Inducible Nitric Oxide Synthase and Inflammatory Diseases

Dietary inorganic nitrate: From villain to hero in metabolic disease?

Historically, inorganic nitrate was believed to be an inert by‐product of nitric oxide (NO) metabolism that was readily excreted by the body. Studies utilising doses of nitrate far in excess of dietary and physiological sources reported potentially toxic and carcinogenic effects of the anion. However, nitrate is a significant component of our diets, with the majority of the anion coming from green leafy vegetables, which have been consistently shown to offer protection against obesity, type 2 diabetes and metabolic diseases. The discovery of a metabolic pathway in mammals, in which nitrate is reduced to NO, via nitrite, has warranted a re‐examination of the physiological role of this small molecule. Obesity, type 2 diabetes and the metabolic syndrome are associated with a decrease in NO bioavailability. Recent research suggests that the nitrate‐nitrite‐NO pathway may be harnessed as a therapeutic to supplement circulating NO concentrations, with both anti‐obesity and anti‐diabetic effects, as well as improving vascular function. In this review, we examine the key studies that have led to the re‐evaluation of the physiological function of inorganic nitrate, from toxic and carcinogenic metabolite, to a potentially important and beneficial agent in the treatment of metabolic disease.

Resveratrol neuroprotection in stroke and traumatic CNS injury

Resveratrol, a stilbene formed in many plants in response to various stressors, elicits multiple beneficial effects in vertebrates. Particularly, resveratrol was shown to have therapeutic properties in cancer, atherosclerosis and neurodegeneration. Resveratrol-induced benefits are modulated by multiple synergistic pathways that control oxidative stress, inflammation and cell death. Despite the lack of a definitive mechanism, both in vivo and in vitro studies suggest that resveratrol can induce a neuroprotective state when administered acutely or prior to experimental injury to the CNS. In this review, we discuss the neuroprotective potential of resveratrol in stroke, traumatic brain injury and spinal cord injury, with a focus on the molecular pathways responsible for this protection.

Novel synthetic pyridyl analogues of CDDO-Imidazolide are useful new tools in cancer prevention

Two new analogues of CDDO-Imidazolide (CDDO-Im), namely 1-[2-Cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]-4(-pyridin-2-yl)-1H-imidazole ("CDDO-2P-Im") and 1-[2-Cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]-4(-pyridin-3-yl)-1H-imidazole ("CDDO-3P-Im") have been synthesized and tested for their potential use as chemopreventive drugs. At nanomolar concentrations, they were equipotent to CDDO-Im for inducing differentiation and apoptosis in U937 leukemia cells. As inflammation and oxidative stress contribute to carcinogenesis, we also assessed their cytoprotective potential. The new compounds suppressed inducible nitric oxide synthase (iNOS) expression in RAW264.7 macrophage-like cells and significantly elevated heme oxygenase-1 (HO-1) and quinone reductase (NQO1) mRNA and protein levels in various mouse tissues in vivo. Most importantly, pharmacokinetic studies performed in vitro in human plasma and in vivo showed that each new analogue was more stable than CDDO-Im. Much higher concentrations of the new derivatives were found in mouse liver, lung, pancreas and kidney after gavage in contrast to CDDO-Im. Because of their better bioavailability and their excellent anti-inflammatory profile in vitro, CDDO-2P-Im and CDDO-3P-Im were tested for prevention in a highly relevant mouse lung cancer model, in which A/J mice develop lung carcinomas after injection of vinyl carbamate, a potent carcinogen. CDDO-2P-Im and CDDO-3P-Im were as effective as CDDO-Im for reducing the size and the severity of the lung tumors.

Daily Oxygen/O₃ Treatment Reduces Muscular Fatigue and Improves Cardiac Performance in Rats Subjected to Prolonged High Intensity Physical Exercise

Rats receiving daily intraperitoneal administration of O2 and running on a treadmill covered an average distance of 482.8 ± 21.8 m/week as calculated during 5-week observation. This distance was increased in rats receiving daily intraperitoneal administration of an oxygen/O3 mixture at a dose of 100; 150; and 300 μg/kg with the maximum increase being +34.5% at 300 μg/kg and still present after stopping the administration of oxygen/O3. Oxygen/O3 decreased the mean arterial blood pressure (-13%), the heart rate (-6%), the gastrocnemius and cardiac hypertrophy, and fibrosis and reduced by 49% the left ventricular mass and relative wall thickness measurements. Systolic and diastolic functions were improved in exercised oxygen/O3 rats compared to O2 rats. Oxygen/O3 treatment led to higher MPI index starting from the dose of 150 μg/kg (p < 0.05) and more effective (+14%) at a dose of 300 μg/kg oxygen/O3. Oxygen/O3 dose-dependently increased the expression of the antioxidant enzymes Mn-SOD and GPx1 and of eNOS compared to the exercised O2 rats. The same doses resulted in decrease of LDH levels, CPK, TnI, and nitrotyrosine concentration in the heart and gastrocnemius tissues, arguing a beneficial effect of the ozone molecule against the fatigue induced by a prolonged high intensity exercise.

Achalasia Is Associated With eNOS4a4a, iNOS22GA, and nNOS29TT Genotypes: A Case-control Study

Background/Aims

Achalasia is known to result from degeneration of inhibitory neurons, which are mostly nitrinergic. Characteristic features of achalasia include incomplete lower esophageal sphincter (LES) relaxation and esophageal aperistalsis. Nitric oxide (NO), produced by NO synthase (NOS), plays an important role in peristalsis and LES relaxation. Therefore, we evaluated genetic polymorphisms of NOS gene isoforms (endothelial NOS [eNOS], inducible NOS [iNOS], and neuronal NOS [nNOS]) in patients with achalasia and healthy subjects (HS).

Methods

Consecutive patients with achalasia (diagnosed using esophageal manometry) and HS were genotyped for 27-base pair (bp) eNOS variable number of tandem repeats (VNTR), iNOS22G/A (rs1060826), nNOS C/T (rs2682826) polymorphisms by polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP), respectively.

Results

Among 183 patients (118 [64.5%] male, age 39.5 ± 13.0 years) with achalasia and 366 HS (254 [69.4%] male, age 40.8 ± 11.0 years), eNOS4a4a genotype of 27-bp VNTR was more common among achalasia than HS (20 [10.9%] vs 13 [3.6%]; P < 0.001; OR, 3.72; 95% CI, 1.8–7.7). Patients with achalasia had iNOS22GA genotypes more often than HS (95 [51.9%] vs 93 [25.4%]; P < 0.001; OR, 3.0; 95% CI, 2.1–4.4). Frequency of genotypes GA + AA was higher in patients than HS (97 [53%] vs 107 [29.2%]; P < 0.001; OR, 2.7; 95% CI, 1.8–3.9). Also, nNOS29TT variant genotype in rs2682826 was more common among patients compared to HS (14 [7.7%] vs 6 [1.6%]; P < 0.001; OR, 5.91; 95% CI, 2.2–15.8).

