PGE2 Release Research Articles

Effects of hypoxia on bronchial and alveolar epithelial cells linked to pathogenesis in chronic lung disorders.

Introduction: Chronic lung disorders involve pathological alterations in the lung tissue with hypoxia as a consequence. Hypoxia may influence the release of inflammatory mediators and growth factors including vascular endothelial growth factor (VEGF) and prostaglandin (PG)E2. The aim of this work was to investigate how hypoxia affects human lung epithelial cells in combination with profibrotic stimuli and its correlation to pathogenesis. Methods: Human bronchial (BEAS-2B) and alveolar (hAELVi) epithelial cells were exposed to either hypoxia (1% O2) or normoxia (21% O2) during 24h, with or without transforming growth factor (TGF)-β1. mRNA expression of genes and proteins related to disease pathology were analysed with qPCR, ELISA or immunocytochemistry. Alterations in cell viability and metabolic activity were determined. Results: In BEAS-2B and hAELVi, hypoxia significantly dowregulated genes related to fibrosis, mitochondrial stress, oxidative stress, apoptosis and inflammation whereas VEGF receptor 2 increased. Hypoxia increased the expression of Tenascin-C, whereas both hypoxia and TGF-β1 stimuli increased the release of VEGF, IL-6, IL-8 and MCP-1 in BEAS-2B. In hAELVi, hypoxia reduced the release of fibroblast growth factor, epidermal growth factor, PGE2, IL-6 and IL-8, whereas TGF-β1 stimulus significantly increased the release of PGE2 and IL-6. TGF-β1 stimulated BEAS-2B cells showed a decreased release of VEGF-A and IL-8, while TGF-β1 stimulated hAELVi cells showed a decreased release of PGE2 and IL-8 during hypoxia compared to normoxia. Metabolic activity was significantly increased by hypoxia in both epithelial cell types. Discussion: In conclusion, our data indicate that bronchial and alveolar epithelial cells respond differently to hypoxia and profibrotic stimuli. The bronchial epithelium appears more responsive to changes in oxygen levels and remodelling processes compared to the alveoli, suggesting that hypoxia may be a driver of pathogenesis in chronic lung disorders.

Licochalcone A Inhibits Prostaglandin E2 by Targeting the MAPK Pathway in LPS Activated Primary Microglia.

Neuroinflammation and oxidative stress are conditions leading to neurological and neuropsychiatric disorders. Natural compounds exerting anti-inflammatory and anti-oxidative effects, such as Licochalcone A, a bioactive flavonoid present in a traditional Chinese herb (licorice), might be beneficial for the treatment of those disorders. Therefore, this study aimed to investigate the anti-inflammatory and anti-oxidative effects of Licochalcone A in LPS-activated primary rat microglia. Licochalcone A dose-dependently prevented LPS-induced PGE2 release by inhibiting the arachidonic acid (AA)/cylcooxygenase (COX) pathway decreasing phospholipase A2, COX-1, and COX-2 protein levels. Furthermore, LPS-induced levels of the cytokines IL-6 and TNFα were reduced by Licochalcone A, which also inhibited the phosphorylation and, thus, activation of the mitogen-activated protein kinases (MAPK) p38 MAPK and Erk 1/2. With the reduction of 8-iso-PGF2α, a sensitive marker for oxidative stress, anti-oxidative effects of Licochalcone A were demonstrated. Our data demonstrate that Licochalcone A can affect microglial activation by interfering in important inflammatory pathways. These in vitro findings further demonstrate the potential value of Licochalcone A as a therapeutic option for the prevention of microglial dysfunction related to neuroinflammatory diseases. Future research should continue to investigate the effects of Licochalcone A in different disease models with a focus on its anti-oxidative and anti-neuroinflammatory properties.

The dose-response effects of arachidonic acid on primary human skeletal myoblasts and myotubes.

