synthesis, the discovery of new biological activities, metabolism, toxicology, and establishment of analytical methods for determining rutaecarpine content. The present review focuses on the synthesis, biological activities, and structure-activity relationships of rutaecarpine derivatives, with respect to their antiplatelet, vasodilatory, cytotoxic, and anticholinesterase activities.

15,16-Dihydrotanshinone I suppresses IgE-Ag stimulated mouse bone marrow-derived mast cell activation by inhibiting Syk kinase.

ETHNOPHARMACOLOGICAL RELEVANCE: 15,16-Dihydrotanshinone I (DHT-I), isolated from the dried root of Salvia miltiorrhiza Bung, which is traditionally used to treat cardiovascular and inflammatory diseases agent in Chinese medicine. DHT-I has been reported to have a broad range of biological activities, including antibacterial activity, and has been used to treat circulatory disorders, hepatitis, inflammation, cancer, and neurodegenerative diseases. AIM OF THE STUDY: The aim of this study was to evaluate the anti-allergic inflammatory effects of DHT-I on degranulation and on the generation of eicosanoids, such as, prostaglandin D2 (PGD2) and leukotriene C4 (LTC4), in IgE/Ag-stimulated bone marrow-derived mast cells (BMMCs). MATERIALS AND METHODS: The anti-allergic inflammatory activity of DHT-I was evaluated using BMMCs. The effects of DHT-I on mast cell activation were investigated by following degranulation and eicosanoid generation using ELISA and immunoblotting and immunoprecipitation techniques. RESULTS: DHT-I at a concentration of 20µM markedly inhibited degranulation and the generation of PGD2 and LTC4 in IgE/Ag-stimulated BMMCs (about 90% inhibitions, respectively). Analyses of FcεRI-mediated signaling pathways demonstrated that DHT-I inhibited the phosphorylations of spleen tyrosine kinase (Syk) and linker for activation of T cells (LAT), and inhibited downstream signaling process, including [Ca(2+)]i mobilization induced by the phosphorylation of phospholipase Cγ1 (PLCγ1), and the activations of mitogen-activated protein kinases (MAPKs) and the Akt-nuclear factor-κB (NF-κB) pathway. CONCLUSIONS: DHT-1 inhibits the release of allergic inflammatory mediators from IgE/Ag-stimulated mast cells by suppressing a FcεRI-mediated Syk-dependent signal pathway. This result suggests DHT-I offers a novel developmental basis for drugs targeting allergic inflammatory diseases.

B-cell translocation gene 2 promotes hepatic hepcidin production via induction of Yin Yang 1.

Hepcidin is a peptide hormone secreted in the liver and plays a key role in maintaining iron homeostasis. Here, we demonstrate that B-cell translocation gene 2 (BTG2) is a key player in hepatic hepcidin regulation via induction of Yin Yang 1 (YY1). Hepatic hepcidin gene expression significantly enhanced by fasting states and glucagon exposure led to induction of gluconeogenic gene expression, and elevated serum hepcidin production in mice. Notably, overexpression of BTG2 using adenoviral system (Ad-BTG2) significantly elevated serum hepcidin levels via a significant induction of YY1 gene transcription. Immunoprecipitation studies demonstrated that BTG2 physically interacted with YY1 and recruited on the hepcidin gene promoter. Finally, ablation of hepatic BTG2 gene by gene silencing markedly attenuated the elevation of serum hepcidin production along with YY1 and hepcidin mRNA expression in fasting state. Likewise, forskolin (FSK)-stimulated hepcidin promoter activity was dramatically disrupted by endogenous BTG2 knockdown. Overall, our current study provides a novel molecular mechanism of BTG2-mediated induction of hepcidin gene expression, thereby contributing to a better understanding of the hepatic hepcidin production involved in iron homeostasis.

Melittin has a chondroprotective effect by inhibiting MMP-1 and MMP-8 expressions via blocking NF-κB and AP-1 signaling pathway in chondrocytes.