Conclusions

Achalasia is associated with eNOS4a4a, iNOS22GA, and nNOS29TT genotypes. This may suggest that polymorphisms of eNOS, iNOS, and nNOS genes are risk factors for achalasia.

Possible pathophysiology of ketamine-related cystitis and associated treatment strategies

Ketamine-related cystitis is characterized by ketamine-induced urinary frequency and bladder pain. It has become a serious problem in recent years. The most typical grossly pathological bladder change with ketamine related cystitis is a contracted bladder and bladder wall thickening. Ulcerative cystitis with an easily bleeding mucosa is a common cystoscopic finding. Microscopically, the urothelium is denuded and is infiltrated by inflammatory cells, such as mast cells and eosinophils. The pathogenesis of ketamine-related cystitis is complicated and involves many different pathways. Past evidence suggests a direct toxic effect, bladder barrier dysfunction, neurogenic inflammation, immunoglobulin-E-mediated inflammation, overexpression of carcinogenic genes, abnormal apoptosis and nitric oxide synthase-mediated inflammation contribute to the pathogenesis of ketamine-related cystitis. The first step to managing ketamine-related cystitis is always asking patients to cease ketamine. Medical treatment might be helpful in patients with early ketamine-related cystitis and abstinence from ketamine. Several case studies showed that the intravesical installation of hyaluronic acid and intravesical injection of botulinum toxin type A were effective for symptom relief in selected patients. For patients with irreversible pathological change, such as contracted bladder, augmentation enterocystoplasty might be the only solution to increase bladder capacity and relieve intractable bladder pain.

Mechanisms and consequences of endothelial nitric oxide synthase dysfunction in hypertension

Reduced nitric oxide bioavailability contributes to endothelial dysfunction and hypertension. The endothelial isoform of nitric oxide synthase (eNOS) is responsible for the production of nitric oxide within the endothelium. Loss of eNOS cofactor tetrahydrobiopterin to initial increase in oxidative stress leads to uncoupling of eNOS, in which the enzyme produces superoxide anion rather than nitric oxide, further substantiating oxidative stress to induce vascular pathogenesis. The current review focuses on recent advances on the molecular mechanisms and consequences of eNOS dysfunction in hypertension, and potential novel therapeutic strategies restoring eNOS function to treat hypertension.

Modulation of nitric oxide by flavonoids

One of the main mechanisms by which dietary flavonoids are thought to influence cardiovascular disease is via protection of the bioactivity of the endothelium-derived nitric oxide (NO). Additionally, flavonoids may also interfere with the signalling cascades of inflammation and prevent overproduction of NO and its deleterious consequences in shock and ischemia-reperfusion injury. In the present paper we review the evidence of the effects of flavonoids on NO. Flavonoids exert complex actions on the synthesis and bioavailability of NO which may result both in enhanced or decreased NO levels: (1) in cell free systems, several flavonoids may scavenge NO via its pro-oxidant properties by increasing superoxide. However, under conditions of oxidative stress, flavonoids may also protect NO from superoxide-driven inactivation. (2) In intact healthy tissues, some flavonoids increase eNOS activity in endothelial cells. Paradoxically this effect involves a pro-oxidant effect which results in Ca(2+)-dependent activation of eNOS. As inhibitors of PI3K, flavonoids may potentially inhibit the PI3K/Akt-dependent activation of eNOS. (3) Under conditions of inflammation and oxidative stress, flavonoids may prevent the inflammatory signalling cascades via inhibition of NFκB and thereby downregulate iNOS. On the other hand, they also prevent the overexpression of ROS generating enzymes, reducing superoxide and peroxynitrite levels, and hence preventing superoxide-induced NO inactivation and eNOS uncoupling. Therefore, the final effect of flavonoids on NO levels will depend on the flavonoid structure and the concentrations used, on the cell type under study and particularly on the presence of inflammatory/oxidative conditions.

Antioxidant effects of pineapple vinegar in reversing of paracetamol-induced liver damage in mice

Background

Pineapple (Ananas comosus) was demonstrated to be hepatoprotective. This study aims to investigate the reversing effects of pineapple vinegar on paracetamol-induced liver damage in murine model.

Methods

Pineapple juice was fermented via anaerobic and aerobic fermentation to produce pineapple vinegar. Male BALB/c mice (n = 70) were separated into 7 treatment groups (n = 10). Pineapple vinegar (0.08 and 2 mL/kg BW) and synthetic vinegar were used to treat paracetamol-induced liver damage in mice. The hepatoprotective effects were determined by serum biochemistry profiles (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and triglyceride (TG)), liver antioxidant levels (ferric-reducing ability plasma (FRAP), superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione assays (GSH)) and histopathological examination with hematoxylin and eosin (H&E) staining. The effects were further evaluated by the expression levels of iNOS, NF-κB, and cytochrome P450 2E1 by quantitative real-time PCR and Western blot analyses. Vinegar samples were also tested for in vitro antioxidant (FRAP, 2,2-diphenyl-2-picrylhydrazyl (DPPH), and total phenolic content (TPC)). Soluble phenolic acid contents in the samples were identified by HPLC.

Results

Pineapple vinegar contained 169.67 ± 0.05 μg GAE/mL of TPC, with 862.61 ± 4.38 μg/mL gallic acid as the main component. Oral administration of pineapple vinegar at 2 mL/kg BW reduced serum enzyme biomarker levels, including AST (P = 0.008), ALT (P = 0.006), ALP (P₌ 0.002), and TG (P = 0.006) after 7 days of paracetamol treatment. Liver antioxidant levels such as hepatic glutathione (P = 0.003), SOD (P < 0.001), lipid peroxidation (P = 0.002) and FRAP (P <0.001) were restored after the treatment. Pineapple vinegar reduced the expressions of iNOS (P = 0.003) and NF-kB (P = 0.003) and the level of NO (P = 0.003) significantly. Pineapple vinegar also downregulated liver cytochrome P450 protein expression.

Conclusions

Oral administration of pineapple vinegar at 0.08 and 2 mL/kg BW reduced serum enzyme biomarker levels, restored liver antioxidant levels, reduced inflammatory factor expressions, and down regulated liver cytochrome P450 protein expression in paracetamol-induced liver damage in mice.

