Cyclooxygenase-2 biology

Neohesperidin dihydrochalcone down-regulates MyD88-dependent and -independent signaling by inhibiting endotoxin-induced trafficking of TLR4 to lipid rafts

Fulminant hepatic failure (FHF) is a lethal clinical syndrome characterized by the activation of macrophages and the increased production of inflammatory mediators. The purpose of this study was to investigate the effects of neohesperidin dihydrochalcone (NHDC), a widely-used low caloric artificial sweetener against FHF. An FHF experimental model was established in mice by intraperitoneal injection of D-galactosamine (d-GalN) (400mg/kg)/lipopolysaccharides (LPS) (10 μg/kg). Mice were orally administered NHDC for 6 continuous days and at 1h before d-GalN/LPS administration. RAW264.7 macrophages were used as an in vitro model. Cells were pre-treated with NHDC for 1h before stimulation with LPS (10 μg/ml) for 6h. d-GalN/LPS markedly increased the serum transaminase activities and levels of oxidative and inflammatory markers, which were significantly attenuated by NHDC. Mechanistic analysis indicated that NHDC inhibited LPS-induced myeloid differentiation factor 88 (MyD88) and TIR-containing adapter molecule (TRIF)-dependent signaling. Transient transfection of TLR4 or MyD88 siRNA inhibited the downstream inflammatory signaling. This effect could also be achieved by the pretreatment with NHDC. The fluorescence microscopy and flow cytometry results suggested that NHDC potently inhibited the binding of LPS to TLR4 in RAW264.7 macrophages. In addition, the inhibitory effect of NHDC on LPS-induced translocation of TLR4 into lipid raft domains played an important role in the amelioration of production of downstream pro-inflammatory molecules. Furthermore, the activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) by NHDC inhibited TLR4 signaling. In conclusion, our results suggest that NHDC attenuates d-GalN/LPS-induced FHF by inhibiting the TLR4-mediated inflammatory pathway, demonstrating a new application of NHDC as a hepatoprotective agent.

Methanol extracts of Xanthium sibiricum roots inhibit inflammatory responses via the inhibition of nuclear factor-κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) in murine macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Xanthium sibiricum has been used as a traditional Chinese medicine for the treatment of appendicitis, bronchitis, arthritis, and other inflammatory ailments. However, its pharmacological activity related to an anti-inflammatory effect remain unknown. This present study aims to investigate the anti-inflammatory effect of methanol extracts of X. sibiricum roots (MXS), and to further determine its underlying mechanism of action in order to assess the medicinal value of X. sibiricum roots.

MATERIALS AND METHODS

To assess the anti-inflammatory activity of MXS in lipopolysaccharides (LPS)-stimulated RAW 264.7 macrophages, the production of nitric oxide (NO) was measured using the Griess reagent system. The levels of pro-inflammatory cytokines and mediators were quantified using an Enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR). Subsequently, immunoblotting analyses were employed to detect inflammatory mediators as well as to elucidate the underlying regulatory mechanisms suppressed by MXS.

RESULTS

MXS inhibited LPS-stimulated NO production and inducible nitric oxide synthase (iNOS) expression in RAW 264.7 macrophages within the non-cytotoxic concentration range (50-400 μg/ml). In addition, mRNA and protein levels of pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α were significantly suppressed by MXS at the concentration of 400 μg/ml. Furthermore, MXS (200 μg/ml) clearly reduced the phosphorylation levels of the inhibitor of kappa Bα (IκBα) and signal transducer and activator of transcription 3 (STAT3), without affecting changes in the phosphorylation levels of mitogen-activated protein kinases (MAPKs). When five major components (betulin, betulinic acid, β-sitosterol, stigmasterol, and scopoletin) of MXS were separately investigated, stigmasterol and β-sitosterol seemed to play major inhibitory roles in the LPS-induced production of inflammatory mediators such as NO, IL-6, and TNF-α.

CONCLUSION

Our results demonstrate that MXS has an anti-inflammatory property in LPS-stimulated RAW 264.7 macrophages, and its anti-inflammatory activity is exerted by the regulation of nuclear factor-κB (NF-κB) and STAT3 signaling pathways.

Toxicological Effect of Manganese on NF-κB/iNOS-COX-2 Signaling Pathway in Chicken Testes

Manganese (Mn) pollution can cause tissue and organ dysfunction and structural damage. The toxicity of Mn in poultry was reported, but inflammatory damage that Mn induced in the testicular tissue has not been reported. The aim of this study was to investigate the effect of Mn poisoning on NF-κB/iNOS-COX-2 signaling pathway in chicken testes. One hundred eighty Hyline male chickens at 7 days of age were fed either commercial diet or MnCl2-added commercial diet containing 600, 900, and 1800 mg/kg Mn for 30, 60, and 90 days, respectively. The messenger RNA (mRNA) expression of nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS), nitric oxide (NO) content, iNOS activity, and histopathology were examined in chicken testes. The results showed that excess Mn upregulated mRNA expression of NF-κB, COX-2, TNF-α, and iNOS, NO content, and iNOS activity at 60th and 90th day. Mn had a time-dependent effect on NF-κB and TNF-α mRNA expression. Mn had a dose- and time-dependent effect on NO content and iNOS activity. Mn exposure induced chicken testis histological changes in dose- and time-dependent manner. It indicated that Mn exposure resulted in inflammatory injury of chicken testis tissue through NF-κB/iNOS-COX-2 signaling pathway.

NSAIDs and Cardiovascular Diseases: Role of Reactive Oxygen Species

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used drugs worldwide. NSAIDs are used for a variety of conditions including pain, rheumatoid arthritis, and musculoskeletal disorders. The beneficial effects of NSAIDs in reducing or relieving pain are well established, and other benefits such as reducing inflammation and anticancer effects are also documented. The undesirable side effects of NSAIDs include ulcers, internal bleeding, kidney failure, and increased risk of heart attack and stroke. Some of these side effects may be due to the oxidative stress induced by NSAIDs in different tissues. NSAIDs have been shown to induce reactive oxygen species (ROS) in different cell types including cardiac and cardiovascular related cells. Increases in ROS result in increased levels of oxidized proteins which alters key intracellular signaling pathways. One of these key pathways is apoptosis which causes cell death when significantly activated. This review discusses the relationship between NSAIDs and cardiovascular diseases (CVD) and the role of NSAID-induced ROS in CVD.

Computational Structure-Based De Novo Design of Hypothetical Inhibitors against the Anti- Inflammatory Target COX-2

Cyclooxygenase-2 (COX-2) produces prostaglandins in inflamed tissues and hence has been considered as an important target for the development of anti-inflammatory drugs since long. Administration of traditional non-steroidal anti-inflammatory drugs (NSAIDs) and other COX-2 selective inhibitors (COXIBS) for the treat of inflammation has been found to be associated with side effects, which mainly includes gastro-intestinal (GI) toxicity. The present study involves developing a virtual library of novel molecules with high druglikeliness using structure-based de novo drug designing and 2D fingerprinting approach. A library of 2657 drug like molecules was generated. 2D fingerprinting based screening of the designed library gave a unique set of compounds. Molecular docking approach was then used to identify two compounds highly specific for COX-2 isoform. Molecular dynamics simulations of protein-ligand complexes revealed that the candidate ligands were dynamically stable within the cyclooxygenase binding site of COX-2. The ligands were further analyzed for their druglikeliness, ADMET properties and synthetic accessibility using knowledge based set of rules. The results revealed that the molecules are predicted to selectively bind to COX-2 enzyme thereby potentially overcoming the limitations posed by the drugs in clinical use.

