Effects of Tithonia diversifolia (Asteraceae) extract on innate inflammatory responses.

ETHNOPHARMACOLOGICAL RELEVANCE: Tithonia diversifolia (Helms.) A. Gray, popularly known in Brazil as "margaridão" or "mão-de-Deus" has been used in the folk medicine as anti-inflammatory and against other illnesses in several countries. Indeed, many studies show de effect of T. diversifolia in the inflammatory process, however, any of them have demonstrated the mechanism of cell migration. AIM OF THE STUDY: The aim of this investigation was to show the in vivo and in vitro effects of T. diversifolia leaves ethanol extract on neutrophil trafficking from the blood to the inflamed tissue and on cell-derived secretion of chemical mediators, as well as, the effects on inflammatory resolution and inflammatory pain. MATERIALS AND METHODS: Anti-inflammatory activity was investigated using carrageenan-induced inflammation in the subcutaneous tissue of male Swiss mice orally treated with the T. diversifolia extract (0.1, 1 or 3 mg/kg). The leukocyte influx (optical microscopy) and the secretion of chemical mediators (TNF, IL-6, IL-1ß and CXCL1, by enzyme-linked immunosorbent assay) were quantified in the inflamed exudate. Histological analysis of the pouches was performed. N-Formyl-methionine-leucine-phenylalanine-induced chemotaxis, lipopolysaccharide-induced TNF, IL-6, IL-1ß, CXCL1 and NO production, and adhesion molecule expression (CD62L and CD18, flow cytometry) were in vitro quantified using oyster glycogen recruited peritoneal neutrophils previous treated with the extract (1, 10, or 100 µg/mL). The resolution of inflammation was accessed by efferocytosis assay, and the antinociceptive activity was investigated using carrageenan-induced mechanical hypersensitivity. RESULTS: The oral treatment with T. diversifolia promoted reduction in the neutrophil migration as well as the decrease in total protein, TNF, IL-1ß and CXCL1 levels in the inflamed exudate. In vitro treatment with T. diversifolia shedding of ß2 integrin expressions, without alter CD62L expression. The extract was able to increase the efferocytosis of apoptotic neutrophils, and the increase of the IL-10 and the decrease of TNF secretion. Additionally, the extract reduced the hypersensitivity induced by carrageenan. CONCLUSIONS: Together, the data herein obtained showed that T. diversifolia extract presented anti-inflammatory activity by inhibiting the cytokine and NO production, and also the leukocyte migration. The mechanisms involved in the extract anti-inflammatory effects include the impairment in the leukocyte migration to the inflamed tissue, the pro-resolution activity, and consequently the anti-hypersensitivity.

The anti-inflammatory and antioxidant effects of leonurine hydrochloride after lipopolysaccharide challenge in broiler chicks.

This study was carried out to investigate the protective effects of leonurine hydrochloride (LH, from Leonurus sibiricus) on lipopolysaccharide (LPS)-stimulated broiler chicks. A total of 120 one-day-old male Ross broilers were randomly divided into 4 treatment groups with 6 replicates of 5 birds per cage. The experiment was designed as a 2 × 2 factorial arrangement with LH (0 or 120 mg/kg) and LPS (injection of saline or 1.5 mg/kg body weight) levels as treatments. On days 14, 16, 18, and 20 of the trial, broilers were intraperitoneally injected with LPS or saline. Blood, spleen, and liver samples were collected on days 21 and 28 for analysis. The results showed that dietary LH had no effect on growth performance or immunoglobulin concentrations in the serum. However, dietary LH prevented LPS-induced reductions in average daily gain and average daily feed intake in the broilers on days 15-21 of the trial (P > 0.05). Dietary LH supplementation dramatically attenuated the LPS-induced increases in the spleen index, reduced glutathione (GSH) activity (serum and liver) and total superoxide dismutase (T-SOD) activity (serum and spleen), and significantly reduced malondialdehyde (MDA) levels (serum, spleen, and liver) on days 21 and 28 (P < 0.05). Additionally, LH supplementation significantly mitigated the LPS-induced increases in the tumor necrosis factor (TNF)-α (serum and spleen), interleukin (IL)-1ß (serum, spleen and liver), IL-2 (liver), IL-6 (serum, spleen and liver), toll-like receptor 4 (TLR4) (spleen and liver), and nuclear factor (NF)-κB (spleen and liver) levels on days 21 and 28 (P < 0.05). Therefore, this study revealed that LH could downregulate the expression of proinflammatory factors, mainly by inhibiting the expression of TLR4 and the activation of NF-κB. LH may be a potential feed additive with dual efficacy as an anti-inflammatory and antioxidant agent.