Cellular inflammatory response, mediated by arachidonic acid (AA) and cyclooxygenase, is a highly regulated process that leads to the repair of damaged tissue. Recent studies on murine C2C12 cells have demonstrated that AA supplementation leads to myotube hypertrophy. However, AA has not been tested on primary human muscle cells. Therefore, the purpose of this study was to determine whether AA supplementation has similar effects on human muscle cells. Proliferating and differentiating human myoblasts were exposed to AA in a dose-dependent manner (50-0.80µM) for 48 (myoblasts) or 72 (myotubes) hours. Cell viability was tested using a 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay and cell counting; myotube area was determined by immunocytochemistry and confocal microscopy; and anabolic signaling pathways were evaluated by western blot and RT-PCR. Our data show that the treatment of primary human myoblasts treated with 50µM and 25µM of AA led to the release of PGE2 and PGF2α at levels higher than those of control-treated cells (p <0.001 for all concentrations). Additionally, 50µM and 25µM of AA suppressed myoblast proliferation, myotube area, and myotube fusion. Anabolic signaling indicated reductions in total and phosphorylated TSC2, AKT, S6, and 4EBP1 in myoblasts at 50µM of AA (p <0.01 for all), but not in myotubes. These changes were not affected by COX-2 inhibition with celecoxib. Together, our data demonstrate that high concentrations of AA inhibit myoblast proliferation, myotube fusion, and myotube hypertrophy, thus revealing potential deleterious effects of AA on human skeletal muscle cell health and viability.

Preimplantation apoptotic endometrial caspase-3–mediated phospholipase A2 activation: a potential component in programming uterine receptivity

To examine the activation and consequence of uterine apoptotic caspase-3 action on day 1 post coitus (dpc) in the pregnant mouse. Previously we have demonstrated that pregnant uterine caspase-3 activation from mid to late gestation isolated to the myometrial compartment is largely non-apoptotic and controls uterine quiescence. We have also previously demonstrated that apoptotic caspase-3 activation, isolated to the endometrial compartment at term regulated endometrial prostaglandin synthesis METHODS: Uteri were isolated from pseudo pregnant (PsP) and non-ligated controls (GD), unilateral (UL) and bilateral ligated (BL) uterine horn mouse models at 1, 3 and 6 dpc. Uteri were examined for apoptotic indices, such as caspase-3 activation and TUNEL staining. Immunohistochemical analysis identified the site of uterine apoptotic caspase-3 activation. The truncated form of phospholipase A2 (tiPLA2) was examined as a measure of apoptotic caspase-3 mediated iPLA2 activation. We have identified the site and impact of uterine apoptotic caspase-3 activation utilizing uteri isolated from non-pregnant control animals at estrous and diestrous and control pregnant mice at 1-19 dpc. Our analysis determined that apoptotic caspase-3 and iPLA2 activation were limited to the endometrial compartments of the control and unilateral ligated uteri on 1dpc and were not found in the pseudo pregnant or bilateral ligated uterine horn or on 3 or 6 dpc in the control and unilateral ligated uteri. In this study we determined that uterine caspase-3 activation on 1 dpc, which is endometrial and apoptotic in nature, may play a potential role in regulating the previously reported pre-implantation surge in endometrial PGE2 synthesis through apoptotic caspase-3 mediated iPLA2 activation. Our data indicates that the presence of a conceptus on 1 dpc likely triggers an increase in endometrial apoptotic caspase-3 mediated iPLA2 activation. iPLA2 when activated causes the hydrolysis of fatty acids resulting in arachidonic acid release and production of PGE2, which in early pregnancy has been demonstrated to act in a leutoprotective manner, prolonging progesterone synthesis and promoting uterine receptivity.

Epoxymicheliolide prevents dextran sulfate sodium-induced colitis in mice by inhibiting TAK1-NF-κB pathway and activating Keap1-NRF2 signaling in macrophages.

Ulcerative colitis (UC) is an unspecific colorectal inflammation associated with macrophages overactivation. Therefore, macrophage-targeted treatment has been considered a promising strategy for UC therapy. Epoxymicheliolide (EMCL) is a compound from Aucklandia lappa Decne, a TCM for treating gastrointestinal inflammatory diseases. The purpose of this study is to investigate the therapeutic effect of EMCL on DSS-induced mice colitis through the anti-inflammatory activity on macrophages and its underlying mechanisms. We found that EMCL inhibited the release of NO and PGE2 by down-regulating the expression of iNOS and COX2, while suppressed the expression of IL-1β, IL-6, and TNF-α in LPS-stimulated RAW264.7 macrophages. EMCL also inhibited NO production in LPS-activated peritoneal macrophages and TNFα-stimulated RAW264.7 cells. Moreover, EMCL blocked the phosphorylation of TAK1, IKKα/β, and IκBα, as well as IκBα degradation, thereby inhibiting the NF-κB pro-inflammatory signaling. Furthermore, EMCL decreased the intracellular ROS, by activating the NRF2 antioxidant pathway. CETSA and molecular docking showed that EMCL might form a covalent bond with Cys174 of TAK1 or Cya151 of Keap1, which may contribute to EMCL-mediated actions. Additionally, a thiol donor β-mercaptoethanol obviously abolished EMCL-mediated actions in vitro, suggesting the crucial role of the α, γ-unsaturated lactone of EMCL on its anti-inflammatory effects. Furthermore, EMCL not only ameliorated symptoms of colitis and colon barrier injury, but also decreased the levels of pro-inflammatory cytokines, MPO, NO, and MDA in DSS-challenged mice. Thus, our study demonstrated that EMCL ameliorated UC by targeting NF-κB and Nrf2 pathways, indicating it may server as a promising drug candidate for UC therapy.

