Endothelial Cell Protein C Receptor Deficiency Attenuates Streptococcus pneumoniae-induced Pleural Fibrosis

Streptococcus pneumoniae is the leading cause of hospital community-acquired pneumonia. Patients with pneumococcal pneumonia may develop complicated parapneumonic effusions or empyema that can lead to pleural organization and subsequent fibrosis. The pathogenesis of pleural organization and scarification involves complex interactions between the components of the immune system, coagulation, and fibrinolysis. EPCR (endothelial protein C receptor) is a critical component of the protein C anticoagulant pathway. The present study was performed to evaluate the role of EPCR in the pathogenesis of S. pneumoniae infection-induced pleural thickening and fibrosis. Our studies show that the pleural mesothelium expresses EPCR. Intrapleural instillation of S. pneumoniae impairs lung compliance and lung volume in wild-type and EPCR-overexpressing mice but not in EPCR-deficient mice. Intrapleural S. pneumoniae infection induces pleural thickening in wild-type mice. Pleural thickening is more pronounced in EPCR-overexpressing mice, whereas it is reduced in EPCR-deficient mice. Markers of mesomesenchymal transition are increased in the visceral pleura of S. pneumoniae-infected wild-type and EPCR-overexpressing mice but not in EPCR-deficient mice. The lungs of wild-type and EPCR-overexpressing mice administered intrapleural S. pneumoniae showed increased infiltration of macrophages and neutrophils, which was significantly reduced in EPCR-deficient mice. An analysis of bacterial burden in the pleural lavage, the lungs, and blood revealed a significantly lower bacterial burden in EPCR-deficient mice compared with wild-type and EPCR-overexpressing mice. Overall, our data provide strong evidence that EPCR deficiency protects against S. pneumoniae infection-induced impairment of lung function and pleural remodeling.

Antioxidant and anti-inflammatory action (in vivo and in vitro) from the trunk barks of Cabreúva (Myrocarpus frondosus Allemao, Fabaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Myrocarpus frondosus, known as cabreúva, is a tree whose trunk barks are used in folk medicine as tea, syrup, ointments, and tinctures for the treatment of inflammation. However, there is no scientific evidence demonstrating this activity.

AIM OF THE STUDY

The present investigation was focused on evaluating the antioxidant and anti-inflammatory activities of M. frondosus, using the in vitro model of RAW 264.7 macrophages induced by LPS and the in vivo model of mouse pleurisy induced by carrageenan.

MATERIALS AND METHODS

M. frondosus trunk barks were dried at room temperature for seven days and subjected to exhaustive maceration with ethanol (70%) to obtain its crude extract (CE). CE was subjected to UPLC-HRMS analysis to establish its chemical profile. Its antioxidant activity was evaluated using the DPPH method, reducing power by the iron (III) to iron (II) reduction assay and the β-carotene-linoleic acid bleaching assay. The RAW 264.7 macrophages were pretreated with the CE in a non-cytotoxic concentration and induced by LPS (1 μg/mL). After 24 h, using the supernatant, we evaluated the nitric oxide (NOx) and interleukin-6 (IL-6) levels. The anti-inflammatory effects of CE (at doses of 30, 100 and 300 mg/kg) were evaluated on leukocyte migration (total and differential), exudate concentrations, myeloperoxidase (MPO) and adenosine-deaminase (ADA) activities, NOx, tumor necrosis factor-α (TNF-α), and IL-6 levels, by using a murine model of neutrophilic inflammation.

RESULTS

The UPLC-HRMS of CE revealed the presence of isoflavonones, including biochanin A and formononetin. CE exhibited good antioxidant activity by quenching and decreasing free radicals, as well as reducing pro-oxidant metals. CE did not show cytotoxicity at a concentration below 11 μg/mL and reduced the secretion of the pro-inflammatory NOx in the inflamed macrophages. In vivo assay revealed that CE caused a pronounced inhibition on leukocyte migration, and this inhibition was due to its ability to reduce neutrophil migration. Moreover, CE was also able to reduce the release of critical pro-inflammatory mediators such as MPO, NOx, TNF-α, and IL-6.

CONCLUSIONS

All these findings indicate that M. frondosus exhibited antioxidant activity and anti-inflammatory effect.

Nootkatone Inhibits Acute and Chronic Inflammatory Responses in Mice

Nootkatone (NTK) is a sesquiterpenoid found in essential oils of many species of Citrus (Rutaceae). Considering previous reports demonstrating that NTK inhibited inflammatory signaling pathways, this study aimed to investigate the effects of this compound in mice models of acute and chronic inflammation. Murine models of paw edema induced by carrageenan, dextran, histamine, and arachidonic acid, as well as carrageenan-induced peritonitis and pleurisy, were used to evaluate the effects of NTK on acute inflammation. A murine model of granuloma induced by cotton pellets was used to access the impact of NTK treatment on chronic inflammation. In the acute inflammation models, NTK demonstrated antiedematogenic effects and inhibited leukocyte recruitment, which was associated with decreased vascular permeability, inhibition of myeloperoxidase (MPO), interleukin (IL)1-β, and tumor necrosis factor (TNF)-α production. In silico analysis suggest that NTZ anti-inflammatory effects may also occur due to inhibition of cyclooxygenase (COX)-2 activity and antagonism of the histamine receptor type 1 (H₁). These mechanisms might have contributed to the reduction of granuloma weight and protein concentration in the homogenates, observed in the chronic inflammation model. In conclusion, NTK exerted anti-inflammatory effects that are associated with inhibition of IL1-β and TNF-α production, possibly due to inhibition of COX-2 activity and antagonism of the H1 receptor. However, further studies are required to characterize the effects of this compound on chronic inflammation.

Phenolic Compounds Isolated from Calea uniflora Less. Promote Anti-Inflammatory and Antioxidant Effects in Mice Neutrophils (Ex Vivo) and in Mice Pleurisy Model (In Vivo)

The literature shows that phenolic compounds possess important antioxidant and anti-inflammatory activities; however, the mechanism underlying these effects is not elucidated yet. The genus Calea is used in folk medicine to treat rheumatism, respiratory diseases, and digestive problems. In this context, some phenolic compounds were isolated with high purity from Calea uniflora Less. and identified as noreugenin (NRG) and α-hydroxy-butein (AH-BU). The aim of this study was to analyze the effect of these compounds on cell viability, the activity of myeloperoxidase (MPO), and apoptosis of mouse neutrophils using ex vivo tests. Furthermore, the effect of these compounds on the cytokines, interleukin 1 beta (IL-1β), interleukin 17A (IL-17A), and interleukin 10 (IL-10), and oxidative stress was investigated by analyzing lipid peroxidation (the concentration of thiobarbituric acid reactive substances (TBARS)) and activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST), using a murine model of neutrophilic inflammation. The NRG and AH-BU reduce MPO activity and increase neutrophil apoptosis (p < 0.05). These compounds reduced the generation of oxygen reactive species and IL-1β and IL-17A levels but increased IL-10 levels (p < 0.05). This study demonstrated that NRG and AH-BU show a significant anti-inflammatory effect by inhibiting the MPO activity and increasing neutrophil apoptosis in primary cultures of mouse neutrophils. These effects were at least partially associated with blocking reactive species generation, inhibiting IL-1β and IL-17A, and increasing IL-10 levels.

Anti-Inflammatory Potential of 1-Nitro-2-Phenylethylene

Inflammation is a reaction of the host to infectious or sterile stimuli and has the physiological purpose of restoring tissue homeostasis. However, uncontrolled or unresolved inflammation can lead to tissue damage, giving rise to a plethora of chronic inflammatory diseases, including metabolic syndrome and autoimmunity pathologies with eventual loss of organ function. Beta-nitrostyrene and its derivatives are known to have several biological activities, including anti-edema, vasorelaxant, antiplatelet, anti-inflammatory, and anticancer. However, few studies have been carried out regarding the anti-inflammatory effects of this class of compounds. Thereby, the aim of this study was to evaluate the anti-inflammatory activity of 1-nitro-2-phenylethene (NPe) using in vitro and in vivo assays. Firstly, the potential anti-inflammatory activity of NPe was evaluated by measuring TNF-α produced by human macrophages stimulated with lipopolysaccharide (LPS). NPe at non-toxic doses opposed the inflammatory effects induced by LPS stimulation, namely production of the inflammatory cytokine TNF-α and activation of NF-κB and ERK pathways (evaluated by phosphorylation of inhibitor of kappa B-alpha [IκB-α] and extracellular signal-regulated kinase 1/2 [ERK1/2], respectively). In a well-established model of acute pleurisy, pretreatment of LPS-challenged mice with NPe reduced neutrophil accumulation in the pleural cavity. This anti-inflammatory effect was associated with reduced activation of NF-κB and ERK1/2 pathways in NPe treated mice as compared to untreated animals. Notably, NPe was as effective as dexamethasone in both, reducing neutrophil accumulation and inhibiting ERK1/2 and IκB-α phosphorylation. Taken together, the results suggest a potential anti-inflammatory activity for NPe via inhibition of ERK1/2 and NF-κB pathways on leukocytes.

Anti-inflammatory effect of a new piperazine derivative: (4-methylpiperazin-1-yl)(1-phenyl-1H-pyrazol-4-yl)methanone

AIMS

This study investigates the anti-nociceptive and anti-inflammatory effects of new piperazine compound (LQFM182) as well as the toxicity acute in vitro.

MAIN METHODS

To evaluate the anti-nociceptive activity, the acetic acid-induced abdominal writhing test, tail flick test and formalin-induced pain test were used. The anti-inflammatory activity was evaluated using the models of paw oedema and pleurisy induced by carrageenan and some inflammatory parameters were evaluated, including cell migration, myeloperoxidase enzyme activity and the levels of TNF-α and IL-1β cytokines in pleural exudate. The acute oral systemic toxicity of LQFM182 in mice was evaluated through the neutral red uptake (nru) assay.