ANTI-INFLAMMATORY ACTIVITY OF EUCALYPTUS SPP. AND PISTASCIA LENTISCUS LEAF EXTRACTS.

BACKGROUND: Eucalyptus spp. and Pistascia lentiscus are among the Palestinian trees that are traditionally used in folkloric medicine in treating many diseases; leaves of which are thought to have anti-inflammatory, antibacterial and antioxidant effects. The goal of this study is to evaluate the in vitro inhibitory effect of Eucalyptus spp. and Pistascia lentiscus extracts on Lipopolysacaride (LPS)-induced Interlukin-6 (Il-6) and Tumor Necrosis Factor-α (TNF-α) by polymorphonuclear Cells (PMNCs). MATERIALS AND METHODS: Polymorphonuclear cells were isolated from the whole blood using Histopaque (Ficol-1077) method and then cultured in an enriched Roswell Park Memorial Institute (RBMI) medium. Supernatants' Interlukin-6 (IL-6) and Tumor Necrosis Factor (TNF-α) levels were determined 24 hour after LPS stimulation. HPLC was employed to determine the concentration of phenolic compounds in the extracts. The concentrations of TNF-α and IL-6 were compared using paired-samples t test. RESULTS: Eucalyptus spp. and Pistascia lentiscus leaves extracts have shown significant reduction in the levels of both Il-6 and TNF-α Gallic acid; a strong anti-inflammatory agent was found to be the major phenolic compound in both leaf extracts. However, other anti-inflammatory phenolic compounds were detected in Pitascia lentiscus extract including syringic acid and p-coumaric acid, while chlorogenic acid was detected in Eucalyptus spp. leaf extract. CONCLUSION: Reduction in the levels of Il-6 and TNF-α upon the effect of both Eucalyptus spp. and Pistascia lentiscus extract is an indication of their anti-inflammatory effects. Our results may also indicate that the observed anti-inflammatory effect of the above extracts may be due to the presence of gallic acid and other phenolic compounds. List of Abbreviations and Nomenclature: LPS: Lipopolysacaride, Il-6: Interlukin-6, TNF-α: Tumor Necrosis Factor-α, PMNCs: Polymorphonuclear Cells, HPLC: High Performance Liquid Chromatography, ELISA: Enzyme Linked Immune Sorbent Assay, EDTA: Ethylene Diamine Tetra Acetic acid, PBS: phosphate buffered saline, RPMI: Roswell Park Memorial Institute medium FBS: Fetal Bovine Serum.

Flavonoid fraction of guava leaf extract attenuates lipopolysaccharide-induced inflammatory response via blocking of NF-κB signalling pathway in Labeo rohita macrophages.

Psidium guajava L. is a well-known traditional medicinal plant widely used in folk medicine. To explore the anti-inflammatory activity of the flavonoid fraction of guava leaf extract (FGLE), we investigated its ability to suppress the levels of inflammatory mediators elevated by lipopolysaccharide (LPS) in Labeo rohita head-kidney (HK) macrophages. HK macrophages of L. rohita were treated with LPS in the presence or absence of the FGLE. We examined the inhibitory effect of FGLE on LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production. The inhibitory effect of FGLE on nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were investigated by RT-PCR and western blot. The effect of FGLE on proinflammatory cytokines tumour necrosis factor alpha (TNF-α) or interleukin-1ß (IL-1ß) was also investigated by ELISA and RT-PCR. The phosphorylation of three mitogen activated protein kinases (MAPK) molecules ERK, JNK and p38 was analysed by western blot analysis. FGLE inhibited LPS-induced NO and PGE2 production. It also effectively inhibited TNF-α, IL-1ß, IL-10, iNOS, and COX-2 production in a concentration-dependent manner. In addition, FGLE suppressed the mRNA expression levels of TNF-α and IL-1ß in LPS-stimulated HK macrophages. RT-PCR and western blot analysis showed that FGLE decreased both the mRNA and protein expression levels of LPS-induced iNOS and COX-2 in HK macrophages. FGLE suppresses the phosphorylation of MAPK molecules in LPS-stimulated HK macrophages. FGLE also significantly inhibited LPS-induced NF-κB transcriptional activity. The molecular mechanism by which FGLE suppresses the expression of inflammatory mediators appears to involve the inhibition of NF-κB activation, through the suppression of LPS-induced IκB-α degradation. Together these results suggest that FGLE contains potential therapeutic agent(s), which regulate NF-κB activation, for the treatment of inflammatory conditions in L. rohita macrophages.