Amorfrutins Are Natural PPARγ Agonists with Potent Anti-inflammatory Properties

Amorfrutins are isoprenoid-substituted benzoic acid derivatives, which were found in Amorpha fruticosa L. (bastard indigo) and in Glycyrrhiza foetida Desf. (licorice). Recently, amorfrutins were shown to be selective activators of the nuclear receptor PPARγ. Here, we investigated the effects and PPARγ-based mechanisms of reducing inflammation in colon cells by treatment with amorfrutins. In TNF-α-stimulated colon cells amorfrutin A (1) reduced significantly the expression and secretion of several inflammation mediators, in part due to interaction with PPARγ. These results support the hypothesis that amorfrutins may have the potential to treat inflammation disorders such as chronic inflammatory bowel diseases.

Nicotine in high concentration causes contraction of isolated strips of rabbit corpus cavernosum

It is well known that cigarette smoke can cause erectile dysfunction by affecting the penile vascular system. However, the exact effects of nicotine on the corpus cavernosum remains poorly understood. Nicotine has been reported to cause relaxation of the corpus cavernosum; it has also been reported to cause both contraction and relaxation. Therefore, high concentrations of nicotine were studied in strips from the rabbit corpus cavernosum to better understand its effects. The proximal penile corpus cavernosal strips from male rabbits weighing approximately 4 kg were used in organ bath studies. Nicotine in high concentrations (10^-5~10^-4 M) produced dose-dependent contractions of the corpus cavernosal strips. The incubation with 10^-5 M hexamethonium (nicotinic receptor antagonist) significantly inhibited the magnitude of the nicotine associated contractions. The nicotine-induced contractions were not only significantly inhibited by pretreatment with 10^-5 M indomethacin (nonspecific cyclooxygenase inhibitor) and with 10^-6 M NS-398 (selective cyclooxygenase inhibitor), but also with 10^-6 M Y-27632 (Rho kinase inhibitor). Ozagrel (thromboxane A2 synthase inhibitor) and SQ-29548 (highly selective TP receptor antagonist) pretreatments significantly reduced the nicotine-induced contractile amplitude of the strips. High concentrations of nicotine caused contraction of isolated rabbit corpus cavernosal strips. This contraction appeared to be mediated by activation of nicotinic receptors. Rho-kinase and cyclooxygenase pathways, especially cyclooxygenase-2 and thromboxane A₂, might play a pivotal role in the mechanism associated with nicotine-induced contraction of the rabbit corpus cavernosum.

Decoding the oxidative stress hypothesis in diabetic embryopathy through proapoptotic kinase signaling

Maternal diabetes-induced birth defects occur in 6-10% of babies born to mothers with pregestational diabetes, representing a significant maternal-fetal health problem. Currently, these congenital malformations represent a significant maternal-fetal medicine issue, but are likely to create an even greater public health threat as 3 million women of reproductive age (19-44 years) have diabetes in the United States alone, and this number is expected to double by 2030. Neural tube defects (NTDs) and congenital heart defects are the most common types of birth defects associated with maternal diabetes. Animal studies have revealed that embryos under hyperglycemic conditions exhibit high levels of oxidative stress resulting from enhanced production of reactive oxygen species and impaired antioxidant capability. Oxidative stress activates a set of proapoptotic kinase signaling intermediates leading to abnormal cell death in the embryonic neural tube, which causes NTD formation. Work in animal models also has revealed that maternal diabetes triggers a series of signaling intermediates: protein kinase C (PKC) isoforms, PKCα, βII and δ; apoptosis signal-regulating kinase 1; c-Jun-N-terminal kinase (JNK)1/2; caspase; and apoptosis. Specifically, maternal diabetes in rodent models activates the proapoptotic unfolded protein response and endoplasmic reticulum (ER) stress. A reciprocal causation between JNK1/2 activation and ER stress exists in diabetic embryopathy. Molecular studies further demonstrate that deletion of the genes for Prkc, Ask1, Jnk1, or Jnk2 abolishes maternal diabetes-induced neural progenitor apoptosis and ameliorates NTD formation. Similar preventive effects are also observed when apoptosis signal-regulating kinase 1, JNK1/2, or ER stress is inhibited. Cell membrane stabilizers and antioxidant supplements are also effective in prevention of diabetes-induced birth defects. Mechanistic studies have revealed important insights into our understanding the cause of diabetic embryopathy and have provided a basis for future interventions against birth defects or other pregnancy complications associated with maternal diabetes. The knowledge of a molecular pathway map identified in animal studies has created unique opportunities to identify molecular targets for therapeutic intervention.

Cyclooxygenase-2 and the inflammogenesis of breast cancer

Cohesive scientific evidence from molecular, animal, and human investigations supports the hypothesis that constitutive overexpression of cyclooxygenase-2 (COX-2) is a ubiquitous driver of mammary carcinogenesis, and reciprocally, that COX-2 blockade has strong potential for breast cancer prevention and therapy. Key findings include the following: (1) COX-2 is constitutively expressed throughout breast cancer development and expression intensifies with stage at detection, cancer progression and metastasis; (2) essential features of mammary carcinogenesis (mutagenesis, mitogenesis, angiogenesis, reduced apoptosis, metastasis and immunosuppression) are linked to COX-2-driven prostaglandin E2 (PGE-2) biosynthesis; (3) upregulation of COX-2 and PGE-2 expression induces transcription of CYP-19 and aromatase-catalyzed estrogen biosynthesis which stimulates unbridled mitogenesis; (4) extrahepatic CYP-1B1 in mammary adipose tissue converts paracrine estrogen to carcinogenic quinones with mutagenic impact; and (5) agents that inhibit COX-2 reduce the risk of breast cancer in women without disease and reduce recurrence risk and mortality in women with breast cancer. Recent sharp increases in global breast cancer incidence and mortality are likely driven by chronic inflammation of mammary adipose and upregulation of COX-2 associated with the obesity pandemic. The totality of evidence clearly supports the supposition that mammary carcinogenesis often evolves as a progressive series of highly specific cellular and molecular changes in response to induction of constitutive over-expression of COX-2 and the prostaglandin cascade in the “inflammogenesis of breast cancer”.

Effects of taraxasterol on iNOS and COX-2 expression in LPS-induced RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Taraxasterol was isolated from the Chinese medicinal herb Taraxacum officinale which has been frequently used as a remedy for inflammatory diseases. Our previous study has shown that taraxasterol inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in RAW 264.7 macrophages. To elucidate the underlying mechanism responsible for these effects, in the present study, we investigated the effects of taraxasterol on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, and mitogen-activated protein kinases (MAPKs) signaling pathway in LPS-induced RAW 264.7 macrophages.

