Search

The aim of the present study was to assess the contribution of peroxynitrite formation in the pathophysiology of spinal cord injury (SCI) in mice. To this purpose, we used a peroxynitrite decomposition catalyst, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinato iron III chloride (FeTSPP). Spinal cord trauma was induced by the application of vascular clips (force of 24g) to the dura via a four-level T5-T8 laminectomy. SCI in mice resulted in severe trauma characterized by edema, neutrophil infiltration, production of inflammatory mediators, tissue damage, and apoptosis. FeTSPP treatment (10-100 mg/kg, i.p.) significantly reduced in dose-dependent manner 1 and 4 h after the SCI (1) the degree of spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (myeloperoxidase activity), (3) nitrotyrosine formation and poly-(ADP-ribose) polymerase activation, (4) proinflammmaory cytokines expression, (5) NF-kappaB activation, and (6) apoptosis (TUNEL staining, Bax and Bcl-2 expression). Moreover, FeTSPP significantly ameliorated the recovery of limb function (evaluated by motor recovery score) in a dose-dependent manner. Taken together, our results clearly demonstrate that FeTSPP treatment reduces the development of inflammation and tissue injury associated with spinal cord trauma similarly to dexamethasone, a well-known antiinflammatory agent which we have used as positive control.

Background Poly (ADP-ribose) polymerase (PARP), a nuclear enzyme activated by strand breaks in DNA, plays an important role in the tissue injury associated with ischaemia-reperfusion and inflammation. Recent studies have demonstrated that PARP activation plays a crucial role in the pathogenesis of acute periodontal injury. Aim We have investigated the effect of 5-aminoisoquinolin-1(2H)-one (5-AIQ), a water-soluble PARP inhibitor, in a rat model of periodontitis. Materials and methods Periodontitis was induced in rats by placing a 2/0 braided silk ligature around the lower left first molar. At day eight, the gingivomucosal tissue encircling the mandibular first molar was removed for biochemical and histological analysis. Results and conclusions Ligation significantly induced an increased neutrophil infiltration and a positive staining for PARP activation. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone destruction. Intraperitonial injection of 5-aminoisoquinolin-1(2H)-one (5-AIQ) (5 mg/kg daily for eight days) significantly decreased all of the parameters of inflammation as described above. This suggests that inhibition of PARP may represent a novel approach for the treatment of periodontal disease.

Etanercept is a tumour necrosis factor antagonist with anti-inflammatory effects. The aim of our study was to evaluate, for the first time, the therapeutic efficacy of in vivo inhibition of TNF-alpha in an experimental model of periodontitis.Periodontitis was induced in adult male Sprague-Dawley rats by placing a nylon thread ligature around the lower 1st molars. Etanercept was administered at a dose of 5 mg kg-1, s.c., after placement of the ligature.Periodontitis in rats resulted in an inflammatory process characterized by oedema, neutrophil infiltration and cytokine production that was followed by the recruitment of other inflammatory cells, production of a range of inflammatory mediators, tissue damage, apoptosis and disease. Treatment of the rats with etanercept (5 mg kg-1, s.c., after placement of the ligature) significantly reduced the degree of (1) periodontitis inflammation and tissue injury (histological score), (2) infiltration of neutrophils (MPO evaluation), (3) iNOS (the expression of nitrotyrosine and cytokines (eg TNF-alpha)) and (4) apoptosis (Bax and Bcl-2 expression).Taken together, our results clearly demonstrate that treatment with etanercept reduces the development of inflammation and tissue injury, events associated with periodontitis.

The aim of this study was to investigate the effects of N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketones (z-VAD-fmk) on the degree of experimental spinal cord trauma induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration, production of a range of inflammatory mediators, tissue damage, and apoptosis. Treatment of the mice with z-VAD-fmk, a potent broad specific caspase inhibitor, significantly reduced the degree of (1) spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (myeloperoxidase activity), (3) nitrotyrosine formation, and (4) apoptosis (TUNEL staining and Bax and Bcl-2 expression). In a separate set of experiments, z-VAD-fmk significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results clearly demonstrate that treatment with z-VAD-fmk reduces the development of inflammation and tissue injury associated with spinal cord trauma.