Bee venom is a natural ingredient produced by the honey bee (Apis mellifera), and has been widely used in China, Korea and Japan as a traditional medicine for various diseases such as arthritis, rheumatism, and skin diseases However, the regulation of the underlying molecular mechanisms of the anti-arthritis by bee venom and its major peptides is largely unknown. In this study, we investigated the potential molecular mechanisms underlying the anti-arthritis effect of bee venom and its major peptides, melittin and apamin, in tumor necrosis factor-α (TNF-α) responsive C57BL/6 mice chondrocyte cells. The bee venom and melittin significantly and selectively suppressed the TNF-α-mediated decrease of type II collagen expression, whereas the apamin had no effects on the type II collagen expression. We, furthermore, found that the bee venom and melittin inhibited the protein expression of matrix metalloproteinase (MMP)-1 and MMP-8, which suggests that the chondroprotective effect of bee venom may be caused by melittin. The inhibitory effects of melittin on the TNF-α-induced MMP-1 and MMP-8 protein expression were regulated by the inhibition of NF-kB and AP-1. In addition, melittin suppressed the TNF-α-induced phosphorylation of Akt, JNK and ERK1/2, but did not affect the phosphorylation of p38 kinase. These results suggest that melittin suppresses TNF-α-stimulated decrease of type II collagen expression by the inhibiting MMP-1 and MMP-8 through regulation of the NF-kB and AP-1 pathway and provision of a novel role for melittin in anti-arthritis action.

Quality evaluation of Carthami Flos by HPLC-UV.

A HPLC-DAD method was developed for simultaneous determination of four marker compounds, kaempferol-3-O-rutinoside, safflomin A, safflomin B and bidenoside C, in the extract of the flowers of Carthamus tinctorius Linne. Natural samples were extracted in 50% aqueous methanol by ultra-sonication for 60 min. Marker compounds were separated on a C18 column by two-step gradient elution of mobile phase (acetonitrile/water) at a flow rate of 0.75 mL/min and detected at 210 nm. The retention times of safflomin A and safflomin B were shifted according to the pH of the mobile phase. The optimized analytical method was validated to confirm linearity, precision, accuracy and stability of marker compounds. The method was successfully employed to analyze 17 natural samples from different regions, and the data matrix was monitored and visualized by principal component analysis. The assay method could be applied for quality control of the flowers of C. tinctorius Linne.

Moringa fruit inhibits LPS-induced NO/iNOS expression through suppressing the NF-κ B activation in RAW264.7 cells.

In this study, we evaluated the anti-inflammatory effects of moringa (Moringa oleifera Lam.), a natural biologically active substance, by determining its inhibitory effects on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated macrophage RAW264.7 cells. Extracts from different parts of moringa (root, leaf, and fruit) reduced LPS-induced nitric oxide (NO) release in a dose-dependent manner. The moringa fruit extract most effectively inhibited LPS-induced NO production and levels of inducible nitric oxide synthase (iNOS). The moringa fruit extract also was shown to suppress the production of inflammatory cytokines including IL-1ß, TNF-α, and IL-6. Furthermore, moringa fruit extract inhibited the cytoplasmic degradation of I κ B -α and the nuclear translocation of p65 proteins, resulting in lower levels of NF -κ B transactivation. Collectively, the results of this study demonstrate that moringa fruit extract reduces the levels of pro-inflammatory mediators including NO , IL-1ß, TNF-α, and IL-6 via the inhibition of NF -κ B activation in RAW264.7 cells. These findings reveal, in part, the molecular basis underlying the anti-inflammatory properties of moringa fruit extract.

Pinusolide improves high glucose-induced insulin resistance via activation of AMP-activated protein kinase.