Hedychium flavum flower essential oil: Chemical composition, anti-inflammatory activities and related mechanisms in vitro and in vivo

Ethnopharmacological relevanceHedychium flavum, an ornamental, edible, and medicinal plant, is extensively cultivated as a source of aromatic essential oils (EO). Its flower is a traditional Chinese medicine for treating inflammation-related diseases like indigestion, diarrhea, and stomach pain. In particular, H. flavum flower EO has been used in cosmetics and as an aromatic stomachic to treat chronic gastritis in China. Aim of the studyThis research aimed to analyze H. flavum flower EO's chemical composition and explore its anti-inflammatory activities and related mechanisms in vitro and in vivo. Materials and methodsEO's chemical composition was determined by GC-FID/MS analysis. For in vitro test, the anti-inflammatory activity of EO was demonstrated by measuring the LPS-induced release of NO, PGE2, IL-1β, TNF-α, and IL-6 in RAW264.7 macrophages, and then its related mechanisms were explored using qRT-PCR, western blot, and immunofluorescent staining analysis. Next, EO's in vivo anti-inflammatory potential was further evaluated using a xylene-induced ear edema model, in which ear swelling and TNF-α, IL-6, and IL-1β levels in serum and tissue were examined. ResultsThe main components of EO were β-pinene (20.2%), α-pinene (9.3%), α-phellandrene (8.3%), 1,8-cineole (7.1%), E-nerolidol (5.4%), limonene (4.4%), borneol (4.1%), and β-caryophyllene (3.7%). For the anti-inflammatory activities in vitro, EO dramatically reduced the LPS-stimulated NO and PGE2 release by suppressing the mRNA and protein expression of iNOS and COX-2. Meanwhile, it remarkably decreased IL-6, TNF-α, and IL-1β production by inhibiting their mRNA levels. Related mechanism studies indicated that it not only inhibited IκBα phosphorylation and degradation, leading to blockade of NF-κB nuclear transfer but also suppressed MAPKs (ERK, p38, and JNK) phosphorylation in LPS-stimulated RAW264.7 cells. Further in vivo assay showed that EO ameliorated xylene-induced ear edema in mice and reduced TNF-α, IL-6, and IL-1β levels in serum and tissue. ConclusionsH. flavum EO exerted significant anti-inflammatory activity in vivo and in vitro, and its mechanism of action is related to the inhibition of MAPK and NF-κB activation. Thus, H. flavum EO could be considered a novel and promising anti-inflammatory agent and possess high potential for utilization in the pharmaceutical field.

Network and Experimental Pharmacology to Decode the Action of Wendan Decoction Against Generalized Anxiety Disorder.

ObjectiveThe mechanism of Wendan Decoction (WDD) against Generalized Anxiety Disorder (GAD) was predicted by network pharmacology and validated by in vivo and in vitro experiments.MethodsThe targets of WDD for the treatment of GAD were obtained by a search of online databases. Further, PPI network and KEGG enrichment were used to identify the key targets and pathways. Ultimately, these key targets and pathways were validated by in vivo experiments on GAD mice modeled by repeated restraint stress (RRS) and in vitro experiments on inflammatory factor stimulated BV-2 cells.ResultsThrough searching the databases, the 137 ingredients of WDD that correspond to 938 targets and 4794 targets related to GAD were identified. Among them, 569 overlapping targets were considered as the therapeutic targets of WDD for GAD. PPI analysis showed that the inflammation-related proteins IL-6, TNF, SRC and AKT1 were the key targets, and KEGG enrichment suggested that PI3K/AKT and MAPK signaling pathways were key pathways of WDD in the treatment of GAD. In vivo experiments, RRS mice exhibited abnormality in behavioristics in open field test (OFT) and elevated plus maze (EPM) and increases in serum corticosterone and the percentage of lymphocytes positive for IL-6 in peripheral blood. These abnormal changes can be reversed by WDD and the positive control drug paroxetine. In vitro experiments, WDD can inhibit IL-6 induced activation of PI3K/AKT and MAPK signaling pathways in BV2 cells, and suppress the ensuing release of inflammatory factors TNF-α, IL-1β and PGE2, and showed a dose-dependent effect.ConclusionWDD is able to resist GAD by relieving inflammatory response in peripheral and central system.

