Anti-inflammatory lipid mediators and insights into the resolution of inflammation

Potential anti-inflammatory natural products from marine algae

Inflammatory diseases have become one of the leading causes of health issue throughout the world, having a considerable influence on healthcare costs. With the emerging developments in natural product, synthetic and combinatorial chemistry, a notable success has been achieved in discovering natural products and their synthetic structural analogs with anti-inflammatory activity. However, many of these therapeutics have indicated detrimental side effects upon prolonged usage. Marine algae have been identified as an underexplored reservoir of unique anti-inflammatory compounds. These include polyphenols, sulfated polysaccharides, terpenes, fatty acids, proteins and several other bioactives. Consumption of these marine algae could provide defense against the pathophysiology of many chronic inflammatory diseases. With further investigation, algal anti-inflammatory phytochemicals have the potential to be used as therapeutics or in the synthesis of structural analogs with profound anti-inflammatory activity with reduced side effects. The current review summarizes the latest knowledge about the potential anti-inflammatory compounds discovered from marine algae.

Withanolides against TLR4-Activated Innate Inflammatory Signalling Pathways: A Comparative Computational and Experimental Study

Innate inflammations are dominant causes of poor health and high mortality. The pathogen-associated molecular pattern and lipopolysaccharide (LPS) are sensed by immune cells through activation of toll-like receptor 4 leading to mitogen-activated protein kinases (MAPKs) and NF-κB activations. Controlled MAPK and Nf-κB inhibitors have been proposed as potential antiinflammatory drugs. Withania somnifera is an important medicinal herb with known antiinflammatory activity. In this study, the selected Withania somnifera extracts and withanolides were analysed on LPS-induced macrophages comparatively. Molecular docking analysis revealed withaferin A, withanone and withanolide A as effective withanolides against inflammatory target molecules. In experiments, withaferin A and withanone treatment had prominent suppressions on LPS-induced expression of pro-inflammatory cytokines in bone marrow-derived macrophages. Withaferin A regulated all the major four pathways (MAPKs and NF-κB) involved in innate inflammations. Similarly among the Withania extracts analysed, the in vitro propagated leaf and field grown root extracts containing high withaferin A content suppressed the inflammatory molecules through NF-κB and MAPK pathways. Withaferin A was found to be best in suppressing the activated inflammatory pathways among all the analysed withanolides. Therefore, withaferin A and extracts with high withaferin A content can be used as promising drug candidates against innate inflammations. Copyright © 2016 John Wiley & Sons, Ltd.

Inflamm-Aging of Hematopoiesis, Hematopoietic Stem Cells, and the Bone Marrow Microenvironment

All hematopoietic and immune cells are continuously generated by hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) through highly organized process of stepwise lineage commitment. In the steady state, HSCs are mostly quiescent, while HPCs are actively proliferating and contributing to daily hematopoiesis. In response to hematopoietic challenges, e.g., life-threatening blood loss, infection, and inflammation, HSCs can be activated to proliferate and engage in blood formation. The HSC activation induced by hematopoietic demand is mediated by direct or indirect sensing mechanisms involving pattern recognition receptors or cytokine/chemokine receptors. In contrast to the hematopoietic challenges with obvious clinical symptoms, how the aging process, which involves low-grade chronic inflammation, impacts hematopoiesis remains undefined. Herein, we summarize recent findings pertaining to functional alternations of hematopoiesis, HSCs, and the bone marrow (BM) microenvironment during the processes of aging and inflammation and highlight some common cellular and molecular changes during the processes that influence hematopoiesis and its cells of origin, HSCs and HPCs, as well as the BM microenvironment. We also discuss how age-dependent alterations of the immune system lead to subclinical inflammatory states and how inflammatory signaling might be involved in hematopoietic aging. Our aim is to present evidence supporting the concept of “Inflamm-Aging,” or inflammation-associated aging of hematopoiesis.

In vitro immunomodulatory activity and in vivo anti-inflammatory and analgesic potential with gastroprotective effect of the Mediterranean red alga Laurencia obtusa

CONTEXT

Red algae have been recognized as a rich natural source of compounds possessing interesting biological and pharmacological activities.

OBJECTIVE

This work investigates anti-inflammatory, analgesic and gastroprotective activities of MeOH/CH₂Cl₂ crude extract and its fractions F1 (50% MeOH) and F2 (80% MeOH) from the whole alga plant Laurencia obtusa Hudson (Rhodomelaceae).

MATERIALS AND METHODS

Anti-inflammatory activity was evaluated in vitro using cytometric bead array (CBA) technology to follow up the secretion of tumour necrosis factor alpha (TNF-α) in lipopolysaccharide activated THP-1 monocytic cells at doses of 10-250 μg/mL and in vivo using carrageenan-induced paw oedema in Wistar rats at doses of 25, 50, 100 and 200 mg/kg. Crude extract and fractions were tested at the doses of 25, 50, 100 and 200 mg/kg for peripheral and central analgesic activity by acetic acid-induced writhing test and hot-plate method, respectively, in Swiss albino mice. Gastroprotective activity was evaluated using HCl/ethanol-induced gastric ulcer test in rats at doses of 25, 50, 100 and 200 mg/kg.

RESULTS

Crude extract, F1 and F2 showed an interesting inhibition of TNF-α secretion with IC₅₀ values of 25, 52 and 24 μg/mL, respectively, and a significant anti-inflammatory activity in vivo (p <  0.01), 3 h after carrageenan injection, the oedema inhibition was 55.37%, 52.18% and 62.86%, respectively, at the dose of 100 mg/kg. Furthermore, they showed a significant peripheral analgesic activity with 53.79%, 55.92% and 57.37% (p <  0.01) of writhing inhibition, respectively. However, no significant activity was found in the hot-plate test. An interesting gastroprotective effect was observed with crude extract and its fractions F1 and F2 with a gastric ulcer inhibition of 65.48%, 77.42% and 81.29%, respectively, at the dose of 50 mg/kg.

DISCUSSION AND CONCLUSION

These results suggest that L. obtusa might be used as a potential source of natural anti-inflammatory and analgesic agents with gastroprotective effect.