KEY FINDINGS

LQFM182 (50, 100 or 200 mg/kg, p.o.) decreased the number of writhings induced by acetic acid in a dose-dependent manner, and an intermediate dose (100 mg/kg, p.o.) reduced the paw licking time of animals in the second phase of the formalin test. Furthermore, LQFM182 (100 mg/kg, p.o.) reduced oedema formation at all hours of the paw oedema induced by carrageenan test and in pleurisy test reduced cell migration from the reduction of polymorphonuclear cells, myeloperoxidase enzyme activity and the levels of pro-inflammatory cytokines IL-1β and TNF-α. Therefore, it was classified in GHS category 300 < LD₅₀ < 2000 mg/kg.

SIGNIFICANCE

Reduction of the TNF-α and IL-1β levels.

Inhibition of inflammasome activation improves lung acute injury induced by carrageenan in a mouse model of pleurisy

The inflammasome NLRP3 is a molecular pathway activated by a wide range of cellular insults to elicit innate immune defenses through the activation of caspase-1 and the maturation of proinflammatory cytokines, such as IL-1β and IL-18. The expression of NRLP3 is abnormally elevated in numerous human inflammatory diseases, including pulmonary diseases. An injection of carrageenan (CAR) into the pleural cavity triggered an acute inflammatory response, leading to tissue damage, inflammatory exudates, leukocyte infiltration, and increased myeloperoxidase activity. The aim of this study was to assess the effect of the inflammasome blocking agents BAY 11-7082 (30 mg/kg, i.p.) and Brilliant Blue G (BBG) (45.5 mg/kg, i.p.) in a mouse model of CAR-induced pleurisy. Treatment with BAY 11-7082 or BBG 1 h after CAR injection attenuated pulmonary membrane thickening and polymorphonuclear leukocyte infiltration, reduced NF-κB translocation in the nucleus, and inhibited the assembly of the NRLP3/ASC/caspase-1 complex. Treatment with BAY 11-7082 or BBG also down-regulated iNOS, nitrotyrosine, and poly-ADP-ribosyl polymerase expression and inhibited CAR-induced apoptosis. Our results demonstrate that treatment with inflammasome-blocking agents can significantly reduce the development of acute CAR-induced lung injury.-Fusco, R. Gugliandolo, E., Biundo, F., Campolo, M., Di Paola, R., Cuzzocrea, S. Inhibition of inflammasome activation improves lung acute injury induced by carrageenan in a mouse model of pleurisy.

Evidence for the involvement of TNF-α and IL-1β in the antinociceptive and anti-inflammatory activity of Stachys lavandulifolia Vahl. (Lamiaceae) essential oil and (-)-α-bisabolol, its main compound, in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Stachys lavandulifolia Vahl (Lamiaceae) is a medicinal plant widely used in Turkey and Iranian folk medicine due to its analgesic and anti-inflammatory properties, but little is known about its essential oil.

AIM OF THIS STUDY

We studied the antinociceptive and anti-inflammatory effects of S. lavandulifolia essential oil (EOSl) and (-)-α-bisabolol (BIS), its main compound, in algogen-induced orofacial nociceptive behavior in mice, and assessed the possible involvement of pro-inflammatory cytokines in these profiles.

MATERIALS AND METHODS

The GC-FID and GC-MS analysis of EOSl demonstrated the presence of (-)-α-bisabolol (56.4%), bicyclogermacrene (5.3%), δ-cadinene (4.2%) and spathulenol (2.9%) as the main compounds. Male Swiss mice were pretreated with EOSl (25 or 50mg/kg, p.o.), BIS (25 or 50mg/kg, p.o.), morphine (3mg/kg, i.p.) or vehicle (saline 0.9% with two drops of tween 80, 0.2%), before formalin- (20μl, 2%), capsaicin- (20μl, 2.5µg) or glutamate- (20μl, 25Mm) injection into the right upper lip (perinasal area) in mice. The anti-inflammatory profile of EOSl or BIS (50mg/kg) was assessed by the inflammatory response induced by carrageenan (2% in 0.2mL) in mice (pleurisy model).

RESULTS

Our results showed that p.o. treatment with EOSl and BIS displayed significant inhibitory (p<0.05 or p<0.01 or p<0.001) effects in different orofacial pain tests on mice, but BIS proved to be more effective, significantly reducing nociceptive behavior in all tests including both phases of the formalin test. The analgesic effect is not related to any abnormality since EOSl- or BIS-treated mice exhibited no performance alteration in grip strength. Moreover, EOS1 and BIS exhibited a significant anti-inflammatory effect (p<0.001) in the pleurisy model of inflammation, which seems to be related to a significant reduction (p<0.05) of the pro-inflammatory cytokine TNF-α in BIS treatment, and of the pro-inflammatory cytokine IL-1β (p<0.01) in EOS1 treatment.

CONCLUSION

Our results corroborate the use of S. lavandulifolia in traditional medicine as an analgesic and anti-inflammatory, which seems to be related to (-)-α-Bisabolol, the main compound of EOSl.

Naringin attenuates the development of carrageenan-induced acute lung inflammation through inhibition of NF-κb, STAT3 and pro-inflammatory mediators and enhancement of IκBα and anti-inflammatory cytokines

Naringin has been reported to possess diverse pharmacological properties, including anti-arthritic and anti-inflammatory activities. The aim of the present study was to determine the potential anti-inflammatory effect of naringin in a mouse model of carrageenan-induced pleurisy. A single dose of naringin (40 and 80 mg/kg) was administered per oral (p.o.) 1 h before carrageenan (Cg) administration. Pro- and anti-inflammatory cytokines were analysed in pleural fluid. We also assessed the effects of naringin on the expression levels of iNOS, inducible cyclooxygenase isoform (COX-2), ICAM-1, MIP-2, PGE2, STAT3, TGF-β1, nuclear factor kappa B (NF-κB) and inhibitor of kappa B (IκBα) in lung tissue. The histological examinations revealed anti-inflammatory effect of naringin while Cg group deteriorated. Naringin downregulated Th1 and upregulated Th2 cytokines. Western blot analyses revealed increased protein expression of NF-κB, STAT3 and COX-2 and decreased IκBα in response to Cg treatment, which were reversed by the treatment with naringin. In the Cg group, mRNA expression levels of pro-inflammatory mediators upregulated and anti-inflammatory mediators downregulated. Naringin reversed these actions.

Systemic administration of Rosmarinus officinalis attenuates the inflammatory response induced by carrageenan in the mouse model of pleurisy

Rosmarinus officinalis, also named rosemary, is a native plant from the Mediterranean region that is useful for the treatment of inflammatory diseases. Studies using experimental models and/or in vitro tests have shown the important biological effects of rosemary. In this context, the mechanism of the anti-inflammatory activity of rosemary must be investigated to support the discovery of new substances with anti-inflammatory effects. The aim of the present study was to investigate the anti-inflammatory effects of crude extract oil free obtained from the leaves of rosemary in an animal model of inflammation, thus evaluating its medicinal use for the treatment of inflammatory conditions. Also its ethanol, hexane, and ethyl acetate fractions, as well as its isolated compounds carnosol and rosmarinic acid were analyzed. Swiss mice were used for the in vivo experiments. The effect of this herb on the inhibition of the leukocytes, exudation, myeloperoxidase, and adenosine-deaminase activities, nitrite/nitrate, interleukin 17A, and interleukin 10 levels and mRNA expression was determined. The crude extract and its derived fractions, in addition to its isolated compounds, inhibited leukocytes and decreased exudation and myeloperoxidase and adenosine-deaminase activities, as well as nitrite/nitrate and interleukin 17A levels and mRNA expression, besides increasing interleukin 10 levels and mRNA expression. Rosemary showed important anti-inflammatory activity by inhibiting leukocytes and decreasing exudation. These effects were associated with a decrease in the proinflammatory parameters (myeloperoxidase, adenosine-deaminase, nitrite/nitrate, and interleukin 17A) and an increase in the anti-inflammatory cytokine (interleukin 10). This study confirms the anti-inflammatory properties of rosemary and validates its use in folk medicine to treat inflammatory diseases such as rheumatism and asthma.

Anti-inflammatory and antioxidant properties of hydroalcoholic crude extract from Casearia sylvestris Sw. (Salicaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Casearia sylvestris Sw. is widely used in popular medicine to treat inflammatory conditions.

AIM OF THE STUDY

To investigate the anti-inflammatory and antioxidant properties of hydroalcoholic crude extract (HCE) taken from Casearia sylvestris Sw. (Salicaceae).

METHODS AND RESULTS

The effect of the HCE from this plant (3-300 mg/kg) on the reduction of inflammatory response to carrageenan was investigated in pleurisy in rats (intrapleural, 2% in 0.2 mL) or paw edema in mice (intraplantar, 300 μg/20 μL, right hind paw). The plant anti-inflammatory action was assessed by its capability in inhibiting cell migration, enzymatic activity of myeloperoxidase (MPO) and production of nitrite/nitrate or edema. The in vitro antioxidant activity of this extract against lipid peroxidation and damage to proteins was assessed as possible pathways to contribute as anti-inflammatory mechanisms. Carrageenan-induced hind paw edema (739.3 ± 11.9 μm) was reduced by HCE (30 mg/kg: 462.8 ± 28.38 μm) to similar extents as dexametasone (365.1 ± 16.7). In pleurisy, treatment of the animals with HCE (100mg/kg: 0.010 ± 0.001 mU/mg of protein) also reduced MPO activity augmented by carrageenan (0.020 ± 0.001 mU/mg of protein) as well as leukocytes migration (carrageenan: 17.8890 ± 2.3900 leukocytes/mL, HCE 100mg/kg: 7.0880 ± 9631 leukocytes/mL). Significant effects were also observed in animals treated with different doses of HCE in biochemical tests for oxidative stress analysis.

