Effects of sesame oil on oxidative stress and hepatic injury after cecal ligation and puncture in rats

Oxidative stress is known to be involved in the development of organ failure and death in sepsis. Sesame oil attenuates oxidative stress induced by endotoxin; however, whether sesame oil is still effective in rats with sepsis has never been investigated. The aim of the present study was to determine the effect of sesame oil on oxidative stress-associated hepatic injury in cecal ligation and puncture-induced rats with sepsis. We examined the effect of sesame oil (4 mL/kg daily for 1 week) on lipid peroxidation, hydroxyl radical, superoxide anion, and nitrite levels in rats with sepsis. In addition, hepatic injury was also assessed by blood biochemistry. Sesame oil significantly decreased lipid peroxidation and serum nitrite levels, but affected neither superoxide anion nor hydroxyl radical in cecal ligation and puncture-treated rats. Furthermore, sesame oil significantly attenuated cecal ligation and puncture-induced hepatic injury in rats. Nevertheless, oxidative stress and hepatic injury were not affected by corn oil or mineral oil in rats with sepsis. Thus, attenuation of oxidative stress and hepatic injury may be associated with inhibition of nitric oxide in sesame oil-associated protection in rats with sepsis.     

Sesame oil protects against lipopolysaccharide-stimulated oxidative stress in rats

OBJECTIVE: The aim of this study was to determine the effects and the defense mechanisms of sesame oil on lipopolysaccharide-induced oxidative stress in rats. DESIGN: Laboratory in vivo study of the effect of sesame oil on lipid peroxide, superoxide anion, superoxide dismutase, catalase, glutathione, and nitrite concentrations. To assess the effect of sesame oil on hepatic function, we determined serum aspartate aminotransferase, total bilirubin, and liver histology. SETTING: University laboratory. SUBJECTS: Male SPF Wistar rats. INTERVENTIONS: Blood testing, administration of oils, and liver biopsies. MEASUREMENTS AND MAIN RESULTS: Oxidative stress induced by lipopolysaccharide (5 mg/kg, intraperitoneally) was assessed by determination of lipid peroxidation. Sesame oil was given orally immediately after lipopolysaccharide administration, and lipid peroxidation concentrations were determined. The reactive oxygen species superoxide anion was measured by chemiluminescence analyzer. The enzyme activities of superoxide dismutase and catalase and the concentrations of glutathione and nitrite also were determined. Hepatic injury was evaluated by determining the concentrations of serum aspartate aminotransferase and total bilirubin and by liver histologic examination. Sesame oil significantly reduced lipid peroxidation but failed to affect nitrite concentrations in lipopolysaccharide-treated rats. Superoxide anion counts were decreased, and glutathione, but not superoxide dismutase or catalase, was increased in sesame oil-treated groups with lipopolysaccharide-induced oxidative stress. Only sesame oil-treated groups, but not corn oil- or mineral oil-treated groups, showed attenuated hepatic disorder induced by lipopolysaccharide. In addition, sesame oil given 6 hrs after lipopolysaccharide also attenuated lipid peroxidation and hepatic disorder. Furthermore, sesame oil given immediately or 6 hrs after lipopolysaccharide administration significantly reduced morphologic changes induced by lipopolysaccharide. CONCLUSION: A single dose of sesame oil may attenuate oxidative stress and subsequently relieve hepatic disorder in endotoxemic rats.     

Sesamol delays mortality and attenuates hepatic injury after cecal ligation and puncture in rats: role of oxidative stress

Sesame oil potently protects rats against sepsis, and sesamol appears to be the protective ingredient in sesame oil. The aims of the present study were to examine the effects of sesamol on mortality and reactive oxygen species-associated liver injury in Wistar rats with cecal-ligation-and-puncture-induced sepsis (septic rats). After sepsis was induced, sesamol was administered every 6 h. The survival rate was determined during the ensuing 48 h. Hepatic injury was assessed using blood biochemistry and histological examination. Hepatic oxidative stress was assessed by determining the levels of liver lipid peroxidation, hydroxyl radical, and superoxide anion generation, and nitric oxide production 12 h after cecal ligation and puncture. Inducible nitric oxide synthase expression was also determined. Sesamol delayed mortality and attenuated hepatic injury in septic rats. Hepatic lipid peroxidation, hydroxyl radical, and superoxide anion levels were significantly lower in sesamol-treated septic rats. Furthermore, sesamol inhibited the production of nitrite and the expression of inducible nitric oxide synthase in the liver in septic rats. Therefore, sesamol may delay mortality and attenuate oxidative stress-associated liver injury by inhibiting the production of nitric oxide, at least partially, in septic rats.     