Cigarette smoke is associated with up-regulation of inducible NOS and COX-2 protein expression and activity in granulosa cells of women undergoing in vitro fertilization

Cigarette smoke exposure represents a well-established ovotoxic exogenous stress, but the molecular mechanisms underlying of this effect are still unclear. Cigarette smoke upregulates inflammatory genes in the female reproductive organs, therefore an abnormal inflammation response may contribute to the impairment of female fertility. In this study we investigated for the first time the effect of cigarette smoke exposure on NOS and COX expression and activity and on their transcription factors (CREB and NF-kB) in human GCs and on the release of NO and PGE2 in the FF in smoking and non-smoking patients undergoing IVF treatment. In addition, correlation analysis between AMH serum levels, an index of ovarian reserve, and smoking exposure or iNOS and COX-2 protein expression levels were performed using a Pearson correlation method. Cigarette smoke exposure resulted in a significant increase of iNOS and COX-2 protein expression together with an increase of iNOS activity and PGE2 levels. pNF-kB and pCREB protein expression were upregulated in the GCs of smokers compared to non-smokers. The habit of smoking was negatively correlated with serum AMH levels, and positively correlated with iNOS and COX-2 protein expression levels. The data presented in the current study revealed a novel molecular mechanism underlying the toxic effects of cigarette smoke on fertility. Additional pathways mediating the effects of cigarette smoke exposure in human GCs cannot be excluded and should be investigated in future studies.

Adverse effect of FTY720P on colonic Na+ /K+ ATPase is mediated via ERK, p38MAPK, PKC, and PI3K.

FTY720P, an analogue of sphingosine 1-phosphate, has emerged lately as a potential causative agent of inflammatory bowel disease, in which electrolytes movements driven by the sodium gradient established by the Na+ /K+ ATPase are altered. We showed previously in Caco-2 cells, a 50% FTY720P-induced decrease in the ATPase activity, mediated via S1PR2 and PGE2. This work aims at delineating the mechanism underlying PGE2 release and at investigating if the ATPase inhibition is due to changes in its abundance. The activity of the ATPase and the localization of a GFP-tagged Na+ /K+ -ATPase α1 -subunit were assessed in cells treated with 7.5nM FTY720P. The involvement of ERK, p38 MAPK, PKC, and PI3K was studied in cells treated with 7.5nM FTY720P or 1nM PGE2 in presence of their inhibitors, or by determining changes in the protein expression of their activated phosphorylated forms. Imaging data showed ∼30% reduction in the GFP-tagged Na+ /K+ ATPase at the plasma membrane. Both FTY720P and PGE2 showed, respectively, 50% and 60% reduction in ATPase activity that disappeared when p38 MAPK, PKC, and PI3K were inhibited individually but not with ERK inhibition. The effect of FTY720P was imitated by PMA, an activator of PKC. Western blotting revealed inhibition of ERK by FTY720P. It was concluded that FTY720P, through activation of S1PR2, downregulates the Na+ /K+ ATPase by inhibiting ERK, which in turn activates p38 MAPK leading to the sequential activation of PKC and PI3K, PGE2 release, and a decrease in the Na+ /K+ ATPase activity and membrane abundance.

Bothrops moojeni snake venom induces an inflammatory response in preadipocytes: Insights into a new aspect of envenomation.