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) plays a crucial role in the maintenance of cellular energy homeostasis, and several natural compounds that activate AMPK possibly enhance glucose uptake by muscle cells. In this study, we found that pinusolide stimulated AMPK phosphorylation and glucose uptake and these effects were significantly reduced by siRNA LKB1 or compound C, suggesting that enhanced glucose uptake by pinusolide is predominantly accomplished via an LKB1-mediated AMPK activation pathway. An insulin resistance state was induced by exposing cells to 30mM glucose, as indicated by reduced insulin-stimulated tyrosine phosphorylation of IRS-1 and glucose uptake. Under these conditions, the phosphorylation of AMPK and ACC were decreased. Surprisingly, disrupted insulin signaling and decreased AMPK activity by high glucose concentrations were prevented by pinusolide. Moreover, this treatment increased insulin-stimulated glucose uptake via AMPK activation. Taken together, our findings suggest a link between high glucose and insulin resistance in muscle cells, and provide further evidence that pinusolide attenuates blockade of insulin signaling by enhancing IRS-1 tyrosine phosphorylation by the activating the AMPK pathway. In addition, this study indicates the targeting of AMPK represents a new therapeutic strategy for hyperglycemia-induced insulin resistance and type 2 diabetes.

Manassantin B isolated from Saururus chinensis inhibits cyclooxygenase-2-dependent prostaglandin D2 generation by blocking Fyn-mediated nuclear factor-kappaB and mitogen activated protein kinase pathways in bone marrow derived-mast cells.

The authors investigated the effect of manassantin B (Man B) isolated from Saururus chinensis (S. chinensis) on cyclooxygenase-2 (COX-2)-dependent prostaglandin D2 (PGD2) generation in mouse bone marrow derived-mast cells (BMMCs). Man B inhibited the generation of PGD2 dose-dependently by inhibiting COX-2 expression in immunoglobulin E (IgE)/Ag-stimulated BMMCs. To elucidate the mechanism responsible for the inhibition of COX-2 expression by Man B, the effects of Man B on the activation of nuclear factor-kappaB (NF-κB), a transcription factor essential and mitogen-activated protein kinases (MAPKs) for COX-2 induction, were examined. Man B attenuated the nuclear translocation of NF-κB p65 and its DNA-binding activity by inhibiting inhibitors of kappa Bα (IκBα) degradation and concomitantly suppressing IκB kinase (IKK) phosphorylation. In addition, Man B suppressed phosphorylation of MAPKs including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK) and p38. It was also found that Man B suppressed Fyn kinase activation and consequent downstream signaling processes, including those involving Syk, Gab2, and Akt. Taken together, the present results suggest that Man B suppresses COX-2 dependent PGD2 generation by primarily inhibiting Fyn kinase in FcεRI-mediated mast cells.

Quality assessment and discrimination of the roots of Cynanchum auriculatum and Cynanchum wilfordii by HPLC-UV analysis.

Cynanchum auriculatum and Cynanchum wilfordii are widely used as folk medicine in Eastern Asia. However, the indeterminacy in the authentic original plant material has resulted in the same appellative name being given to the two plants, and they are commonly misused. Therefore, it is necessary to establish an analytical method for discrimination as well as quality control of the two species. This study was to develop HPLC-UV methods for quality assessment of C. auriculatum and C. wilfordii and discrimination between the two species. Two HPLC methods to analyze eight marker compounds were established and validated. The first method analyzed seven marker compounds simultaneously on a reversed-phase column, while the second method analyzed a single marker compound, conduritol F, which exists only in C. wilfordii, on a Si-column. Thirty-nine batches of C. auriculatum and nineteen batches of C. wilfordii that were collected from different geographical regions of South Korea were analyzed by these methods. The constructed data matrix was subjected to principal components analysis and hierarchical cluster analysis in order to classify the samples. The established methods offer a potential strategy for authentication and differentiation of the two species.

Inhibition of prostaglandin D2 production by trihydroxy fatty acids isolated from Ulmus davidiana var. japonica.