Stemona tuberosa prevented inflammation by suppressing the recruitment and the activation of macrophages in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Stemona tuberosa (ST) is a traditional herbal medicine used for the treatment of various respiratory diseases in eastern Asia.

AIM OF THE STUDY

We investigated the anti-inflammatory effects of a ST water extract in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and in cigarette smoke (CS)-induced lung inflammation mouse models.

MATERIALS AND METHODS

RAW 264.7 macrophages were treated with the ST extract and stimulated by LPS. The expressions of pro-inflammatory mediators were evaluated by using nitric oxide (NO) assay, enzyme-linked immunosorbent assay and Western blot analysis. After the C57BL/6 mice were exposed to CS, they were administrated with the ST extract. The accumulated inflammatory cells in the bronchoalveolar lavage fluid (BALF) were counted. Also, real-time polymerase chain reaction and hematoxylin and eosin staining were performed in lung tissues.

RESULTS

The ST extract treatment reduced the production of NO via blocking the expressions of cyclooxygenase-2 and inducible nitric oxide synthase protein in RAW 264.7 macrophages. In addition, ST extract treatment decreased the secretions of inflammatory cytokines and regulated NF-κB activation by inhibiting the phosphorylation of IκB and the mitogen-activated protein kinase pathway. Also, ST extract administration to mice reduced the infiltrations of macrophages into BALF and the histological inflammatory changes in lung tissues. Furthermore, administration of the ST extract regulated the levels of tumor necrosis factor-α, interleukin (IL)-6, IL-1β, monocyte chemoattractant protein-1 and matrix metalloproteinases-12 in the lungs.

CONCLUSION

These findings suggested that ST extract attenuated pulmonary inflammatory responses by inhibiting the expression of diverse inflammatory mediators in vivo and in vitro.

Response of the nitrergic system to activation of the neuroendocrine stress axis

Exposure to stressful stimuli causes activation of the hypothalamic-pituitary-adrenal axis which rapidly releases high concentrations of glucocorticoid stress hormones, resulting in increased cellular metabolism and spontaneous oxygen and nitrogen radical formation. High concentrations of nitrogen radicals, including nitric oxide, cause damage to cellular proteins in addition to inhibiting components of the mitochondrial transport chain, leading to cellular energy deficiency. During stress exposure, pharmacological inhibition of nitric oxide production reduces indicators of anxiety- and depressive-like behavior in animal models. Therefore, the purpose of this review is to present an overview of the current literature on stress-evoked changes in the nitrergic system, particularly within neural tissue.

Lotus leaf (Nelumbo nucifera) and its active constituents prevent inflammatory responses in macrophages via JNK/NF-κB signaling pathway

Inflammation is a serious health issue worldwide that induces many diseases, such as inflammatory bowel disease (IBD), sepsis, acute pancreatitis and lung injury. Thus, there is a great deal of interest in new methods of limiting inflammation. In this study, we investigated the leaves of Nelumbo nucifera Gaertn, an aquatic perennial plant cultivated in eastern Asia and India, in anti-inflammatory pharmacological effects in the murine macrophage cell line RAW264.7. Results showed that lipopolysaccharide (LPS) increased the protein expression of inducible nitric oxide synthase (iNOS) and COX-2, as well as the mRNA expression and level of IL-6 and TNF-α, while NNE significantly reduced these effects of LPS. LPS also induced phospho-JNK protein expression. The JNK-specific inhibitor SP600125 decreased the proteins expression of phospho-JNK, iNOS, COX-2, and the mRNAs expression and levels of IL-6 and TNF-α. Further, NNE reduced the protein expression of phospho-JNK. LPS was also found to promote the translocation of NF-κB from the cytosol to the nucleus and to decrease the expression of cytosolic IκB. NNE and SP600125 treatment recovered the LPS-induced expression of NF-κB and IκB. While phospho-ERK and phospho-p38 induced by LPS, could not be reversed by NNE. To further investigate the major components of NNE in anti-inflammatory effects, we determined the quercetin and catechin in inflammatory signals. Results showed that quercetin and catechin significantly decreased the proteins expression of iNOS, COX-2 and phospho-JNK. Besides, the mRNAs and levels of IL-6 and TNF-α also decreased by quercetin and catechin treatment in LPS-induced RAW264.7 cells. These results showed that NNE and its major components quercetin and catechin exhibit anti-inflammatory activities by inhibiting the JNK- and NF-κB-regulated pathways and could therefore be an useful anti-inflammatory agent.

H2S regulation of nitric oxide metabolism

Nitric oxide (NO) and hydrogen sulfide (H2S) are two major gaseous signaling molecules that regulate diverse physiological functions. Recent publications indicate the regulatory role of H2S on NO metabolism. In this chapter, we discuss the latest findings on H2S-NO interactions through formation of novel chemical derivatives and experimental approaches to study these adducts. This chapter also addresses potential H2S interference on various NO detection techniques, along with precautions for analyzing biological samples from various sources. This information will facilitate critical evaluation and clearer insight into H2S regulation of NO signaling and its influence on various physiological functions.

8,8'-Bieckol, isolated from edible brown algae, exerts its anti-inflammatory effects through inhibition of NF-κB signaling and ROS production in LPS-stimulated macrophages

Ecklonia cava (E. cava) is an abundant brown alga that contains high levels of phlorotannins, which are unique marine polyphenolic compounds. It has been suggested that E. cava phlorotannins exert anti-inflammatory effects. However, the anti-inflammatory effects and underlying molecular mechanism exerted by 8,8'-bieckol isolated from E. cava have not been reported. Thus, in this study, we examined the anti-inflammatory effects of 8,8'-bieckol on lipopolysaccharide (LPS)-stimulated primary macrophages and RAW 264.7 macrophages. We found that 8,8'-bieckol suppressed key inflammatory mediator [i.e., nitric oxide (NO) and prostaglandin E2 (PGE2)] production in both primary and RAW 264.7 macrophages. 8,8'-Bieckol inhibited NO by suppressing LPS-induced expression of inducible nitric oxide synthase (iNOS) at the mRNA and protein levels in primary macrophages and RAW 264.7 cells. In addition, 8,8'-bieckol decreased the production and mRNA expression of the inflammatory cytokine interleukin-6 (IL-6), but not tumor necrosis factor (TNF)-α, in RAW 264.7 cells. Moreover, 8,8'-bieckol treatment diminished transactivation of nuclear factor-kappa B (NF-κB) and nuclear translocation of the NF-κB p65 subunit and suppressed LPS-induced intracellular reactive oxygen species (ROS) production in macrophages. Furthermore, 8,8'-bieckol markedly reduced mortality in LPS-induced septic mice. Taken together, these data indicate that the anti-inflammatory properties of 8,8'-bieckol are associated with the suppression of NO, PGE2, and IL-6 via negative regulation of the NF-κB pathway and ROS production in LPS-stimulated RAW 264.7 cells. Moreover, 8,8'-bieckol protects mice from endotoxin shock.