MATERIALS AND METHODS

RAW 264.7 cells were pretreated with 2.5, 5 and 12.5 μg/ml of taraxasterol 1 h prior to treatment with 1 μg/ml of LPS. The mRNA expression levels of iNOS and COX-2 were examined by RT-PCR. The protein expression levels of iNOS and COX-2, and the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38 and c-Jun N-terminal kinase (JNK) MAPKs were measured by Western blot.

RESULTS

The mRNA and protein expression levels of iNOS and COX-2 were inhibited by taraxasterol in a concentration-dependent manner. Further studies revealed that taraxasterol suppressed the phosphorylation of ERK1/2 and p38 in LPS-induced RAW 264.7 macrophages.

CONCLUSIONS

These results indicate that taraxasterol inhibits iNOS and COX-2 expression by blocking ERK1/2 and p38 MAPKs signaling pathway.

Inhibition of COX-2 and PGE2 in LPS-stimulated RAW264.7 cells by lonimacranthoide VI, a chlorogenic acid ester saponin

Lonimacranthoide VI, first isolated from the flower buds of Lonicera macranthoides in our previous study, is a rare chlorogenic acid ester acylated at C-23 of hederagenin. In the present study, the anti-inflammatory effects of lonimacranthoide VI were studied. Lipopolysaccharides (LPS) induced an inflammatory response through the production of prostaglandin E₂ (PGE₂), and these levels were reduced when lonimacranthoide VI was pre-administered. Additionally, the mechanism of the anti-inflammatory effects of lonimacranthoide VI was investigated by measuring cyclooxygenase (COX) activity and mRNA expression. The results showed that lonimacranthoide VI inhibited mRNA expression and in vitro activity of COX-2 in a dose-dependent manner, whereas only the higher lonimacranthoide VI concentration possibly reduced COX-1 expression and in vitro activity. Taken together, these results indicate that lonimacranthoide VI is an important anti-inflammatory constituent of Lonicera macranthoides and that the anti-inflammatory effect is attributed to the inhibition of PGE₂ production through COX activity and mRNA expression.

Anti-inflammatory R-prostaglandins from Caribbean Colombian soft coral Plexaura homomalla

OBJECTIVES

This study aims to evaluate the effect of prostaglandins isolated from soft coral Plexaura homomalla, collected in Colombian Caribbean Sea, on in vivo and in vitro inflammation models.

METHODS

Extracts from P. homomalla were fractionated and sequentially chromatographed to obtain the prostaglandins: (15R)-PGA2 (1), (15R)-PGA2 -Me (2), (15R)-O-Ac-PGA2 (3), (15R)-O-Ac-PGA2 -Me (4) and (15R)-PGE2 (5) in addition to three semi-synthetic prostaglandins obtained by transformations of the natural products. The anti-inflammatory properties of natural and semi-synthetic compounds were determined in vivo using 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear oedema model and in vitro leucocyte degranulation, myeloperoxidase (MPO) and elastase enzymatic activities from human polymorphonuclear cells (PMNs). The cell viability was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

KEY FINDINGS

In the in vivo assay, (15R)-PGE2 (1) and (15R)-O-Ac-PGA2 (3) showed anti-inflammatory activity, as well as in vitro inhibition of elastase release from PMNs. In the PMNs degranulation assay, (15R)-PGE2 (5), was the most active compound in the inhibition of MPO release. Finally, all the tested prostaglandins showed moderate inhibition for elastase enzyme activity, whereas none of the prostaglandins exhibit significative inhibition on MPO activity.

CONCLUSION

(15R)-PGE2 (1) and (15R)-O-Ac-PGA2 (3) present significant inhibition on three important events related to the topical inflammatory response induced by TPA: the oedema formation, the PMNs degranulation, events that modulate MPO and elastase levels at inflammation site, and the inhibition of the enzyme activity.

Floridoside suppresses pro-inflammatory responses by blocking MAPK signaling in activated microglia

Inflammatory conditions mediated by activated microglia lead to chronic neuro-degenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. This study was conducted to determine the effect of floridoside isolated from marine red algae Laurencia undulata on LPS (100 ng/ml) activated inflammatory responses in BV-2 microglia cells. The results show that floridoside has the ability to suppress pro-inflammatory responses in microglia by markedly inhibiting the production of nitric oxide (NO) and reactive oxygen species (ROS). Moreover, floridoside down-regulated the protein and gene expression levels of iNOS and COX-2 by significantly blocking the phosphorylation of p38 and ERK in BV-2 cells. Collectively, these results indicate that floridoside has the potential to be developed as an active agent for the treatment of neuro-inflammation. [BMB Reports 2013; 46(8): 398-403]

The bitter barricading of prostaglandin biosynthesis pathway: understanding the molecular mechanism of selective cyclooxygenase-2 inhibition by amarogentin, a secoiridoid glycoside from Swertia chirayita

Swertia chirayita, a medicinal herb inhabiting the challenging terrains and high altitudes of the Himalayas, is a rich source of essential phytochemical isolates. Amarogentin, a bitter secoiridoid glycoside from S. chirayita, shows varied activity in several patho-physiological conditions, predominantly in leishmaniasis and carcinogenesis. Experimental analysis has revealed that amarogentin downregulates the cyclooxygenase-2 (COX-2) activity and helps to curtail skin carcinogenesis in mouse models; however, there exists no account on selective inhibition of the inducible cyclooxygenase (COX) isoform by amarogentin. Hence the computer-aided drug discovery methods were used to unravel the COX-2 inhibitory mechanism of amarogentin and to check its selectivity for the inducible isoform over the constitutive one. The generated theoretical models of both isoforms were subjected to molecular docking analysis with amarogentin and twenty-one other Food and Drug Authority (FDA) approved lead molecules. The post-docking binding energy profile of amarogentin was comparable to the binding energy profiles of the FDA approved selective COX-2 inhibitors. Subsequent molecular dynamics simulation analysis delineated the difference in the stability of both complexes, with amarogentin-COX-2 complex being more stable after 40ns simulation. The total binding free energy calculated by MMGBSA for the amarogentin-COX-2 complex was −52.35 KCal/mol against a binding free energy of −8.57 KCal/mol for amarogentin-COX-1 complex, suggesting a possible selective inhibition of the COX-2 protein by the natural inhibitor. Amarogentin achieves this potential selectivity by small, yet significant, structural differences inherent to the binding cavities of the two isoforms. Hypothetically, it might block the entry of the natural substrates in the hydrophobic binding channel of the COX-2, inhibiting the cyclooxygenation step. To sum up briefly, this work highlights the mechanism of the possible selective COX-2 inhibition by amarogentin and endorses the possibility of obtaining efficient, futuristic and targeted therapeutic agents for relieving inflammation and malignancy from this phytochemical source.