Effect of sesame oil on oxidative-stress-associated renal injury in endotoxemic rats: involvement of nitric oxide and proinflammatory cytokines

This study aimed to investigate the effect of sesame oil on oxidative stress-associated renal injury induced by lipopolysaccharide in rats. The effects of sesame oil on renal injury, oxidative stress, hydroxyl radical, superoxide anion, nitric oxide, and proinflammatory cytokines were assessed after a lipopolysaccharide challenge. Sesame oil attenuated lipopolysaccharide-induced renal injury, decreased lipid peroxidation, increased the activities of superoxide dismutase, catalase, and glutathione peroxidase, reduced hydroxyl radical generation and nitric oxide production, and had no effect on superoxide anion generation in lipopolysaccharide-challenged rats. In addition, sesame oil significantly decreased tumor necrosis factor-alpha and interleukin 1beta production 1 and 6 h, respectively, after lipopolysaccharide administration in mice. Thus, sesame oil attenuates oxidative stress-associated renal injury via reduction of the production of nitric oxide and the generation of proinflammatory cytokines in endotoxemic rats.     

Oxidative parameters and mortality in sepsis induced by cecal ligation and perforation

OBJECTIVE: This study assessed parameters of free radical damage to biomolecules, mitochondrial superoxide production, superoxide dismutase, and catalase activities and their relationship to sepsis mortality. DESIGN AND SETTING: Prospective animal study in a university laboratory for experimental. SUBJECTS: 140 male Wistar rats. INTERVENTIONS: The animals were randomly divided into three groups: sham-operated (n=20), cecal ligation and perforation resuscitated with normal saline (n=40), and cecal ligation and perforation with normal saline plus antibiotics (n=40). MEASUREMENTS AND RESULTS: Blood samples were collected from all animals 3, 12, and 24 h after CLP through a jugular catheter inserted before CLP. Rats were evaluated during 5 days after the intervention. Nonsurvivor animals were grouped according to the duration between sepsis induction and death, and oxidative parameters were compared to survivors and sham-operated. Lipid peroxidation, protein carbonyls, and superoxide dismutase were significantly increased in nonsurvivor septic rats and were predictive of mortality. We demonstrated that there is a different modulation of superoxide dismutase and catalase in nonsurvivors during the course of septic response. There was a marked increase in superoxide dismutase activity without a proportional increase in catalase activity in nonsurvivors. CONCLUSIONS: This is the first report of plasma superoxide dismutase as an earlier marker of mortality. Ours results might help to clarify an important aspect of oxidative response to sepsis, i.e., an increase in superoxide dismutase activity without a proportional increase in catalase activity     

Attenuation of endotoxin-induced oxidative stress and multiple organ injury by 3,4-Methylenedioxyphenol in rats

Endotoxin is a potent inducer of lipid peroxidation (LPO), which is associated with the development of endotoxemia. 3,4-Methylenedioxyphenol (sesamol) is one of the sesame oil lignans with a high anti-LPO effect. Whether sesamol can attenuate endotoxin-induced LPO and multiple organ injury is unknown. After a dose response for sesamol in endotoxin-challenged rats was established, experiments were conducted to assess its effects on hydroxyl radical, peroxynitrite, and superoxide anion counts, activities of superoxide dismutase, catalase, and glutathione peroxidase, as well as the production of nitric oxide (NO) and the expression of inducible NO synthase. In addition, the effects of sesamol on endotoxin-induced hepatic and renal injuries were assessed. Sesamol (a) dose dependently reduced serum LPO inendotoxin-challenged rats, (b) decreased hydroxyl radical and peroxynitrite, but not superoxide anion counts, (c)increased the activities of superoxide dismutase, catalase, and glutathione peroxidase in endotoxin-treated rats, (d)reduced NO production and inducible NO synthase expression, and (e) attenuated hepatic and renal injuries induced by endotoxin in rats. We concluded that sesamol might protect against organ injury by decreasing NO-associated LPO in endotoxemic rats.     