Lycopene reduces the negative effects induced by lipopolysaccharide in breeding hens.

This study assessed the effects of lycopene on the antioxidant capacity, biochemical parameters, and immune organ index of breeding hens following lipopolysaccharide (LPS) injection. The study had a 2 × 2 factorial design. Healthy Xing-hua breeding hens (720) were divided into groups with 6 replicates per group and 30 hens per replicate. Hens were fed on a rice-soya bean basal meal supplemented with different levels of lycopene (0, 20, 40, or 80 mg/kg diet). On d 35, two hens from each replicate were injected subcutaneously with 1 mg/kg body weight of either LPS or sterile saline (control group). Blood samples were collected at 0, 6, and 24 h post-injection. At 24 h post-injection, hens were sacrificed and the thymus, spleen, and bursa of Fabricius were removed. The results revealed that LPS significantly decreased high density lipoprotein cholesterol (HDLC), triidothyronine (T3), reduced glutathione to oxidised glutathione ratio (GSH/GSSG), thymus and bursal indexes, and increased low density lipoprotein cholesterol (LDLC). Lycopene supplementation significantly increased HDLC, T3, GSH/GSSG, and immune organ index, and decreased total cholesterol, LDLC, and blood urea nitrogen (BUN). The interaction effects of lycopene and LPS were significant on BUN and T3. Lycopene supplementation affected inflammatory immune response based on increased immune organ index of breeding hens by relieving the LPS-induced stress.

Aryl hydrocarbon receptor protein and Cyp1A1 gene induction by LPS and phenanthrene in Atlantic cod (Gadus morhua) head kidney cells.

The objective of this study was to evaluate interactions between environmental toxicants and cod immune cells during inflammation. Phenanthrene is abundant in plant oils (rapeseed, palm, and soya oil) as compared to fish oils, and consequently constitute an undesirable element in plant replacement diets in aquaculture. Phenanthrene was added to head kidney cell cultures, alone or together with LPS (lipopolysaccharide) or poly I: C (polyinosinic acid: polycytidylic acid), and the responses were evaluated in terms of protein and gene expression. The results showed that LPS, poly I: C or phenanthrene, added to the cultures separately, induced aryl hydrocarbon receptor (AhR) protein expression. Phenanthrene treatment in combination with LPS induced AhR protein expression and Cyp1A1 gene transcription, which not was observed combining poly I: C and phenanthrene. Phenanthrene exposure up regulated the transcription of common stress and detoxification enzymes like catalase, caspase 3 and glutathione S-transferase alfa 3 subunit B (GSTAB3), while LPS exposure alone or combined with phenanthrene down regulated GSTAB3 and catalase in cod leukocytes. It seems clear that immune regulation and phenanthrene induced signaling pathways interact; transcriptional down regulation of detoxification and antioxidant enzymes by LPS could indicate that combating bacterial infections is the number one priority in these cells, and that AhR and Cyp1A1 is somehow involved in this signaling cascade. LPS seems to affect the mitogen activated protein kinases (MAPKs) pathways (P-p38 and ERK1/2) thus modulating the AhR protein and Cyp1A1 gene transcription, while phenanthrene possibly activates AhR by ligand binding.

Boswellic acids from frankincense inhibit lipopolysaccharide functionality through direct molecular interference.

Lipophilic extracts of gum resins of Boswellia species (BSE) are used in folk medicine to treat various inflammatory disorders and infections. The molecular background of the beneficial pharmacological effects of such extracts is still unclear. Various boswellic acids (BAs) have been identified as abundant bioactive ingredients of BSE. Here we report the identification of defined BAs as direct inhibitors of lipopolysaccharide (LPS) functionality and LPS-induced cellular responses. In pull-down experiments, LPS could be precipitated using an immobilized BA, implying direct molecular interactions. Binding of BAs to LPS leads to an inhibition of LPS activity which was observed in vitro using a modified limulus amoebocyte lysate assay. Analysis of different BAs revealed clear structure-activity relationships with the classical ß-BA as most potent derivative (IC(50)=1.8 µM). In RAW264.7 cells, LPS-induced expression of inducible nitric oxide synthase (iNOS, EC 1.14.13.39) was selectively inhibited by those BAs that interfered with LPS activity. In contrast, interferon-γ-induced iNOS induction was not affected by BAs. We conclude that structurally defined BAs are LPS inhibiting agents and we suggest that ß-BA may contribute to the observed anti-inflammatory effects of BSE during infections by suppressing LPS activity.