Tenuigenin exhibits anti-inflammatory activity via inhibiting MAPK and NF-κB and inducing Nrf2/HO-1 signaling in macrophages

Tenuigenin (TNG), isolated from the root of the Chinese herb Polygala tenuifolia, possesses various biological and pharmacological activities, including anti-oxidation and anti-inflammation activities. In this study, we aimed to further investigate whether its anti-inflammatory activity is associated with the inhibition of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Our results showed that TNG treatment dramatically reduced prostaglandin E2 (PGE2) and NO production, decreased iNOS and COX-2 gene expression, inhibited JNK1/2, ERK1/2, p38 and NF-κB (p65) phosphorylation, and blocked IκBα phosphorylation and degradation. Further studies revealed that TNG dramatically up-regulated heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression, which was related to the induction of Nrf2 nuclear translocation and decreased Keap1 protein expression. Additionally, treatment with JNK1/2, ERK1/2 or p38 inhibitors had no effect on the TNG-induced HO-1 protein expression. Furthermore, the LPS-induced iNOS and COX-2 expression levels were inhibited by TNG, which was partially reversed by the HO-1-siRNA and HO-1 inhibitors. Together, these results showed that TNG's anti-inflammatory activity is related to the inhibition of iNOS and COX-2 expression via down-regulation of the MAPK and NF-κB, and up-regulation of the Nrf2/HO-1 signaling pathways.

γ-Glutamyltranspeptidase is an endogenous activator of Toll-like receptor 4-mediated osteoclastogenesis

Chronic inflammation-associated bone destruction, which is observed in rheumatoid arthritis (RA) and periodontitis, is mediated by excessive osteoclastogenesis. We showed previously that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, acts as an endogenous activator of such pathological osteoclastogenesis, independent of its enzymatic activity. GGT accumulation is clinically observed in the joints of RA patients, and, in animals, the administration of recombinant GGT to the gingival sulcus as an in vivo periodontitis model induces an increase in the number of osteoclasts. However, the underlying mechanisms of this process remain unclear. Here, we report that Toll-like receptor 4 (TLR4) recognizes GGT to activate inflammation-associated osteoclastogenesis. Unlike lipopolysaccharide, GGT is sensitive to proteinase K treatment and insensitive to polymyxin B treatment. TLR4 deficiency abrogates GGT-induced osteoclastogenesis and activation of NF-κB and MAPK signaling in precursor cells. Additionally, GGT does not induce osteoclastogenesis in cells lacking the signaling adaptor MyD88. The administration of GGT to the gingival sulcus induces increased osteoclastogenesis in wild-type mice, but does not induce it in TLR4-deficient mice. Our findings elucidate a novel mechanism of inflammation-associated osteoclastogenesis, which involves TLR4 recognition of GGT and subsequent activation of MyD88-dependent signaling.

Anti-Inflammatory Effects of Liriope platyphylla in LPS-Stimulated Macrophages and Endotoxemic Mice

In the present study, the anti-inflammatory and antisepticemic activities of a water extract of Liriope platyphylla (LP) were investigated. We first estimated the scavenging activity of DPPH and the hydroxyl radical and total phenolic contents of LP. Results indicated that LP, a rich source of phenolic compounds, showed a remarkable radical scavenging capacity. A MTT assay showed that LP treatment did not affect the toxicity against the RAW 264.7 macrophage cells, up to the concentration of 500[Formula: see text][Formula: see text]g/mL. Treatment of LP significantly attenuated the production of inflammatory mediators, such as nitric oxide (NO), interleukin-6 (IL-6), tumor-necrosis factor (TNF)-[Formula: see text] and prostaglandin (PG)E2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages cells. Moreover, LP contributed to the down-regulation of inducible NO synthase (iNOS) and TNF-[Formula: see text] mRNA expression, as well as cyclooxygenase-2 (COX-2) protein expression. A western blotting assay further showed that LP inhibited activation of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-[Formula: see text]B. In an animal experiment using an LPS-induced septicemia model in C57BL/6 mice, oral administration of LP (40[Formula: see text]mg/kg body weight) markedly reduced the level of TNF-[Formula: see text] and IL-6 in serum and protected against LPS-induced lethal shock in mice. Taken together, the results of treatments of LP on inhibited LPS-induced inflammatory responses in both in vitro and in vivo models and indicate it may be a promising neutraceutical or medicinal agent to prevent or cure inflammation-related disease.

Sesquiterpenes from the roots of Lindera strychnifolia with inhibitory effects on nitric oxide production in RAW 264.7 cells

Seven new sesquiterpenes, linderolides N-T (1-7), along with nine known compounds, were isolated from roots of Lindera strychnifolia (Lauraceae). Their structures were established by extensive spectroscopic analysis. The relative and absolute configurations were determined by NOESY and CD analysis, respectively. Among the isolated compounds, two new compounds, linderolide O (2) and linderolide P (3) inhibited lipopolysaccharide-stimulated nitric oxide production in murine RAW 264.7 macrophage cells, with IC₅₀ values of 6.3 and 9.6μM, respectively.

Anti-inflammatory effect of a resveratrol derivative 3,4,5-trimethoxy-4',5'-dihydroxy-trans-stilbene (WL-09-5) via ROS-mediated NF-κB pathway

Inflammation derived from macrophages activation leads to various diseases. Synthetic modifications of resveratrol have been shown to have better anti-inflammatory activities. In this study, croton oil-induced mouse ear edema and lipopolysaccharides (LPS)-stimulated RAW264.7 macrophages were used to evaluate the anti-inflammatory effects of WL-09-5, a derivative of resveratrol. Furthermore, the activation of NF-κB was determined. Results showed that WL-09-5 significantly reduced the croton oil-induced ear edema, scavenged NO and ROS production, and reduced the levels of TNF-α, IL-6, and IL-1β. Furthermore, WL-09-5 may significantly inhibit the translocation of NF-κB in macrophage cells stimulated by LPS in a dose-dependent manner, which is a potent mechanism of its anti-inflammatory effects. In conclusion, WL-09-5 is an underlying candidate for inflammatory diseases that need further investigations.