Oxidative variables in the rat brain after sepsis induced by cecal ligation and perforation

OBJECTIVE: The underlying mechanisms of the changes in mental status, septic encephalopathy, and long-term cognitive symptoms in sepsis survivors have only been defined in part. The present study was undertaken to assess different variables of oxidative stress in several brain structures after cecal ligation and perforation in the rat. DESIGN: Prospective animal study. SETTING: Animal basic science laboratory. SUBJECTS: Male Wistar rats, weighing 250-350 g. INTERVENTIONS: Rats were subjected to cecal ligation and perforation (sepsis group) with saline resuscitation (at 50 mL/kg immediately and 12 hrs after cecal ligation and perforation) or sham operation (control group). MEASUREMENTS AND MAIN RESULTS: Oxidative damage, assessed by the thiobarbituric acid reactive species and the protein carbonyl assays, occurred early (after 6 hrs) in the course of sepsis development in the hippocampus, cerebellum, and cortex. At longer times after sepsis induction (12-96 hrs), there was no evidence of oxidative damage in all analyzed structures. Except for the striatum, earlier in sepsis development (6 hrs) we demonstrated an increase in superoxide dismutase activity without a proportional increase in catalase activity with a consequent increase in the relation of superoxide dismutase/catalase. The balance between these enzymes was restored in the studied structures 12-96 hrs after sepsis induction. CONCLUSIONS: The short-term oxidative damage demonstrated here could participate in the development of central nervous system symptoms during sepsis development, or even septic encephalopathy. The alterations in the superoxide dismutase/catalase relation were temporally related to the occurrence or not of oxidative damage in the central nervous system.     

Sesame oil prevents acute kidney injury induced by the synergistic action of aminoglycoside and iodinated contrast in rats

The aim of the study was to investigate the effect of sesame oil on acute kidney injury induced by the synergistic action of aminoglycoside and iodinated contrast in rats. Acute kidney injury was induced by a 5-day course of daily gentamicin injections (100 mg/kg of body weight, subcutaneously) and then iodinated contrast (4 ml/kg, intravenously) in male specific-pathogen-free Sprague-Dawley rats. Sesame oil (0.5 ml/kg, orally) was given 1 h before iodinated contrast. Renal function and oxidative stress were assessed 6 h after iodinated contrast injection. Renal function was evaluated by measuring serum blood urea nitrogen and creatinine levels. Renal oxidative stress was assessed by determining renal lipid peroxidation, myeloperoxidase, hydroxyl radical, superoxide anion, nitrite/nitrate, and inducible nitric oxide synthase levels. Sesame oil significantly prevented the rise of serum blood urea nitrogen and creatinine levels. Furthermore, there was a parallel inhibition of the rise in levels of expression of renal lipid peroxidation, myeloperoxidase, hydroxyl radicals, superoxide anion, nitrite/nitrate, and inducible nitric oxide synthase in rats with gentamicin-plus-iodinated contrast-induced acute kidney injury. We conclude that sesame oil may attenuate aminoglycoside-plus-iodinated contrast-induced acute kidney injury by inhibiting renal oxidative stress in rats.     

Bicuculline methiodide attenuates hepatic injury and decreases mortality in septic rats: role of cytokines

Bicuculline methiodide attenuates inflammation by inhibiting the production of proinflammatory cytokines, such as tumor necrosis factor-alpha, and by increasing the production of the anti-inflammatory cytokine interleukin-10, both of which play important roles in the pathogenesis of sepsis. The aim of this study was to examine the effects of bicuculline methiodide on sepsis in the cecal ligation and puncture septic-rat model. Cytokine production was measured by enzyme-linked immunosorbent assay. Oxidative stress was assessed by determining serum lipid peroxidation and nitrite levels. Hepatic injury was evaluated by determining the levels of serum aspartate aminotransferase, alkaline phosphatase, and total bilirubin. Mortality was recorded within 24 h. Bicuculline methiodide potently decreased the production of tumor necrosis factor-alpha and interleukin-1beta but increased interleukin-10 in serum. Bicuculline methiodide significantly decreased serum lipid peroxidation and nitrite levels. Further, bicuculline methiodide attenuated hepatic injury and reduced mortality after cecal ligation and puncture. Therefore, the alteration of cytokine production may be involved in the effects of bicuculline methiodide on hepatic injury and mortality in septic rats.     