This study investigated the effects of TDZD-8, a potent and selective GSK-3beta inhibitor, on tissue injury caused by ischaemia/reperfusion (I/R) of the gut.Animal study in the Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, Italy.Splanchnic artery occlusion (SAO) shocked rats.I/R injury of the intestine was caused by clamping both the superior mesenteric artery and the coeliac trunk for 45 min followed by release of the clamp allowing reperfusion for 1 or 6 h. This procedure results in SAO shock.Only 10% of the SAO animals survived the entire 6 h reperfusion period. In a separate set of experiments after 60 min of reperfusion animals were killed for histological examination and biochemical studies. Administration of TDZD-8 (1 mg/kg i.v.) 5 min prior to the reperfusion significantly reduced the (a) fall in mean arterial blood pressure, (b) mortality rate, (c) infiltration of the reperfused intestine with polymorphonuclear neutrophils (MPO activity), (d) production of pro-inflammatory cytokines (TNF-alpha and IL-1 beta and (e) histological evidence of gut injury. Administration of TDZD-8 also markedly reduced the immunoreactivity of nitrotyrosine formation and the expression of ICAM-1 and P-selectin during reperfusion.Based on these findings we propose that TDZD-8 would be useful in the treatment of various ischaemia and reperfusion diseases.

TNF-alpha plays a pivotal role in the pathogenesis of acute pancreatitis. Recent studies have shown that TNF-alpha inhibition significantly ameliorates the course of experimental acute pancreatitis, but in this context, the effects of Etanercept, a novel anti-TNF-alpha agent, have not been investigated so far. The aims of the present study are (i) to assess the effects of pharmacological inhibition of TNF-alpha by means of Etanercept on the inflammatory response and apoptosis in a murine model of necrotizing acute pancreatitis and (ii) to compare the results to those observed in TNF-alpha receptor 1 knockout (TNFR1-KO) mice. Necrotizing acute pancreatitis was induced in TNF-alpha wild type for TNFR1 (WT) and TNFR1-KO mice by intraperitoneal injection of cerulein (hourly x5, 50 microg/kg). In another group of WT mice, Etanercept was administered (5 or 10 mg/kg, s.c.) at 1 h after first cerulein injection. Control groups received saline treatment. After 24 h, biochemical, histological, and immunohistochemical evidences of acute pancreatitis developed in all cerulein-treated mice; apoptosis was also present in the pancreas. Contrarily, pancreatitis histological features, amylase and lipase levels, pancreas water content, and myeloperoxidase activity were reduced in a similar degree in Etanercept-treated and TNFR1-KO mice. Likewise, in these two groups, immunohistochemical stainings and terminal deoxynucleotidyltransferase-mediated UTP nick-end labeling assay were found negative. TNF-alpha receptor 1 gene deletion and Etanercept administration ameliorate the course of experimental acute pancreatitis in a similar degree. Future studies on clinical applications of Etanercept in pancreatitis seem promising.

Protein tyrosine kinases help to regulate the expression of many genes, which play an important role in the pathophysiology of a number of diseases. Here we investigate the effects of the tyrosine kinase inhibitors, AG126 and AG556 on the degree of experimental spinal cord trauma induced by the application of vascular clips to the dura via a four-level T4-T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by oedema, neutrophil infiltration, production of a range of inflammatory mediators, tissue damage, and apoptosis. Treatment of the mice with AG126 and AG556 significantly reduced the degree of (1) spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (myeloperoxidase activity), (3) iNOS, nitrotyrosine, and PARP expression and (4) apoptosis (TUNEL staining and Bax and Bcl-2 expression). In a separate set of experiments, AG126 and AG556 significantly ameliorated the recovery of limb function (evaluated by motor recovery score). This study provides an experimental evidence that (1) prevention of the activation of protein tyrosine kinases reduces the development of inflammation and tissue injury associated with spinal cord trauma, and (2) inhibition of the activity of certain tyrosine kinases may represent a novel approach for the therapy of spinal cord trauma.