Bothrops envenomation is a public health problem in Brazil. Despite the advances in the knowledge of the pathogenesis of systemic and local effects induced by Bothrops venom, the target tissues to this venom are not completely characterised. As preadipocytes are important cells of the adipose tissue and synthesize inflammatory mediators, we investigated the ability of B. moojeni snake venom (Bmv) to stimulate an inflammatory response in 3T3-L1 preadipocytes in vitro, focusing on (1) the release of PGE2, IL-6, TNF-α, MCP-1, KC, leptin and adiponectin; (2) the mechanisms involved in PGE2 release and (3) differentiation of these cells. Cytotoxicity of Bmv was determined by MTT assay. The concentrations of PGE2, cytokines and adipokines were quantified by EIA. Participation of the COX-1 and COX-2 enzymes, NF-κB and PGE2 receptors (EP1-4) was assessed using a pharmacological approach, and protein expression of the COX enzymes and P-NF-κB was analysed by western blotting. Preadipocyte differentiation was quantified by Oil Red O staining. Bmv (1 μg/mL) induced release of PGE2, IL-6 and KC and increased expression of COX-2 in preadipocytes. Basal levels of TNF-α, MCP-1, leptin and adiponectin were not modified. Treatment of cells with SC560 (COX-1 inhibitor) and NS398 (COX-2 inhibitor) inhibited Bmv-induced PGE2 release. Bmv induced phosphorylation of NF-κB, and treatment of the cells with TPCK and SN50, which inhibit distinct NF-κB domains, significantly reduced Bmv-induced PGE2 release, as did the treatment with an antagonist of PGE2 receptor EP1, unlike treatment with antagonists of EP2, EP3 or EP4. Bmv also induced lipid accumulation in differentiating cells. These results demonstrate that Bmv can activate an inflammatory response in preadipocytes by inducing the release of inflammatory mediators; that PGE2 production is mediated by the COX-1, COX-2 and NF-κB pathways; and that engagement of EP1 potentiates PGE2 synthesis via a positive feedback mechanism. Our findings highlight the role of the adipose tissue as another target for Bmv and suggest that it contributes to Bothrops envenomation by producing inflammatory mediators.

Osteocytes regulate bone anabolic response to mechanical loading in male mice via activation of integrin α5

Physical mechanical stimulation can maintain and even increase bone mass. Here, we report an important role of osteocytic integrin α5 in regulating the anabolic response of bone to mechanical loading using an Itga5 conditional gene knockout (cKO) mouse model. Integrin α5 gene deletion increased apoptotic osteocytes and reduced cortical anabolic responses to tibial compression including decreased endosteal osteoblasts and bone formation, and increased endosteal osteoclasts and bone resorption, contributing to the decreased bone area fraction and biomechanical properties, leading to an enlarged bone marrow area in cKO mice. Similar disruption of anabolic responses to mechanical loading was also detected in cKO trabecular bone. Moreover, integrin α5 deficiency impeded load-induced Cx43 hemichannel opening, and production and release of PGE2, an anabolic factor, resulting in attenuated effects of the loading on catabolic sclerostin (SOST) reduction and anabolic β-catenin increase. Together, this study shows an indispensable role of integrin α5 in osteocytes in the anabolic action of mechanical loading on skeletal tissue through activation of hemichannels and PGE2-evoked gene expression. Integrin α5 could act as a potential new therapeutic target for bone loss, especially in the elderly population with impeded mechanical sensitivity.

Osteoarthritis-Induced Metabolic Alterations of Human Hip Chondrocytes.

Osteoarthritis (OA) alters chondrocyte metabolism and mitochondrial biology. We explored whether OA and non-OA chondrocytes show persistent differences in metabolism and mitochondrial function and different responsiveness to cytokines and cAMP modulators. Hip chondrocytes from patients with OA or femoral neck fracture (non-OA) were stimulated with IL-1β, TNF, forskolin and opioid peptides. Mediators released from chondrocytes were measured, and mitochondrial functions and glycolysis were determined (Seahorse Analyzer). Unstimulated OA chondrocytes exhibited significantly higher release of IL-6, PGE2 and MMP1 and lower production of glycosaminoglycan than non-OA chondrocytes. Oxygen consumption rates (OCR) and mitochondrial ATP production were comparable in unstimulated non-OA and OA chondrocytes, although the non-mitochondrial OCR was higher in OA chondrocytes. Compared to OA chondrocytes, non-OA chondrocytes showed stronger responses to IL-1β/TNF stimulation, consisting of a larger decrease in mitochondrial ATP production and larger increases in non-mitochondrial OCR and NO production. Enhancement of cAMP by forskolin prevented IL-1β-induced mitochondrial dysfunction in OA chondrocytes but not in non-OA chondrocytes. Endogenous opioids, present in OA joints, influenced neither cytokine-induced mitochondrial dysfunction nor NO upregulation. Glycolysis was not different in non-OA and OA chondrocytes, independent of stimulation. OA induces persistent metabolic alterations, but the results suggest upregulation of cellular mechanisms protecting mitochondrial function in OA.

Cyclooxygenase-Derived Prostaglandin E2 Drives IL-1-Independent Mycobacterium bovis Bacille Calmette-Guérin-Triggered Skin Dendritic Cell Migration to Draining Lymph Node.