Chlojaponilactone B from Chloranthus japonicus: Suppression of Inflammatory Responses via Inhibition of the NF-κB Signaling Pathway

Bioassay-guided fractionation of an ethanolic extract of Chloranthus japonicus led to the isolation of the known lindenane-type sesquiterpenoid chlojaponilactone B (1). This compound exhibited pronounced inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Further anti-inflammatory assays showed that 1 suppressed the levels of some key inflammation mediators, such as iNOS, TNF-α, and IL-6, in a dose-dependent manner, and reduced the ear thickness and neutrophil infiltration in 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated mice. A mechanistic study revealed that compound 1 exerted its anti-inflammatory effects via the suppression of the NF-κB signaling pathway, which inhibited NF-κB-dependent transcriptional activity, IκBα phosphorylation, and p65 nuclear translocation. In contrast, chlojaponilactone B (1) was found to exert little influence on the MAPK signaling pathway.

Is monocyte- and macrophage-derived tissue transglutaminase involved in inflammatory processes?

Monocytes and macrophages are key players in inflammatory processes following an infection or tissue damage. Monocytes adhere and extravasate into the inflamed tissue, differentiate into macrophages, and produce inflammatory mediators to combat the pathogens. In addition, they take up dead cells and debris and, therefore, take part in the resolution of inflammation. The multifunctional enzyme tissue Transglutaminase (TG2, tTG) is known to participate in most of those monocyte- and macrophage-mediated processes. Moreover, TG2 expression and activity can be regulated by inflammatory mediators. In the present review, we selectively elaborate on the expression, regulation, and contribution of TG2 derived from monocytes and macrophages to inflammatory processes mediated by those cells. In addition, we discuss the role of TG2 in certain pathological conditions, in which inflammation and monocytes and/or macrophages are prominently present, including atherosclerosis, sepsis, and multiple sclerosis. Based on the studies and considerations reported in this review, we conclude that monocyte- and macrophage-derived TG2 is clearly involved in various processes contributing to inflammation. However, TG2’s potential as a therapeutic target to counteract the possible detrimental effects or stimulate the potential beneficial effects on monocyte and macrophage responses during inflammation should be carefully considered. Alternatively, as TG2-related parameters can be used as a marker of disease, e.g., in celiac disease, or of disease-stage, e.g., in cancer, we put forward that this could be subject of research for monocyte- or macrophage-derived TG2 in inflammatory diseases.

Juniperus rigida Sieb. extract inhibits inflammatory responses via attenuation of TRIF-dependent signaling and inflammasome activation

ETHNOPHARMACOLOGICAL RELEVANCE

Juniperus rigida Sieb. (J. rigida) is used for medicinal purposes in Asian countries to treat inflammation-related disorders, such as neuralgia, dropsy, and gout.

AIM OF THE STUDY

The anti-inflammatory effects of J. rigida extract (JR) and its underlying mechanisms were explored both in in vitro cell lines and in vivo metabolic disease models.

MATERIAL AND METHODS

Lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophages were used to study the changes in inflammatory responses in vitro. Bone marrow-derived macrophages (BMDMs) were used to study the regulatory effect of JR on inflammasome activation. The murine model for monosodium urate (MSU)-induced peritonitis and high-fat diet (HFD)-induced type 2 diabetes were employed to study the effect of JR on in vivo efficacy.

RESULTS

JR suppressed the MSU-induced in vivo inflammatory response by attenuation of proinflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α). In the in vitro study, JR suppressed IL-1β secretion via regulation of apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization, leading to the inhibition of inflammasome activation. JR also inhibited the LPS-stimulated release of proinflammatory mediators, such as nitric oxide (NO), TNF-α, and IL-6 in RAW264.7 cells. The inhibitory effects of JR were mediated through the regulation of the TRIF-dependent signaling pathway from JAK1/STAT1 phosphorylation. Furthermore, JR showed inhibitory effects on HFD-induced type 2 diabetes in a mouse model through the regulation of blood glucose and serum IL-1β.

CONCLUSIONS

Our results indicate that JR attenuates both LPS-stimulated and danger-signal-induced inflammatory responses in macrophages via regulation of the key inflammatory mechanisms, providing scientific support for its traditional use in the treatment of various inflammation-related metabolic disorders.

Anti-inflammatory effects of 6'-O-acetyl mangiferin from Iris rossii Baker via NF-κb signal blocking in lipopolysaccharide-stimulated RAW 264.7 cells

A series of acylated xanthone C-glucosides were identified from the methanolic extract of whole Iris rossii Baker. The major constituent was characterized as 6'-O-acetyl mangiferin (OAM), and complete structure elucidation was carried out using 2D NMR (COSY, HSQC, and HMBC) and LC-IT-TOF-MS analyses. The present study is the first to report the anti-inflammatory effects of 6'-O-acetyl mangiferin from Iris rossii Baker on the lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 macrophage cells. OAM strongly suppressed protein expression of inducible nitric oxide (iNOS) and cyclooxygenase-2 (COX-2), thereby inhibiting the production of nitric oxide (NO), prostaglandin E2 (PGE2), and cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). Furthermore, OAM inhibited the LPS-induced phosphorylation of ERK, JNK, and p38, which led to the blockade of nuclear factor-kappa B (NF-κB) and inhibitor kappa B (IκB)-α activation. These results suggest that the anti-inflammatory effects of OAM may be attributed to the downregulation of COX-2 and iNOS via the suppression of NF-κB and the MAPK signaling pathway in RAW264.7 macrophages.

Transportome Profiling Identifies Profound Alterations in Crohn's Disease Partially Restored by Commensal Bacteria

BACKGROUND AND AIMS

Several transport alterations have been described in intestinal inflammatory diseases. This is relevant because the primary function of the intestine is nutrient and mineral absorption. However, analysis of the transportome as a whole and the effect of commensal bacteria on it have not been addressed so far.

METHODS

Five healthy and 6 Crohn's disease (CD) samples were hybridized to human HT-12 V4 Illumina GeneChip. Results were validated by reverse transcription-polymerase chain reaction (RT-PCR) analysis and with additional array data. Organ culture assays were performed from mucosa ileal wall specimens collected at surgery. Samples were incubated with or without commensal bacteria for 4 hours. Finally, RNA was isolated for microarray processing.

RESULTS

The analysis of CD versus healthy ileal mucosa demonstrated upregulation of previously described genes involved in immunity and the inflammatory response in this disease. Interestingly, whole transcriptional analysis revealed profound alterations in the transportome profile. Sixty-two solute carrier (SLC) transporters displayed different expression patterns, most of them being downregulated. Changes were confirmed by RT-PCR in a randomly chosen subset of SLCs. A large number of amino acid transporters and most members of the enteric purinome were found to be altered. Most of these proteins were found at the apical membrane of the enterocyte, which could impair both amino acid absorption and purinergic signalling. Treatment of ileum specimen explants with commensal bacteria restored almost all CD transportome alterations.