Hypericum perforatum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. Since polyphenolic compounds have high antioxidant potential, we have investigated the effects of H. perforatum extract on the development of multiple organ dysfunction syndrome caused by zymosan (500 mg/kg, administered i.p. as a suspension in saline) in mice. Organ failure and systemic inflammation in rats was assessed 18 h after administration of zymosan and/or H. perforatum extract and monitored for 12 days (for loss of body weight and mortality). Treatment of mice with H. perforatum extract (30 mg/kg i.p., 1 and 6h after zymosan) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan, pulmonary, intestinal and pancreatic injury, and renal dysfunction as well as the increase in myeloperoxidase in the lung and intestine. Immunohistochemical analysis for inducible nitric oxide synthase (iNOS), nitrotyrosine, and poly(ADP-ribose) (PAR) revealed positive staining in lung and intestine tissues obtained from zymosan-injected mice. The degree of staining for nitrotyrosine, iNOS, and PAR was markedly reduced in tissue sections obtained from zymosan-treated mice, which received H. perforatum extract. In conclusion, this study provides evidence, for the first time, that H. perforatum extract attenuates the degree of zymosan-induced multiple organ dysfunction syndrome in mice.

Glycogen synthase kinase-3 (GSK-3) is an ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and has recently been implicated in the pathophysiology of a number of diseases. The aim of this study is to investigate the effects of TDZD-8, a potent and selective GSK-3beta inhibitor, on the development of lung injury caused by administration of bleomycin (BLM). Mice subjected to intra-tracheal administration of BLM developed significant lung injury characterized by marked neutrophil infiltration and tissue edema. An increase in immunoreactivity to nitrotyrosine, iNOS, TNF-alpha and IL-1beta was also observed in the lungs of BLM-treated mice. In contrast, administration of BLM-treated mice with TDZD-8 (1 mg/kg daily) significantly reduced (I) the degree of lung injury, (II) the increase in staining (immunohistochemistry) for myeloperoxidase (MPO), nitrotyrosine, iNOS, TNF-alpha and IL-1beta and (III) the degree of apoptosis, as evaluated by Bax and Bcl-2 immunoreactivity and TUNEL staining. Taken together, these results clearly demonstrate treatment with the GSK-3beta inhibitor TDZD-8 reduces the development of lung injury and inflammation induced by BLM in mice.

The aim of our study was to evaluate the therapeutic efficacy of combination therapy with etanercept and dexamethasone (DEX) in vivo in experimental murine model of spinal cord trauma, which was induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5–T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and cytokine production followed by recruitment of other inflammatory cells, production of inflammation mediators, tissue damage, apoptosis and disease. Treatment of the mice with etanercept (1.25 mg/kg) and DEX (0.025 mg/kg) when administered as a combination therapy but not as a single treatment significantly reduced the degree of (1) spinal cord inflammation and tissue injury (histological score), (2) infiltration of neutrophils (MPO evaluation), (3) inducible nitric oxide synthase, nitrotyrosine, and cytokines expression (tumor necrosis factor-α and interleukin-1β), (4) and apoptosis (Terminal deoxynucleotidyltransferase-mediated UTP end labeling staining, Fas-ligand expression and Bax and Bcl-2 expression). In a separate set of experiments we have also clearly demonstrated that the combination therapy significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results clearly demonstrate for the first time that strategies targeting multiple proinflammatory pathways may be more effective than a single effector molecule for the treatment of spinal cord trauma.