Caffeic acid phenethyl ester reduces mortality and sepsis-induced lung injury in rats

OBJECTIVE: Sepsis and ensuing multiorgan failure continue to be the major causes of mortality in intensive care units. Nuclear factor (NF)-kappaB activation is supposed to be one of the targets in the treatment of sepsis. We studied the effectiveness of caffeic phenethyl ester (CAPE), a known NF-kappaB inhibitor, in cecal ligation and puncture (CLP)-induced sepsis and lung injury. DESIGN: Randomized, controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Female Sprague-Dawley rats. INTERVENTIONS: CLP was performed in all rats except the rats in control and sham+CAPE groups. CAPE was administered to rats at the time of operation in sham+CAPE and CAPE+sepsis 0 groups. CAPE was administered to rats in the CAPE+sepsis12 group 12 hrs after CLP. Eight rats from each group were killed 24 hrs after CLP. Blood was taken for assessment of interleukin-1, interleukin-6, interleukin-10, and tumor necrosis factor-alpha; the right lung was removed for histopathologic examination and the left lung for biochemical examination. Apoptosis, inducible nitric oxide synthase, heat shock protein 70, malondialdehyde, catalase, superoxide dismutase, and glutathione peroxidase were studied. The rest of the rats were observed for mortality. MEASUREMENTS AND MAIN RESULTS: Mortality was significantly decreased in groups that received CAPE compared with the sepsis group. All cytokine levels were similar to control levels only in the CAPE+sepsis12 group. Apoptosis, inducible nitric oxide synthase, and heat shock protein 70 evaluation were significantly changed between all groups in the following order: control < sham+CAPE< CAPE+sepsis12 < CAPE+sepsis 0 < sepsis. Malondialdehyde and catalase were increased in the sepsis group. CONCLUSIONS: CAPE reduced mortality in sepsis and improved histopathologic variables best when it was administered after the onset of sepsis.     

Magnolol attenuates peroxidative damage and improves survival of rats with sepsis

Reactive oxygen species and peroxidative damage are implicated in the pathophysiology of sepsis. Magnolol is a compound extracted from the Chinese medicinal herb Magnolia officinalis and has multiple pharmacological effects, notably antioxidant functions. To determine whether magnolol can modulate the course of sepsis, survival rate and biochemical parameters were analyzed in rats with sepsis with various treatment protocols. Magnolol at doses ranging from 10(-9) g/kg to 10(-5) g/kg was administered either before or after induction of sepsis by cecal ligation and puncture. Magnolol did not modulate the course of sepsis induced by two cecal punctures. When one cecal puncture was performed, a moderately evolving type of sepsis was induced, and the survival rate of affected rats was significantly improved by pretreatment with 10(-7) g/kg magnolol. The beneficial effect was partially retained if magnolol was administered 6 hours after onset of sepsis when a higher dose (10(-5) g/kg) was used. The intensity of lipid peroxidation in plasma, liver, and lung of septic rats was also attenuated in a treatment-dependent manner. Magnolol at this dose range exerted these beneficial effects probably through its antioxidant efficacy. These significant results may suggest magnolol as a candidate agent for the treatment of sepsis.     

Effect of sesame oil against acetaminophen-induced acute oxidative hepatic damage in rats

Acetaminophen (APAP) overdose causes acute liver injury or even death in both humans and experimental animals. We investigated the effect of sesame oil on APAP-induced acute liver injury. Male Wistar rats were given APAP (1,000 mg/kg; orally) to induce acute liver injury. Acetaminophen significantly increased aspartate transaminase, alanine transaminase, lipid peroxidation, and superoxide anion and hydroxyl radical generation levels; it also induced glutathione depletion. Sesame oil (8 mL/kg; orally) did not alter the gastric absorption of APAP, but it inhibited all the parameters altered by APAP and protected the rats against APAP-induced acute liver injury. We hypothesize that sesame oil maintained the intracellular glutathione levels, reduced reactive oxygen species levels, and inhibited lipid peroxidation in rats with APAP-induced acute liver injury.     