Cytotoxic and apoptotic functions of licofelone on rat glioma cells

Gliomas are the largest group of central nervous system tumors and despite of clinical treatments death rate is very high. Inhibition of both cyclooxygenase and lipoxygenase pathways that take role in arachidonic acid metabolism prevents cancer development and induces apoptosis. One of the most promising compounds that blocks both of these pathways is licofelone. Using colchicine and 5-fluorouracil as positive controls, we questioned whether licofelone affects the survival of rat glioma cell line (C6) and induces apoptosis in vitro. After growing the cells in culture, we determined viability with MT, apoptosis with flow cytometry and activity of caspase enzymes with real time PCR. All used doses of colchicine and 5-fluorouracil were cytotoxic and reduced the number of surviving C6 cells as much as 44% and 60%, respectively. Comparing to the control, treatments with 10, 50 and 100 μM licofelone for 24 or 48 h did not influence C6 survival, however, 150, 200 and 250 μM licofelone reduced the number of living cells by 58, 88 and 93%, respectively, and induced apoptosis of C6 cells in a dose and time dependent manner. Licofelone did not change the level of caspase-9, but increased the level of caspase-3. Comparing with 5-fluorouracil and colchicine, the present study reveals for the first time the possibility that licofelone possesses a strong dose and time dependent antiproliferative and proapoptotic properties on glioma cells.

Anti-inflammatory effect of procyanidins from wild grape (Vitis amurensis) seeds in LPS-induced RAW 264.7 cells

In the present study, the anti-inflammatory effect and underlying mechanisms of wild grape seeds procyanidins (WGP) were examined using lipopolysaccharide- (LPS-) stimulated RAW 264.7 cells. We used nitric oxide (NO) and prostaglandin E₂ (PGE₂) and reactive oxygen species (ROS) assays to examine inhibitory effect of WGP and further investigated the mechanisms of WGP suppressed LPS-mediated genes and upstream expression by Western blot and confocal microscopy analysis. Our data indicate that WGP significantly reduced NO, PGE₂, and ROS production and also inhibited the expression of proinflammatory mediators such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expressions. Consistently, WGP significantly reduced LPS-stimulated expression of proinflammatory cytokines such as tumor necrosis factor α (TNF-α) and interleukin- (IL-) 1β. Moreover, WGP prevented nuclear translocation of nuclear factor-κB (NFκB) p65 subunit by reducing inhibitory κB-α (IκBα) and NFκB phosphorylation. Furthermore, we found that WGP inhibited LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK). Taken together, our results demonstrated that WGP exerts potent anti-inflammatory activity through the inhibition of iNOS and COX-2 by regulating NFκB and p38 MAPK pathway.

Arzanol, a potent mPGES-1 inhibitor: novel anti-inflammatory agent

Arzanol is a novel phloroglucinol α-pyrone, isolated from a Mediterranean plant Helichrysum italicum (Roth) Don ssp. microphyllum which belongs to the family Asteraceae. Arzanol has been reported to possess a variety of pharmacological activities. However, anti-inflammatory, anti-HIV, and antioxidant activities have been studied in some detail. Arzanol has been reported to inhibit inflammatory transcription factor NFκB activation, HIV replication in T cells, releases of IL-1β, IL-6, IL-8, and TNF-α, and biosynthesis of PGE₂ by potentially inhibiting mPGES-1 enzyme. Diversity of mechanisms of actions of arzanol may be useful in treatment of disease involving these inflammatory mediators such as autoimmune diseases and cancer. This review presents comprehensive information on the chemistry, structure-activity relationship, and pharmacological activities of arzanol. In addition this review discusses recent developments and the scope for future research in these aspects.

The role of melatonin in the cells of the innate immunity: a review

Melatonin is the major secretory product synthesized and secreted by the pineal gland and shows both a wide distribution within phylogenetically distant organisms from bacteria to humans and a great functional versatility. In recent years, a considerable amount of experimental evidence has accumulated showing a relationship between the nervous, endocrine, and immune systems. The molecular basis of the communication between these systems is the use of a common chemical language. In this framework, currently melatonin is considered one of the members of the neuroendocrine-immunological network. A number of in vivo and in vitro studies have documented that melatonin plays a fundamental role in neuroimmunomodulation. Based on the information published, it is clear that the majority of the present data in the literature relate to lymphocytes; thus, they have been rather thoroughly investigated, and several reviews have been published related to the mechanisms of action and the effects of melatonin on lymphocytes. However, few studies concerning the effects of melatonin on cells belonging to the innate immunity have been reported. Innate immunity provides the early line of defense against microbes and consists of both cellular and biochemical mechanisms. In this review, we have focused on the role of melatonin in the innate immunity. More specifically, we summarize the effects and action mechanisms of melatonin in the different cells that belong to or participate in the innate immunity, such as monocytes-macrophages, dendritic cells, neutrophils, eosinophils, basophils, mast cells, and natural killer cells.

Anti-Inflammatory Effects of Hyptis albida Chloroform Extract on Lipopolysaccharide-Stimulated Peritoneal Macrophages

We examined the effects of a chloroform extract of Hyptis albida (CHA) on inflammatory responses in mouse lipopolysaccharide (LPS) induced peritoneal macrophages. Our findings indicate that CHA inhibits LPS-induced production of tumor necrosis factor (TNF- α ) and interleukin-6 (IL-6). During the process, levels of cyclooxygenase-2 (COX-2), nitric oxide synthase (iNOS), and nitric oxide (NO) increased in the mouse peritoneal macrophages; however, the extract suppressed them significantly. These results provide novel insights into the anti-inflammatory actions of CHA and support its potential use in the treatment of inflammatory diseases.

Tocotrienol Attenuates Stress-Induced Gastric Lesions via Activation of Prostaglandin and Upregulation of COX-1 mRNA

The present study aims to distinguish the effect of tocotrienol on an important gastric protective factor, prostaglandin E2 (PGE2), in stress-induced gastric injury. Twenty-eight Wistar rats were divided into four groups of seven rats each. Two control groups were fed commercial rat diet, and two treatment groups were fed the same diet but with additional dose of omeprazole (20 mg/kg) or tocotrienol (60 mg/kg). After 28 days, rats from one control group and both treated groups were subjected to water-immersion restraint stress for 3.5 hours once. The rats were then sacrificed, their stomach isolated and gastric juice collected, lesions examined, and gastric PGE2 content and cyclooxygenase (COX) mRNA expression were determined. Both the regimes significantly attenuated the total lesion area in the stomach compared to the control. Gastric acidity, which was increased in stress, was significantly reduced in rats supplemented with omeprazole and tocotrienol. The PGE2 content was also significantly higher in the rats given tocotrienol supplementation compared to the control followed by an increase in COX-1 mRNA expression. We conclude that tocotrienol supplementation protected rat gastric mucosa against stress-induced lesions possibly by reducing gastric acidity and preserving gastric PGE2 by increasing COX-1 mRNA.