Mycoplasma gallisepticum lipid associated membrane proteins up-regulate inflammatory genes in chicken tracheal epithelial cells via TLR-2 ligation through an NF-κB dependent pathway

Mycoplasma gallisepticum-mediated respiratory inflammation in chickens is associated with accumulation of leukocytes in the tracheal submucosa. However the molecular mechanisms underpinning these changes have not been well described. We hypothesized that the initial inflammatory events are initiated upon ligation of mycoplasma lipid associated membrane proteins (LAMP) to TLRs expressed on chicken tracheal epithelial cells (TEC). To test this hypothesis, live bacteria or LAMPs isolated from a virulent (R_low) or a non-virulent (R_high) strain were incubated with primary TECs or chicken tracheae ex vivo. Microarray analysis identified up-regulation of several inflammatory and chemokine genes in TECs as early as 1.5 hours post-exposure. Kinetic analysis using RT-qPCR identified the peak of expression for most genes to be at either 1.5 or 6 hours. Ex-vivo exposure also showed up-regulation of inflammatory genes in epithelial cells by 1.5 hours. Among the commonly up-regulated genes were IL-1β, IL-6, IL-8, IL-12p40, CCL-20, and NOS-2, all of which are important immune-modulators and/or chemo-attractants of leukocytes. While these inflammatory genes were up-regulated in all four treatment groups, R_low exposed epithelial cells both in vitro and ex vivo showed the most dramatic up-regulation, inducing over 100 unique genes by 5-fold or more in TECs. Upon addition of a TLR-2 inhibitor, LAMP-mediated gene expression of IL-1β and CCL-20 was reduced by almost 5-fold while expression of IL-12p40, IL-6, IL-8 and NOS-2 mRNA was reduced by about 2–3 fold. Conversely, an NF-κB inhibitor abrogated the response entirely for all six genes. miRNA-146a, a negative regulator of TLR-2 signaling, was up-regulated in TECs in response to either R_low or R_high exposure. Taken together we conclude that LAMPs isolated from both R_high and R_low induced rapid, TLR-2 dependent but transient up-regulation of inflammatory genes in primary TECs through an NF-κB dependent pathway.

Nitric oxide synthase inhibitors: a review of patents from 2011 to the present

INTRODUCTION

Nitric oxide synthases (NOSs) are a family of enzymes that play an essential role in synthesizing nitric oxide (NO) by oxidizing l-arginine. As previously reported, NO is a significant mediator in cellular signaling pathways. It serves as a crucial regulator in insulin secretion, vascular tone, peristalsis, angiogenesis, neural development and inflammation. Due to its important role, the inhibition of these vital enzymes provides, as tools, the opportunity to gain an insight into potential therapeutic applications targeting NOSs.

AREAS COVERED

This paper reviews the patent literature between 2011 and mid-2014 that specified inhibitors of NOS family members as the significant targets. Google and Baidu search engines were used to find relevant patents and clinical information using NOSs or NOS inhibitor as search terms.

EXPERT OPINION

Considerable recent progress has been made in the development of NOS inhibitors with pharmacodynamic and pharmacokinetic properties, and such development is likely to continue. The patented compounds attenuated mostly embodying evidence from in vitro and in vivo trials that demonstrate good potential for future clinical human trials and industrial applications. Furthermore, new techniques such as X-ray ligand crystallographic study and structure-activity relationship were popularly utilized, which give new insights for developing novel, safe, efficient and selective NOS inhibitors.

Veratric acid inhibits iNOS expression through the regulation of PI3K activation and histone acetylation in LPS-stimulated RAW264.7 cells

In the present study, we investigated regulatory effects of veratric acid on the production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. NO production was significantly decreased by veratric acid in the LPS-stimulated RAW264.7 cells in a dose-dependent manner. The reduction in nitric oxide production was induced by the downregulation of inducible NO synthase (iNOS) expression. Veratric acid suppressed the LPS-induced effects on the regulatory and catalytic subunits of phosphoinositide 3-kinase (PI3K), comprised of p85, p110α, p110β and Akt. The acetylation of p300 and the phosphorylation of activating transcription factor 2 (ATF-2) induced by LPS were downregulated following treatment with veratric acid; similar effects were observed following treatment with LY294002, a specific inhibitor of PI3K/Akt. The LPS-induced expression of histone deacetylase (HDAC)3 decreased to basal levels following treatment with veratric acid, and its expression was also downregulated by LY294002. In the measurement of histone acetylation levels, the LPS-stimulated acetylation of histone H4 was significantly attenuated by veratric acid, and was also reduced following the inhibition of PI3K/Akt with LY294002. From our data, it can be concluded that veratric acid exerts a regulatory effect on LPS-induced iNOS expression. Our results suggest that veratric acid impedes the PI3K/Akt-mediated histone acetyl-transferase (HAT) activation and HDAC expression induced by LPS, thereby abrogating iNOS expression.

Protective effects of esculentic acid against endotoxic shock in Kunming mice

Esculentic acid (EA), a triterpene compound extracted from the root of Phytolacca esculenta (the Chinese name Shang Lu), has been widely used to therapy a variety of inflammatory diseases such as rheumatoid arthritis, edema, hepatitis and bronchitis. The present study was designed to investigate the protective effects of EA against LPS-induced endotoxic shock by the intraperitoneal injection of EA (1, 5 and 10 mg/kg) prior to LPS stimulation (1 mg/kg, i.p.). We examined the effects of EA on the survival rate of mice, inflammatory cytokine and pro-inflammatory mediator production, histopathological changes and protein expression of COX-2 in tissue sections from lung, liver and kidney. The results indicate that EA not only increases the survival rate of mice, but decreases the levels of TNF-α, IL-6, NO and PGE2 in serum or tissues, histopathological changes and COX-2 protein expression also. Furthermore, EA also increases the levels of anti-inflammatory cytokine IL-10 in serum. Overall, these data suggest that the protective effects of EA against LPS-induced endotoxic shock may be mediated, at least in part, by regulation the release of inflammatory cytokines and mediators, and protein expression of COX-2 in mice.