Treatment with recombinant human tumor necrosis factor-alpha protects rats against the lethality, hypotension, and hypothermia of gram-negative sepsis.

Tumor necrosis factor (TNF) is a peptide secreted by macrophages in response to endotoxin that can produce many of the changes seen in septic shock. After cecal ligation and puncture (CLP) rats gradually develop tachycardia, hypotension, tachypnea, and hypothermia. At 5 h post-CLP, rats have a peak in serum levels of endotoxin and 60% of rats have blood cultures that grow Gram-negative rods (Escherichia coli and Klebsiella pneumonia). At 20 h post-CLP all rats develop positive blood cultures. Serum levels of TNF are not reproducibly measurable in rats following CLP. Rats undergoing CLP have a 50-80% mortality with deaths usually occurring 24-72 h postinjury. Repetitive (twice daily x 6 d) i.p. injection of sublethal doses of recombinant human TNF-alpha (100 micrograms/kg) to rats undergoing CLP 1 d after the treatment period resulted in a significant reduction in mortality compared to control rats previously unexposed to rTNF (P less than 0.03). Animals treated with rTNF had no hypotension or hypothermia after CLP and regained normal food intake faster than control rats. 12 h after CLP the gene expression for manganous superoxide dismutase (MnSOD), an inducible mitochondrial metalloenzyme responsible for cellular resistance to injury from toxic reactive oxygen species, was higher in livers of rats treated with rTNF suggesting that the TNF treatment augmented expression of this protective enzyme. Unlike MnSOD, expression of the gene for copper-zinc SOD was not affected by CLP or rTNF treatment. The results suggest that prior treatment with recombinant TNF can ameliorate the lethality, hypotension, hypothermia, and anorexia of Gram-negative sepsis in rats and that the mechanism may be related to enhanced hepatic expression of the gene for MnSOD. Repeated administration of recombinant TNF may be a strategy to minimize mortality and morbidity of Gram-negative sepsis.     

Suppression of hepatic cytochrome p450-mediated drug metabolism during the late stage of sepsis in rats

The effects of polymicrobial sepsis on the activity and gene expression of hepatic microsomal cytochrome P450 (CYP) were examined. Rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). Liver and blood samples were taken 2, 6, and 24 h after CLP. The serum aminotransferase levels and lipid peroxidation increased 24 h after CLP. The hepatic concentrations of reduced glutathione and total CYP content decreased 24 h after CLP. The CYP1A1 activity and its protein level decreased 24 h after CLP. The CYP1A2 activity decreased 2 h and 24 h after CLP. Although the CYP2B1 mRNA expression level decreased 6 h and 24 h after CLP, the CYP2B1 activity and its protein level did not change in any of the experimental groups. The CYP2E1 activity and its protein level decreased 24 h after CLP. The CYP2E1 mRNA levels were lower at both 6 h and 24 h after CLP. The TNF-alpha mRNA expression level increased 2, 6, and 24 h after CLP. The iNOS mRNA expression level increased 24 h after CLP. These findings suggest that sepsis causes abnormalities in the microsomal drug-metabolizing function, particularly in the late stage, which is associated with higher level of oxidant stress and lipid peroxidation.     

Role of mitochondrial oxidants in an in vitro model of sepsis-induced renal injury

Oxidative stress has been implicated to play a major role in multiorgan dysfunction during sepsis. To study the mechanism of oxidant generation in acute kidney injury (AKI) during sepsis, we developed an in vitro model of sepsis using primary cultures of mouse cortical tubular epithelial cells exposed to serum (2.5-10%) collected from mice at 4 h after induction of sepsis by cecal ligation and puncture (CLP) or Sham (no sepsis). CLP serum produced a concentration-dependent increase in nitric oxide (NO) (nitrate + nitrite) release at 6 h and cytotoxicity (lactate dehydrogenase release) at 18 h compared with Sham serum treatment. Before cytotoxicity there was a decrease in mitochondrial membrane potential, which was followed by increased superoxide and peroxynitrite levels compared with Sham serum. The role of oxidants was evaluated by using the superoxide dismutase mimetic and peroxynitrite scavenger manganese(III)tetrakis(1-methyl-4-pyridyl)porphyrin tetratosylate hydroxide (MnTmPyP). MnTmPyP (10-100 μM) produced a concentration-dependent preservation of ATP and protection against cytotoxicity. MnTmPyP blocked mitochondrial superoxide and peroxynitrite generation produced by CLP serum but had no effect on NO levels. Although MnTmPyP did not block the initial CLP serum-induced fall in mitochondrial membrane potential, it allowed mitochondrial membrane potential to recover. Data from this in vitro model suggest a time-dependent generation of mitochondrial oxidants, mitochondrial dysfunction, and renal tubular epithelial cell injury and support the therapeutic potential of manganese porphyrin compounds in preventing sepsis-induced AKI.     