In vivo and in vitro anti-inflammatory activity of neorogioltriol, a new diterpene extracted from the red algae Laurencia glandulifera.

Neorogioltriol is a tricyclic brominated diterpenoid isolated from the organic extract of the red algae Laurencia glandulifera. In the present study, the anti-inflammatory effects of neorogioltriol were evaluated both in vivo using carrageenan-induced paw edema and in vitro on lipopolysaccharide (LPS)-treated Raw264.7 macrophages. The in vivo study demonstrated that the administration of 1 mg/kg of neorogioltriol resulted in the significant reduction of carregeenan-induced rat edema. In vitro, our results show that neorogioltriol treatment decreased the luciferase activity in LPS-stimulated Raw264.7 cells, stably transfected with the NF-κB-dependent luciferase reporter. This effect on NF-κB activation is not mediated through MAPK pathways. The inhibition of NF-κB activity correlates with decreased levels of LPS-induced tumor necrosis factor-alpha (TNFα) present in neorogioltriol treated supernatant cell culture. Further analyses indicated that this product also significantly inhibited the release of nitric oxide and the expression of cyclooxygenase-2 (COX-2) in LPS-stimulated Raw264.7 cells. These latter effects could only be observed for neorogioltriol concentrations below 62.5 µM. To our knowledge, this is the first report describing a molecule derived from Laurencia glandulifera with anti-inflammatory activity both in vivo and in vitro. The effect demonstrated in vitro may be explained by the inhibition of the LPS-induced NF-κB activation and TNFα production. NO release and COX-2 expression may reinforce this effect.

Low-dose endotoxin induces inflammation by selectively removing nuclear receptors and activating CCAAT/enhancer-binding protein δ.

Subclinical levels of circulating endotoxin are associated with the pathogenesis of diverse human inflammatory diseases, by mildly inducing the expression of proinflammatory mediators. In this study, we examined the molecular mechanism responsible for the effect of low-dose LPS in macrophages. In contrast to high-dose LPS, which activates NF-κB and induces the robust expression of proinflammatory mediators, we observed that low-dose LPS failed to activate NF-κB. Instead, it selectively activated C/EBPδ and removed nuclear repressors, including peroxisome proliferator-activated receptor α and retinoic acid receptor α, enabling a mild and leaky expression of proinflammatory mediators. The effect of low-dose LPS required IRAK-1, which interacts with and acts upstream of IκB kinase ε to contribute to LPS-mediated induction of C/EBPδ and proinflammatory mediators. Additionally, mice fed a high-fat diet acquired elevated levels of endotoxin and proinflammatory mediators in an IRAK-1-dependent fashion. Taken together, these data reveal a distinct pathway preferentially used by low-dose endotoxin in initiating low-grade inflammation.

α-melanocyte-stimulating hormone modulates lipopolysaccharide plus interferon-γ-induced tumor necrosis factor-α expression but not tumor necrosis factor-α receptor expression in cultured hypothalamic neurons.

In a previous work we showed that the melanocortin alpha-melanocyte-stimulating hormone (α-MSH) exerts anti-inflammatory action through melanocortin 4 receptor (MC4R) in vivo in rat hypothalamus. In this work, we examined the effect of α-MSH on the expression of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) and their receptors in primary cultured rat hypothalamic neurons. We also investigated α-MSH's possible mechanism/s of action. α-MSH (5 µM) decreased TNF-α expression induced by 24h administration of a combination of bacterial lipopolysaccharide (LPS, 1 µg/ml) plus interferon-γ (IFN-γ, 50 ng/ml). Expression of TNF-α and IL-1ß receptors TNFR1, TNFR2 and IL-1RI, was up-regulated by LPS+IFN-γ whereas α-MSH did not modify basal or LPS+IFN-γ-induced-TNFRs or IL-1RI expression. Both α-MSH and LPS+IFN-γ treatments increased CREB activation. α-MSH did not modify NF-κB activation induced by LPS+IFN-γ in hypothalamic neurons. In conclusion, our data show that α-MSH reduces TNF-α expression in hypothalamic neurons by a mechanism which could be mediated by CREB. The regulation of inflammatory processes in the hypothalamus by α-MSH might help to prevent neurodegeneration resulting from inflammation.