CONCLUSION

The anti-inflammatory and antioxidant effects of HCE from Casearia sylvestris Sw. suggests a potential therapeutic benefit of this plant in treatment of inflammatory conditions.

COX-2 expression in stromal fibroblasts self-limits their numbers in lymph node inflammatory responses

We previously reported the expression of cyclooxygenase (COX)-2 in draining lymph nodes during carrageenin-induced pleurisy of rats. Here, we analyzed histological and immunohistochemical characteristics of COX-2-expressing cells. After carrageenin administration into the pleural cavity of rats, parathymic lymph nodes were enlarged beginning at 8h and peaking from 24 to 48h. Lymphatic follicles disappeared 16h after injection, and numerous macrophages and fibroblasts were observed in the cortical region. COX-2-expressing cells in the cortical region showed characteristic dendritic processes from 16 to 48h and primarily co-localized with stromal fibroblastic reticular cell markers, α-smooth muscle actin (α-SMA), and desmin. Expression of α-SMA increased following COX-2 expression. Nimesulide, a COX-2 inhibitor, increased the dendritic processes of COX-2-expressing cells as well as expression of both COX-2 and α-SMA. These results suggest that COX-2-expressing cells may be stromal fibroblastic cells, which negatively self-regulate their proliferation and modulate tissue remodeling of draining lymph nodes at inflammatory sites.

From popular use to pharmacological validation: a study of the anti-inflammatory, anti-nociceptive and healing effects of Chenopodium ambrosioides extract

ETHNO-PHARMACOLOGICAL RELEVANCE: Chenopodium ambrosioides (Amarantaceae) is an annual or perennial plant popularly known as 'erva de Santa Maria', 'mastruço' and 'erva-do-formigueiro'. This herb is used in folk medicine in the form of teas, poultices and infusions for inflammatory problems, contusions and lung infections, and as an anthelmintic and anti-fungal.

AIM OF THE STUDY

The aim of the present study was to further the understanding of the anti-nociceptive, anti-inflammatory and wound healing effects of ethanol extract (EE) obtained from the leaves and stems of Chenopodium ambrosioides in animal models of acute pain, inflammation and wound healing, thus supporting its medicinal use for the treatment of pain and inflammatory conditions

MATERIALS AND METHODS

The anti-nociceptive activity of EE (150-500 mg/kg) was evaluated using the nociception induced by formalin (2.5%), prostaglandin-E(2) (PGE2; 3 nmol/paw), capsaicin (CAP, 1.6 μg/paw) and bradykinin (BK, 10 nmol/paw). The anti-inflammatory activity of EE (150-500 mg/kg) was evaluated in carrageenan- (Cg, 300 μg/paw), PGE(2)- (3 nmol/paw), substance P- (SP, 20 nmol/paw) and BK- (3 nmol/paw) induced paw oedema. The topical anti-inflammatory activity of EE (1%, 3% and 5%) was evaluated in arachidonic acid- (AA, 2mg/ear), oil croton- (1 μg/ear) and CAP- (250 μg/ear) induced ear oedema. The effect of this extract in the inhibition of the influx of neutrophil, myeloperoxidase (MPO) and adenosine-deaminase (ADA) activities and nitric oxide (NO) and TNF-á levels was also determined using the mouse of pleurisy induced by Cg. The excision wound model in rats was used to evaluate the wound healing efficacy of EE (1%, 3% and 5%). To exclude the possible non-specific muscle relaxant or sedative effects of EE, mice motor performance was also evaluated with the rota-rod test.

RESULTS

EE (5% per ear) was effective in reducing ear oedema induced by croton oil by 78.09%, CAP by 70.85% and AA by 77.02%. EE (500 mg/kg; p.o.) also significantly inhibited paw oedema induced by Cg by 40%, PGE(2) by 51%, SP by 56% and BK by 57%. EE (500 mg/kg; p.o.) inhibited the cell influx of leucocytes by 78% and neutrophils by 53%, MPO activity by 62.22% and ADA activity by 23.07%, as well as NO by 77.77% and TNF-á levels by 50% in the fluid leakage due to the carrageenan-induced pleurisy. EE also inhibited the formalin-induced nociceptive in both phases of pain (neurogenic and inflammatory) at a dose of 500 mg/kg, resulting in inhibitions of 77.39% and 95.60%, respectively. EE (500 mg/kg; p.o.) was also effective in inhibiting the nociception induced by PGE(2) (68%), CAP (53%) and BK (32%). Topical application of EE (5%) on excision wounds caused a significant reduction in wound area when compared with the untreated controls. Finally, treatment with EE (150-500 mg/kg) did not show any significant alterations in motor performance or body temperature compared with the control group.

CONCLUSIONS

The results, including the inhibition of mediators (BK, NO, SP, PGE(2) and TNF-á) and enzyme (MPO and ADA) activity, validate the use of the plant under study for therapeutic treatment of anti-inflammatory, painful and wound healing processes.

β-catenin expression in benign and malignant pleural disorders

Benign and malignant pleural processes display a large and overlapping spectrum of morphological appearances, and can be difficult to distinguish, histologically, from each other. β-catenin, a participant in the wingless-type (Wnt) transduction pathway, is involved in the pathogenesis of malignant mesothelioma and has received limited evaluation for its ability to serve as a diagnostic aid for distinguishing between individual pleural disorders. We performed immunohistochemistry for β-catenin on 10 pleural malignant mesotheliomas, 10 examples of mesothelial hyperplasia and 18 cases of organizing pleuritis. Although differences were noted in staining intensity between the mesothelioma and mesothelial hyperplasia groups, extensiveness and cellular location were similar. Staining intensity (mean +/- s.d.) in mesotheliomas (2.00 +/- 0.67) was significantly less intense than in mesothelial hyperplasia cases (3.00 +/- 0.00) (p=0.0005). Stromal cell staining was cytoplasmic in all cases, and endothelial cell staining was membranous, submembranous and cytoplasmic. Nuclear expression of β-catenin was not observed in any of the cases studied. This lack of nuclear staining in the stromal cells of organizing pleuritis differs markedly from the previously reported high frequencies of nuclear β-catenin expression in other pleural spindle cell proliferations (desmoid tumors and solitary fibrous tumors). In summary, the current study adds to previous work indicating a role for β-catenin in the genesis of pleural conditions including organizing pleuritis, mesothelial hyperplasia and malignant mesothelioma. Although IHC for β-catenin does not appear to be conclusive for separating benign from malignant mesothelial proliferations, it may be valuable for assisting in the differential diagnosis of mesothelial and spindle cell proliferations in the pleura.

Pleural effects of indium phosphide in B6C3F1 mice: nonfibrous particulate induced pleural fibrosis

The mechanism(s) by which chronic inhalation of indium phosphide (InP) particles causes pleural fibrosis is not known. Few studies of InP pleural toxicity have been conducted because of the challenges in conducting particulate inhalation exposures, and because the pleural lesions developed slowly over the 2-year inhalation study. The authors investigated whether InP (1 mg/kg) administered by a single oropharyngeal aspiration would cause pleural fibrosis in male B6C3F1 mice. By 28 days after treatment, protein and lactate dehydrogenase (LDH) were significantly increased in bronchoalveolar lavage fluid (BALF), but were unchanged in pleural lavage fluid (PLF). A pronounced pleural effusion characterized by significant increases in cytokines and a 3.7-fold increase in cell number was detected 28 days after InP treatment. Aspiration of soluble InCl(3) caused a similar delayed pleural effusion; however, other soluble metals, insoluble particles, and fibers did not. The effusion caused by InP was accompanied by areas of pleural thickening and inflammation at day 28, and by pleural fibrosis at day 98. Aspiration of InP produced pleural fibrosis that was histologically similar to lesions caused by chronic inhalation exposure, and in a shorter time period. This oropharyngeal aspiration model was used to provide an initial characterization of the progression of pleural lesions caused by InP.

Antioxidant effects of mycophenolate mofetil in a murine pleurisy model

Generation of oxidative stress induced by reactive oxygen species (ROS) and nitrogen (RNS) is believed to be a primary factor in the etiology of various inflammatory diseases. Although, the process of generation of oxygen species is a physiological event, in the inflammatory process this event is increased and produces large amounts of reactive species that leads to lipid peroxidation and to cell death. Mycophenolate mofetil (MMF) is a drug effective in protecting against chronic allograft failure and recently was introduced as an alternative for the treatment of various inflammatory diseases such as glomerulopathies, systemic lupus erythematosus and systemic vasculitis. Based on studies of the anti-inflammatory effect of MMF the aim of this study was to evaluate the effects of MMF on the inhibition of leukocytes and exudation, as well as myeloperoxidase and some antioxidant enzyme activities using carrageenan-induced pleurisy in mice. Our results showed that MMF significantly decreased leukocyte influx (P<0.01), exudation (P<0.01), superoxide dismutase (P<0.05), catalase (P<0.05), glutathione peroxidase (P<0.01), glutathione S-transferase (P<0.01) activities, levels of lipid peroxidation (P<0.05), as well as myeloperoxidase activity (P<0.05) on both phases (4h and 48h) of the inflammatory response induced by carrageenan into the mice pleural cavity. In conclusion, the anti-inflammatory effect of MMF may be, at least in part, via inhibition of ROS and/or NRS overgeneration, and consequently, attenuating the related oxidative stress.

[Inhibiting effect of Shuang-huang-lian microemulsion on cytokines of carrageenan induced pleuritis in rats]

OBJECTIVE

To explore the anti-inflammatory effect and possible mechanism of Shuang-huang-lian (SHL) microemulsion.