Age-related inflammation and insulin resistance: a review of their intricate interdependency

Chronic inflammation is a major risk factor underlying aging and the associated diseases of aging; of particular interest is insulin resistance during aging. Chronic inflammation impairs normal lipid accumulation, adipose tissue function, mitochondrial function, and causes endoplasmic reticulum (ER) stress, which lead to insulin resistance. However, some studies show that insulin resistance itself amplifies chronic inflammation. The activity of the insulin-dependent Akt signaling pathway is highlighted because of its decrease in insulin-sensitive organs, like liver and muscle, which may underlie insulin resistance and hyperinsulinemia, and its increased levels in non-metabolic organs, such as kidney and aorta. In that the prevalence of obesity has increased substantially for all age groups in recent years, our review summarizes the data showing the involvement of chronic inflammation in obesity-induced insulin resistance, which perpetuates reciprocal interactions between the chronic inflammatory process and increased adiposity, thereby accelerating the aging process.

High levels of γ-H2AX foci and cell membrane oxidation in adolescents with type 1 diabetes

Oxidative stress caused by an excess of free radicals is implicated in the pathogenesis and development of type 1 diabetes mellitus (T1DM) and, in turn, it can lead to genome damage, especially in the form of DNA double-strand break (DSB). The DNA DSB is a potentially carcinogenic lesion for human cells. Thus, we aimed to evaluate whether the level of oxidative stress was increased in peripheral blood lymphocytes of a group of affected adolescents. In 35 T1DM adolescents and 19 healthy controls we assessed: (1) spontaneous and H2O2-induced oxidation of cell membrane using a fluorescence lipid probe; (2) spontaneous and LPS-induced expression of iNOS protein and indirect NO determination via cytofluorimetric analysis of O2(-); (3) immunofluorescent detection of the basal level of histone H2AX phosphorylation (γ-H2AX foci), a well-validated marker of DNA DSB. In T1DM, the frequencies of oxidized cells, both spontaneous and H2O2-induced (47.13±0.02) were significantly higher than in controls (35.90±0.03). Patients showed, in general, both a reduced iNOS expression and production of NO. Furthermore, the level of spontaneous nuclear damage, quantified as γ-H2AX foci, was markedly increased in T1DM adolescents (6.15±1.08% of γ-H2AX(+) cells; 8.72±2.14 γ-H2AXF/n; 9.26±2.37 γ-H2AXF/np), especially in females. In the present study, we confirmed the role that oxidative stress plays in the disease damaging lipids of cell membrane and, most importantly, causing genomic damage in circulating white blood cells of affected adolescents. This also indicates that oxidative stress can affect several tissues in the body. However, although the observed DNA damage is a clear indication that the proper DNA repair mechanisms are activated, the risk for young T1DM subjects of developing not only cardiovascular complications but also some type of cancer cannot be ruled out. In this view, females, probably due to hormonal imbalance typical of adolescence, might represent a more susceptible population.

Global sensitivity analysis of a mathematical model of acute inflammation identifies nonlinear dependence of cumulative tissue damage on host interleukin-6 responses

The precise inflammatory role of the cytokine interleukin (IL)-6 and its utility as a biomarker or therapeutic target have been the source of much debate, presumably due to the complex pro- and anti-inflammatory effects of this cytokine. We previously developed a nonlinear ordinary differential equation (ODE) model to explain the dynamics of endotoxin (lipopolysaccharide; LPS)-induced acute inflammation and associated whole-animal damage/dysfunction (a proxy for the health of the organism), along with the inflammatory mediators tumor necrosis factor (TNF)-α, IL-6, IL-10, and nitric oxide (NO). The model was partially calibrated using data from endotoxemic C57Bl/6 mice. Herein, we investigated the sensitivity of the area under the damage curve (AUCD) to the 51 rate parameters of the ODE model for different levels of simulated LPS challenges using a global sensitivity approach called Random Sampling High Dimensional Model Representation (RS-HDMR). We explored sufficient parametric Monte Carlo samples to generate the variance-based Sobol' global sensitivity indices, and found that inflammatory damage was highly sensitive to the parameters affecting the activity of IL-6 during the different stages of acute inflammation. The AUCIL6 showed a bimodal distribution, with the lower peak representing healthy response and the higher peak representing sustained inflammation. Damage was minimal at low AUCIL6, giving rise to a healthy response. In contrast, intermediate levels of AUCIL6 resulted in high damage, and this was due to the insufficiency of damage recovery driven by anti-inflammatory responses from IL-10 and the activation of positive feedback sustained by IL-6. At high AUCIL6, damage recovery was interestingly restored in some population of simulated animals due to the NO-mediated anti-inflammatory responses. These observations suggest that the host's health status during acute inflammation depends in a nonlinear fashion on the magnitude of the inflammatory stimulus, on the host's propensity to produce IL-6, and on NO-mediated downstream responses.

N-[3-(aminomethyl)benzyl]acetamidine (1400 W) as a potential immunomodulatory agent

This study was designed to investigate the relationship between NO, IL-12, and TNF-α production by J774A.1 macrophages activated with LPS and IFN-γ in the presence of N-[3-(aminomethyl)benzyl]acetamidine (1400 W). 1400 W is a novel, highly selective inhibitor of inducible nitric oxide synthase (iNOS). We compared the obtained data with the effect of N^G-monomethyl-L-arginine (L-NMMA) (a nonselective NOS inhibitor) and L-N^G-(1-iminoethyl)lysine (L-NIL) (a relatively selective inhibitor of iNOS activity) on cells in this model. To investigate the involvement of an exogenous NO on IL-12 and TNF-α production we used NO donor—S-nitrosocaptopril (S-NO-Cap). The most potent inhibitor of NO generation was 1400 W. This compound also markedly increased IL-12 p40 secretion and decreased TNF-α release. L-NIL suppressed both NO and TNF-α production, but it did not change IL-12 p40 synthesis. The effect of L-NMMA on NO generation was weaker than other inhibitors. Moreover, it decreased TNF-α secretion slightly but not significantly. IL-12 p40 production by stimulated cells was inhibited by S-NO-Cap in a dose dependent manner, but no effect on TNF-α release was observed. The potency and selectivity of 1400 W as an inhibitor of iNOS and cytokine release modifier are encouraging for therapeutic use.

The anti-inflammatory effect of Indonesian Areca catechu leaf extract in vitro and in vivo

BACKGROUND/OBJECTIVES

Overproduction of nitric oxide (NO) by the inducible nitric oxide synthase (iNOS) enzyme can cause inflammation. Cyclooxygenase-2 (COX-2) is also involved in the inflammatory response through regulation of nuclear factor-kappa B (NF-κB). Areca catechu is one of the known fruit plants of the Palmaceae family. It has been used for a long time as a source of herbal medicine in Indonesia. In this study, we explored the effect of Indonesian Areca catechu leaf ethanol extract (ACE) in lipopolysaccharide (LPS)-induced inflammation and carrageenan-induced paw edema models. Recently, this natural extract has been in the spotlight because of its efficacy and limited or no toxic side effects. However, the mechanism underlying its anti-inflammatory effect remains to be elucidated.