CONCLUSIONS

These results describe the altered transportome profile in CD and open the possibility of restoring transportome complications with commensal bacteria.

Anti-inflammatory activity of ethanolic extract from skipjack tuna (Katsuwonus pelamis) heart in LPS-induced RAW 264.7 cells and mouse ear edema model

This study investigated the anti-inflammatory activity of the ethanolic extract (THEE) obtained from the heart of skipjack tuna using lipopolysaccharide (LPS)-induced RAW 264.7 cells. THEE markedly suppressed the production of nitric oxide (NO), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β in a dose-dependent manner. In addition, THEE decreased the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-kappa B p65 (NF-κB p65), and mitogen-activated protein kinases (MAPKs) including phosphorylated c-Jun NH₂-terminal kinase (p-JNK), phosphorylated extracellular signal-related kinase (p-ERK), and p-p38 proteins. Moreover, THEE orally treated at doses of 50, 100, and 250 mg/kg inhibited the croton oil-induced edema formation and the reduction of the epidermal/dermal thickness and the mast cell numbers was observed in histological analysis. There were no mortalities occurred in mice administered THEE at 5,000 mg/kg body weight. Taken together, these results indicate that THEE exerts the anti-inflammatory activities via inhibition of NF-κB and MAPKs activation.

Amelioration of an LPS-induced inflammatory response using a methanolic extract of Lagerstroemia ovalifolia to suppress the activation of NF-κB in RAW264.7 macrophages

Lagerstroemia ovalifolia Teijsm. & Binn. has traditionally been used as an herbal medicine and possesses anti-inflammatory properties. However, the mechanisms underlying its anti-inflammatory effects remain poorly understood. For this purpose, we aimed to investigate the effects of methanolic extract of L. ovalifolia (LOME) on nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as the underlying molecular mechanisms responsible for these effects, in lipopolysaccharide (LPS)‑stimulated RAW264.7 macrophages. We examined the effects of LOME on the production of NO and PGE2 in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of LOME, we measured the mRNA or protein expression of the pro‑inflammatory mediators induced by LOME in the LPS-stimulated RAW264.7 cells. LOME significantly inhibited the production of NO, PGE2, interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) in LPS-stimulated RAW264.7 cells. Moreover, LOME suppressed the mRNA and protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and inhibited the phosphorylation of the mitogen-activated protein kinases (MAPKs), with a reduction in the nuclear translocation of nuclear factor (NF)-κB in LPS-stimulated RAW264.7 cells. Taken together, these findings suggest that LOME may exert anti-inflammatory effects in vitro in LPS-stimulated RAW264.7 macrophages and thus, may have potential for use as an adjuvant treatment of inflammatory diseases.

Anti-inflammatory effects of Viola yedoensis and the application of cell extraction methods for investigating bioactive constituents in macrophages

BACKGROUND

Viola yedoensis (VY, Violaceae) is a popular medicinal herb used in traditional eastern medicine for treating lots of diseases, including inflammation and its related symptoms. However, the anti-inflammatory properties of VY have not been demonstrated. In the present study, we investigated the anti-inflammatory effects of VY ethanol extract (VYE) on macrophages and attempted to identify the bioactive components of VYE.

METHODS

We assessed the effects of VYE on secretion of nitric oxide (NO) and inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β. In addition, we explored the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and changes in heme oxygenase (HO)-1, nuclear factor (NF)-kB, and mitogen-activated protein kinase (MAPK) signaling pathways in RAW 264.7 macrophages stimulated by lipopolysaccharide (LPS). In addition, a rapid and useful approach to identify potential bioactive components in VYE with anti-inflammatory effects was developed using murine macrophage cell extraction coupled with high-performance liquid chromatography tandem mass spectrometry (LC-MS).

RESULTS

We found that VYE exerted anti-inflammatory activity by inhibiting the production of key inflammation mediators and related products, as well as suppression of HO-1, NF-kB, and MAPK signaling pathway activation in RAW 264.7 cells. In addition, we identified two compounds in VYE via the cell extraction method.

CONCLUSIONS

Our results revealed that VYE exerts anti-inflammatory activities and its detailed inhibitory mechanism in macrophages. Furthermore, we identified bioactive components of VYE.

Early life programming of pain: focus on neuroimmune to endocrine communication

Chronic pain constitutes a challenge for the scientific community and a significant economic and social cost for modern societies. Given the failure of current drugs to effectively treat chronic pain, which are based on suppressing aberrant neuronal excitability, we propose in this review an integrated approach that views pain not solely originating from neuronal activation but also the result of a complex interaction between the nervous, immune, and endocrine systems. Pain assessment must also extend beyond measures of behavioural responses to noxious stimuli to a more developmentally informed assessment given the significant plasticity of the nociceptive system during the neonatal period. Finally integrating the concept of perinatal programming into the pain management field is a necessary step to develop and target interventions to reduce the suffering associated with chronic pain. We present clinical and animal findings from our laboratory (and others) demonstrating the importance of the microbial and relational environment in programming pain responsiveness later in life via action on hypothalamo-pituitary adrenal (HPA) axis activity, peripheral and central immune system, spinal and supraspinal mechanisms, and the autonomic nervous system.

Antioxidant and Anti-Inflammatory Effects of Chaenomeles sinensis Leaf Extracts on LPS-Stimulated RAW 264.7 Cells

The fruit of Chaenomeles sinensis has been traditionally used in ethnomedicine for the treatment of various human ailments, including pneumonia, bronchitis, and so on, but the pharmacological applications of the leaf part of the plant have not been studied. In this study, we evaluated the various radical scavenging activities and anti-inflammatory effects of different Chaenomeles sinensis leaf (CSL) extracts. The water extract showed a higher antioxidant and radical scavenging activities. However the ethanolic extracts showed higher NO scavenging activity than water extract, therefore the ethanolic extract of CSL was examined for anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The 70% ethanol extract of CSL (CSLE) has higher anti-inflammatory activity and significantly inhibited the production of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). In addition, CSLE suppressed LPS-stimulated inducible nitric oxide synthase (iNOS) and NO production, IL-1β and phospho-STAT1 expression. In this study, we investigated the effect of CSLE on the production of inflammatory mediators through the inhibition of the TRIF-dependent pathways. Furthermore, we evaluated the role of CSLE on LPS-induced expression of pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6. Our results suggest that CSLE attenuates the LPS-stimulated inflammatory responses in macrophages through regulating the key inflammatory mechanisms, providing scientific support for its traditional uses in treating various inflammatory diseases.