Glycogen synthase kinase 3 has recently been identified as a ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and plays an important role in the pathophysiology of a number of diseases. In the present study, we have investigated the effects of 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), a glycogen synthase kinase 3beta inhibitor, on the development of nonseptic shock caused by zymosan (dose, 500 mg/kg i.p. suspension in saline) in mice. Organ failure and systemic inflammation in mice was assessed 18 h after administration of zymosan and/or TDZD-8; another group of mice was monitored for 12 days (for clinical score and mortality). Treatment of mice with TDZD-8 (dose, 10 mg/kg i.p., 1 and 6 h after zymosan administration) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan. TDZD-8 also attenuated the lung, liver, and pancreatic injury, the renal dysfunction caused by zymosan, and the increase in myeloperoxidase activity caused by zymosan in the lung and in the intestine. Immunohistochemical analysis for inducible nitric oxide synthase, nitrotyrosine, poly(ADP-ribose), CD30, CD30 ligand, and Fas ligand revealed positive staining in lung and intestinal tissues obtained from zymosan-injected mice. The degree of staining for inducible nitric oxide synthase, nitrotyrosine, poly(ADP-ribose), CD30, CD30 ligand, and Fas ligand were markedly reduced in tissue sections obtained from zymosan-injected mice that had received TDZD-8. This study provides the first evidence that TDZD-8 attenuates the degree of zymosan-induced, nonseptic shock in mice.

We have recently identified a gene named GITR (glucocorticoid-induced TNF receptor related gene). GITR is expressed in different cells and tissues such as T lymphocytes from thymus and spleen and lymph nodes, and also in the lung. GITR ligand (GITRL) is expressed in several cells including macrophages, B cells, dendritic cells, and endothelial cells. In the present study, by comparing the responses in wild-type (WT) mice (GITR+/+) and GITR-deficient mice (GITR-/-), we investigated the role played by GITR-GITRL interaction in the development of chronic lung injury caused by bleomycin instillation. When compared with bleomycin-treated GITR+/+ mice, bleomycin-treated GITR-/- mice exhibited a reduced degree of i) lung infiltration with polymorphonuclear neutrophils (MPO activity); ii) edema formation; iii) histological evidence of lung injury; iv) TNF-alpha and interleukin (IL)-1beta production; v) nitrotyrosine formation; and vi) NF-kappaB activation. The cotreatment of GITR+/+ mice with Fc-GITR fusion protein (6.25 microg/mouse) also significantly attenuated all of the above indicators of lung damage and inflammation. Our results clearly demonstrate that GITR-GITRL interaction plays an important role in the chronic lung injury induced by bleomycin in the mice.

Glycogen synthase kinase-3 (GSK-3) is a ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and has recently been implicated in the pathophysiology of a number of diseases. The aim of this study was to investigate the effects of GSK-3beta inhibition in a model of acute inflammation. Here, we have investigated the effects of TDZD-8, a potent and selective GSK-3beta inhibitor, in a mouse model of carrageenan-induced pleurisy.Injection of carrageenan into the pleural cavity of mice elicited an acute inflammatory response characterized by: accumulation of fluid containing a large number of neutrophils (PMNs) in the pleural cavity, infiltration of PMNs in lung tissues and subsequent lipid peroxidation, and increased production of nitrite/nitrate (NOx), prostaglandin E2 (PGE2), tumour necrosis factor-alpha, (TNF-alpha) and interleukin-1beta (IL-1beta). Furthermore, carrageenan induced an upregulation of the adhesion molecules ICAM-1 and P-selectin, iNOS, COX-2 as well as nitrotyrosine as determined by immunohistochemical analysis of lung tissues.Administration of TDZD-8 (1, 3 or 10 mg kg(-1), i.p.), 30 min prior to injection of carrageenan, caused a dose-dependent reduction in all the parameters of inflammation measured.Thus, based on these findings we propose that inhibitors of the activity of GSK-3beta, such as TDZD-8, may be useful in the treatment of various inflammatory diseases.