Octacosanol attenuates disrupted hepatic reactive oxygen species metabolism associated with acute liver injury progression in rats intoxicated with carbon tetrachloride

We examined whether octacosanol, the main component of policosanol, attenuates disrupted hepatic reactive oxygen species metabolism associated with acute liver injury progression in rats intoxicated with carbon tetrachloride (CCl(4)). In rats intoxicated with CCl(4) (1 ml/kg, i.p.), the activities of serum transaminases increased 6 h after intoxication and further increased at 24 h. In the liver of CCl(4)-intoxicated rats, increases in lipid peroxide (LPO) concentration and myeloperoxidase activity and decreases in superoxixde dismutase activity and reduced glutathione (GSH) concentration occurred 6 h after intoxication and these changes were enhanced with an increase in xanthine oxidase activity and a decrease in catalase activity at 24 h. Octacosanol (10, 50 or 100 mg/kg) administered orally to CCl(4)-intoxicated rats at 6 h after intoxication attenuated the increased activities of serum transaminases and the increased hepatic myeloperoxidase and xanthine oxidase activities and LPO concentration and the decreased hepatic superoxide dismutase and catalase activities and GSH concentration found at 24 h after intoxication dose-dependently. Octacosanol (50 or 100 mg/kg) administered to untreated rats decreased the hepatic LPO concentration and increased the hepatic GSH concentration. These results indicate that octacosanol attenuates disrupted hepatic reactive oxygen species metabolism associated with acute liver injury progression in CCl(4)-intoxicated rats.     

Mechanisms of the beneficial effect of adrenomedullin and adrenomedullin-binding protein-1 in sepsis: down-regulation of proinflammatory cytokines

OBJECTIVE: Our recent study indicates that administration of adrenomedullin (AM) in combination with AM-binding protein-1 (AMBP-1) before sepsis (i.e., pretreatment) maintains cardiovascular stability and reduces the mortality rate. The aim of the present study was to determine whether administration of AM/AMBP-1 after the onset of sepsis (posttreatment) has any salutary effects on the septic host, and if so, whether AM/AMBP-1 down-regulates proinflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6. DESIGN: Prospective, controlled, randomized animal study. SETTING: A university research laboratory. SUBJECTS: Male adult Sprague-Dawley rats. INTERVENTIONS: Rats were subjected either to polymicrobial sepsis by cecal ligation and puncture or to sham operation followed by the administration of normal saline solution (i.e., fluid resuscitation). MEASUREMENTS AND MAIN RESULTS: At 5 hrs after cecal ligation and puncture, AM (12 microg/kg body weight) and AMBP-1 (40 microg/kg body weight) were administered intravenously over 1 hr. At 20 hrs after cecal ligation and puncture (i.e., the late, hypodynamic stage of sepsis), cardiac output, stroke volume, total peripheral resistance, systemic oxygen delivery, and organ blood flow were determined by radioactive microspheres, and circulating concentrations of proinflammatory cytokines were measured using enzyme-linked immunosorbent assay kits. Moreover, plasma concentrations of transaminases and lactate were measured. The results indicated that administration of AM/AMBP-1 at 5 hrs after cecal ligation and puncture prevented the decrease in measured systemic and regional hemodynamic variables and reduced plasma concentrations of tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 at 20 hrs after the onset of sepsis. Moreover, administration of AM/AMBP-1 attenuated hepatic damage and the increase in plasma lactate and prevented hemoconcentration. CONCLUSION: Administration of AM/AMBP-1 may provide a novel approach to the treatment of sepsis. Moreover, because AM/AMBP-1 significantly reduced circulating concentrations of tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6, down-regulation of those proinflammatory cytokines by AM/AMBP-1 appears to play an important role for the beneficial effects of these agents in polymicrobial sepsis.     