Atypical sensors for direct and rapid neuronal detection of bacterial pathogens

Bacterial infection can threaten the normal biological functions of a host, often leading to a disease. Hosts have developed complex immune systems to cope with the danger. Preceding the elimination of pathogens, selective recognition of the non-self invaders is necessary. At the forefront of the body’s defenses are the innate immune cells, which are equipped with particular sensor molecules that can detect common exterior patterns of invading pathogens and their secreting toxins as well as with phagocytic machinery. Inflammatory mediators and cytokines released from these innate immune cells and infected tissues can boost the inflammatory cascade and further recruit adaptive immune cells to maximize the elimination and resolution. The nervous system also seems to interact with this process, mostly known to be affected by the inflammatory mediators through the binding of neuronal receptors, consequently activating neural circuits that tune the local and systemic inflammatory states. Recent research has suggested new contact points: direct interactions of sensory neurons with pathogens. Latest findings demonstrated that the sensory neurons not only share pattern recognition mechanisms with innate immune cells, but also utilize endogenous and exogenous electrogenic components for bacterial pathogen detection, by which the electrical firing prompts faster information flow than what could be achieved when the immune system is solely involved. As a result, rapid pain generation and active accommodation of the immune status occur. Here we introduced the sensory neuron-specific detector molecules for directly responding to bacterial pathogens and their signaling mechanisms. We also discussed extended issues that need to be explored in the future.

Purinergic Signaling to Terminate TLR Responses in Macrophages

Macrophages undergo profound physiological alterations when they encounter pathogen-associated molecular patterns (PAMPs). These alterations can result in the elaboration of cytokines and mediators that promote immune responses and contribute to the clearance of pathogens. These innate immune responses by myeloid cells are transient. The termination of these secretory responses is not due to the dilution of stimuli, but rather to the active downregulation of innate responses induced by the very PAMPs that initiated them. Here, we describe a purinergic autoregulatory program whereby TLR-stimulated macrophages control their activation state. In this program, TLR-stimulated macrophages undergo metabolic alterations that result in the production of ATP and its release through membrane pannexin channels. This purine nucleotide is rapidly hydrolyzed to adenosine by ectoenzymes on the macrophage surface, CD39 and CD73. Adenosine then signals through the P1 class of seven transmembrane receptors to induce a regulatory state that is characterized by the downregulation of inflammatory cytokines and the production of anti-inflammatory cytokines and growth factors. This purinergic autoregulatory system mitigates the collateral damage that would be caused by the prolonged activation of macrophages and rather allows the macrophage to maintain homeostasis. The transient activation of macrophages can be prolonged by treating macrophages with IFN-γ. IFN-γ-treated macrophages become less sensitive to the regulatory effects of adenosine, allowing them to sustain macrophage activation for the duration of an adaptive immune response.

Acute phase inflammation is characterized by rapid changes in plasma/peritoneal fluid N-glycosylation in mice

Murine zymosan-induced peritonitis is a widely used model for studying the molecular and cellular events responsible for the initiation, persistence and/or resolution of inflammation. Among these events, it is becoming increasingly evident that changes in glycosylation of proteins, especially in the plasma and at the site of inflammation, play an important role in the inflammatory response. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based glycosylation profiling, we investigated the qualitative and quantitative effect of zymosan-induced peritonitis on N-glycosylation in mouse plasma and peritoneal fluid. Our results show that both N-glycomes exhibit highly similar glycosylation patterns, consisting mainly of diantennary and triantennary complex type N-glycans with high levels (>95 %) of galactosylation and sialylation (mostly NeuGc) and a medium degree of core fucosylation (30 %). Moreover, MS/MS structural analysis, assisted by linkage-specific derivatization of sialic acids, revealed the presence of O-acetylated sialic acids as well as disialylated antennae (“branching sialylation”) characterized by the presence of α2-6-linked NeuGc on the GlcNAc of the NeuGcα2-3-Galβ1-3-GlcNAc terminal motif. A significant decrease of (core) fucosylation together with an increase of both α2-3-linked NeuGc and “branching sialylation” were observed in N-glycomes of mice challenged with zymosan, but not in control mice injected with PBS. Importantly, substantial changes in glycosylation were already observed 12 h after induction of peritonitis, thereby demonstrating an unexpected velocity of the biological mechanisms involved.

The binding capability of plasma phospholipid transfer protein, but not HDL pool size, is critical to repress LPS induced inflammation

Phospholipid transfer protein (PLTP) participates in high density lipoprotein (HDL) metabolism. Increased plasma PLTP activity was observed in lipopolysaccharide (LPS) triggered acute inflammatory diseases. This study aimed to determine the exact role of PLTP in LPS induced inflammation. HDL pool size was shrunk both in PLTP deficient mice (PLTP−/−) and PLTP transgenic mice (PLTP-Tg). PLTP displayed a strong protective effect on lethal endotoxemia in mice survival study. Furthermore, after LPS stimulation, the expression of pro-inflammatory cytokines were increased in bone marrow derived macrophage (BMDM) from PLTP−/−, while decreased in BMDM from PLTP-Tg compared with BMDM from wild-type mice (WT). Moreover, LPS induced nuclear factor kappa-B (NFκB) activation was enhanced in PLTP−/− BMDM or PLTP knockdown RAW264.7. Conversely, PLTP overexpression countered the NFκB activation in LPS challenged BMDM. Additionally, the activation of toll like receptor 4 (TLR4) induced by LPS showed no alteration in PLTP−/− BMDM. Finally, PLTP could bind to LPS, attenuate the pro-inflammatory effects of LPS, and improve the cell viability in vitro. To sum up, these findings elucidated that PLTP repressed LPS induced inflammation due to extracellular LPS binding capability, and the protective effects were not related to HDL pool size in mice.