Glucocorticoid-induced TNFR-related gene (GITR) participates in the immune/inflammatory response. Because GITR expression has been described in cells other than T lymphocytes, we investigated whether it also modulates acute inflammatory response. Using GITR-deficient (GITR−/−) mice, we analyzed the role of GITR in the development of carrageenan-induced lung inflammation (pleurisy) by studying several proinflammatory markers 2–8 h after carrageenan injection. When compared with GITR+/+, GITR−/− mice exhibited decreased production of turbid exudate containing a lower number of leukocytes. This was correlated with the reduction of inflammatory markers (including TNF-α, IL-1β, myeloperoxidase, inducible NO synthase, and cyclooxygenase 2) in the pleural exudate and/or in the lung. Moreover, endothelial cells expressed lower levels of adhesion molecules. In lungs of GITR+/+ mice, GITR ligand expression was not modulated during pleurisy, while that of GITR increased, as a consequence of increased infiltration by GITR-expressing cells and of GITR up-regulation in macrophages and endothelial cells. Finally, cotreatment of GITR+/+ mice with carrageenan and Fc-GITR fusion protein decreased the number of inflammatory cells (pleural macrophages and lung neutrophils) as compared with carrageenan treatment alone, confirming that GITR plays a role in the modulation of pleurisy.

Glycogen synthase kinase-3 (GSK-3) has recently been identified as an ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and plays an important role in the pathophysiology of a number of diseases. The aim of this study was to investigate the effects of GSK-3beta inhibition on the degree of experimental spinal cord trauma induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord injury (SCI) in mice resulted in severe trauma characterized by edema, neutrophil infiltration, production of a range of inflammatory mediators, tissue damage, and apoptosis. Treatment of the mice with 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), a potent and selective GSK-3beta inhibitor, significantly reduced the degree of 1) spinal cord inflammation and tissue injury (histological score); 2) neutrophil infiltration (myeloperoxidase activity); 3) inducible nitric-oxide synthase, nitrotyrosine, and cyclooxygenase-2 expression; and 4) and apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling staining and Bax and Bcl-2 expression). In a separate set of experiments, TDZD-8 significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results clearly demonstrate that treatment with TDZD-8 reduces the development of inflammation and tissue injury associated with spinal cord trauma.

Etanercept is a tumor necrosis factor antagonist with anti-inflammatory effects. The aim of our study was to evaluate for the first time the therapeutic efficacy of in vivo inhibition of tumor necrosis factor-alpha (TNF-alpha) in experimental model of spinal cord trauma, which was induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and cytokine production that it is followed by recruitment of other inflammatory cells, such as production of a range of inflammation mediators, tissue damage, apoptosis, and disease. Treatment of the mice with etanercept significantly reduced the degree of 1) spinal cord inflammation and tissue injury (histological score); 2) neutrophil infiltration (myeloperoxidase evaluation); 3) inducible nitric-oxide synthase, nitrotyrosine, cyclooxygenase-2, and cytokines expression (TNF-alpha and interleukin-1beta); and 4) apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling staining and Bax and Bcl-2 expression). In a separate set of experiment, we have also clearly demonstrated that TNF-alpha inhibitor significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results clearly demonstrate that treatment with etanercept reduces the development of inflammation and tissue injury events associated with spinal cord trauma.

Oxidative stress results from an oxidant/antioxidant imbalance, an excess of oxidants, and/or a depletion of antioxidants. A considerable body of recent evidence suggests that oxidative stress and exaggerated production of reactive oxygen species play a major role in several aspects of inflammation. Hypericum perforatum is a medicinal plant species containing many polyphenolic compounds, namely, flavonoids and phenolic acids. Because polyphenolic compounds have high antioxidant potential, in this study, we evaluated the effect of H. perforatum (given at 30 mg . kg (-1)) in an experimental animal model of spinal cord injury, which was induced by the application of vascular clips to the dura via a four-level T5 through T8 laminectomy. The degree of (a) spinal cord inflammation and tissue injury (histological score), (b) nitrotyrosine, (c) poly(adenosine diphosphate-ribose), (d) neutrophils infiltration, and (e) the activation of signal transducer and activator transcription 3 was markedly reduced in spinal cord tissue obtained from H. perforatum extract-treated mice. We have also demonstrated that H. perforatum extract significantly ameliorated the recovery of limb function.