The stem and root barks of Ulmus davidiana var. japonica (Ulmaceae) have been used to treat inflammatory diseases including mastitis, rhinitis, sinusitis, and enteritis. In an ongoing study focused on the discovery of natural anti-inflammatory compounds from natural products, a methanol extract of the stem and root barks of U. davidiana var. japonica showed anti-inflammatory activities. Activity-guided fractionation of the methanol extract yielded a new trihydroxy fatty acid, 9,12,13-trihydroxyoctadeca-10(Z),15(Z)-dienoic acid (1), and a known compound, pinellic acid (2). These two trihydroxy fatty acids 1 and 2 inhibited prostaglandin D2 production with IC50 values of 25.8 and 40.8 µM, respectively. These results suggest that 9,12,13-trihydroxyoctadeca-10(Z),15(Z)-dienoic acid (1) and pinellic acid (2) are among the anti-inflammatory principles in this medicinal plant.

Tanshinone IIA improves endoplasmic reticulum stress-induced insulin resistance through AMP-activated protein kinase.

The aim of the present study was to determine the effect of Tanshinone IIA (Tan IIA) on endoplasmic reticulum (ER) stress-induced insulin resistance in L6 myotubes and db/db mice. ER stress markers, RNA-activated protein kinase-like ER resident kinase (PERK), JNK, and AMPK activity were determined in tunicamycin-treated L6 myotubes. Insulin resistance was monitored using glucose uptake assays in vitro and blood glucose levels in vivo. Tan IIA clearly suppressed the phosphorylations of PERK and JNK and potentiated insulin-mediated Akt phosphorylation as well as glucose uptake via AMPK activation under ER stress. Furthermore, these effects are completely abrogated by siRNA-mediated knockdown of AMPK or LKB1. In addition, Tan IIA reduced blood glucose levels and body weights in db/db mice without altering food intake. These findings suggest that Tan IIA enhances insulin sensitivity and improves glucose metabolic disorders by increasing AMPK activity and attenuating ER stress-induced insulin resistance.

High-performance liquid chromatographic analysis for quantitation of marker compounds of Artemisia capillaris Thunb.

Two stable high-performance liquid chromatography (HPLC) methods were developed that could quantitatively analyze 10 major marker compounds of Artemisia capillaris Thunb and could also distinguish among 'Injinho' and 'Myeon-injin' and 'Haninjin'--A. capillaris collected in autumn, A. capillaris collected in spring and A. iwayomogi, which can be misused as 'Injinho' in Korean herbal drug markets. The first HPLC method was a reversed-phase chromatography using a C18 column with an isocratic solvent system of phosphoric acid (0.05%) and acetonitrile at the flow rate of 1.0 mL/min, ultraviolet (UV) detection wavelength at 254 nm and column temperature at 40°C. Calibration and quantitation were made by using acetaminophen as an internal standard (I.S-A) and chlorogenic acid (1) was determined within 20 min. The second HPLC method was a reversed-phase chromatography using a C18 column with a gradient solvent system of phosphate buffer (0.015 M, pH 6) and acetonitrile at the flow rate of 1.0 mL/min, UV detection wavelength at 254 nm and column temperature at 40°C. Calibration and quantitation were made by using ethylparaben as an internal standard (I.S-B) and 3,5-di-O-caffeoylquinic acid (2), 3,4-di-O-caffeoylquinic acid (3), 4,5-di-O-caffeoylquinic acid (4), hyperoside (5), isoquercitrin (6), isorhamnetin 3-O-robinobioside (7), isorhamnetin-3-O-galactoside (8), isorhamnetin-3-O-glucoside (9) and scoparone (10) were determined within 60 min. Pattern recognition analysis of data from the 60 samples classified them clearly into three groups. These assay methods could be applied for QA/QC of A. capillaris and Artemisia iwayomogi.

Saucerneol D inhibits eicosanoid generation and degranulation through suppression of Syk kinase in mast cells.