Haloperidol Suppresses NF-kappaB to Inhibit Lipopolysaccharide-Induced Pro-Inflammatory Response in RAW 264 Cells

Background

Haloperidol, a tranquilizing agent, is administered both to treat symptoms of psychotic disorders and to sedate agitated and delirious patients. Notably, haloperidol has been suggested to inhibit the immune response through unknown mechanisms. We hypothesized that the sedative modulates the immune response via NF-κB.

Material/Methods

Using flow cytometry, we analyzed the effects of haloperidol on expression CD80 and CD86 in RAW 264 cells and in primary macrophages derived from bone marrow. Secretion of interleukin (IL)-1β, IL-6, and IL-12 p40 was measured by enzyme-linked immunosorbent assay. In addition, NF-κB activation was evaluated using a reporter assay based on secretory embryonic alkaline phosphatase. Finally, synthetic antagonists were used to identify the dopamine receptor that mediates the effects of haloperidol.

Results

Haloperidol inhibited NF-κB activation, and thereby suppressed expression of CD80, as well as secretion of IL-1β, IL-6, and IL-12 p40. CD80 and IL-6 levels were similarly attenuated by a D2-like receptor antagonist, but not by a D1-like receptor antagonist.

Conclusions

The data strongly suggest that haloperidol inhibits the immune response by suppressing NF-κB signaling via the dopamine D2 receptor.

Peripheral Nociceptors as Immune Sensors in the Development of Pain and Itch

The peripheral nervous system and the immune system perform a series of similar functionalities such as recognizing, responding, and adapting to external or internal stimuli despite significant morphological differences. The peripheral nervous system actively communicates and coordinates with the immune system to function as a unified defense system. The peripheral nervous system is highly regulated by the immune system, especially under inflammatory conditions. On the other hand, the nervous system can modulate the immune system via neurotransmitters and chemokines released by the peripheral nerve endings, particularly from nociceptors. In both physiological and pathological conditions, peripheral nociceptive (including pruriceptive) neurons may express a variety of immune-related receptors, such as chemokine receptors and immunoglobulin (Fc) receptors that are usually found on immune cells. Certain ligands such as chemokines and immune complexes may induce abnormal neuronal hyperexcitability and even ectopic action potential discharges, therefore producing the sensation of pain and/or itch in immune-related diseases. The immune-sensing mechanisms of peripheral nociceptors may play an important role in the development of chronic pain and pruritus and may indicate novel therapeutic strategies for these pathological conditions.

Anti-inflammatory effects of the extract of Gnaphalium affine D. Don in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Gnaphalium affine D. Don (GA) has been traditionally used as a medicinal herb in China for the treatment of many ailments including rheumatoid arthritis. However, the anti-arthritic mechanism of GA has still not been demonstrated. This study aims to reveal the anti-inflammatory activity and anti-arthritic mechanism of ethanol extract of G. affine D. Don.

MATERIALS AND METHODS

Anti-inflammatory potential of GA was analyzed in vivo in carrageenan induced mice paw edema (acute study). Also, in vivo study was applied in collagen-induced arthritis (CIA) rats. In vitro experiments for analyzing the anti-inflammatory potential of GA were performed on rat alveolar macrophages cell line (NR8383). Analysis of nitric oxide release in NR8383 cells was done by Griess reaction. RT-PCR and western blotting experiment was performed to analyze the expression of phosphorylated p65 and IκBα/β-actin in NF-κB pathway. The production of TNF-α, IL-1β, and COX-2 in NR8383 cells were measured by enzyme-linked immunosorbent assay. The chemical profile of GA was analyzed by HPLC-VWD.

RESULTS

GA significantly reduced the paw volume in carrageenan induced rat paw edema rat at different doses (300 and 600 mg/kg), compared with the standard indomethacin treatment. In CIA, GA can obviously ameliorate the inflammatory symptom, including cytokine, histological symptom and paw swelling. In the vitro study, GA was able to reduce the nitric oxide (NO) levels in NR8383 cells that had been stimulated with lipopolysaccharide (LPS). The level of TNF-α, IL-1β, and COX-2 was also decreased with GA treatment in NR8383 cells that had been stimulated with lipopolysaccharide (LPS). Interestingly, GA was found to decrease the level of phosphorylated p65 and IκBα in NR8383 cells. Fifteen compounds were identified by HPLC-VWD with the reference substances and verified by LC-MS.

CONCLUSIONS

The results of the experiment scientifically validated its traditional use in inflammatory conditions.

Xanthii fructus inhibits inflammatory responses in LPS-stimulated RAW 264.7 macrophages through suppressing NF-κB and JNK/p38 MAPK

ETHNOPHARMACOLOGICAL RELEVANCE

Xanthii fructus (XF) has long been used to treat a variety of inflammatory conditions in Korean traditional medicine, but the underlying mechanisms that could explain the anti-inflammatory actions of XF remain largely unknown.

AIM OF THE STUDY

This study aimed to elucidate the anti-inflammatory effects of X. fructus (XF) and to examine its underlying molecular mechanisms in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

MATERIALS AND METHODS

The effect of XF on LPS-induced mRNA and protein expressions of inflammatory mediators and cytokines were determined. Moreover, the activation of the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and the expression of heme oxygenase-1 (HO-1) were explored to elucidate the anti-inflammatory mechanisms.

RESULTS

XF significantly inhibited LPS-induced production of inflammatory mediators, interleukin-6 (IL-6), nitric oxide (NO), and prostaglandin E2 (PGE2), without any cytotoxicity. However, it did not affect tissue necrosis factor (TNF)-α or IL-1β production in LPS-stimulated RAW 264.7 cells. Expression levels of inducible nitric oxide synthase (iNOS) mRNA and protein were inhibited dose-dependently by XF in LPS-stimulated RAW 264.7 cells, but there were no changes in cyclooxygenase-2 (COX-2) mRNA and protein. XF significantly attenuated LPS-induced phosphorylation and degradation of inhibitory kappa Bα (IκBα) and consequently reduced the nuclear translocation of p65 NF-κB. Pretreatment with XF also strongly inhibited the LPS-induced phosphorylation of p38 kinase and JNK, whereas the phosphorylation of ERK1/2 was not affected. In addition, XF led to an increase in HO-1 expression.