Inoculation of Mycobacterium bovis Bacille Calmette-Guérin (BCG) in the skin mobilizes local dendritic cells (DC) to the draining lymph node (dLN) in a process that remains incompletely understood. In this study, a mouse model of BCG skin infection was used to investigate mechanisms of skin DC migration to dLNs. We found enhanced transcription of cyclooxygenase (COX)-2 and production of COX-derived PGE2 early after BCG infection in skin. Animals treated with antagonists for COX or the PGE2 receptors EP2 and EP4 displayed a marked reduction in the entry of skin DCs and BCG to dLNs, uncovering an important contribution of COX-derived PGE2 in this migration process. In addition, live BCG bacilli were needed to invoke DC migration through this COX-PGE2 pathway. Having previously shown that IL-1R partially regulates BCG-induced relocation of skin DCs to dLNs, we investigated whether PGE2 release was under control of IL-1. Interestingly, IL-1R ligands IL-1α/β were not required for early transcription of COX-2 or production of PGE2 in BCG-infected skin, suggesting that the DC migration-promoting role of PGE2 is independent of IL-1α/β in our model. In DC adoptive transfer experiments, EP2/EP4, but not IL-1R, was needed on the moving DCs for full-fledged migration, supporting different modes of action for PGE2 and IL-1α/β. In summary, our data highlight an important role for PGE2 in guiding DCs to dLNs in an IL-1–independent manner.

COX-2 is required to mediate crosstalk of ROS-dependent activation of MAPK/NF-κB signaling with pro-inflammatory response and defense-related NO enhancement during challenge of macrophage-like cell line with Giardia duodenalis.

Giardia duodenalis, the causative agent of giardiasis, is among the most important causes of waterborne diarrheal diseases around the world. Giardia infection may persist over extended periods with intestinal inflammation, although minimal. Cyclooxygenase (COX)-2 is well known as an important inducer of inflammatory response, while the role it played in noninvasive Giardia infection remains elusive. Here we investigated the regulatory function of COX-2 in Giardia-induced pro-inflammatory response and defense-related nitric oxide (NO) generation in macrophage-like cell line, and identified the potential regulators. We initially found that Giardia challenge induced up-regulation of IL-1β, IL-6, TNF-α, prostaglandin (PG) E2, and COX-2 in macrophages, and pretreatment of the cells with COX-2 inhibitor NS398 reduced expressions of those pro-inflammatory factors. It was also observed that COX-2 inhibition could attenuate the up-regulated NO release and inducible NO synthase (iNOS) expression induced by Giardia. We further confirmed that Giardia-induced COX-2 up-regulation was mediated by the phosphorylation of p38 and ERK1/2 MAPKs and NF-κB. In addition, inhibition of reactive oxygen species (ROS) by NAC was shown to repress Giardia-induced activation of MAPK/NF-κB signaling, up-regulation of COX-2 and iNOS, increased levels of PGE2 and NO release, and up-expressions of IL-1β, IL-6, and TNF-α. Collectively, in this study, we revealed a critical role of COX-2 in modulating pro-inflammatory response and defense-related NO production in Giardia-macrophage interactions, and this process was evident to be controlled by ROS-dependent activation of MAPK/NF-κB signaling. The results can deepen our knowledge of anti-Giardia inflammatory response and host defense mechanisms.

New Lanostane-Type Triterpenes with Anti-Inflammatory Activity from the Epidermis of Wolfiporia cocos.

A chemical study on the epidermis of cultivated edible mushroom Wolfiporia cocos resulted in the isolation and identification of 46 lanostane triterpenoids, containing 17 new compounds (1-17). An experimental determination of their anti-inflammatory activity showed that poricoic acid GM (39) most strongly inhibited NO production in LPS-induced RAW264.7 murine macrophages with an IC50 value at 9.73 μM. Furthermore, poricoic acid GM induced HO-1 protein expression and inhibited iNOS and COX2 protein expression as well as the release of PGE2, IL-1β, IL-6, TNF-α, and reactive oxygen species (ROS) in LPS-induced RAW264.7 cells. Mechanistically, poricoic acid GM suppressed the phosphorylation of the IκBα protein, which prevented NF-κB from entering the nucleus to lose transcriptional activity and inhibited the dissociation of Keap1 from Nrf2, thereby activating Nrf2 into the nucleus to regulate antioxidant genes. Furthermore, the MAPK signaling pathway may play a significant role in poricoic acid GM-induced elimination of inflammation. This work further confirms that lanostane triterpenoids are key ingredients responsible for the anti-inflammatory properties of the edible medicinal mushroom W. cocos.

Sanguinarine-Chelerythrine Fraction of Coptis chinensis Exerts Anti-inflammatory Activity in Carrageenan Paw Oedema Test in Rats and Reveals Reduced Gastrotoxicity.