Licofelone abolishes survival of carcinogenic fibroblasts by inducing apoptosis

Dual inhibitors of cyclooxygenase (COX) and lipoxygenase (LOX) pathways of arachidonic acid metabolism prevent cancer development and induce apoptosis. One of the most promising compounds that blocks both of these pathways is licofelone. We questioned whether licofelone affects the survival and/or promotes apoptosis of H-ras transformed rat embryonic fibroblast (5RP7) cells in vitro. Using 5-fluorouracil (5-FU) and colchicine as positive controls, we determined cell viability with 3-3-(4,5-D-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, thyazolyl blue (MTT), apoptosis with flow cytometry and activity of caspase enzyme with real-time reverse transcription polymerase chain reaction (PCR). Compared to the control, all used six doses (10, 50, 100, 150, 250 and 250 µM) of 5-FU, colchicine and licofelone, which were cytotoxic and reduced the number of H-Ras transformed 5RP7 cells by as much as 78, 72 and 92%, respectively. In addition, we found that 150, 200 and 250 µM of licofelone induced apoptosis and necrosis of H-Ras transformed 5RP7 cells in a dose- and time-dependent manner. Each three tested drugs at 250 µM also increased the level of caspase-3 enzyme up to 5-fold. Although colchicine was effective in inducing early apoptosis, licofelone had much more capacity to induce the total of early plus late apoptosis by approximately 96% in cells after 48 hours. The present study reveals the possibility that licofelone posseses strong dose- and time-dependent anticancer and apoptotic properties on carcinogenic fibroblasts.

Effect of kramecyne on the inflammatory response in lipopolysaccharide-stimulated peritoneal macrophages

Kramecyne is a new peroxide, it was isolated from Krameria cytisoides, methanol extract, and this plant was mostly found in North and South America. This compound showed potent anti-inflammatory activity; however, the mechanisms by which this compound exerts its anti-inflammatory effect are not well understood. In this study, we examined the effects of kramecyne on inflammatory responses in mouse lipopolysaccharide- (LPS-) induced peritoneal macrophages. Our findings indicate that kramecyne inhibits LPS-induced production of tumor necrosis factor (TNF-α) and interleukin- (IL-) 6. During the inflammatory process, levels of cyclooxygenase- (COX-) 2, nitric oxide synthase (iNOS), and nitric oxide (NO) increased in mouse peritoneal macrophages; however, kramecyne suppressed them significantly. These results provide novel insights into the anti-inflammatory actions and support its potential use in the treatment of inflammatory diseases.

Comparison of the anti-inflammatory and analgesic effects of Gentiana macrophylla Pall. and Gentiana straminea Maxim., and identification of their active constituents

ETHNOPHARMACOLOGICAL RELEVANCE

Tibetan medicine get used to use the flowers of Gentiana straminea Maxim. to cure inflammation of stomach and intestines, hepatitis, cholecystitis, etc. The flowers of Gentiana macrophylla Pall. have been traditionally treated as an anti-inflammatory agent to clear heat in Mongolian medicine. In traditional Chinese medicine, Gentiana macrophylla Pall. and Gentiana straminea Maxim. have also been used under the name "Gentianae Macrophyllae Radix" and prescribed for the treatment of pain and inflammatory conditions.

AIM OF STUDY

The present study evaluated the pharmacological effects of two species of "Radix Gentianae Macrophyllae" in experimental inflammation and pain models, and determined the chemical compounds that may correlate with their pharmacological activities. The comparison is needed to identify whether the two related plants can be used interchangeably.

MATERIALS AND METHODS

We evaluated the pharmacological effects of the flowers of Gentiana macrophylla Pall. and Gentiana straminea Maxim. in experimental inflammation and pain models. An HPLC-MS method was developed to analyze the chemical composition. The effects of Gentiana macrophylla Pall. and Gentiana straminea Maxim. on the p65 and p50 phosphorylation were examined by immunblotting. NF-κB transcriptional activity was measured using the luciferase assay, in vitro kinase assay and Griess reaction.

RESULTS

The extracts of Gentiana macrophylla Pall. and Gentiana straminea Maxim. possessed significant antinociceptive and anti-inflammatory activities. Flavonoids, secoiridoid glycosides and triterpines were determined in the extracts and may be the basis of the observed pharmacological effects. Nuclear translocation of p65, p50 and NF-κB transcriptional activity induced by LPS were suppressed by Gentiana macrophylla Pall. and Gentiana straminea Maxim.

CONCLUSION

The results clearly demonstrated that the chemical composition and pharmacological activities of the two herbs were similar, which support the interchangeability among the two herbs when using them in folk medicine.

Hispidin analogue davallialactone attenuates carbon tetrachloride-induced hepatotoxicity in mice

In this study the protective effects of davallialactone (1), isolated from Inonotus xeranticus, have been examined against carbon tetrachloride (CCl₄-induced acute liver injury. Mice received subcutaneous injection of 1 (2.5, 5, and 10 mg/kg) for three days before CCl₄ injection (1 mg/kg). Protection from liver injury by 1 was confirmed by the observation of decreased serum transaminases and diminished necrosis of liver tissue. Reduced hepatic injury was very similar to that observed with silymarin, a known hepatoprotective drug used in this work for comparison. The groups treated with 1 had reduced reactive oxygen species (ROS), reduced serum malonyldialdehyde levels, and increased levels of liver Cu/Zn superoxide dismutase, as compared to the CCl₄ control group. The expression of heme oxygenase-1 in the liver tissue was increased and the activity of liver cytochrome P4502E1 was restored in the mice treated with 1. In addition, levels of serum tumor necrosis factor-alpha (TNF-α), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2), numbers of macrophage, and cleaved caspase-3-positive hepatocytes were reduced in the groups treated with 1. These findings suggest that davallialactone has protective effects against CCl₄-induced acute liver injury, and this protection is likely due to the suppression of ROS-induced lipid peroxidation and inflammatory response.

A review of the efficacy, safety, and cost-effectiveness of COX-2 inhibitors for Africa and the Middle East region

Despite an increasingly sophisticated understanding of pain mechanisms, acute and chronic pain remain undertreated throughout the world. This situation reflects the large gap that exists between evidence and practice in pain management and is typified by inappropriate use of nonsteroidal anti-inflammatory drugs (NSAIDs). The scientific evidence around these drugs continues to expand at a high rate, yet physicians are often unaware of best practice. To address this gap among physicians in Africa and the Middle East, an Expert Panel meeting was convened with representatives from the region. The principal objective of the meeting was to review the latest guidelines on the management of acute and chronic pain and to review the efficacy, safety, and cost-effectiveness of cyclooxygenase-2 (COX-2) inhibitors in these settings. The main outcome of this review process was a number of consensus statements concerning the definitions of acute and chronic pain, and the efficacy, safety and cost-effectiveness of traditional nonselective NSAIDs (nsNSAIDs) and selective COX-2 inhibitors (coxibs). The panel agreed that nsNSAIDs and coxibs are effective analgesics with similar efficacy for acute pain; for chronic musculoskeletal pain, NSAIDs are significantly more effective than either placebo or paracetamol. Coxibs offer important safety advantages over nsNSAIDs, including gastrointestinal safety and preservation of platelet function; notably, the cardiovascular safety of coxibs has been the subject of much recent debate. Furthermore, the panel agreed there is substantial evidence to indicate that cost savings can be achieved by using celecoxib in patients at moderate to high risk of gastrointestinal adverse events, even in countries with moderate healthcare expenditures.

Effect of Rhizoma Polygonati on 12-O-tetradecanoylphorbol-acetate-induced ear edema in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Polygonati is originated from the dried rhizomes of Polygonatum sibircum Red. It has long been used in traditional Chinese medicine for the treatment of inflammatory disorders.