METHOD

Rat model of pleuritis was established by thoracic injecting 0.2 mL of 1% carrageenan. Rats in the treated groups were orally administered with SHL microemulsion prescription 1, 2, and oral liquid, while those in the positive control group were given aspirin. Rats in the normal group and the model group were given equal volume of water. Each groups were given their medicine for successive 6 days. Modeling was performed 30 mins after the 5th day medication. After 12 hrs of modeling, took suction of the pleurorrhea and measured the amount of tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8), prostaglandin E2 (PGE2) and protein (pro).

RESULT

Compared with the normal group, all the parameters were higher in model group (TNF-alpha and IL-8 P<0.01, PGE2 and pro P<0.05). While compared with the model group, only the amount of TNF-alpha and PGE2 were lower in all the treated group (P<0.01).

CONCLUSION

Both SHL microemulsion prescription 1 and 2 have obvious anti-inflammatory effect. The effect might be related to inhibiting the increase of cytokines as TNF-alpha and PGE2, and intervening of the metabolic process of arachidonic acid (AA).

Anti-inflammatory evaluation of Solidago chilensis Meyen in a murine model of pleurisy

The aim of this study was to investigate the anti-inflammatory effects and the mechanism of action of the aqueous extracts obtained from rhizomes, leaves and inflorescences of Solidago chilensis in the mouse model of pleurisy. The extracts were prepared by infusion and were lyophilized.

RESULTS

The aqueous extracts of rhizomes, leaves or inflorescences inhibited leukocytes, neutrophils and exudation (P<0.05) in the inflammation induced by carrageenan. The rhizomes aqueous extract, butanolic and aqueous residual fractions inhibited leukocytes, neutrophils, myeloperoxidase, adenosine-deaminase, and tumor necrosis factor alpha levels in the inflammation induced by carrageenan (P<0.05). The rhizome aqueous extract and butanolic fraction also inhibited exudation, nitric oxide, and interleukin-1 beta levels (P<0.05). The rhizomes aqueous extract and its two derived fractions reduced leukocytes and mononuclears in the pleurisy induced by bradykinin, histamine, or substance P (P<0.05) and neutrophils in the pleurisy induced by histamine or substance P (P<0.05). Only aqueous residual fraction inhibited neutrophils induced by bradykinin (P<0.05).

CONCLUSION

Solidago chilensis aqueous extracts from leaves, inflorescences and rhizomes demonstrated an important anti-inflammatory effect, inhibiting cells in the inflammation caused by carrageenan. In addition, the rhizomes aqueous extract and its derived fractions also decreased pro-inflammatory mediators release into the site of the inflammatory process. The rhizomes aqueous extract and the butanolic fraction showed more evident anti-inflammatory actions.

Gelatinolytic activities (matrix metalloproteinase-2 and -9) and soluble extracellular domain of Her-2/neu in pleural effusions

Matrix metalloproteinases (MMPs) are proteolytic enzymes that are implicated in multiple stages of cancer progression including invasion and metastasis. MMPs exert these effects by cleaving a diverse group of substrates, which include not only structural components of the extracellular matrix, but also growth factor receptors. By gelatin zymography we verified MMP activity in the pleural effusions of patients with benign and malignant disease. Of these patients, 32 had malignant pleural effusion, consisting of 20 breast cancer, 6 non-small cell lung carcinoma, 4 ovarian carcinoma, and 2 colonic adenocarcinoma, and 10 had benign pleural effusion (5 pleurisy and 5 cirrhosis). Zymography showed the constant presence of a substantial amount of MMP-2 in all samples analyzed, whereas MMP-9 was present to lesser quantities. MMP-2 activity was enhanced in pleural effusions from patients with benign diseases compared with cancer patients. MMP-9 was present in 59% of cancer patients and the lytic activity was enhanced in pleurisy and absent in cirrhosis. Furthermore, we determined the pleural effusion levels of the soluble extracellular domain of HER-2/neu. The levels of HER-2/neu ECD were above the cut-off value in breast cancer patients. No correlation between gelatinolytic activities and high HER-2/neu ECD values was found.

Acute immune and non-immune inflammatory response in spontaneously hypertensive rats and normotensive rats. Role of endogenous nitric oxide

The present study investigated the acute inflammatory response (increase in vascular permeability and leukocytes migration) in the pleura of spontaneously hypertensive rats (SHR) and normotensive rats (NTR), using two different stimulus: carrageenan and active anaphylaxis. In addition, the role of endogenous nitric oxide in these responses was investigated.

RESULTS

The inflammatory response induced by intrapleural carrageenan injection in SHR developed similarly to that in NTR. Treatment with L-NAME, reduced the intensity of this response in both groups of rats. The inflammatory response induced by active anaphylaxis in SHR and NTR was different. The increase in vascular permeability occurred later in the SHR compared to NTR. The number of leukocyte present in inflammatory exudates was increased at 4 h in both groups of rats. L-NAME treatment did not inhibit exudation at the intervals under analysis, however, reduced the number of mononuclear cells in the inflammatory exudate of SHR.

CONCLUSION

The development of the inflammatory response in SHR differs from that in NTR, depending on the nature of the inflammatory stimulus. Endogenous NO plays a clear role in carrageenan-induced inflamma-tion, but not in immunologically mediated inflammation in the analyzed period.

Inhibition of inducible nitric oxide synthase in vitro and in vivo by a water-soluble extract of Wendita calysina leaves

Wendita calysina is a Paraguayan herbaceous plant commonly known as burrito. Our previous study indicated that burrito leaves are a very good source of phenylpropanoid glycosides, principally verbascoside. From W. calysina leaves, a standardized, water-soluble extract (WSE) rich in phenylpropanoid glycosides has been developed on an industrial scale to be used as a food supplement, cosmetic, phytomedicine, and ingredient of different formulations. In this study, we investigated the effect of the W. calysina WSE both in vitro in murine macrophage cell line J774.A1 stimulated with lipopolysaccharide (LPS) and, in vivo in an animal model of acute inflammation, carrageenan-induced pleurisy. Here we report that W. calysina WSE (0.05, 0.1, and 0.5 mg/ml) inhibited inducible nitric oxide synthase (iNOS) expression and activity in LPS-stimulated J774.A1. In vivo experiments showed that injection of carrageenan (2%) into the pleural cavity of rats elicited an acute inflammatory response characterized by iNOS expression, intercellular adhesion molecule-1 (ICAM-1) up-regulation, nitrotyrosine and poly (ADP-ribose) synthase (PARS) formation, and lung tissue damage-all parameters significantly reduced by W. calysina WSE (500 mg/kg per os). These results report, for the first time, that a treatment with W. calysina WSE exerts anti-inflammatory effects both in vitro and in vivo.

Prostaglandin F2alpha produced by inducible cyclooxygenase may contribute to the resolution of inflammation

Cyclooxygenase-2 may play a role in resolution of carrageenan-induced pleurisy in rats by generating anti-inflammatory prostanoids. Here, we show exudate prostaglandin F2alpha concentrations rise during resolution of this model. These were reduced by the selective cyclooxygenase-2 inhibitor NS-398, which exacerbated inflammation. Concomitant treatment with NS-398 and the synthetic FP receptor agonist fluprostenol reversed this exacerbation. This suggests prostaglandin F2alpha produced by cyclooxygenase-2 contributes to resolution of this inflammatory reaction.

Anti-inflammatory activity of crude extract and fractions of Nectandra falcifolia leaves

The present study evaluated the effect of the crude extract of the leaves of Nectandra falcifolia (NEES) Castiglioni and its fractions in different experimental models of inflammation (paw edema, pleurisy, and ear edema). Carrageenan-induced edema of the paw and pleurisy were evaluated in Wistar rats (180-220 g), which were treated with different doses of the total extract (250, 500 mg.kg-1). Edema of the ear, induced by croton oil, and determination of myeloperoxidase activity were evaluated in Swiss mice (25-35 g). In this experiment, the crude extract of Nectandra falcifolia (Nf) (1.25, 2.5, 5.0, 7.5 mg) and the hexane, chloroform, ethyl-acetate and hydromethanol fractions (5.0 mg) were applied topically, immediately after application of the oil. The crude extract of Nf (500 mg.kg-1) significantly reduced edema of the paw compared to the control group. Similarly, at doses of 250 and 500 mg.kg-1 it significantly reduced the volume of pleural inflammatory exudate compared to the control animals. However, it did not change the number of migrated cells. At doses of 2.5, 5.0 and 7.5 mg, the crude extract significantly inhibited edema of the ear and the influx of neutrophils. The fractions from Nectandra falcifolia (hexane, chloroform, ethyl acetate and hydromethanol) also inhibited edema of the ear. Taken together, the results demonstrated that the crude extract and its fractions administered to animals orally or topically showed an anti-inflammatory effect.

Immunohistochemical detection of GLUT-1 can discriminate between reactive mesothelium and malignant mesothelioma

The separation of benign reactive mesothelium (RM) from malignant mesothelial proliferation can be a major challenge. A number of markers have been proposed, including epithelial membrane antigen, p53 protein, and P-glycoprotein. To date, however, no immunohistochemical marker that allows unequivocal discrimination of RM from malignant pleural mesothelioma (MPM) has been available. A family of glucose transporter isoforms (GLUT), of which GLUT-1 is a member, facilitate the entry of glucose into cells. GLUT-1 is largely undetectable by immunohistochemistry in normal epithelial tissues and benign tumors, but is expressed in a variety of malignancies. Thus, the expression of GLUT-1 appears to be a potential marker of malignant transformation. Recently, in fact, some studies have shown that GLUT-1 expression is useful for distinguishing benign from malignant lesions. The purpose of the present study was to evaluate the diagnostic utility of GLUT-1 expression for diagnostic differentiation between RM and MPM. Immunohistochemical staining for GLUT-1 was performed in 40 cases of RM, 48 cases of MPM, and 58 cases of lung carcinoma. Immunohistochemical GLUT-1 expression was seen in 40 of 40 (100%) MPMs, and in all cases the expression was demonstrated by linear plasma membrane staining, sometimes with cytoplasmic staining in addition. GLUT-1 expression was also observed in 56 out of 58 (96.5%) lung carcinomas. On the other hand, no RM cases were positive for GLUT-1. GLUT-1 is a sensitive and specific immunohistochemical marker enabling differential diagnosis of RM from MPM, whereas it cannot discriminate MPM from lung carcinoma.