Inflammatory diseases are a common therapeutic problem and nonsteroidal anti-inflammatory drugs are not deprived of side effects, of which ulcerogenic activity is one of the most frequent. The aim of the study was to evaluate the anti-inflammatory activity of the sanguinarine-chelerythrine (SC) fraction of Coptis chinensis and its influence on the integrity of gastric mucosa. The study was conducted on sixty male rats randomly divided into six experimental groups: two control groups (a negative control group CON and a positive control group CAR); three groups receiving an investigational fraction of C. chinensis (1, 5, 10 mg/kg i.g.) named SC1, SC5, and SC10, respectively; and a group receiving indomethacin (IND) (10 mg/kg i.g.) as a reference drug. In all animals, the carrageenan-induced paw oedema was measured; PGE2 release, TNFα production, and MMP-9 concentration in inflamed tissue were determined. Additionally, the macroscopic and microscopic damage of gastric mucosa was evaluated. Administration of SC dose-dependently inhibited the second phase of carrageenan rat paw oedema and PGE2 release, decreased the production of TNFα, and reduced the concentration of MMP-9, and the efficacy of the highest dose was comparable to the effect of IND. Contrary to IND, no gastrotoxic activity of SC was detected. The investigated sanguinarine-chelerythrine fraction of C. chinensis seems to be a promising candidate for further research on new anti-inflammatory and analgesic drugs characterized with a safer gastric profile compared to existing NSAIDs.

Glaucocalyxin A Attenuates IL-1β-Induced Inflammatory Response and Cartilage Degradation in Osteoarthritis Chondrocytes via Inhibiting the Activation of NF-κB Signaling Pathway.

Glaucocalyxin A (GLA) is a bioactive natural compound with anti-inflammatory activity. Herein, the role of GLA in osteoarthritis (OA) was evaluated. Our results demonstrated that the IL-1β-induced inducible nitric oxide synthase (iNOS) and cyclooygenase-2 (COX-2) expression, two enzymes resulting in the release of nitric oxide (NO) and PGE2, were also prevented by GLA in chondrocytes. Moreover, GLA suppressed inflammatory cytokines production in chondrocytes. In addition, the elevated expressions of MMPs and ADAMTSs and the degradation of aggrecan and collagen II were reversed by GLA in chondrocytes. Furthermore, GLA decreased p-p65 level and suppressed the nuclear p65 accumulation in the nucleus of chondrocytes. Collectively, we concluded that GLA attenuated inflammatory response in chondrocytes via NF-κB pathway. These findings suggested that GLA might become an effective agent for OA treatment.

Ameliorative effect of the ethnomedicinal plant Blepharis maderaspatensis (L.) B.Heyne ex Roth on lipopolysaccharide-induced acute liver inflammation and oxidative stress in Wistar rat model

BackgroundBlepharis maderaspatensis is an ethnomedicinal plant used by the Mavilan and Koraga tribes of Kerala state, India for the treatment of liver diseases. Thus, the present study aims to evaluate the liver protective activity of defatted ethanolic extract of B. maderaspatensis on lipopolysaccharide-induced acute liver inflammation and oxidative stress in Wistar rat model. MethodsPreliminary phytochemical evaluation and high-performance thin-layer chromatography fingerprint validation were performed. The total phenolic and flavonoid contents were measured using the Folin-Ciocalteu method and the aluminium chloride method, respectively. The acute oral toxicity study was conducted in Swiss albino mice in accordance with OECD 423 guideline. Effect of defatted ethanolic extract of the whole plant of B. maderaspatensis (BmE) on liver inflammation was evaluated in LPS-induced Wistar rat model. The rats were treated with BmE (100, 250 and 500 mg/kg body weight) once daily for 7 days prior to the LPS (single dose i.p., 10 mg/kg b.w.) challenge. Liver tissue biochemicals (ALT, AST and ALP), and antioxidant status (SOD, CAT, GSH, MDA, NO and MPO) in euthanised experimental rats were carried out using commercial kits/standard procedures. Haematology (RBC, WBC, Hb and PLT; 4 and 24 h), and histopathology analysis were also performed. Serum IL-1β, IL-6, TNF-α and PGE2 production were determined by ELISA. The expressions of COX-2, iNOS, IL-1β, IL-6, TNF-α and NF-κB were analysed by qRT-PCR. Phosphorylation of IκB-α was measured by Western blotting. LC-MS analysis of BmE was also performed. ResultsThe LD50 value of BmE was found to be >5000 mg/kg b.w. BmE500 showed significant protection from LPS-induced liver injury as evidenced by reduced serum enzyme levels (AST, ALT and ALP; p≤ 0.001) and markedly improved the liver antioxidant status (MDA, GSH, SOD and CAT; p≤ 0.001), when compared to the LPS alone treated group. Haematology (24 h, RBC, WBC, Hb and PLT; p≤ 0.001) and histopathology also supported the above results. BmE500 pre-treatment significantly suppressed the LPS-induced expression of iNOS (p≤ 0.001) and COX-2 (p≤ 0.001), and the subsequent release of NO (p≤ 0.001) and PGE2 (p≤ 0.001). Moreover, BmE500 inhibited the gene expression of pro-inflammatory cytokines, including IL-1β (p≤ 0.001), IL-6 (p≤ 0.001), and TNF-α (p≤ 0.01), which is supported by ELISA results. In addition, BmE500 markedly attenuated the activation of transcription factor NF-κB (p≤ 0.001) as well as phosphorylation of IκBα, as evidenced from the qRT-PCR and Western blot analysis, respectively. The silymarin (100 mg/kg b.w.) drug standard also showed significant improvement in all parameters analysed. ConclusionResults of the present investigation suggest that BmE has a significant protective effect on LPS-induced acute liver inflammation via attenuating inflammatory reactions, evidenced by the inhibition of NF-κB signalling cascade, and also through its antioxidant effects. Thus, the pharmacological data generated provide experimental evidence that clearly justifies the use of B. maderaspatensis as a liver protective agent in tribal medicine.