AIM OF THE STUDY

The present study aims to investigate the anti-inflammatory effect of aqueous extract of Rhizoma Polygonati (ERP) in a mouse model of inflammation induced by 12-O-tetradecanoylphorbol-acetate (TPA).

MATERIALS AND METHODS

The anti-inflammatory effect was evaluated by measuring the ear thickness and activity of myeloperoxidase (MPO). The anti-inflammatory mechanism was explored by determining the protein and mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6.

RESULTS

The results showed that ERP significantly decreased the ear thickness and MPO activity in mouse model of inflammation induced by TPA. In addition, ERP also remarkably inhibited the protein and mRNA levels of iNOS, COX-2, TNF-α, IL-1β, and IL-6.

CONCLUSIONS

These results indicate that ERP has potential anti-inflammatory effect on TPA-induced inflammatory in mice, and the anti-inflammatory effect may be mediated, at least in part, by inhibiting the mRNA expression of a panel of inflammatory mediators including iNOS, COX-2, TNF-α, IL-1β, and IL-6.

Isodesacetyluvaricin, an Annonaceous acetogenin, specifically inhibits gene expression of cyclooxygenase-2

Cyclooxygenase-2 (COX-2) is an inducible isoform of the enzyme responsible for the synthesis of several inflammatory mediators. In a search for phytochemicals with anti-inflammatory activity, the COX-2 inhibitory activity of 15 typical Annonaceous acetogenins was examined. Isodesacetyluvaricin (1), from the Formosan tropical fruit tree Annona glabra, exhibited the most potent activity. Reverse transcription PCR was used to test the effect of 1 on epidermal growth factor-stimulated expression of COX-2 in cultures of A431 human epidermoid carcinoma cells. Three hours after exposure to 1 (5 μM), A431 cells had barely detectable levels of COX-2 mRNA. A corresponding but smaller decline in the COX-2 protein appeared on using Western blots. Lipopolysaccharide-stimulated expression of COX-2 in Raw 264.7 mouse leukemic monocyte-macrophages showed a similar decrease. Luciferase assays revealed that cells exposed to 1 had reduced activities of two COX-2 promoter-transcription factors: cAMP response element-binding factor and nuclear factor of activated T-cells. Compound 1 did not affect cell proliferation, as measured by a colorimetric assay, or intracellular store-operated calcium influx, as determined by fluorescence imaging. Thus, 1 may serve as a lead compound for targeting inflammatory diseases as well as angiogenesis and cancer metastasis.

Role of PGE2 in asthma and nonasthmatic eosinophilic bronchitis

Eosinophilic bronchitis is a common cause of chronic cough, which like asthma is characterized by sputum eosinophilia, but unlike asthma there is no variable airflow obstruction or airway hyperresponsiveness. Several studies suggest that prostaglandins may play an important role in orchestrating interactions between different cells in several inflammatory diseases such as asthma. PGE₂ is important because of the multiplicity of its effects on immune response in respiratory diseases; however, respiratory system appears to be unique in that PGE₂ has beneficial effects. We described that the difference in airway function observed in patients with eosinophilic bronchitis and asthma could be due to differences in PGE₂ production. PGE₂ present in induced sputum supernatant from NAEB patients decreases BSMC proliferation, probably due to simultaneous stimulation of EP2 and EP4 receptors with inhibitory activity. This protective effect of PGE₂ may not only be the result of a direct action exerted on airway smooth-muscle proliferation but may also be attributable to the other anti-inflammatory actions.

Pharmacological properties of guggulsterones, the major active components of gum guggul

Oleo gum resin secreted by Commiphora mukul, also known as gum guggul, has been used widely as an ayurvedic drug. Commiphora mukul is a short thorny shrub that is native to the Indian subcontinent. Oleo gum resin extracted by incision of the bark is a very complex mixture of gum, minerals, essential oils, terpenes, sterols, ferrulates, flavanones and sterones. Its active constituents, the Z- and E-guggulsterones, have been demonstrated to exhibit their biological activities by binding to nuclear receptors and modulating the expression of proteins involved in carcinogenic activities. Guggulsterones have also been reported to regulate gene expression by exhibiting control over other molecular targets including transcription factors such as nuclear factor (NF)-κB, signal transducer and activator of transcription (STAT) and steroid receptors. Considerable scientific evidence indicates the use of gum guggul as a therapeutic agent in the treatment of inflammation, nervous disorders, hyperlipidaemia and associated cardiac disorders such as hypertension and ischaemia, skin disorders, cancer and urinary disorders. This review highlights the taxonomic details, phytochemical properties and pharmacological profile of gum guggul.

Antiviral effect of a selective COX-2 inhibitor on H5N1 infection in vitro

A selective cyclooxygenase-2 (COX-2) inhibitor has been previously shown to suppress the hyper-induced pro-inflammatory responses in H5N1 infected primary human cells. Here, we demonstrate that COX-2 inhibitors suppress H5N1 virus replication in human macrophages suggesting that H5N1 virus replication (more so than seasonal H1N1 virus) is dependent on activation of COX-2 dependent signaling pathways in host cells. COX-2 and its downstream signaling pathways deserve detailed investigation as a novel therapeutic target for treatment of H5N1 disease.

Mitragynine inhibits the COX-2 mRNA expression and prostaglandin E₂ production induced by lipopolysaccharide in RAW264.7 macrophage cells

ETHNOPHARMACOLOGICAL RELEVANCE

[corrected] Mitragyna speciosa Korth (Rubiaceae) is one of the medicinal plants used traditionally to treat various types of diseases especially in Thailand and Malaysia. Its anti-inflammatory and analgesic properties in its crude form are well documented. In this study, the cellular mechanism involved in the anti-inflammatory effects of mitragynine, the major bioactive constituent, was investigated.

MATERIALS AND METHODS

The effects of mitragynine on the mRNA and protein expression of COX-1 and COX-2 and the production of prostaglandin E(2) (PGE(2)) were investigated in LPS-treated RAW264.7 macrophage cells. Quantitative RT-PCR was used to assess the mRNA expression of COX-1 and COX-2. Protein expression of COX-1 and COX-2 were assessed using Western blot analysis and the level of PGE(2) production was quantified using Parameter™ PGE(2) Assay (R&D Systems).

RESULTS

Mitragynine produced a significant inhibition on the mRNA expression of COX-2 induced by LPS, in a dose dependent manner and this was followed by the reduction of PGE(2) production. On the other hand, the effects of mitragynine on COX-1 mRNA expression were found to be insignificant as compared to the control cells. However, the effect of mitragynine on COX-1 protein expression is dependent on concentration, with higher concentration of mitragynine producing a further reduction of COX-1 expression in LPS-treated cells.

CONCLUSIONS

These findings suggest that mitragynine suppressed PGE(2) production by inhibiting COX-2 expression in LPS-stimulated RAW264.7 macrophage cells. Mitragynine may be useful for the treatment of inflammatory conditions.