CONCLUSION

Taken together, our findings support that XF inhibits LPS-induced inflammatory responses by blocking NF-κB activation, inhibiting JNK/p38 MAPK phosphorylation, and enhancing HO-1 expression in macrophages, suggesting that it could be an attractive therapeutic candidate for various inflammatory diseases.

New pathogenic insights into rheumatoid arthritis

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is a heterogeneous chronic immune-mediated inflammatory disease, associated with significant morbidity and reduced life expectancy. Here, we review recent discoveries; particularly those which have attempted to integrate genome-wide association studies (GWAS) with biological pathways and cell types known to play a role in disease pathology in order to expand our current understanding of the pathogenesis of RA. As the role of stromal cells in the pathogenesis of RA has been reviewed in detail in Current Opinions in Rheumatology, this area will not be covered in this review.

RECENT FINDINGS

Although our understandings of the pathogenic processes that drive disease in RA remain incomplete, remarkable advances over the past year can be highlighted. GWAS have raised awareness of important new risk loci with genes that either are the targets of approved therapies for RA, or involve pathways for drugs that could be repurposed from other disease indications such as cancer. Furthermore, promising strides have been made in predicting the likelihood of developing RA in those at risk using human leukocyte antigen (HLA), smoking, and autoantibody status prediction models. These findings give a fresh insight into RA pathogenesis and help identify new, or repurpose known therapeutic targets from other disease areas.

SUMMARY

The findings discussed in this review underscore the progress made to date and the need for future studies, investigating disease mechanisms in RA, with particular interest in at-risk RA gene loci, their function in immune and stromal cells within the synovium, and how they interact with environmental factors to initiate and perpetuate disease.

Pharmacological evidence favouring the traditional use of the root bark of Condalia buxifolia Reissek in the relief of pain and inflammation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The Condalia buxifolia root bark infusion is used in traditional medicine in Brazil as antipyretic, anti-inflammatory and against dysentery. This study was designed to investigate whether the methanolic extract of the root bark of Condalia buxifolia (MECb) exhibits antinociceptive and anti-inflammatory effects in mice. Furthermore, also was investigated the involvement of glutamatergic and opioidergic system in the antinociceptive effect induced by MECb.

MATERIALS AND METHODS

The antinociceptive and anti-inflammatory effects of intra-gastric gavage (i.g.) administered MECb (10-300 mg/kg) were evaluated in mice subjected to chemical (formalin, acetic-acid, glutamate) or thermal (hot plate) models of pain. The involvement of opioid system in the antinociceptive effect of the MECb was investigated in formalin test. Furthermore, a nonspecific effect of MECb was evaluated by measuring locomotor activity and exploratory behavior in open field test. Finally, was performed a phytochemical analysis of MECb.

RESULTS

The phytochemical analysis of MECb was performed through HPLC analysis showing that the alkaloid Condaline-A is the main constituent. The intragastric administration of MECb (100-300 mg/kg) significantly inhibited the nociception caused by acetic acid (48 ± 2%), inflammatory phase (49 ± 3%) and paw edema (32 ± 6) caused by formalin, and MECb (100mg/kg, i.g.) also inhibited nociception caused by glutamate (41 ± 7%). In addition, MECb (100-300 mg/kg, i.g.) increased the paw withdrawal latency in hot-plate test, without affecting the locomotor activity and exploratory behavior in open field test. Finally, the antinociceptive effects of MECb (100mg/kg, i.g.) were significantly reversed by naloxone (1mg/kg, i.p.) in the formalin test.

CONCLUSION

These data show, for the first time, that MECb has significant antinociceptive and anti-inflammatory effects, which appear to be related to the inhibition of the glutamatergic system and the activation of opioid mechanism, besides present central effects. These results support the use of Condalia buxifolia in traditional medicine and demonstrate that this plant has therapeutic potential for the development of phytomedicines with antinociceptive and anti-inflammatory properties.

Innate immunity is a key factor for the resolution of inflammation in asthma

The resolution of inflammation is an integral and natural part of the physiological response to tissue injury, infection and allergens or other noxious stimuli. Resolution is now recognised as an active process with highly regulated cellular and biochemical events. Recent discoveries have highlighted that innate inflammatory cells have bimodal effector functions during the inflammatory response, including active roles during the resolution process. Several mediators displaying potent pro-resolving actions have recently been uncovered. Lipoxin A4, the lead member of this new class of pro-resolving mediators, has anti-inflammatory actions on type 2 innate lymphoid cells and pro-resolving actions through natural killer cells in asthma immunobiology. Eosinophils are also able to control crucial aspects of resolution through the generation of pro-resolving mediators. Uncontrolled asthma has been associated with a defect in the generation of specialised pro-resolving mediators, including lipoxin A4 and protectin D1. Thus, bioactive stable analogue mimetics of these mediators that can harness endogenous resolution mechanisms for inflammation may offer new therapeutic strategies for asthma and airway inflammation associated diseases.

Resveratrol as a Bioenhancer to Improve Anti-Inflammatory Activities of Apigenin

The aim of this study was to improve the anti-inflammatory activities of apigenin through co-treatment with resveratrol as a bioenhancer of apigenin. RAW 264.7 cells pretreated with hepatic metabolites formed by the co-metabolism of apigenin and resveratrol (ARMs) in HepG2 cells were stimulated with lipopolysaccharide (LPS). ARMs prominently inhibited (p < 0.05) the production of nitric oxide (NO), prostaglandin E₂ (PGE₂), interleukin (IL)-1β, IL-6 and TNF-α. Otherwise no such activity was observed by hepatic metabolites of apigenin alone (AMs). ARMs also effectively suppressed protein expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Co-administration of apigenin (50 mg/kg) and resveratrol (25 mg/kg) also showed a significant reduction of carrageenan-induced paw edema in mice (61.20% to 23.81%). Co-administration of apigenin and resveratrol led to a 2.39 fold increase in plasma apigenin levels compared to administration of apigenin alone, suggesting that co-administration of resveratrol could increase bioavailability of apigenin. When the action of resveratrol on the main apigenin metabolizing enzymes, UDP-glucuronosyltransferases (UGTs), was investigated, resveratrol mainly inhibited the formation of apigenin glucuronides by UGT1A9 in a non-competitive manner with a K_i value of 7.782 μM. These results suggested that resveratrol helps apigenin to bypass hepatic metabolism and maintain apigenin’s anti-inflammatory activities in the body.

