Poly-ADP-ribose polymerase inhibition provides protection against lung injury in a rat paraquat toxicity model.

OBJECTIVES: Paraquat (PQ) is a widely used herbicide. Exposure to PQ at toxic doses can result in fatal acute lung injury. Inhibition of the poly-(ADP-ribose) polymerase (PARP) enzyme alleviates inflammation and necrosis in various pathologies. Here we aimed to evaluate the effects of PARP inhibition on PQ-induced lung damage in a rat experimental model. METHODS: Female Sprague-Dawley rats (n = 24) were allocated into three groups: sham, PQ and PQ + 3-aminobenzamide (3-AB) that is a PARP inhibitor, groups. Experimental lung injury was induced by administration of 15 mg/kg PQ intraperitoneally in PQ and PQ + 3-AB groups. 3-AB (10 mg/kg twice per day) was administered to the PQ + 3-AB group for four consecutive days. The animals were killed on the fifth day following PQ administration. Lung tissue and blood samples were collected and stored until analysis. RESULTS: Serum lactate dehydrogenase (LDH) and neopterin levels, tissue oxidative stress parameters, transforming growth factor-beta1 (TGF-ß) levels and histological injury scores in the PQ + 3-AB group were significantly lower than in the PQ group (P < 0.05, PQ vs. PQ + 3-AB). Total antioxidant capacity in the PQ + 3-AB group was significantly higher than in the PQ group (P < 0.05, PQ + 3-AB vs. PQ). CONCLUSION: Our results suggested that the use of PARP inhibitors following PQ toxicity might be useful for minimizing lung injury due to paraquat toxicity.

Evaluation and comparison of the effect of hypothermia and ozone on ischemia-reperfusion injury of skeletal muscle in rats.

BACKGROUND: Tourniquet-induced ischemia-reperfusion, which affects local and distant organs, is very common in orthopedic surgery. Hypothermia is used in traumatic tissue during ischemic period commonly. Ozone (O3) has been recommended as a novel therapeutic agent in various medical conditions. The objective of the study was to evaluate and compare the effect of hypothermia (H) and O3 on ischemia-reperfusion injury of skeletal muscle in rats by measuring oxidative parameters and inducible nitric oxide synthase (iNOS) levels. MATERIALS AND METHODS: Eighteen rats (Wistar albino) were separated into five groups randomly (sham, IR, IR + H, IR + O3, IR + H + O3; n = 6). The lower right extremity of all rats was subjected to 2 h of ischemia and 22 h of reperfusion clamping the common iliac artery and using the rubber-band technique at the level of the lesser trochanter under general anesthesia. Two hours of hypothermia were applied during the first 2 h of reperfusion in two groups. O3 was applied in two groups. All rats were sacrificed after the IR period with high dose of anesthesia. The tibialis anterior muscle and blood were saved. Levels of superoxide dismutase, glutathione peroxidase, MDA, NOx, and interleukin-1ß were measured in the muscle. Creatinine kinase, lactate dehydrogenase, aspartate aminotransferase, urea, creatinine, and electrolytes were measured in serum. Immunohistochemical iNOS staining was performed on muscle samples. RESULTS: The levels of MDA, NOx, and interleukin-1ß in muscle were raised in the IR group compared with those in the sham group. The same parameters were lower in the groups of IR + H, IR + O3, and IR + H + O3 compared with those in the IR group. Superoxide dismutase and glutathione peroxidase activities in muscle were lower in the IR group compared with those in the sham group; however, same parameters were higher in the groups of IR + H, IR + O3, and IR + H + O3 compared with those in the IR group. Score and intensity of iNOS staining in skeletal muscle in the IR group was increased compared with that in the sham group and decreased in the groups of IR + H, IR + O3, and IR + H + O3 compared with that in the IR group. Levels of creatinine kinase, aspartate aminotransferase, and K in the three treatment groups decreased compared with those in the IR group. CONCLUSIONS: These findings showed that hypothermia, which has more affect, and O3 decreased the tourniquet-induced IR injury in the rat's muscle-skeletal system by reducing the levels of oxidative and nitrosative stress parameters and enhancing antioxidant enzymes. Hypothermia and O3 had no synergistic effect. Hypothermic reperfusion and O3 preconditioning might be beneficial in skeletal muscle IR injury-associated tourniquet.

Efficacy of poly(adenosine diphosphate-ribose) polymerase inhibition in extracorporeal shock wave-induced renal injury.

OBJECTIVES: Extracorporeal shock wave lithotripsy (ESW) induces renal damage by excessive production of free oxygen radicals. Free Oxygen radicals cause cellular injury by inducing nicks in DNA. The enzyme poly(adenosine diphosphate-ribose) polymerase (PARP) involved in the process of repair of DNA in damaged cells. However, its activation in damaged cells can lead to adenosine triphosphate depletion and death. Thus, we designed a study to evaluate the efficacy of 3-aminobenzamide (3-AB), a PARP inhibitor, against extracorporeal shock wave induced renal injury. METHODS: Twenty-four Sprague-Dawley rats were divided into three groups: control, ESW, ESW + 3-AB groups. All groups except control group were subjected to ESW procedure. ESW + 3-AB group received 20 mg/kg/day 3-aminobenzamide intraperitoneally at 2 h before ESW and continued once a day for consecutive 3 days. The surviving animals were sacrificed at the 4th day and their kidneys were harvested for biochemical and histopathologic analysis. Blood samples from animals were also obtained. RESULTS: Serum ALT and AST levels, serum neopterin and tissue oxidative stress parameters were increased in the ESW group and almost came to control values in the treatment group (p < 0.05, ESW vs. ESW + 3-AB). Histopathological injury score were significantly lower in treatment group than the ESW group (p < 0.05, ESW vs. ESW + 3-AB). CONCLUSION: Our data showed that PARP inhibition protected renal tissue against ESW induced renal injury. These findings suggest that it would be possible to improve the outcome of ESW induced renal injury by using PARP inhibitors as a preventive therapy.