Previously we reported that saucerneol D (SD), a naturally occurring sesquilignan isolated from Saururus chinensis (S. chinensis) suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells. The aim of this study was to elucidate whether SD modulates the generation of other inflammatory mediators in activated mast cells. We investigated the effects of SD on cyclooxygenase-2 (COX-2)-dependent prostaglandin D(2) (PGD(2)) and 5-lipoxygenase (5-LO)-dependent leukotriene C(4) (LTC(4)) generations as well as degranulation in cytokine-stimulated mouse bone marrow-derived mast cells (BMMCs). Biochemical analyses of the cytokine-mediated signaling pathways showed that SD suppressed the phosphorylation of Syk kinase and multiple downstream signaling processes including phospholipase Cγ1 (PLCγ1)-mediated intracellular Ca(2+) influx and activation of mitogen-activated protein kinases (MAPKs; including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH(2)-terminal kinase (JNK) and p38) and the nuclear factor-κB (NF-κB) pathway. Taken together, the present study suggests that SD suppresses eicosanoid generation and degranulation through Syk-dependent pathway in BMMCs.

Pinusolide isolated from Biota orientalis inhibits 5-lipoxygenase dependent leukotriene C4 generation by blocking c-Jun N-terminal kinase pathway in mast cells.

Pinusolide, an herbal medicine isolated from Biota orientalis L. (B. orientalis), inhibited 5-lipoxygenase (5-LO)-dependent leukotriene C4 (LTC4) generation in immunoglobulin E (IgE)/Ag-induced bone marrow-derived mast cells (BMMCs) in a concentration-dependent manner. To clarify the action mechanism of pinusolide on the inhibition of LTC4 generation, we examined the effect of pinusolide on phosphorylation of cytosolic phospholipase A2 (cPLA2), as well as translocation phospho-cPLA2 and 5-LO to nucleus. Inhibition of LTC4 generation by pinusolide was accompanied by a decrease in cPLA2 phosphorylation which occurred via a decrease in intracellular Ca2+ influx and blocking the c-Jun N-terminal kinase (JNK) pathways. However, pinusolide had no effect on extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinas phosphorylation. Taken together, the present results suggest that potent inhibition of 5-LO dependent LTC4 generation by pinusolide requires both suppression of calcium influx and JNK phosphorylation.

Inula japonica extract inhibits mast cell-mediated allergic reaction and mast cell activation.

ETHNOPHARMACOLOGICAL RELEVANCE: The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for the treatment of bronchitis, digestive disorders, and inflammation. However, the mechanisms underlying its anti-inflammatory effects remain yet to be elucidated. The objectives of this study were 1) to assess the anti-allergic activity of the ethanol extract of flowers of Inula japonica extract (IFE) in vivo, 2) to investigate the mechanism of its action on mast cells in vitro, and 3) to identify its major phytochemical compositions. MATERIALS AND METHODS: The anti-allergic activity of IFE was evaluated using mouse bone marrow-derived mast cells (BMMCs) in vitro and a passive cutaneous anaphylaxis (PCA) animal model in vivo. The effects of IFE on mast cell activation were evaluated in terms of degranulation, eicosanoid generation, Ca(2+) influx, and immunoblotting of various signaling molecules. RESULTS: IFE inhibited degranulation and the generation of eicosanoids (PGD(2) and LTC(4)) in stem cell factor (SCF)-stimulated BMMCs. Biochemical analysis of the SCF-mediated signaling pathways demonstrated that IFE inhibited the activation of multiple downstream signaling processes including mobilization of intracellular Ca(2+) and phosphorylation of the mitogen-activated protein kinases (MAPKs), PLCγ1, and cPLA(2) pathways. When administered orally, IFE attenuated the mast cell-mediated PCA reaction in IgE-sensitized mice. Its major phytochemical composition included three sesquiterpenes, 1-O-acetylbritannilactone, britanin and tomentosin. CONCLUSIONS: This study suggests that IFE modulates eicosanoids generation and degranulation through the suppression of SCF-mediated signaling pathways that would be beneficial for the prevention of allergic inflammatory diseases. Anti-allergic activity of IFE may be in part attributed particularly to the presence of britanin and tomentosin as major components evidenced by a HPLC analysis.

Saucerneol F, a New Lignan Isolated from Saururus chinensis, Attenuates Degranulation via Phospholipase Cγ 1 Inhibition and Eicosanoid Generation by Suppressing MAP Kinases in Mast Cells.