The molecular events behind ferulic acid mediated modulation of IL-6 expression in LPS-activated Raw 264.7 cells

Identification of new antioxidant and anti-inflammatory bioactive molecules is an important tool for selecting effective formulations for the treatment of inflammation. The mouse macrophage cell line RAW 264.7, lipopolysaccharide (LPS)-activated, is associated with an inflammation response. Activated macrophages produce reactive oxygen species (ROS), nitric oxide (NO) and inflammatory cytokines such as IL-6, TNF-α and IL-10. In the present study we have showed that pre-treatment with Ferulic Acid (FA) reduces NO accumulation in the culture medium of LPS-induced macrophage cells. Moreover, real-time experiments have revealed that FA has an inhibitory effect at the transcriptional level on the expression of some inflammatory mediators such as IL-6, TNF-α and iNOS and an activation effect on the expression of some antioxidant molecules such as Metallothioneins (MT-1, MT-2). Importantly, we have found that FA reduced the translocation of NF-E2-related factor 2 (Nrf2) and nuclear transcription factor-κB (NF-κB) into the nuclei through a reduction of the expression of phosphorylated IKK and consequently inhibited IL-6 and NF-κB promoter activity in a luciferase assay. Our data clearly suggest that FA anti-inflammatory effects are mainly mediated through IKK/NF-κB signalling pathway. Therefore, FA could represent a new natural drug extremely useful to improve anti-inflammatory treatment.

Hederagenin, a major component of Clematis mandshurica Ruprecht root, attenuates inflammatory responses in RAW 264.7 cells and in mice

Clematis mandshurica Ruprecht root has been used in Asia as a traditional anti-inflammatory, analgesic, and antitumor agent. Its main active component is hederagenin, a naturally occurring triterpene, and in this study, we examined the anti-inflammatory effects of hederagenin in lipopolysaccharide-stimulated RAW 264.7 cells using an enzyme-linked immunosorbent assay, Western blot, and RT-PCR. In addition, its effects on acute inflammation in vivo were observed using a carrageenan-induced mouse hind paw edema assay. Furthermore, the changes on the histopathology and histomorphometry of hind paw skins were examined using carrageenan-treated mice. Treatment with hederagenin (10, 30 and 100μM) resulted in inhibited levels of protein expression of lipopolysaccharide-stimulated iNOS, COX-2, and NF-κB as well as production of NO, PGE2, TNF-α, IL-1β, and IL-6 induced by lipopolysaccharide. Consistent with these results, hederagenin also dose-dependently reduced the lipopolysaccharide-induced mRNA levels of iNOS and COX-2, and of the above-mentioned cytokines. Interestingly, results of the carrageenan-induced mouse hind paw edema assay showed an anti-edema effect of hederagenin. Furthermore, hederagenin (30mg/kg) inhibited the carrageenan-induced increases in skin thicknesses, infiltrated inflammatory cells, and mast cell degranulation. These results suggest that hederagenin may possess anti-inflammatory activities.

Evaluation of the Anti-Inflammatory, Antioxidant and Immunomodulatory Effects of the Organic Extract of the Red Sea Marine Sponge Xestospongia testudinaria against Carrageenan Induced Rat Paw Inflammation

Marine sponges are found to be a rich source of bioactive compounds which show a wide range of biological activities including antiviral, antibacterial, and anti-inflammatory activities. This study aimed to investigate the possible anti-inflammatory, antioxidant and immunomodulator effects of the methanolic extract of the Red Sea marine sponge Xestospongia testudinaria. The chemical composition of the Xestospongia testudinaria methanolic extract was determined using Gas chromatography-mass spectroscopy (GC-MS) analysis. DPPH (2, 2-diphenyl-1-picryl-hydrazyl) was measured to assess the antioxidant activity of the sponge extract. Carrageenan-induced rat hind paw edema was adopted in this study. Six groups of rats were used: group1: Control, group 2: Carrageenan, group 3: indomethacin (10 mg/kg), group 4-6: Xestospongia testudinaria methanolic extract (25, 50, and 100 mg/kg). Evaluation of the anti-inflammatory activity was performed by both calculating the percentage increase in paw weight and hisopathologically. Assessment of the antioxidant and immunomodulatory activity was performed. GC-MS analysis revealed that there were 41 different compounds present in the methanolic extract. Sponge extract exhibited antioxidant activity against DPPH free radicals. Xestospongia testudinaria methanolic extract (100 mg/kg) significantly decreased % increase in paw weight measured at 1, 2, 3 and 4 h after carrageenan injection. Histopathologically, the extract caused a marked decrease in the capillary congestion and inflammatory cells infiltrate. The extract decreased paw malondialdehyde (MDA) and nitric oxide (NO) and increased the reduced glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT) activity. It also decreased the inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1 β(IL-1β) and IL-6. The results of this study demonstrated the anti-inflammatory, antioxidant, and immunomodulatory effects of the methanolic extract of the Red Sea sponge Xestospongia testudinaria (100 mg/kg).

Esculin exhibited anti-inflammatory activities in vivo and regulated TNF-α and IL-6 production in LPS-stimulated mouse peritoneal macrophages in vitro through MAPK pathway

Esculin, a coumarinic derivative found in Aesculus hippocastanum L. (Horse-chestnut), has been reported to have potent anti-inflammatory properties. The present study is designed to investigate the protective effects of esculin on various inflammation models in vivo and in vitro and to clarify the possible mechanism. Induced-animal models of inflammation and lipopolysaccharide (LPS)-challenged mouse peritoneal macrophages were used to examine the anti-inflammatory activity of esculin. In present study, xylene-induced mouse ear edema, carrageenan-induced rat paw edema, and carrageenan-induced mouse pleurisy were attenuated by esculin. In vitro, the pro-inflammatory cytokine levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in supernatant were reduced by esculin. Meanwhile, we found that esculin significantly inhibited LPS-induced activation of mitogen-activated protein kinase (MAPK) pathway in peritoneal macrophages. These results suggest that esculin has potent anti-inflammatory activities in vivo and in vitro, which may involve the inhibition of the MAPK pathway. Esculin may be a promising preventive agent for inflammatory diseases in human.