The aim of the present study was to examine the role of poly-(ADP-ribose) glycohydrolase (PARG) on the modulation of the inflammatory response and tissue injury associated with neurotrauma. Spinal cord trauma was induced in wild-type (WT) mice by the application of vascular clips (force of 24 g) to the dura via a two-level T(6) to T(7) laminectomy. Spinal cord injury in WT mice resulted in severe trauma characterized by edema, neutrophil infiltration, and cytokine production followed by recruitment of other inflammatory cells, production of a range of inflammation mediators, tissue damage, apoptosis, and disease. The genetic disruption of the PARG gene in mice or the pharmacological inhibition of PARG with GPI 16552 [N-bis-(3-phenyl-propyl)9-oxo-fluorene-2,7-diamide] (40 mg/kg i.p. bolus), a novel and potent PARG inhibitor, significantly reduced the degree of spinal cord inflammation and tissue injury (histological score), neutrophil infiltration, cytokine production (tumor necrosis factor-alpha and interleukin-1beta), and apoptosis. In a separate experiment, we have clearly demonstrated that PARG inhibition significantly ameliorated the recovery of limb function. Taken together, our results indicate that PARG activity modulates the inflammatory response and tissue injury events associated with spinal cord trauma and participate in target organ damage under these conditions.

A considerable body of recent evidence suggests that oxidative stress and exaggerated production of reactive oxygen species play a major role in several aspects of inflammation and shock. Hypericum perforatum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. Because polyphenolic compounds have high antioxidant potential, in this study we evaluated the effect of Hypericum perforatum extract on acute pancreatitis induced by cerulein administration in male CD mice. Intraperitoneal injection of cerulein in mice resulted in a severe, acute pancreatitis, which was characterized by edema, neutrophil infiltration, tissue hemorrhage, and cell necrosis as well as increases in the serum levels of amylase and/or lipase in comparison to sham-treated mice. The infiltration of the pancreatic tissue of these animals with neutrophils (measured as increase in myeloperoxidase activity) was associated with expression of the adhesion molecule ICAM-1. Immunohistochemical examination demonstrated a marked increase in the staining (immunoreactivity) for nitrotyrosine and poly(ADP-ribose) (PAR) in the pancreas of cerulein-treated mice in comparison to sham-treated mice. In contrast, the degree of (a) pancreatic inflammation and tissue injury (histological score), (b) expression of ICAM-1, (c) the staining for nitrotyrosine and PAR, and (d) myeloperoxidase activity was markedly reduced in pancreatic tissue sections obtained from cerulein-treated mice administered Hypericum perforatum extract (30 mg/kg, suspended in 0.2 mL of saline solution, o.s.). Moreover, the treatment with Hypericum perforatum extract significantly reduced the mortality rate at 5 days after cerulein administration. Taken together, our results indicate that Hypericum perforatum extract reduces the development of acute pancreatitis.

The aim of the present study was to assess the relative contributions of peroxynitrite formation following induction of nitric-oxide synthase (iNOS) in the pathophysiology of endotoxin-induced shock in the rat. To this end, we used a selective inhibitor of iNOS, N-(3-(aminomethyl)benzyl)acetamidine (1400W), and a peroxynitrite decomposition catalyst, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinato iron III chloride (FeTTPs). Intravenous (i.v.) administration of Escherichia coli lipopolysaccharide (LPS; 4 mg/kg) elicited a time-dependent fall in mean arterial pressure as well as liver, renal, and pancreatic tissue damage. 1400W (3-10 mg/kg i.v.) administered 30 min before LPS delayed the development of hypotension but did not improve survival. On the other hand, FeTTPs administered (10-100 mg/kg i.v.) inhibited in a dose-dependent manner LPS-induced hypotension, tissue injury, and improved mortality rate. In separate experiments, rats were treated with LPS (4 mg/kg) or saline for control, and their aortas were isolated and placed in organ baths 2 h later. Tissues from LPS-treated rats had significant inhibition of contractile activity to phenylephrine as well as a significantly impaired relaxation response to acetylcholine. FeTPPs, when administered (100 mg/kg i.v.) 1 h before LPS, prevented the LPS-induced aortic contractile and endothelial dysfunction. These results demonstrate that nitric oxide-derived peroxynitrite formation plays an important role in this model of endotoxemia. Our results also suggest that use of an iNOS inhibitor in this setting has little beneficial effect in part because, in the presence of a failing eNOS system, some NO is needed to maintain adequate organ function.