Effects of combination of melatonin and dexamethasone on acute lung injury in a mice model of carrageenan-induced pleurisy

The aim of this study was to investigate the effects of combination therapy with melatonin and dexamethasone (DEX) on acute lung injury. In particular, we investigated the effects of combination therapy in animal models of acute lung inflammation (carrageenan-induced pleurisy). Injection of carrageenan into the pleural cavity of rats elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity which contained a large number of neutrophils [polymorphonuclear leukocyte (PMN)] as well as an infiltration of PMN in lung tissues and subsequent lipid peroxidation, and increased production of nitrite/nitrate (NOx), and prostaglandin E2 (PGE2). Furthermore, carrageenan induced an upregulation of the adhesion molecules ICAM-1 and P-selectin, inducible nitric oxide synthase, cycloxygenase-2 as well as nitrotyrosine as determined by immunohistochemical analysis of lung tissues. No anti-inflammatory effect was observed in animals treated with melatonin (10 mg/kg) or with DEX (0.01 mg/kg) alone. This study shows that the combination therapy with melatonin and DEX reduced the degree of acute lung inflammation and tissue damage associated with carrageenan-induced pleurisy in mice and supports the possible use of melatonin in combination with steroids in order to reduce the dose and the side effects related with the use of steroids for the management of inflammatory disease.

Activation and degradation of protein C by primary rabbit pleural mesothelial cells

The protein C (PC) anticoagulant pathway is the major mechanism that controls thrombin generation in vivo and may thereby influence pathophysiologic fibrin turnover associated with intrapleural inflammation. We hypothesized that pleural mesothelial cells could regulate local expression of PC in evolving pleurodesis where inflammation and thrombosis play an important role. To test this hypothesis, we determined the ability of rabbit pleural mesothelial cells (RPMC) to support the activation of PC as well as its binding, internalization, and degradation. Lung fibroblasts were also assessed to test the specificity of the responses. We found that both cell types could support thrombin-dependent activation of PC in vitro. Both cell types were capable of binding, internalizing, and degrading 125I-PC. Degradation of 125I-PC by these cells was prevented by the lysosomal inhibitor chloroquine but not the proteasomal inhibitor lactacystin, supporting involvement of a lysosomal mechanism of PC degradation. During evolving tetracycline (TCN)-induced pleural injury in rabbits, PC levels in pleural fluids were sustained, exhibited a trend toward progressive decline, and were temporally correlated with pleural adhesion formation in vivo. These observations indicate that sustained expression of PC during evolving pleurodesis induced by TCN is subject to regulation by resident pleural cells: both RPMC and lung fibroblasts. Both cell types support local generation of APC. Internalization and degradation of PC by RPMC and fibroblasts may regulate its intrapleural expression and influence remodeling of extravascular fibrin in the setting of evolving pleurodesis induced by TCN.

Role of prostaglandin E2 in the invasiveness, growth and protection of cancer cells in malignant pleuritis

The recurrence of pleural effusions is a common event in a variety of neoplastic diseases. The objective of this study was to identify the mechanisms promoting the homing and growth of cancer cells within the pleural space. A cancer cell line recovered from malignant pleural fluids (lung adenocarcinoma cell line) that constitutively expresses cyclooxygenase 2 (COX-2) and all types of prostaglandin receptors was studied. It was first demonstrated using a matrigel system, that malignant pleural fluids increase the invasiveness of adenocarcinoma cells more than congestive heart failure (CHF) pleural fluids. Moreover, exposure to exudative malignant, but not to CHF pleural fluids, increased the mRNA (measured by real-time polymerase chain reaction (PCR)) and protein expression of COX-2 (measured by Western blot), as well as the activation and nuclear translocation of nuclear factor kappaB (NFkappaB) in cancer cells. These events are all actively regulated by prostaglandin E2 (PGE2), since the addition of synthetic PGE2 to cancer cells and the depletion of PGE2 from malignant pleural fluids or the inhibition of COX-2 activity significantly increased and reduced these phenomena, respectively. Moreover, malignant pleural effusions and synthetic PGE2 increased the long-term proliferation of cancer cells and reverted the impairment in long-term proliferation due to talc exposure. This study demonstrates that PGE2 present in malignant effusions contributes to cancer expansion and may protect cancer cells by anti-proliferative effects induced by talc.

Pharmacokinetic study of pleural fluid penetration of carbapenem antibiotic agents in chemical pleurisy

STUDY OBJECTIVES

We investigated pleural fluid penetration of carbapenem antibiotic agents [imipenem (IPM), panipenem (PAPM), meropenem (MEPM), and biapenem (BIPM)] using an experimental rabbit pleuritis model to clarify the usefulness of the carbapenem agents for the treatment of bacterial pleurisy or pyothorax.

MEASUREMENTS AND RESULTS

Serum and pleural fluid specimens were serially collected at 5, 10, 15, 30, 60, 90, 120, 180, 240, 300, and 360 min after antibiotic administration for measurement of antibiotic levels. We investigated each agent alone as well as drug solutions containing each agent and a dehydropeptidase-I-specific inhibitor, cilastatin (CS), to remove the influence of dehydropeptidase-I-related hydrolysis. Groups of animals (n=3) received each carbapenem agent with or without CS. Serum and pleural fluid antibiotic levels were measured by high-performance liquid chromatography (HPLC). Because Cmax is not useful for evaluating the antimicrobial effects of carbapenem antibiotic agents due to their dose-dependent antimicrobial activity, we also investigated the AUC, which is correlated with the total drug levels in vivo. Among the drug solutions containing CS, MEPM/CS had the highest pleural fluid AUC0-360 (1594.8+/-510.3 microg min/ml), and the highest pleural fluid AUC0-360/plasma AUC0-360 ratio (0.79+/-0.04). BIPM/CS had the highest plasma AUC0-360 (3040.1+/-1525.9 microg min/ml). In pleural fluid AUC0-360/plasma AUC0-360 ratio MEPM/CS was significantly higher than those for the remaining agents. In pleural fluid AUC0-360 and plasma AUC0-360 there were no significant differences among these mixed solutions.

CONCLUSIONS

MEPM had the most favorable pleural fluid penetration. Pleural fluid penetration should be examined in infection models and in clinical trials.

Vascular endothelial growth factor levels in post-CABG pleural effusions are associated with pleural inflammation and permeability

BACKGROUND

Vascular endothelial growth factor (VEGF) participates in the pathogenesis of exudative pleural effusions (PEs). In the present study, we determined the pleural fluid (PF) and serum VEGF levels in patients with post-coronary artery by-pass grafting (post-CABG) PEs.

METHODS

Thirty-eight patients with post-CABG (two with bilateral) PEs were studied. PEs were divided into "early" (occurring earlier than 30 days after surgery) and "late" ones. VEGF levels were measured using ELISA.

RESULTS

(i) Serum and PF VEGF levels did not differ significantly when all the patients (P=0.053) or those with late effusions (P=0.6) were analyzed; serum VEGF levels were significantly elevated in comparison to PF VEGF levels in patients with early (P=0.007) effusions. (ii) Serum VEGF levels were significantly higher in patients with early than in those with late effusions (P=0.033), while PF VEGF levels were not significantly different between the two groups (P=0.77). (iii) PF VEGF levels were higher than corresponding serum levels in 4/24 patients with early and in 10/16 patients with late post-CABG PEs (P=0.006). (iv) In PEs VEGF levels significantly correlated with red blood cells (P=0.015), nucleated cells (P=0.003), protein levels (P=0.002) and lactate dehydrogenase (LDH) levels (P=0.04).

CONCLUSION

In post-CABG PEs, preferential local production of VEGF in the pleural cavity is most commonly observed a month or later after surgery. The fact that in PEs VEGF levels correlate with markers of pleural inflammation (inflammatory cells and LDH levels) and vascular hyperpermeability (protein levels) suggests that VEGF may be involved in the pathogenesis of post-CABG PEs.

Comparison of hormone transfer to pleural and synovial exudates

OBJECTIVES

Local effects of hormones on immune and connective tissues could play some role in the development of local inflammation processes. The aim of this study was to investigate the levels of selected hormones in pleural exudates of patients with pleurisy and lung tumours, and compare these levels with hormone concentration in knee synovial fluid.

SUBJECTS AND METHODS

Eleven patients with pleural exudate (mean age 62+/-3) and l9 subjects with rheumatoid arthritis (of the same mean age) participated in the observations. Plasma, pleural exudates and synovial fluid levels of cortisol, prolactin, aldosterone, testosterone, 17-beta-estradiol, dehydroepiandrosterone, progesterone, insulin and C-peptide were determined by specific radioimmunoassay.

RESULTS

It was noted that all estimated hormones are transferred into pleural exudates and synovial fluid. Higher levels of dehydroepiandrosterone and C-peptide were observed in pleural exudates as compared to plasma. The concentrations of testosterone, prolactin and estradiol in males were lower in exudates as compared to plasma. Mean levels of cortisol, aldosterone, progesterone and insulin in plasma were similar to these found in pleural exudates. The comparison of hormone levels in pleural exudates and synovial fluid showed that the levels of cortisol, progesterone and dehydroepiandrosterone tended to be higher in the exudates as compared to synovial fluid. However, the levels of insulin, testosterone and estradiol in exudates were lower than these in inflammatory synovial fluid from patients with rheumatoid arthritis.