MATERIALS/METHODS

We measured NO production by using the Griess reagent, and determined the expression levels of inflammation-related proteins, such as iNOS, COX2, and NF-κB, by western blot. To confirm the effect of ACE in vivo, we used the carrageenan-induced paw edema model.

RESULTS

Compared to untreated cells, LPS-stimulated RAW 264.7 cells treated with ACE showed reduced NO generation and reduced iNOS and COX-2 expression. We found that the acute inflammatory response was significantly reduced by ACE in the carrageenan-induced paw edema model.

CONCLUSION

Taken together, these results suggest that ACE can inhibit inflammation and modulate NO generation via downregulation of iNOS levels and NF-κB signaling in vitro and in vivo. ACE may have a potential medical benefit as an anti-inflammation agent.

Anti-inflammatory effect of tricin 4'-O-(threo-β-guaiacylglyceryl) ether, a novel flavonolignan compound isolated from Njavara on in RAW264.7 cells and in ear mice edema

Although recent study has shown tricin 4'-O-(threo-β-guaiacylglyceryl) ether (TTGE), an isolated compound from Njavara rice, to have the most potent anti-inflammatory effects, the action mechanism has not been fully understood. Here, we examined the effect of TTGE on the inflammation and elucidated the potential mechanism. We demonstrated that TTGE significantly inhibited LPS-induced NO and ROS generation in RAW264.7 cells, which was correlated with the down-regulating effect of TTGE on the iNOS and COX-2 expression via NF-κB and STAT3. TPA-induced ear edema was also efficiently inhibited by the TTGE treatment. TTGE blocked the induction of iNOS and COX-2 through the regulation of NF-κB and STAT3, which could explain the reduced TPA-induced edema symptoms. Moreover, the introduction of ERK inhibitor abrogated the anti-inflammatory effect of TTGE via the recovery of NF-κB and STAT3 signalings. Taken together, these results suggest that TTGE has anti-inflammatory properties through down-regulation of NF-κB and STAT3 pathways.

Effect of matrine on primary human hepatocytes in vitro

Matrine is a bioactive component of the traditional Chinese medical herb Sophora flavescens that has been used in China to treat various kinds of diseases including virus hepatitis. However, the molecular mechanisms underlying its hepatoprotective effects remains elusive. In the present study, primary human hepatocytes were employed to elucidate the protective effects and molecular mechanisms of matrine. We observed that low concentrations of matrine had no significant impact on albumin secretion, but high concentrations (>140 mg/L) of matrine decreased the albumin secretion in hepatocytes. Western blot data indicated that matrine at 140 mg/L at 72 h induced protein expression of CYP2A6, CYP2B6 and CYP3A4. Furthermore, high concentrations of matrine reduced LDH and AST levels and were cytotoxic to hepatocytes, leading to a decreased cell viability and total protein amount. Moreover, low concentrations of matrine, enhanced the ECOD activity and decreased the level of NO2 (-) induced by cytokines in human hepatocytes. Taken together, the present study sheds novel light on the molecular mechanisms of matrine and potential application of matrine in hepatic diseases.

Trichinenlides A-T, mexicanolide-type limonoids from Trichilia sinensis

Twenty new mexicanolide-type limonoids, namely, trichinenlides A-T (1-20), and 11 known analogues were isolated from the leaves and twigs of Trichilia sinensis. Trichinenlides B (2) and C (3) and heytrijunolide D exhibited inhibition against lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages with IC50 values of 2.85, 1.88, and 3.33 μM, respectively.

Apo-9'-fucoxanthinone, isolated from Sargassum muticum, inhibits CpG-induced inflammatory response by attenuating the mitogen-activated protein kinase pathway

Sargassum muticum (S. muticum) is a brown edible alga and widely distributed in Korea. This report was designed to evaluate the anti-inflammatory properties of apo-9'-fucoxanthinone (APO-9') isolated from S. muticum on pro-inflammatory cytokine production. S. muticum extract (SME) exhibited significant inhibitory effects on pro-inflammatory cytokine production in bone marrow-derived macrophages (BMDMs) and dendritic cells (BMDCs). APO-9' pre-treatment in the CpG DNA-stimulated BMDMs and BMDCs showed a strong dose-dependent inhibitory effect on interleukin (IL)-12 p40, IL-6 and tumor necrosis factor (TNF)-α production with IC50 values ranging from 5.31 to 13.79. It exhibited a strong inhibitory effect on the phosphorylation of ERK1/2 and on activator protein (AP)-1 reporter activity. APO-9' pre-treatment exhibited significant inhibition of CpG DNA-induced production of inducible nitric oxide synthase. Taken together, these data suggest that SME and APO-9' have a significant anti-inflammatory property and warrant further studies concerning the potentials of SME and APO-9' for medicinal use.

Anti-inflammatory activity of Cymbopogon citratus leaves infusion via proteasome and nuclear factor-κB pathway inhibition: contribution of chlorogenic acid

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbopogon citratus (DC.) Stapf leaves infusion is used in traditional medicine for the treatment of inflammatory conditions, however little is known about their bioactive compounds.

AIM OF THE STUDY

Investigate the compounds responsible for anti-inflammatory potential of Cymbopogon citratus (Cy) on cytokines production induced by lipopolysaccharide (LPS) in human and mouse macrophages, and the action mechanisms involved.

MATERIALS AND METHODS

An essential oil-free infusion of Cy was prepared and polyphenol-rich fractions (PFs) were obtained from it by column chromatography. Chlorogenic acid (CGA) was identified, by HPLC/PDA/ESI-MS(n). The expression of cytokines, namely TNF-α and CCL5, was analyzed by real-time RT-PCR, on LPS-stimulated human macrophages. Activation of nuclear factor (NF)-κB, a master regulator of inflammation, was investigated by western blot and gene reporter assay. Proteasome activity was assessed using a fluorogenic peptide.

RESULTS

Cymbopogon citratus extract and its polyphenols inhibited the cytokine production on human macrophages. This supports the anti-inflammatory activity of Cy polyphenols in physiologically relevant cells. Concerning the effect on the activation of NF-κB pathway, the results pointed to an inhibition of LPS-induced NF-κB activation by Cy and PFs. CGA was identified, by HPLC/PDA/ESI-MS(n), as the main phenolic acid of the Cy infusion, and it demonstrated to be, at least in part, responsible by that effect. Additionally, it was verified for the first time that Cy and PFs inhibited the proteasome activity, a complex that controls NF-κB activation, having CGA a strong contribution.