Mucosal Serotonin Reuptake Transporter Expression in Irritable Bowel Syndrome Is Modulated by Gut Microbiota Via Mast Cell–Prostaglandin E2

Increased colonic serotonin (5-HT) level and decreased serotonin reuptake transporter (SERT) expression in irritable bowel syndrome (IBS) may contribute to diarrhea and visceral hypersensitivity. We investigated whether mucosal SERT is modulated by gut microbiota via a mast cell-prostaglandin E2 (PGE2) pathway. C57Bl/6 mice received intracolonic infusion of fecal supernatant (FS) from healthy controls or patients with diarrhea-predominant irritable bowel syndrome (IBS-D). The role of mast cells was studied in mast cell-deficient mice. Colonic organoids and/or mast cells were used for invitro experiments. SERT expression was measured by quantitative polymerase chain reaction and Western blot. Visceromotor responses tocolorectal distension and colonic transit were assessed. Intracolonic infusion of IBS-D FS in mice caused an increase in mucosal 5-HT compared with healthy control FS, accompanied by ∼50% reduction in SERT expression. Mast cell stabilizers, cyclooxygenase-2 inhibitors, and PGE2 receptor antagonist prevented SERT downregulation. Intracolonic infusion of IBS-D FS failed to reduce SERT expression in mast cell-deficient (W/Wv) mice. This response was restored by mast cell reconstitution. The downregulation of SERT expression evoked by IBS FS was prevented by lipopolysaccharide (LPS) antagonist LPS from Rhodobacter sphaeroides and a bacterial trypsin inhibitor. Invitro LPS treatment caused increased cyclooxygenase-2 expression and PGE2 release from cultured mouse mast cells. Intracolonic infusion of IBS-D FS in mice reduced colonic transit, increased fecal water content, and increased visceromotor responses to colorectal distension. Ondansetron prevented these changes. Fecal LPS acting in concert with trypsin in patients with IBS-D stimulates mucosal mast cells to release PGE2, which downregulates mucosal SERT, resulting in increased mucosal 5-HT. This may contribute to diarrhea and abdominal pain common in IBS.

Isoxanthanol has protective and anti-inflammatory effects on subchondral bone deterioration in experimental osteoarthritic rat model.

In the present study isoxanthanol was investigated for treatment of monosodium iodoacetate (MIA)-induced osteoarthritis (OA) in vivo. The study demonstrated that isoxanthanol inhibited excessive release of interleukin-6, NO and PGE2 in RAW264.7 cells treated with LPS in dose dependent manner. The effects of isoxanthanol were examined in a rat model of osteoarthritis (OA) and observed to amelio-rate inflammatory damage and protect against OA. Moreover, in vivo data also confirmed inhibition of interleukin-6, NO and PGE2 levels in LPS-induced OA-rats. Deterioration of knee subchondral bone in LPS-induced OA-rats was also prevented effectively by isoxanthanol-treatment. Therefore, isoxanthanol prevents subchondral bone deterioration in OA rats via targeting inflammatory processes.