CONCLUSIONS

This study showed the presence of hormones in pleural exudates. The differences in hormone concentrations in pleural exudates and synovial fluid were observed suggesting a specificity of hormone transfer from plasma to these exudates.

Extract of the bristles of Dirphia sp. increases nitric oxide in a rat pleurisy model

OBJECTIVES

In the present study we assessed the inflammatory potential of venom obtained from caterpillar genus Dirphia in an acute model of lung injury.

MATERIAL AND METHODS

Injection of extract from the bristles of Dirphia sp. (EBD) into the pleural cavity of rats elicited an acute inflammation response characterized by fluid accumulation which contained a large number of polymorphonuclear neutrophils (PMNs).

RESULTS

The results show that EBD induces an inflammatory response, with a significant increase in PMNs, exudate and nitric oxide within 4 h after a 0.04 mg/kg dose. The administration of anti-inflammatory drugs (fructose-1,6-bisphosphate, dexamethasone, rofecoxib, sodium diclofenac and pyrilamine) significantly reduced the inflammatory effect of EBD.

CONCLUSIONS

EBD causes an inflammatory reaction in the pleural cavity of rats involving a variety of inflammatory mediators, its action mechanism probably involving cellular injury and the exacerbated induction of cytokines and nitric oxide.

Implication of glucocorticoid in anti-inflammatory effects of Ro5-4864 in mouse pleurisy induced by carrageenan

Mouse pleurisy induced by carrageenan is used to determine the mechanism of anti-inflammatory action of 7-chloro-5-(4-chlorophenyl)-1,3-dihydro-1-methyl-2-H-1,4-benzodiazepin-2 (Ro5-4864). Pre-treatment with Ro5-4864 inhibits different inflammatory parameters, such as neutrophil influx, MPO activity and NO levels in the early phase (4 h), as well as mononuclear cells and ADA activity in the late phase (48 h) of pleurisy. dl-Aminoglutethimide, inhibitor of steroidal synthesis, reverted the effect of Ro5-4864 on these different inflammatory parameters. Our results suggest that anti-inflammatory action of Ro5-4864 may be partly due to its capacity to inhibit leukocyte migration, as well as leukocyte activation and formation of NO by a mechanism dependent on glucocorticoids.

Hypericum perforatum attenuates the development of carrageenan-induced lung injury in mice

Hypericum perforatum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. Since polyphenolic compounds have a high antioxidant potential, in this study we evaluated the effect of H. perforatum in an animal model of acute inflammation, carrageenan-induced pleurisy. We report here that H. perforatum extract (given at 30 mg/kg orally, bolus prior to carrageenan) exerts potent anti-inflammatory effects in an animal model of acute inflammation. Injection of carrageenan into the pleural cavity of mice elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity which contained a large number of neutrophils (PMNs) as well as an infiltration of PMNs in lung tissues and subsequent lipid peroxidation (as determined by thiobarbituric acid-reactant substance measurement) and increased production of tumor necrosis factor-alpha, (TNF-alpha) and interleukin-1beta (IL-1 beta). All parameters of inflammation were attenuated by H. perforatum extract. Furthermore, carrageenan induced an upregulation of the expression of adhesion molecules ICAM-1, as well as an increase in the amounts of nitrotyrosine and poly(ADP-ribose) (PAR), as determined by immunohistochemical analysis of lung tissues. The degree of staining for the ICAM-1, nitrotyrosine, and PAR was significantly reduced by H. perforatum extract. Additionally, we demonstrate that these inflammatory events were associated with the activation of nuclear factor-kappaB (NF-kappaB) and signal transducer and activator transcription-3 (STAT-31) activation in the lung. NF-kappaB and STAT-3 activation were significantly inhibited by H. perforatum extract treatment. Taken together, our results indicate that prevention of the activation of NF-kappaB and STAT-3 by H. perforatum extract reduces the development of acute inflammation.

Cell proliferation rate and telomerase activity in the differential diagnosis between benign and malignant mesothelial proliferations

AIMS

The differential diagnosis of malignant mesothelioma (MM) from benign mesothelial lesions (BML) based on histopathological criteria is sometimes not satisfying and causes diagnostic problems for histopathologists. We aimed to investigate whether the immunohistochemically determined cell proliferation rate and telomerase activity, using Ki-67 and human telomerase reverse transcriptase (hTERT) immunohistochemistry, respectively, are useful in the differential diagnosis of MM from BML.

METHODS

Sixty-six cases of MM (33 epithelioid, 30 biphasic and 3 sarcomatoid) and 22 cases of BML (15 reactive mesothelial proliferations and 7 fibrous pleuritis/pericarditis) were included in this study. We evaluated the proliferative activity by Ki-67 and telomerase activity by hTERT immunohistochemistries for each case.

RESULTS

The mean value of the Ki-67 proliferation index (PI) in MMs was significantly higher than that of BMLs. Biphasic MMs have higher a Ki-67 PI than epithelioid and sarcomatoid types. Ki-67 immunohistochemistry has a sensitivity of 74%, specificity of 86% and positive predictive value of 94% in detecting MM. hTERT immunohistochemistry detected MM with sensitivity and specificity of 68%.

CONCLUSION

As a result, being cheap and simple methods, Ki-67 and hTERT immunohistochemistries can be used in differentiating malignant and benign mesothelial lesions in routine formalin-fixed, paraffin-embedded material.

Allergic challenge-elicited lipid bodies compartmentalize in vivo leukotriene C4 synthesis within eosinophils

Eosinophils are an important source of leukotriene (LT)C(4), which can be synthesized within lipid bodies-cytoplasmic organelles where eicosanoid formation may take place. Allergy-driven lipid body formation and function have never been investigated. Here, we studied the in vivo induction and role of lipid bodies within eosinophils recruited to sites of allergic inflammation. Using two murine models of allergic inflammation (asthma and pleurisy), we verified that parallel to the eosinophil influx, allergic challenge also induced lipid body formation within recruited eosinophils. Neutralizing antibodies to eotaxin/CCL11, RANTES/CCL5, or CCR3 partially inhibited lipid body formation within recruited eosinophils in the allergic pleurisy model. Likewise, intrapleural administration of RANTES or eotaxin also induced significant influx of eosinophils loaded with lipid bodies. By immunolabeling, we detected the presence of a key enzyme involved in the leukotriene metabolism-5-lipoxygenase-within eosinophil lipid bodies formed in vivo after allergen challenge. Furthermore, specific immunolocalization of newly formed LTC(4) demonstrated that lipid bodies were the sites of formation of this eicosanoid within infiltrating eosinophils. Therefore, allergic inflammation triggers in vivo formation of new lipid bodies within infiltrating eosinophils, a phenomenon largely mediated by eotaxin/RANTES acting via CCR3 receptors. Such in vivo allergen-driven lipid bodies function as intracellular compartments of LTC(4) synthesis.

Differential activation of NF kappa B/RelA-p50 and NF kappa B/p50-p50 in control and alcohol-drinking rats subjected to carrageenin-induced pleurisy

BACKGROUND

Carrageenin (CAR) injection into the pleural cavity causes local inflammation called carrageenin-induced pleurisy (CAR-IP). Inflammation onset is characterized by an activation of pro-inflammatory NFkappaB, RelA-p50, while inflammation resolution is characterized by an activation of an anti-inflammatory NFkappaB, p50-p50, that re-establishes homeostasis, an essential process for an organism's survival. Although chronic alcohol intake disrupts inflammation, the mechanism behind the development of inflammatory disorder in alcoholics is not yet known. Therefore, the aim of this investigation was to study the effects of ethanol intake on CAR-IP and NFkappaB activation in pleural fluid neutrophils in P rats.

METHODS

Alcohol-preferring, P rats were given free choice of alcohol (15% ethanol) and water or water alone (for control) for 15 days. Then, each rat was injected with 0.2 ml of 2% CAR into the pleural cavity under light ether anesthesia. At different time intervals after the CAR injection, rats were anesthetized and their blood and pleural fluid samples were collected. Pleural fluid inflammatory cells were identified with Turk's or Wright-Giemsa staining. Different cell types were sorted using a fluorescence-activated cell sorter. Pleural fluid neutrophils were examined for apoptosis and activation of the two NFkappaB subspecies.

RESULTS

In control rats, fluid began to accumulate in the pleural cavity 0.5 h after, which peaked 24 h after, CAR injection. Then, the values declined gradually. The increase in pleural fluid correlated with RelA-p50 activation, while the decline in pleural fluid correlated with p50-p50 activation and apoptosis in neutrophils. In alcohol-drinking rats, pleural fluid remained elevated for up to 6 days after CAR injection. Neutrophils from alcohol-drinking rats exhibited suppressed apoptosis, augmented RelA-p50 activation, and suppressed p50-p50 activation.

CONCLUSIONS

Alcohol intake prolonged inflammation in P rats. An alcohol-induced upregulation of RelA-p50 activation and downregulation of p50-p50 activation may be causally related to the alcohol-induced inflammation dysregulation.