During our on-going studies to identify bioactive compounds in medicinal herbs, we found that saucerneol F (SF), a naturally occurring sesquilignan isolated from Saururus chinensis (S. chinensis), showed in vitro anti-inflammatory activity. In this study, we examined the effects of SF on the generation of 5-lipoxygenase (5-LO) dependent leukotriene C4 (LTC4), cyclooxygenase-2 (COX-2) dependent prostaglandin D2 (PGD2), and on phospholipase Cγ1 (PLCγ1)-mediated degranulation in SCF-induced mouse bone marrow-derived mast cells (BMMCs). SF inhibited eicosanoid (PGD2 and LTC4) generation and degranulation dose-dependently. To identify the molecular mechanisms underlying the inhibition of eicosanoid generation and degranulation by SF, we examined the effects of SF on the phosphorylation of PLCγ1, intracellular Ca(2+) influx, the translocation of cytosolic phospholipase A2 (cPLA2) and 5-LO, and on the phosphorylation of MAP kinases (MAPKs). SF was found to reduce intracellular Ca(2+) influx by inhibiting PLCγ1 phosphorylation and suppressing the nuclear translocations of cPLA2 and 5-LO via the phosphorylations of MAPKs, including extracellular signal-regulated protein kinase-1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38. Taken together, these results suggest that SF may be useful for regulating mast cell-mediated inflammatory responses by inhibiting degranulation and eicosanoid generation.

Manassantin A isolated from Saururus chinensis inhibits 5-lipoxygenase-dependent leukotriene C4 generation by blocking mitogen-activated protein kinase activation in mast cells.

In this study, manassantin A (Man A), an herbal medicine isolated from Saururus chinensis (S. chinensis), markedly inhibited 5-lipoxygenase (5-LO)-dependent leukotriene C(4) (LTC(4)) generation in bone marrow-derived mast cells (BMMCs) in a concentration-dependent manner. To investigate the molecular mechanisms underlying the inhibition of LTC(4) generation by Man A, we assessed the effects of Man A on phosphorylation of cytosolic phospholipase A(2) (cPLA(2)) and mitogen-activated protein kinases (MAPKs). Inhibition of LTC(4) generation by Man A was accompanied by a decrease in cPLA(2) phosphorylation, which occurred via the MAPKs including extracellular signal-regulated protein kinase-1/2 (ERK1/2) as well as p38 and c-Jun N-terminal kinase (JNK) pathways. Taken together, the present study suggests the Man A represents a potential therapeutic approach for the treatment of airway allergic-inflammatory diseases.

Luteolin-7-O-glucoside suppresses leukotriene C(4) production and degranulation by inhibiting the phosphorylation of mitogen activated protein kinases and phospholipase Cγ1 in activated mouse bone marrow-derived mast cells.

In this study, luteolin-7-O-glucoside (L7G), an herbal medicine isolated from Ailanthus altissima, inhibited 5-lipoxygenase (5-LOX)-dependent leukotriene C(4) (LTC(4)) production in bone marrow-derived mast cells (BMMCs) in a concentration-dependent manner with an IC(50) of 3.0 µM. To determine the action mechanism of L7G, we performed immunoblotting for cytosolic phospholipase A(2) (cPLA(2)) and mitogen-activated protein kinases (MAPKs) following c-kit ligand (KL)-induced activation of BMMCs with or without L7G. Inhibition of LTC(4) production by L7G was accompanied by a decrease in cPLA(2) phosphorylation, which occurred via the extracellular signal-regulated protein kinase-1/2 (ERK1/2) and p38 and c-Jun N-terminal kinase (JNK) pathways. In addition, L7G also attenuated mast cell degranulation in a dose-dependent manner (IC(50), 22.8 µM) through inhibition of phospholipase Cγ1 (PLCγ1) phosphorylation. Our results suggest that the anti-asthmatic activity of L7G may be mediated in part via the inhibition of LTC(4) generation and mast cell degranulation.