CONCLUSIONS

The results evidenced, for the first time, the anti-inflammatory properties of Cymbopogon citratus through proteasome inhibition and, consequently NF-κB pathway and cytokine expression. Additionally, Cy polyphenols, in particular chlorogenic acid, were highlighted as bioactive compounds.

α-Cyperone, isolated from the rhizomes of Cyperus rotundus, inhibits LPS-induced COX-2 expression and PGE2 production through the negative regulation of NFκB signalling in RAW 264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizomes of Cyperus rotundus (Cyperaceae) have been used in Asian traditional medicine for the treatment of several inflammatory diseases. However, the anti-inflammatory effects of α-cyperone, a major active compound of Cyperus rotundus, are poorly understood.

MATERIALS AND METHODS

PGE2 and cytokines released from cells were measured using an EIA assay kit. The expression of iNOS, COX-2, TNF-α, and IL-6 was measured by real-time RT-PCR and/or Western blot analysis. A luciferase assay was performed to measure the effect of α-cyperone on NFκB activity.

RESULTS

The n-hexane fraction of the 80% EtOH extract from the rhizomes of Cyperus rotundus was found to inhibit both NO and PGE2 production in RAW 264.7 cells. α-Cyperone isolated from the n-hexane fraction significantly inhibited PGE2 production by suppressing the LPS-induced expression of inducible COX-2 at both the mRNA and the protein levels. In contrast, α-cyperone had little effect on NO production and iNOS expression. Additionally, α-cyperone downregulated the production and mRNA expression of the inflammatory cytokine IL-6. Moreover, treatment with α-cyperone suppressed the transcriptional activity of NFκB and the nuclear translocation of the p65 NFκB subunit in LPS-induced RAW 264.7 cells.

CONCLUSION

The anti-inflammatory activity of α-cyperone is associated with the down-regulation of COX-2 and IL-6 via the negative regulation of the NFκB pathway in LPS-stimulated RAW 264.7 cells.

Endothelial nitric-oxide synthase activation generates an inducible nitric-oxide synthase-like output of nitric oxide in inflamed endothelium

High levels of NO generated in the vasculature under inflammatory conditions are usually attributed to inducible nitric-oxide synthase (iNOS), but the role of the constitutively expressed endothelial NOS (eNOS) is unclear. In normal human lung microvascular endothelial cells (HLMVEC), bradykinin (BK) activates kinin B2 receptor (B2R) signaling that results in Ca(2+)-dependent activation of eNOS and transient NO. In inflamed HLMVEC (pretreated with interleukin-1β and interferon-γ), we found enhanced binding of eNOS to calcium-calmodulin at basal Ca(2+) levels, thereby increasing its basal activity that was dependent on extracellular l-Arg. Furthermore, B2R stimulation generated prolonged high output eNOS-derived NO that is independent of increased intracellular Ca(2+) and is mediated by a novel Gα(i)-, MEK1/2-, and JNK1/2-dependent pathway. This high output NO stimulated with BK was blocked with a B2R antagonist, eNOS siRNA, or eNOS inhibitor but not iNOS inhibitor. Moreover, B2R-mediated NO production and JNK phosphorylation were inhibited with MEK1/2 and JNK inhibitors or MEK1/2 and JNK1/2 siRNA but not with ERK1/2 inhibitor. BK induced Ca(2+)-dependent eNOS phosphorylation at Ser(1177), Thr(495), and Ser(114) in cytokine-treated HLMVEC, but these modifications were not dependent on JNK1/2 activation and were not responsible for prolonged NO output. Cytokine treatment did not alter the expression of B2R, Gα(q/11), Gα(i1,2), JNK, or eNOS. B2R activation in control endothelial cells enhanced migration, but in cytokine-treated HLMVEC it reduced migration. Both responses were NO-dependent. Understanding how JNK regulates prolonged eNOS-derived NO may provide new therapeutic targets for the treatment of disorders involving vascular inflammation.

New perspectives on central and peripheral immune responses to acute traumatic brain injury

Traumatic injury to the brain (TBI) results in a complex set of responses involving various symptoms and long-term consequences. TBI of any form can cause cognitive, behavioral and immunologic changes in later life, which underscores the problem of underdiagnosis of mild TBI that can cause long-term neurological deficits. TBI disrupts the blood–brain barrier (BBB) leading to infiltration of immune cells into the brain and subsequent inflammation and neurodegeneration. TBI-induced peripheral immune responses can also result in multiorgan damage. Despite worldwide research efforts, the methods of diagnosis, monitoring and treatment for TBI are still relatively ineffective. In this review, we delve into the mechanism of how TBI-induced central and peripheral immune responses affect the disease outcome and discuss recent developments in the continuing effort to combat the consequences of TBI and new ways to enhance repair of the damaged brain.

Oleifolioside A, a New Active Compound, Attenuates LPS-Stimulated iNOS and COX-2 Expression through the Downregulation of NF-κB and MAPK Activities in RAW 264.7 Macrophages

Oleifolioside A, a new triterpenoid compound isolated from Dendropanax morbifera Leveille (D. morbifera), was shown in this study to have potent inhibitory effects on lipopolysaccharide (LPS-)stimulated nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in RAW 264.7 macrophages. Consistent with these findings, oleifolioside A was further shown to suppress the expression of LPS-stimulated inducible nitric oxide synthase (iNOS) and cyclooxigenase-2 (COX-2) in a dose-dependent manner at both the protein and mRNA levels and to significantly inhibit the DNA-binding activity and transcriptional activity of NF-κB in response to LPS. These results were found to be associated with the inhibition of the degradation and phosphorylation of IκB-α and subsequent translocation of the NF-κB p65 subunit to the nucleus. Inhibition of NF-κB activation by oleifolioside A was also shown to be mediated through the prevention of p38 MAPK and ERK1/2 phosphorylation. Taken together, our results suggest that oleifolioside A has the potential to be a novel anti-inflammatory agent capable of targeting both the NF-κB and MAPK signaling pathways.

Pharmacokinetic/pharmacodynamic modeling of methylprednisolone effects on iNOS mRNA expression and nitric oxide during LPS-induced inflammation in rats

PURPOSE

Increased expression of inducible nitric oxide synthase (iNOS) resulting in nitric oxide elevation represents an important component of inflammatory responses. We assess the effects of methylprednisolone (MPL) on these processes during endotoxin-induced acute inflammation and provide a mechanism-based model to quantitatively describe them.