Evaluating the prophylactic potential of the phtalimide derivative LASSBio 552 on allergen-evoked inflammation in rats

A previous study showed that the novel tetrazolephtalimide derivative LASSBio 552 (2-4-[3-(1H-1,2,3,4-tetraazol-5-yl)propoxy]phenethyl-1,3-isoindolinedione) prevents LTD(4)-evoked tracheal contraction. This led us to examine the putative anti-inflammatory effect of LASSBio 552 in comparison with the leukotriene CysLT(1) receptor antagonist zafirlukast using a model of allergic pleurisy in rats. Treatment with either LASSBio 552 (24-96 micromol/kg, i.p.) or zafirlukast (9-72 micromol/kg, i.p.), 1 h before challenge, inhibited eosinophil and mononuclear cell influx into the pleural cavity 24 h post-challenge, but failed to alter the increased levels of eotaxin, plasma leakage, mast cell degranulation and neutrophil infiltration noted 6 h post-challenge. CD4(+) T cell recruitment 24 h post-challenge was also sensitive to LASSBio 552. This treatment failed to alter cysteinyl leukotriene production at 6 h, but clearly inhibited the phenomenon 24 h and 48 h post-challenge. In in vitro settings LASSBio 552 inhibited allergen-evoked cysteinyl leukotriene generation from isolated mast cells, while histamine release remained unchanged. It also slightly inhibited cysteinyl leukotriene production by eosinophils and mononuclear cells triggered by Ca(+2) ionophore A23187. A leukotriene CysLT(1) receptor transfected cell-based assay revealed that LASSBio 552 did not prevent LTD(4)-evoked Ca(+2) influx, indicating that it was not a leukotriene CysLT(1) receptor antagonist. These findings indicate that LASSBio 552 is able to inhibit eosinophil influx triggered by allergen chalenge in a mechanism at least partially associated with suppression of CD4(+) T cell influx and cysteinyl leukotriene production.

Pleural fluid and serum procalcitonin as diagnostic tools in tuberculous pleurisy

BACKGROUND

Diagnosis of tuberculous pleuritis is difficult because of its nonspecific clinical presentation and decreased efficiency of traditional diagnostic methods. We investigated the use of procalcitonin (PCT) concentration in tuberculous pleuritis diagnosis.

METHODS

A prospective clinical study was performed with two different patient groups. A total of 28 patients were included: 18 with tuberculosis and 10 with nontuberculous pleurisy. Serum and pleural fluid PCT concentrations were evaluated before treatment.

RESULTS

Serum and pleural fluid PCT concentrations were statistically different between tuberculous and nontuberculous pleurisy groups (P = 0.012 and P = 0.004, respectively), even though they were not elevated in relation to the cut-off level of 0.5 ng/mL. A positive and significant correlation was detected between serum and pleural fluid PCT levels (r = 0.49, P = 0.008). Diagnostic specificity and sensitivity values for serum and pleural fluid PCT in discriminating tuberculous from nontuberculous pleurisy were 80% and 72.2%, and 90% and 66.7% at the 0.081 and 0.113 ng/mL cut-off values, respectively.

CONCLUSION

Relative to the current cut-off level of 0.5 ng/mL, PCT concentration is not a useful parameter for the diagnosis of tuberculous pleurisy. Because there were PCT levels in patients with tuberculous pleurisy that were below the current cut-off level but were significantly different from those of the nontuberculous group, the use of PCT should be further investigated.

Inflammatory parameters after pleurodesis in recurrent malignant pleural effusions and their predictive value

Recurrent pleural malignant effusion is a common problem which can be treated by inducing symphysis of the pleural sheets. Many different drugs administered into the pleural space can be used to achieve this. The drugs cause an inflammatory response, which in turn is believed to cause the symphysis. Comparatively little has been published on the degree of pleural inflammation and the systemic response and whether this will affect the outcome. The aim of this study was to describe the systemic inflammatory reaction following instillation of a chemical agent into the pleura and to investigate whether this had any predictive value for the outcome (i.e. the pleurodesis). The markers investigated were simple ones: erythrocyte sedimentation rate, C-reactive protein, and leukocyte count from venous blood samples, and the fever reaction. Eighty-nine prospective patients with malignant pleural effusion who underwent pleurodesis with either talc (48 patients) or quinacrine (41 patients) were included in the study. Symphysis was achieved in 82 patients (92 per cent) and all had a prominent transitional elevation of the inflammatory parameters. The unsuccessful attempts caused negligible or very small elevations, but due to the small numbers only the degree of fever after 8 and 48 h showed a statistically significant difference. In conclusion, pleurodesis causes a systemic inflammation and there is a tendency to a correlation between the success of pleurodesis and the degree of inflammation. High fever and high inflammatory parameters including CRP are due to this inflammatory response and do not indicate infection.

Tempol reduces the activation of nuclear factor-kappaB in acute inflammation

Recent studies have demonstrated that Tempol, a membrane-permeable radical scavenger, exerts protective effects in various models of inflammation and shock. Since nuclear factor-kappaB (NF-kappaB) is a transcription factor, which plays a pivotal role in the induction of genes involved in physiological processes as well as in the response to inflammation, we have investigated the effect of Tempol on NF-kappaB activation in a model of acute inflammation in mice. Injection of carrageenan into the pleural cavity of mice induced an acute inflammatory response characterized by fluid accumulation in the pleural cavity, which contained a large number of neutrophils, as well as an increased production of tumor necrosis factor-alpha, (TNF-alpha) and interleukin-1alpha (IL-1alpha). Tempol (100mg/kg i.p 30min prior to carrageenan administration) significantly attenuated the degree of pleuritis caused by carageeenan (all parameters measured). Administration of carageeenan into the chest cavity (pleuritis) was associated with the activation of NF-kappaB in the lung. In particular, the appearance of IkappaB-alpha in homogenates of lung tissue was investigated by immunoblot analysis at 4h after carrageenan administration. IkappaB-alpha levels were substantially reduced in the lung tissue from carrageenan-treated mice in comparison with sham-treated mice. Furthermore, to detect any effects of Tempol on NF-kappaB/DNA binding, lung extracts were analyzed by EMSA. The DNA binding activity significantly increased in extracts obtained from lungs of vehicle-treated mice at 4h after carrageenan administration. Treatment of mice with Tempol caused a significant inhibition of carrageenan-induced IkappaB-alpha degradation and NF-kappaB/DNA binding activity. These data confirm that Tempol exerts potent anti-inflammatory properties and clearly demonstrates for the first time that Tempol reduces the activation of NF-kappaB in vivo.

[Distinguishing pleural transudates and exudates through the quantification of biochemical parameters]

OBJECTIVES

1) to evaluate the possibility of distinguishing pleural transudates and exudates through the joint determination of 26 biochemical parameters in pleural effusion and in plasma (including the determination of high molecular weight proteins, acute phase reactants, and proinflammatory citokines), and 2) to formulate a logistic regression equation for optimizing the classification efficiency, comparing the equation obtained with Light's criteria.

PATIENTS AND METHODS

All diagnostic thoracocentesis carried out in La Rioja Autonomous Community during a 22-month period were evaluated. The 245 clinical records were evaluated periodically along a minimum of 2 years, after the discharge of the patients. In pleural effusion and in plasma the following were quantified: total proteins, LDH, glucose, amylase, cholesterol, albumin, cholinesterase, phosphatase alkaline, urea, beta2-microglobulin, IgG, IgM, alpha2-macroglobulin, C reactive protein, transferrin, alpha1-antitrypsin, serum amyloid A protein, interleukin 1-beta, interleukin 6, tumoral necrosis factor-alpha, and lysozyme. In addition, the cellularity, polymorphonuclear elastase and adenosine deaminase were evaluated in pleural fluid.

RESULTS

The LDH pleural effusion/plasma ratio was the individual parameter that showed higher area under the receiver operating characteristic curve for the separation of pleural transudates and exudates. Interleukin 6 and tumoral necrosis factor-alpha showed pleural effusion/plasma ratios higher than the unit, which suggests an in situ citokines production. An predictive logistic regression equation was obtained that incorporates only LDH and cholesterol ratios, including the diuretic treatment of the patient at the time of thoracocentesis, which did not modify the protein concentrations in pleural effusion. Except for LDH ratio, the logistic regression equation showed an area under the receiver operating characteristic curve higher than that of all the evaluated individual parameters, with a sensitivity of 95% and a specificity of 85% (70% for the Light's criteria).

CONCLUSIONS

LDH ratio is the best individual parameter for distinguishing pleural transudates and exudates. The additional evaluation of cholesterol ratio and of the diuretic state of the patient make possible to improve the clinical efficiency of this classification. The quantification of high molecular weight proteins, acute phase reactants and citokines does not contribute additional significant information.

Effect of invertebrate serine proteinase inhibitors on carrageenan-induced pleural exudation and bradykinin release

The carrageenan model of pleurisy is described as temporal plasma exudation (1-5 h) with extensive neutrophil infiltration and release of proteinases into the pleural cavity. The aim of this work was to study the effects of serine proteinase inhibitors on the inflammatory process induced by administration of carrageenan to the rat pleural cavity and on release of kinins in pleural exudate. Pleurisy was induced by injecting carrageenan and serine proteinase inhibitors simultaneously into the pleural cavity. The proteinase inhibitors used were: aprotinin, a plasma kallikrein inhibitor; recombinant leech derived tryptase inhibitor-2PL (LDTI-2PL), a plasmin inhibitor; Boophilus microplus trypsin inhibitors (BmTIs); trypsin; plasma kallikrein; plasmin and neutrophil elastase inhibitors; and a synthetic neutrophil elastase inhibitor (EIsynt). Administration of carrageenan with LDTI-2PL and BmTIs induced a marked increase in exudation (143% and 201%) and leukocyte migration (288% and 408%), respectively, when compared to the control group. Pleural exudate from LDTI-2PL and BmTIs plus carrageenan-treated rats showed a significant increase in plasma kallikrein-like activity, measured by chromogenic substrate hydrolysis. The specific inhibition of enzymatic activity with aprotinin confirmed that 50% of S2302 hydrolysis was produced by plasma kallikrein-like enzymes. Kinin release was increased by 97% and 103% in exudates from LDTI-2PL and BmTIs plus carrageenan-treated rats, respectively. Considering that the plasmin inhibitors LDTI-2PL and BmTIs increased exudation, leukocyte migration and bradykinin release, our results suggest an anti-inflammatory role for plasmin in the pleurisy model.