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 injury and inflammation. Dithiocarbamates are antioxidants which are potent inhibitors of NF-kappaB. We postulated that pyrrolidine dithiocarbamate (PDTC) would attenuate inflammation. In the present study, we have investigated the effects of PDTC, in a rat model of periodontitis. Periodontitis was induced in rats by placing around the lower left first molar a 2/0 braided silk. At day eight the gingivomucosal tissue encircling the mandibular first molar was removed for biochemical and histological analysis. At day eight ligations significantly induced an increase neutrophil infiltration as well as the gingivomucosal tissue expression of TNF-alpha and iNOS as well as nitrotyrosine formation and poly (ADP-ribose) polymerase activation. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone destruction. Intraperitonial injection of PDTC (10 mg/kg daily for eight days) significantly reduced all of the parameters of inflammation as described above. These data demonstrate that PDTC exerts an anti-inflammatory role during experimental periodontitis and is able to ameliorate the tissue damage associated with ligature-induced periodontitis.

Melatonin is the principal secretory product of the pineal gland and its role as an immuno-modulator is well established. Recent evidence shows that melatonin is a scavenger of oxyradicals and peroxynitrite and exerts protective effects in septic shock, hemorrhagic shock and inflammation. The aim of this study was to investigate the effect of melatonin on the lung injury caused by bleomycin (BLM) administration. Mice subjected to intratracheal administration of BLM developed significant lung injury characterized by a marked neutrophil infiltration [assessed by myeloperoxidase (MPO) activity] and by tissue edema. In addition, an increase of immunoreactivity to nitrotyrosine, poly-ADP-ribose (PAR) was also observed in the lung of BLM-treated mice. Also, lung injury induced by BLM administration was correlated with a significant loss of body weight and with a significant mortality. Administration of melatonin (10 mg/kg i.p.) daily significantly reduced the (i) loss of body weight, (ii) mortality rate, (iii) infiltration of the lung with polymorphonuclear neutrophils (MPO activity), (iv) edema formation and (v) histological evidence of lung injury. Administration of melatonin also markedly reduced the nitrotyrosine and PAR formation. Taken together, our results demonstrate that treatment with melatonin significantly reduces lung injury induced by BLM in the 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.

Various studies have clearly demonstrated that green tea catechins possess potent antioxidative properties, and the preventive effects against various oxidative diseases have been reported. The aim of this study was to investigate the effect of green tea extract on the tissue injury caused by ischemia/reperfusion (I/R) of the gut. I/R injury of the intestine was caused by clamping both the superior mesenteric artery and the celiac trunk for 45 min followed by release of the clamp allowing reperfusion for 1 h or 4 h. This procedure results in splanchnic artery occlusion (SAO) shock. Rats subjected to SAO developed a significant fall in mean arterial blood pressure, and only 10% of the animals survived for the entire 4-h reperfusion period. Surviving animals were sacrificed for histological examination and biochemical studies. Rats subjected to SAO displayed a significant increase in tissue myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels, significant increases in plasma tumor necrosis factor (TNF)-alpha levels and marked injury to the distal ileum. Increased immunoreactivity to nitrotyrosine was observed in the ileum of rats subjected to SAO. Staining of sections of the ileum obtained from SAO rats with anti-intercellular adhesion molecule (ICAM-1) antibody and with anti-P-selectin antibody resulted in diffuse staining. Administration of green tea extract (20 and 10 mg kg(-1) i.v.) 15 min prior to the onset of gut reperfusion significantly reduced in a dose-dependent manner the fall in mean arterial blood pressure, the mortality rate, infiltration of the reperfused intestine with polymorphonuclear neutrophils (MPO activity), lipid peroxidation (MDA levels), production of TNF-alpha, and histological evidence of gut injury. Administration of green tea extract also markedly reduced nitrotyrosine formation and the up-regulation of ICAM-1 and P-selectin during reperfusion. In order to clarify that green tea extract might be useful in the therapy of I/R injury, we also investigated the effect of green tea extract (20 mg kg(-1) i.v.) when administered 5 min after the onset of gut reperfusion. Similar to the pretreatment approach, the post-treatment also significantly reduced the gut injury induced by I/R. These results demonstrate that green tea extract significantly reduces I/R injury of the intestine.