Administration of human inter-alpha-inhibitors maintains hemodynamic stability and improves survival during sepsis

OBJECTIVES: The major forms of human inter-alpha-inhibitor proteins circulating in the plasma are inter-alpha-inhibitor (IalphaI, containing one light peptide chain called bikunin and two heavy chains) and pre-alpha-inhibitor (PalphaI, containing one light and one heavy chain). Although it has been reported that a decrease in IalphaI/PalphaI is correlated with an increased mortality rate in septic patients, it remains unknown whether administration of IalphaI/PalphaI early after the onset of sepsis has any beneficial effects on the cardiovascular response and outcome of the septic animal. The aim of this study, therefore, was to determine whether IalphaI and PalphaI have any salutary effects on the depressed cardiovascular function, liver damage, and mortality rate after polymicrobial sepsis. DESIGN: Prospective, controlled, randomized animal study. SETTING: A university research laboratory. SUBJECTS: Male adult rats were subjected to polymicrobial sepsis by cecal ligation and puncture or sham operation followed by the administration of normal saline (i.e., resuscitation). MEASUREMENTS AND MAIN RESULTS: At 1 hr after cecal ligation and puncture, human IalphaI/PalphaI at a dose of 30 mg/kg body weight or vehicle (normal saline, 1 mL/rat) were infused intravenously over a period of 30 mins. At 20 hrs after cecal ligation and puncture (i.e., the late, hypodynamic stage of sepsis), cardiac output was measured by using a dye dilution technique, and blood samples were collected for assessing oxygen content. Oxygen delivery, consumption, and extraction ratio were determined. Plasma concentrations of liver enzymes alanine aminotransferase and aspartate aminotransferase as well as lactate and tumor necrosis factor-alpha also were measured. In additional animals, the necrotic cecum was excised at 20 hrs after cecal ligation and puncture with or without IalphaI/PalphaI treatment, and survival was monitored for 10 days thereafter. The results indicate that administration of human IalphaI/PalphaI early after the onset of sepsis maintained cardiac output and systemic oxygen delivery, whereas it increased oxygen consumption and extraction at 20 hrs after cecal ligation and puncture. The elevated concentrations of alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor-alpha, and lactate were attenuated by IalphaI/PalphaI treatment. In addition, administration of human IalphaI/PalphaI improved the survival rate from 30% to 89% in septic animals at day 10 after cecal ligation and puncture and cecal excision. CONCLUSION: Human IalphaI/PalphaI appears to be a useful agent for maintaining hemodynamic stability and improving survival during the progression of polymicrobial sepsis.     

Role of interferon-gamma in lung inflammation following cecal ligation and puncture in rats.

Interferon-gamma (IFN-gamma) has been implicated in the mortality of animal models of endotoxemia. On the other hand, the specific role of IFN-gamma in the development of organ inflammation in a model of polymicrobial sepsis has not been elucidated. In this study, we hypothesized that IFN-gamma plays an important role in lung inflammation after cecal ligation and puncture (CLP). To verify this hypothesis, lung tissue was removed 5 h after CLP or from sham controls. The mRNA expression (by RT-PCR) of IFN-gamma was increased in lung homogenates of CLP rats compared to sham controls. Using immunohistochemistry, we show for the first time the increased presence of IFN-gamma staining cells in the lung following CLP. Only very small amounts of positive staining for IFN-gamma was observed in lungs of sham controls. The presence of IFN-gamma in the lung 5 h after CLP correlated with a twofold increases in lung superoxide generation and MPO activity (index of neutrophil sequestration). Plasma and lung nitrite levels (breakdown product of nitric oxide) were also significantly increased in CLP rats. IFN-gamma antibody (1.2 mg/kg, i.v.) administered immediately after CLP significantly decreased lung superoxide levels to levels similar to the sham controls without affecting MPO activity, or lung or plasma nitrite levels. These results provide evidence that IFN-gamma may contribute to lung inflammation 5 h following CLP via increased production of superoxide.