Prevention of carrageenan-induced pleurisy in mice by anti-CD30 ligand monoclonal antibody

CD30 ligand (CD30L) and its receptor CD30 are members of the tumor necrosis factor (TNF) and TNF receptor superfamilies that play a major role in inflammation and immune regulation. To gain insight into the in vivo role of CD30L/CD30 in inflammatory diseases, we have used carrageenan (CAR)-induced pleurisy in mice, a preclinical model of airway inflammation where type 1 proinflammatory cytokines such as interleukin (IL)-1 and TNF-alpha play a key pathogenic role. The data show that prophylactic treatment with anti-CD30L mAb markedly reduces both laboratory and histological signs of CAR-induced pleurisy. These data suggest involvement of CD30-mediated signals in acute immunoinflammatory pathways induced by CAR.

Prostaglandin receptors EP2, EP3, and IP mediate exudate formation in carrageenin-induced mouse pleurisy

The roles of prostaglandins (PGs) as mediators of inflammation have been extensively studied, and production of PGI2 and PGE2 at inflammatory sites has been reported. However, it has not yet been clarified which type of PG receptors has a major role in inflammatory exudation. To examine in vivo role of PG receptors in inflammatory exudation, we induced pleurisy in PG receptors (IP, EP1, EP2, EP3, or EP4) knockout mice by intrapleural injection of carrageenin. Pleural exudate accumulation in wild-type (WT) mice at 1 to 5 h, but not at 24 h, was significantly attenuated by the pretreatment with indomethacin, indicating that PGs are responsible for exudate formation at the early phase of pleurisy. Pleural exudation at 1 to 5 h in IP, EP2, or EP3 knockout mice, but not in EP1 and EP4 knockout, was significantly reduced compared with in WT mice. In the exudates, 6-keto-PGF1alpha and PGE2 were detected as the major PGs, each with its peak concentration at 3 h. In addition, involvement of bradykinin in the phenomenon was suggested by the fact that captopril, a kininase inhibitor, enhanced the exudate formation and increased the amount of 6-keto-PGF1alpha and PGE2 and that a bradykinin B2-receptor antagonist inhibited the exudate formation. In contrast, leukocyte migration into pleural cavity was not influenced by indomethacin-treatment nor by these receptor deficiencies. These results demonstrate participation of EP2 and EP3 along with IP in pleural exudate formation but not in leukocyte migration in carrageenin-induced mouse pleurisy.

Mechanisms underlying the inhibitory effects of tachykinin receptor antagonists on eosinophil recruitment in an allergic pleurisy model in mice

The activation of tachykinin NK receptors by neuropeptides may induce the recruitment of eosinophils in vivo. The aim of the present study was to investigate the effects and underlying mechanism(s) of the action of tachykinin receptor antagonists on eosinophil recruitment in a model of allergic pleurisy in mice. Pretreatment of immunized mice with capsaicin partially prevented the recruitment of eosinophils after antigen challenge, suggesting the potential contribution of sensory nerves for the recruitment of eosinophils Local (10-50 nmol per pleural cavity) or systemic (100-300 nmol per animal) pretreatment with the tachykinin NK1 receptor antagonist SR140333 prevented the recruitment of eosinophils induced by antigen challenge of immunized mice. Neither tachykinin NK2 nor NK3 receptor antagonists suppressed eosinophil recruitment. Pretreatment with SR140333 failed to prevent the antigen-induced increase of interleukin-5 concentrations in the pleural cavity. Similarly, SR140333 failed to affect the bone marrow eosinophilia observed at 48 h after antigen challenge of immunized mice. SR140333 induced a significant increase in the concentrations of antigen-induced eotaxin at 6 h after challenge. Antigen challenge of immunized mice induced a significant increase of Leucotriene B4 (LTB4) concentrations at 6 h after challenge. Pretreatment with SR140333 prevented the antigen-induced increase of LTB4 concentrations. Our data suggest an important role for NK1 receptor activation with consequent LTB4 release and eosinophil recruitment in a model of allergic pleurisy in the mouse. Tachykinins appear to be released mainly from peripheral endings of capsaicin-sensitive sensory neurons and may act on mast cells to facilitate antigen-driven release of LTB4.

A nanometer lipid emulsion, lipid nano-sphere (LNS), as a parenteral drug carrier for passive drug targeting

We attempted to develop an artificial lipoprotein-like particle, lipid nano-sphere (LNS), incorporating dexamethasone palmitate (DMP). LNS is 25-50 nm in diameter and is composed of soybean oil and egg lecithin. Potential drug carriers were compared with a conventional fat emulsion for intravenous nutrition, lipid microsphere (LM, d=200-300 nm), which is already used clinically. LM easily entered reticuloendothelial systems, such as the liver, and was rapidly cleared from the circulation. However, LNS showed much higher plasma levels of DMP after intravenous administration to rats and recovered more than 80% of the injected dose in the perfusate in single-pass rat liver perfusion. The calculated volume for the distribution of the lipid emulsion within the liver showed that LNS underwent fenestration and was distributed into the Disse space in the liver. Because of the lower uptake of LNS particles by the liver, LNS showed good recovery from the liver and prolonged the plasma half-life of DMP after intravenous injection. In addition, higher efficiency in the targeting of DMP into inflammation sites and higher anti-inflammatory efficacy were observed in LNS. Thus, LNS easily and selectively passed through the leaky capillary wall by passive diffusion depending on the plasma concentration. Nanometer-sized lipid emulsion particles, LNS, seem to be a promising carrier system for passive drug targeting of lipophilic drugs.

[Effect of xiaochaihu decoction and different herbal formulations of its components on cytokines of carrageenan induced pleuritis in rats]

OBJECTIVE

To explore the anti-inflammatory effect and possible mechanism of Xiaochaihu Decoction (XCHD) and the different herbal formulations of its components.

METHODS

Rat model of pleuritis was established by thoracic injecting 0.2 ml of 1% carrageenan. Rats in the treated groups were medicated with XCHD (11 g/kg) and the different herbal formulations of its components respectively as follows: thorowax root-scutellaria root (A, 3.5 g/kg), fresh ginger-pinellia tuber (B, 3 g/kg), ginseng-licorice root-jujube (C, 4.5 g/kg), A + B (6.5 g/kg), A + C (8 g/kg) and B + C (7.5 g/kg), and those in the normal group and the model group were given equal volume of instilled water, by way of gastrogavage for successive 5 days. Modeling was performed 2 hrs after the last medication. The amount of pleurorrhea, and leucocyte (WBC), marrow peroxidase (MPO), tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in pleurorrhea, and serum level of interleukin-8 (IL-8) were measured 12 hrs after modeling.

RESULTS

As compared with the model group, all the parameters measured were lower in all the treated group (P < 0.05) , and IL-1beta content in pleurorrhea in the XCHD group and Group A, B and C were significantly lower (P < 0.01).

CONCLUSION

XCHD and the different herbal formulations have obvious anti-inflammatory effect, showing certain preventive and therapeutic effect on pleuritis. Among the different formulations, the XCHD, A, B and C had better effects. The effects might be related to inhibiting the increase of cytokines as TNF-alpha, IL-1beta, and IL-8 to suppress the activation, infiltration and wandering of leucocytes.

Transcription factor Nrf2 regulates inflammation by mediating the effect of 15-deoxy-Delta(12,14)-prostaglandin j(2)

Activated macrophages express high levels of Nrf2, a transcription factor that positively regulates the gene expression of antioxidant and detoxication enzymes. In this study, we examined how Nrf2 contributes to the anti-inflammatory process. As a model system of acute inflammation, we administered carrageenan to induce pleurisy and found that in Nrf2-deficient mice, tissue invasion by neutrophils persisted during inflammation and the recruitment of macrophages was delayed. Using an antibody against 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), it was observed that macrophages from pleural lavage accumulate 15d-PGJ(2). We show that in mouse peritoneal macrophages 15d-PGJ(2) can activate Nrf2 by forming adducts with Keap1, resulting in an Nrf2-dependent induction of heme oxygenase 1 and peroxiredoxin I (PrxI) gene expression. Administration of the cyclooxygenase 2 inhibitor NS-398 to mice with carrageenan-induced pleurisy caused persistence of neutrophil recruitment and, in macrophages, attenuated the 15d-PGJ(2) accumulation and PrxI expression. Administration of 15d-PGJ(2) into the pleural space of NS-398-treated wild-type mice largely counteracted both the decrease in PrxI and persistence of neutrophil recruitment. In contrast, these changes did not occur in the Nrf2-deficient mice. These results demonstrate that Nrf2 regulates the inflammation process downstream of 15d-PGJ(2) by orchestrating the recruitment of inflammatory cells and regulating the gene expression within those cells.

Comparison between C57Bl/6 and C57Bl/10 mycobacterial mouse pleurisy with respect to cellular migration and nitric oxide production

Mycobacterium bovis-BCG (BCG) and Mycobacterium leprae (ML) have opposite inflammatory properties. Mycobacteria-induced pleurisy in C57Bl/6 and C57Bl/10 mice was evaluated to establish if their innate responses could be comparable, verifying cellular migration and nitrite production. Kinetic responses after ML or BCG intrathoracic injection were compared in those mice, sharing the H-2(b) MHC haplotype. BCG led to acute eosinophilia and late neutrophilia in both mice. In C57Bl/6 late pleurisy, monocytes and neutrophil recruitment was dose- and iNOS-dependent, inhibited by methotrexate but not by indomethacin. Pleural macrophages released nitrites ex vivo after 7 days of BCG stimulus, without "priming" and blocked by the nitrite inhibitor L-N5-(1-iminoethyl)-ornithine (L-NIO). ML did not induce cellular migration or nitrite production, independent of the mouse strain, timing, or number of bacilli. Although these mycobacteria have high homology, there was no effect of ML on BCG-evoked secondary cellular recruitment. Both C57Black mice trigger similar onset of inflammatory responses to these mycobacteria, so far can alternatively be used in experimental studies.