Objective Erythropoietin (EPO) is a potent stimulator of erythroid progenitor cells, and its expression is enhanced by hypoxia. The aim of this study was to investigate the effect of EPO on collagen-induced arthritis (CIA) in the mouse. Methods CIA was induced by intradermal injection of bovine type II collagen (CII) and Freund's complete adjuvant. Starting on day 25, some of the mice with CIA received daily subcutaneous injections of EPO (1,000 units/kg). Two other groups of mice received sham treatment alone or sham treatment followed by EPO treatment, respectively. Arthritis was assessed clinically, radiologically, and histologically. Cytokine and chemokine levels were measured, and neutrophil infiltration into inflamed joints was quantitated. Immunohistochemistry studies were performed to measure protein nitrosylation. Chondrocyte apoptosis was assessed by TUNEL assay. Results Macroscopic clinical evidence of CIA first appeared as periarticular erythema and edema in the hind paws. The incidence of CIA was 100% by day 27 in the CII-challenged mice, and the severity of CIA progressed over a 35-day period, with radiographic evaluation revealing focal resorption of bone. Histopathologic features of CIA included erosion of the cartilage at the joint margins. Treatment with EPO starting at the onset of arthritis (day 25) ameliorated the clinical signs on days 26–35 and improved histologic status in the joints and paws. The degree of oxidative and nitrosative damage was significantly reduced in EPO-treated mice as indicated by decreased nitrotyrosine formation and poly(ADP-ribose) polymerase activation. Plasma levels of the proinflammatory cytokine tumor necrosis factor α were also significantly reduced by EPO treatment. In addition, EPO reduced the levels of apoptosis in chondrocytes in articular cartilage, as indicated by decreased TUNEL staining. Conclusion These findings demonstrate that EPO exerts an antiinflammatory effect during chronic inflammation and is able to ameliorate the tissue damage associated with CIA.

The peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors related to retinoid, steroid, and thyroid hormone receptors. The aim of the present study was to examine the effects of endogenous PPAR-alpha ligand in an experimental model of spinal cord trauma. Spinal cord injury was induced in PPAR-alpha wild-type (WT) mice and PPAR-alpha knock out mice (PPAR-alpha KO) mice by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration (measured as an increase in myeloperoxidase activity) and apoptosis (measured by Annexin 5 staining). An increase of immunoreactivity to TNF-alpha was observed in the spinal cord of spinal cord-injured PPAR-alpha WT mice. Absence of a functional PPAR-alpha gene in PPAR-alphaKO mice resulted in a significant augmentation of all the above described parameters. In a separate set of experiments, we have also demonstrated that the absence of PPAR-alpha gene in PPAR-alphaKO mice significantly worsened the recovery of limb function (evaluated by motor recovery score). Thus, endogenous PPAR-alpha ligands reduce the degree of development of inflammation and tissue injury events associated with spinal cord trauma in the mice.

Objective Multiple-organ failure (MOF) is defined as the progressive deterioration in function which occurs in several organs or systems in patients with septic shock, multiple trauma, severe burns, or pancreatitis. This study investigated the effect of 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2), a PPAR-γ ligand, in a model of zymosan-induced nonseptic shock in mice.