A sesquiterpenol extract potently suppresses inflammation in macrophages and mice skin and prevents chronic liver damage in mice through JNK-dependent HO-1 expression

This study aimed to elucidate the anti-inflammatory and hepatoprotective bioactivities of a sesquiterpenol, (1S,6R)-2,7(14),10-bisabolatrien-1-ol-4-one (BSL), isolated from Cryptomeria japonica (Taxodiaceae) wood extract. BSL markedly suppressed TNF-α and IL-6 secretion, PGE(2) production, and mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in lipopolysaccharide (LPS)-stimulated mouse macrophages. BSL also potently inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA) induced protein levels of nitrotyrosine and COX-2 in mouse skin with dermatitis. Conversely, the stress protein heme oxygenase-1 (HO-1) was found upregulated in the same BSL-treated macrophages, probably through activation of the JNK-dependent pathway. LPS-induced activation of NF-κB and mitogen-activated protein kinase signaling pathways, however, was not responsive to BSL treatment. A BSL-enriched extract (BSL-E; 10mg/kg) significantly prevented CCl(4)-induced chronic liver injury, lipid accumulation, and cell necrosis and inhibited aminotransferase activities and iNOS and COX-2 overexpression in mice liver tissues, an effect comparable with that of silymarin, a hepatoprotective drug.

Anti-inflammatory effect of patchouli alcohol isolated from Pogostemonis Herba in LPS-stimulated RAW264.7 macrophages

Pogostemonis Herba has long been used in traditional Chinese medicine for the treatment of inflammation-related disorders. Patchouli alcohol (PA) isolated from Pogostemonis Herba is a tricyclic sesquiterpene that is known to exert a variety of pharmacological activities. The present study aimed to investigate the anti-inflammatory effect of PA on lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Pre-treatment with PA at concentrations of 10, 20 or 40 μM dose-dependently decreased the production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, nitric oxide (NO) and prostaglandin E(2) in LPS-stimulated RAW264.7 cells. In addition, PA treatment also reversed the increased mRNA expression of TNF-α, IL-1β, IL-6, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 caused by LPS in RAW264.7 cells. These results indicate that PA is an important anti-inflammatory constituent of Pogostemonis Herba and that its anti-inflammatory effect may be mediated, at least in part, by down-regulation of the mRNA expression of a panel of inflammatory mediators, such as TNF-α, IL-1β, IL-6, iNOS and COX-2.

Hodgkin disease risk: role of genetic polymorphisms and gene-gene interactions in inflammation pathway genes

Inflammation is a critical component of cancer development. The clinical and pathological features of Hodgkin disease (HD) reflect an abnormal immunity that results from cytokines secreted by Reed-Sternberg cells and the surrounding tumor. Numerous studies have reported the association between genetic polymorphisms in cytokine genes and the susceptibility to different hematologic cancers. However, the effects of such SNPs on modulating HD risk have not yet been investigated. We hypothesized that gene-gene interactions between candidate genes in the anti- and pro-inflammatory pathways carrying suspicious polymorphisms may contribute to susceptibility to HD. To test this hypothesis, we conducted a study on 200 HD cases and 220 controls to assess associations between HD risk and 38 functional SNPs in inflammatory genes. We evaluated potential gene-gene interactions using a multi-analytic strategy combining logistic regression, multi-factor dimensionality reduction, and classification and regression tree (CART) approaches. We observed that, in combination, allelic variants in the COX2, IL18, ILR4, and IL10 genes modify the risk for developing HD. Moreover, the cumulative genetic risk score (CGRS) revealed a significant trend where the risk for developing HD increases as the number of adverse alleles in the cytokine genes increase. These findings support the notion that epigenetic-interactions between these cytokines may influence pathogenesis of HD modulating the proliferation of regulatory T cells. In this way, the innate and adaptative immune responses may be altered and defy their usual functions in the host anti-tumor response. Our study is the first to report the association between polymorphisms in inflammation genes and HD susceptibility risk.

Suppression of neurotensin receptor type 1 expression and function by histone deacetylase inhibitors in human colorectal cancers

Neurotensin, a gut peptide, stimulates the growth of colorectal cancers that possess the high-affinity neurotensin receptor (NTR1). Sodium butyrate (NaBT) is a potent histone deacetylase inhibitor (HDACi) that induces growth arrest, differentiation, and apoptosis of colorectal cancers. Previously, we had shown that NaBT increases nuclear GSK-3beta expression and kinase activity; GSK-3beta functions as a negative regulator of extracellular signal-regulated kinase (ERK) signaling. The purpose of our current study was to determine: (a) whether HDACi alters NTR1 expression and function, and (b) the role of GSK-3beta/ERK in NTR1 regulation. Human colorectal cancers with NTR1 were treated with various HDACi, and NTR1 expression and function were assessed. Treatment with HDACi dramatically decreased endogenous NTR1 mRNA, protein, and promoter activity. Overexpression of GSK-3beta decreased NTR1 promoter activity (> 30%); inhibition of GSK-3beta increased NTR1 expression in colorectal cancer cells, indicating that GSK-3beta is a negative regulator of ERK and NTR1. Consistent with our previous findings, HDACi significantly decreased phosphorylated ERK while increasing GSK-3beta. Selective MAP/ERK kinase/ERK inhibitors suppressed NTR1 mRNA expression in a time- and dose-dependent fashion, and reduced NTR1 promoter activity by approximately 70%. Finally, pretreatment with NaBT prevented neurotensin-mediated cyclooxygenase-2 and c-myc expression and attenuated neurotensin-induced interleukin-8 expression. HDACi suppresses endogenous NTR1 expression and function in colorectal cancer cell lines; this effect is mediated, at least in part, through the GSK-3beta/ERK pathway. The downregulation of NTR1 in colorectal cancers may represent an important mechanism for the anticancer effects of HDACi.

Prostacyclin inhibits non-small cell lung cancer growth by a frizzled 9-dependent pathway that is blocked by secreted frizzled-related protein 1

The goal of this study was to assess the ability of iloprost, an orally active prostacyclin analog, to inhibit transformed growth of human non-small cell lung cancer (NSCLC) and to define the mechanism of iloprost's tumor suppressive effects. In a panel of NSCLC cell lines, the ability of iloprost to inhibit transformed cell growth was not correlated with the expression of the cell surface receptor for prostacyclin, but instead was correlated with the presence of Frizzled 9 (Fzd 9) and the activation of peroxisome proliferator-activated receptor-gamma (PPARgamma). Silencing of Fzd 9 blocked PPARgamma activation by iloprost, and expression of Fzd 9 in cells lacking the protein resulted in iloprost's activation of PPARgamma and inhibition of transformed growth. Interestingly, soluble Frizzled-related protein-1, a well-known inhibitor of Wnt/Fzd signaling, also blocked the effects of iloprost and Fzd 9. Moreover, mice treated with iloprost had reduced lung tumors and increased Fzd 9 expression. These studies define a novel paradigm, linking the eicosanoid pathway and Wnt signaling. In addition, these data also suggest that prostacyclin analogs may represent a new class of therapeutic agents in the treatment of NSCLC where the restoration of noncanonical Wnt signaling maybe important for the inhibition of transformed cell growth.