Roles of flagella, lipopolysaccharide, and a Ca2+-dependent cell surface protein in attachment of Rhizobium leguminosarum biovar viciae to pea root hair tips.

The relationship between Ca2+-dependent cell surface components of Rhizobium leguminosarum biovar viciae, motility, and ability to attach to pea root hair tips was investigated. In contrast to flagella and lipopolysaccharide, a small protein located on the cell surface was identified as the Ca2+-dependent adhesin.

Mutations in Rhizobium phaseoli that lead to arrested development of infection threads.

Two Rhizobium phaseoli mutants, isolated previously by Tn5 mutagenesis, elicited infection threads which ceased development prematurely, usually within root hairs. These infection threads were wide, globular, and otherwise altered in morphology, compared with normal infection threads. Anatomy and division of the root cortical cells during initial stages of nodule morphogenesis appeared normal. However, later nodule differentiation deviated considerably from normal development, and release of bacteria from infection threads was not observed. In tryptone-yeast extract medium the mutants sedimented during growth in shaken cultures and formed rough colonies on agar. Electrophoresis of washed cultures solubilized in dodecyl sulfate revealed that the major carbohydrate band was absent from the mutants. The behavior of this carbohydrate in phenol-water extraction and gel chromatography, its apparent ketodeoxyoctonate content, and its susceptibility to mild acid hydrolysis suggested that it was a lipopolysaccharide. From the results of genetic crosses or reversion analysis, the defect in synthesizing this carbohydrate material and the defect in infection could be attributed to a single mutation in each mutant.

Physical association between the peribacteroid membrane and lipopolysaccharide from the bacteroid outer membrane in Rhizobium-infected pea root nodule cells.

Monoclonal antibodies were used as cytochemical markers to study surface interactions between endosymbiotic Rhizobium bacteroids from pea root nodules and the encircling peribacteroid membranes, which are of plant origin. Monoclonal antibodies that react with Rhizobium lipopolysaccharide (LPS) or with a plant membrane glycoprotein were used as markers for material from the bacteroid outer membrane or the peribacteroid membrane, respectively. Membrane-enclosed bacteroids were isolated from nodule homogenates by sucrose gradient centrifugation, and the encircling peribacteroid membrane was released by mild osmotic shock treatment. Using an immunochemical technique (sandwich ELISA), it was shown that 1-5% of the LPS antigen released into the peribacteroid fraction by mild osmotic shock treatment was physically associated with peribacteroid membrane through a detergent-sensitive linkage. This association could be visualized when freshly prepared peribacteroid material was immobilized on gold grids and examined by electron microscopy after dual antibody immunogold treatment and subsequent negative staining. The distribution of LPS antigen within infected nodule cells was also investigated by immunogold staining for thin sections of nodule tissue fixed in glutaraldehyde, and a close association between LPS antigen and peribacteroid membrane was often seen.

Lipid and protein segregation in Escherichia coli membrane: morphological and structural study of different cytoplasmic membrane fractions.

Lipid and protein segregations can be induced in E. coli cytoplasmic membranes by conformational transitions of their lipid hydrocarbon chains from a disordered to an ordered state. For E. coli strain K 1059 (an unsaturated fatty acid auxotroph) supplemented with linolenic acid, the segregation leads to large areas of membrane surfaces having distinctly different morphological characteristics (smooth compared with strongly particulated fracture faces, as visualized by freeze fracture electron microscopy). The different regions are physically separated by osmotic lysis of spheroplasts at temperatures below those of the order-disorder transition of the lipid hydrocarbon chains. The analysis of the different cytoplasmic membrane fractions provides a direct demonstration and allows a direct analysis of the segregation. As compared to the nonfractionated membranes, the membrane regions corresponding to the smooth fracture surfaces are poor in proteins, rich in lipids, and enriched in saturated fatty acids, while the membrane regions corresponding to the strongly particulated fracture surfaces are rich in proteins, poor in lipids, and enriched in unsaturated fatty acids. Quantitative information about the extent of these segregations is obtained from high-angle x-ray diffraction of the different membrane fractions and of the corresponding total lipid extracts.