METHODS

Male Lewis rats were dosed with lipopolysaccharide (50 μg/kg LPS) alone or with methylprednisolone (10 and 50 mg/kg) and sacrificed at different time points. Plasma MPL, lung iNOS mRNA expression, plasma nitric oxide (NO) and other physiological factors were measured. Sodium nitrate (750 μmole/kg) was given to a separate cohort of rats to assess NO disposition kinetics. PK-PD modeling was performed with ADAPT 5.

RESULTS

Disposition kinetics of plasma MPL and NO showed bi-exponential decline and were described by two-compartment models. LPS increased expression of iNOS mRNA in lung and increased plasma NO, while MPL dosing palliated this increase in a dose-dependent manner. These effects were well captured using tandem indirect response and precursor-pool models.

CONCLUSION

The model provides a quantitative assessment of the suppression of NO production by MPL and shows that the major effects are at the transcriptional level by reducing expression of iNOS mRNA.

6,6'-Bieckol, isolated from marine alga Ecklonia cava, suppressed LPS-induced nitric oxide and PGE₂ production and inflammatory cytokine expression in macrophages: the inhibition of NFκB

Ecklonia cava is an edible brown alga that contains high levels of phlorotannins, which are unique marine polyphenolic compounds. In the present study, we investigated the anti-inflammatory effects and the underlying molecular mechanism of phlorotannin 6,6'-bieckol, which is an active component isolated from E. cava, on lipopolysaccharide (LPS)-stimulated primary macrophages and RAW 264.7 macrophage cells. 6,6'-Bieckol was found to inhibit nitric oxide (NO) and prostaglandin E₂ (PGE₂) production and to suppress the LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the mRNA and protein levels. In addition, 6,6'-bieckol downregulated the production and mRNA expression of the inflammatory cytokines TNF-α and IL-6. Moreover, pretreatment with 6,6'-bieckol decreased LPS-induced transactivation of nuclear factor-kappa B (NFκB) and nuclear translocation of p50 and p65 subunits of NFκB. Furthermore, chromatin immunoprecipitation assay revealed that 6,6'-bieckol inhibited LPS-induced NFκB binding to the TNF-α and IL-6 promoters. Taken together, these data suggest that the anti-inflammatory properties of 6,6'-bieckol are related to the down-regulation of iNOS, COX-2, and pro-inflammatory cytokines through the negative regulation of the NFκB pathway in LPS-stimulated macrophages.

Anti-inflammatory effects of resveratrol occur via inhibition of lipopolysaccharide-induced NF-κB activation in Caco-2 and SW480 human colon cancer cells

Resveratrol, a polyphenol abundantly found in grapes and red wine, exhibits beneficial health effects due to its anti-inflammatory properties. In the present study, we evaluated the effect of resveratrol on inflammatory responses induced by lipopolysaccharide (LPS) treatment of human intestinal Caco-2 and SW480 cell lines. In the LPS-treated intestinal cells, resveratrol dose-dependently inhibited the expression of inducible NO synthase (iNOS) mRNA as well as protein expression, resulting in a decreased production of NO. In addition, Toll-like receptor-4 expression was significantly diminished in LPS-stimulated cells after resveratrol pre-treatment. To investigate the mechanisms by which resveratrol reduces NO production and iNOS expression, we examined the activation of inhibitor of κB (IκB) in LPS-stimulated intestinal cells. Results demonstrated that resveratrol inhibited the phosphorylation, as well as the degradation, of the IκB complex. Overall, these results show that resveratrol is able to reduce LPS-induced inflammatory responses by intestinal cells, interfering with the activation of NF-κB-dependent molecular mechanisms.

Polymorphisms in the nitric oxide synthase 1 gene are associated with severe chronic rhinosinusitis

BACKGROUND

Nitric oxide (NO), is a biological messenger molecule and a component of innate immunity, with important roles in the regulation of inflammation and in defense against bacterial biofilms. Polymorphisms in genes regulating NO production have the potential for a role in the development of chronic rhinosinusitis (CRS). The purpose of this study was to determine whether polymorphisms in genes regulating NO synthesis are associated with CRS.

METHODS

An established population of 206 individuals with severe CRS and 196 postal code-matched controls was previously screened using a pooling genome-wide associations study to estimate allelic frequency. Genes regulating NO synthesis with a maximal probability of association were identified. High-probability single nucleotide polymorphisms SNPs from the NO synthase (NOS1) and its ligand NOS1 adaptor protein (NOS1AP) genes were retained for individual genotyping. PLINK software was used to determine association.

RESULTS

Sixteen SNPs were genotyped successfully with a genotype distribution in agreement with Hardy-Weinberg equilibrium. Two SNPs for NOS1 (rs1483757 and rs9658281) were significantly associated with CRS, with a protective effect. The severe subphenotype showed stronger associations. Subgroup analysis for the presence of nasal polyps, origin, and gender did not influence strength of associations.

CONCLUSION

These data suggest that polymorphisms in the NOS1 gene may play a role in the susceptibility to develop CRS. Study findings apply to patients with severe CRS, unresponsive to surgery.

Anti-inflammatory effects of sophocarpine in LPS-induced RAW 264.7 cells via NF-κB and MAPKs signaling pathways

Sophocarpine, a tetracyclic quinolizidine alkaloid, is one of the most abundant active ingredients in Sophora alopecuroides L. Our previous studies have showed that sophocarpine exerts anti-inflammatory activity in animal models. In the present study, anti-inflammatory mechanisms of sophocarpine were investigated in lipopolysaccharide (LPS)-induced responses in RAW 264.7 cells. Furthermore, the cytotoxicity of sophocarpine was tested. The results indicated that sophocarpine could increase the LDH level and inhibit cell viability up to 800μg/ml, and which was far higher than that of the plasma concentration of sophocarpine in clinical effective dosage. The results also demonstrated that sophocarpine (50 and 100μg/ml) suppressed LPS-stimulated NO production and pro-inflammatory cytokines secretion, including tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). These were associated with the decrease of the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, sophocarpine inhibited LPS-mediated nuclear factor-κB (NF-κB) activation via the prevention of inhibitor κB (IκB) phosphorylation. Sophocarpine had no effect on the LPS-induced phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2), whereas it attenuated the phosphorylation of p38 mitogen-activated protein (MAP) kinase and c-Jun NH(2)-terminal kinase (JNK). Our data suggested that sophocarpine exerted anti-inflammatory activity in vitro, and it might attribute to the inhibition of iNOS and COX-2 expressions via down-regulation of the JNK and p38 MAP kinase signal pathways and inhibition of NF-κB activation.