Continuous lactation effects on mammary remodeling during late gestation and lactation in dairy goats

The present study aimed to 1) elucidate whether continuous milking during late gestation in dairy goats negatively affects mammary remodeling and hence milk production in the subsequent lactation, and 2) identify the regulatory factors responsible for changes in cell turnover and angiogenesis in the continuously lactating mammary gland. Nine multiparous dairy goats were used. One udder half was dried off approximately 9 wk prepartum (normal lactation; NL), and the other udder half of the same goat was milked continuously (continuous lactation; CL) until parturition or until the half-udder milk yields had dropped to below 50 g/d. Mammary biopsies were obtained from each udder half just before the NL gland was dried off (before dry period), within the first 2 wk after drying-off (early dry period, samples available only for NL glands), in the mid dry period, within the last 2 wk before parturition (late dry period), and at d 1 (the day of parturition), 3, 10, 60, and 180 of lactation. Mammary morphology was characterized in biopsies by quantitative histology, and cell turnover was determined by immunohistochemistry (terminal deoxynucleotidyl transferase dUTP nick end labeling and Ki-67). Transcription of genes encoding factors involved in mammary epithelial cell (MEC) turnover and vascular function was quantified by quantitative reverse transcription PCR. Results demonstrated that omitting the dry period was possible in goats but was not as easy as claimed before. Renewal of MEC was suppressed in CL glands, which resulted in a smaller MEC population in the subsequent lactation. At the time of parturition (and throughout lactation), the mammary glands subjected to CL had smaller alveoli, more fully differentiated MEC, and a substantially larger capillary fraction compared with NL glands. The continuously lactating gland thus resembled a normally lactating gland in an advanced stage of lactation. None of the studied genomic factors could account for these treatment differences. The described characteristics in CL glands compared with NL glands indicated a gland maintained in lactation for a longer period.

Rosmanol potently inhibits lipopolysaccharide-induced iNOS and COX-2 expression through downregulating MAPK, NF-kappaB, STAT3 and C/EBP signaling pathways

Rosmanol is a natural polyphenol from the herb rosemary (Rosmarinus officinalis L.) with high antioxidant activity. In this study, we investigated the inhibitory effects of rosmanol on the induction of NO synthase (NOS) and COX-2 in RAW 264.7 cells induced by lipopolysaccharide (LPS). Rosmanol markedly inhibited LPS-stimulated iNOS and COX-2 protein and gene expression, as well as the downstream products, NO and PGE2. Treatment with rosmanol also reduced translocation of the nuclear factor-kappaB (NF-kappaB) subunits by prevention of the degradation and phosphorylation of inhibitor kappaB (IkappaB). Western blot analysis showed that rosmanol significantly inhibited translocation and phosphorylation of NF-kappaB, signal transducer and activator of transcription-3 (STAT3), and the protein expression of C/EBPbeta and C/EBPdelta. We also found that rosmanol suppressed LPS-induced phosphorylation of ERK1/2, p38 mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling. Our results demonstrate that rosmanol downregulates inflammatory iNOS and COX-2 gene expression by inhibiting the activation of NF-kappaB and STAT3 through interfering with the activation of PI3K/Akt and MAPK signaling. Taken together, rosmanol might contribute to the potent anti-inflammatory effect of rosemary and may have potential to be developed into an effective anti-inflammatory agent.

[Basic mechanisms of hepatocellular injury. Role of inflammatory lipid mediators]

The presence of a lesion in the cellular parenchyma is common to a large number of chronic liver diseases, such as viral hepatitides, alcoholic hepatitis, chronic cholestasis and steatohepatitis. Although the pathogenesis may vary according to the etiological agent, a series of mechanisms is common to all. Notable among these mechanisms are Kupffer cell activation and inflammatory cell recruitment, free oxygen radical formation and the development of oxidative stress, cytokine production, mainly TNFa and TGFb, and inflammatory mediator release due to arachidonic acid oxidation through the COX-2 and 5-LO pathways.

Hyperinduction of cyclooxygenase-2-mediated proinflammatory cascade: a mechanism for the pathogenesis of avian influenza H5N1 infection

The mechanism for the pathogenesis of H5N1 infection in humans remains unclear. This study reveals that cyclooxygenase-2 (COX-2) was strongly induced in H5N1-infected macrophages in vitro and in epithelial cells of lung tissue samples obtained during autopsy of patients who died of H5N1 disease. Novel findings demonstrated that COX-2, along with tumor necrosis factor alpha and other proinflammatory cytokines were hyperinduced in epithelial cells by secretory factors from H5N1-infected macrophages in vitro. This amplification of the proinflammatory response is rapid, and the effects elicited by the H5N1-triggered proinflammatory cascade are broader than those arising from direct viral infection. Furthermore, selective COX-2 inhibitors suppress the hyperinduction of cytokines in the proinflammatory cascade, indicating a regulatory role for COX-2 in the H5N1-hyperinduced host proinflammatory cascade. These data provide a basis for the possible development of novel therapeutic interventions for the treatment of H5N1 disease, as adjuncts to antiviral drugs.

Lipid mediators in innate immunity against tuberculosis: opposing roles of PGE2 and LXA4 in the induction of macrophage death

Virulent Mycobacterium tuberculosis (Mtb) induces a maladaptive cytolytic death modality, necrosis, which is advantageous for the pathogen. We report that necrosis of macrophages infected with the virulent Mtb strains H37Rv and Erdmann depends on predominant LXA(4) production that is part of the antiinflammatory and inflammation-resolving action induced by Mtb. Infection of macrophages with the avirulent H37Ra triggers production of high levels of the prostanoid PGE(2), which promotes protection against mitochondrial inner membrane perturbation and necrosis. In contrast to H37Ra infection, PGE(2) production is significantly reduced in H37Rv-infected macrophages. PGE(2) acts by engaging the PGE(2) receptor EP2, which induces cyclic AMP production and protein kinase A activation. To verify a role for PGE(2) in control of bacterial growth, we show that infection of prostaglandin E synthase (PGES)(-/-) macrophages in vitro with H37Rv resulted in significantly higher bacterial burden compared with wild-type macrophages. More importantly, PGES(-/-) mice harbor significantly higher Mtb lung burden 5 wk after low-dose aerosol infection with virulent Mtb. These in vitro and in vivo data indicate that PGE(2) plays a critical role in inhibition of Mtb replication.

Inhibition of MAP kinases and down regulation of TNF-alpha, IL-beta and COX-2 genes by the crude extracts from marine bacteria

Crude ethyl acetate extracts from marine bacterial isolates Staphylococcus arlettae KP2 (GenBank accession No. EU594442) and Planococcus maritimus KP8 (GenBank accession No. EU594443) isolated from Andaman seas were studied for their anti-inflammatory effect by lymphocyte proliferation assay (LPA) employing peripheral blood mononuclear cells (PBMCs). The crude extracts from both the bacteria down regulated the synthesis of inflammatory mediators such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and cyclooxygenase-2 (COX-2), besides markedly inhibiting p38 mitogen activated protein (MAP) kinase. These results suggest that the crude ethyl acetate extracts from both the isolates do contain compounds capable of inhibiting inflammation in mitogen induced PBMC and efforts to score potential bioactive molecules from these extracts may prove to be a promising preposition.