Ozone therapy ameliorates paraquat-induced lung injury in rats.

Paraquat (PQ) overdose can cause acute lung injury and death. Ozone therapy (OT) was previously demonstrated to alleviate inflammation and necrosis in various pathologies. We therefore hypothesized that OT has ameliorative and preventive effects on PQ-induced lung damage due to anti-inflammatory and antioxidants properties. Sprague-Dawley rats (n = 24) were separated into three groups: sham, PQ, and PQ+OT groups. 15 mg/kg PQ was administered intraperitoneally in PQ and PQ+OT groups to induce experimental lung injury. One hour after PQ treatment, PQ+OT group was administered a single dose of ozone-oxygen mixture (1 mg/kg/day) by intraperitoneal route for four consecutive days. The animals were sacrificed on fifth day after PQ administration. Blood samples and lung tissues were collected to evaluate the inflammatory processes, antioxidant defense and pulmonary damage. Serum lactate dehydrogenase (LDH) and neopterin levels, tissue oxidative stress parameters, total TGF-ß1 levels, and histological injury scores in PQ+OT group were significantly lower than PQ group (P<0.05, PQ vs. PQ+OT). Total antioxidant capacity in PQ+OT group was significantly higher than PQ group (P < 0.05, PQ+OT vs. PQ). These findings suggest that outcome in PQ-induced lung injury may be improved by using OT as an adjuvant therapy.

Beneficial effects of Etanercept on experimental necrotizing enterocolitis.

PURPOSE: Tissue damage in necrotizing enterocolitis (NEC) of infants occurs as a result of an uncontrolled inflammatory response. The aim of this study was to investigate any potential anti-inflammatory effects that Etanercept may have on the inflammatory response in an experimental NEC model in newborn rats. METHODS: Newborn pups were randomized into three groups immediately after birth (Control, NEC + Placebo and NEC + Etanercept). Pups in the NEC + Placebo and NEC + Etanercept groups were subjected to an NEC-inducing protocol (hypercarbia, hypothermia and hyperoxia) twice a day for 3 days. Pups in the NEC + Etanercept group were given an intraperitoneal injection of Etanercept. Rats were harvested for biochemical and histopathological examinations. RESULTS: The histopathological injury score of rats in the NEC + Placebo group was significantly higher compared to the NEC + Etanercept and Control groups (p < 0.05 for both comparisons). Tissue levels of tumor necrosis factor-α, interleukin-1ß, and malondialdehyde were higher in the placebo group compared to the Etanercept group. CONCLUSION: Our results suggest that Etanercept attenuates intestinal tissue damage in NEC by reducing inflammation and blocking the production of free-oxygen radicals, while also reducing tissue levels of tumor necrosis factor-α and interleukin-1ß.

The protective effect of melatonin and S-methylisothiourea treatments in nitrogen mustard induced lung toxicity in rats.

OBJECTIVES: Mustard is highly toxic to the lung. Its toxic effects are associated with inflammatory cell accumulation and increased pro-inflammatory cytokines as well as reactive oxygen and nitrogen species. In this study, we aimed to investigate the efficiency of melatonin (MEL) and S-methylisothiourea (SMT) on mechlorethamine (MEC) induced lung toxicity. METHODS: Thirty-six male rats were randomly divided into four groups: control, MEC, MEC+MEL, and MEC+SMT. Control group was given saline only via transdermal route. Other groups were exposured to a single dose of MEC (3.5 mg/kg) via transdermal route. MEL (100 mg/kg) was administered intraperitoneally 30 min after the application of MEC, and after the same dose of MEL was given every 12 h for a total of six doses. SMT (50 mg/kg) was also given intraperitoneally 30 min after the application of MEC. RESULTS: MEC injection resulted in alveolar epithelial injury, hemorrhage, inflammation, edema and interalveolar septal thickening in the lung tissues. The tissue TNF-α, IL-1ß, and nitrate/nitrite (NOx) levels were found significantly different for all groups (p<0.001). TNF-α and IL-1ß levels increased significantly with MEC exposure, and MEL and SMT ameliorated these increases in lung tissues. MEC also elevated NOx levels in lung tissue. Melatonin showed meaningful protection against lung injury. But protection of SMT was weaker. CONCLUSION: Inflammation plays an important role in the MEC induced lung toxicity as well as oxidative and nitrosative stress. Melatonin has also anti-inflammatory properties similar to SMT, as well as anti-oxidant properties. But melatonin treatment was found more efficient than SMT treatment.

All-trans-retinoic acid attenuates intestinal injury in a neonatal rat model of necrotizing enterocolitis.

BACKGROUND: Ischemia/reperfusion-induced intestinal injury is mediated by reactive oxygen species and inflammatory mediators. OBJECTIVES: This study was designed to evaluate whether all-trans-retinoic acid (ATRA) administration can attenuate intestinal injury and to analyze the antioxidant and anti-inflammatory effects of ATRA in a neonatal rat model of necrotizing enterocolitis (NEC). METHODS: Twenty-nine Wistar albino rat pups were randomly divided into 3 groups: group 1 = control, group 2 = NEC and saline, and group 3 = NEC and ATRA treatment. NEC was induced by hyperosmolar enteral formula feeding and exposure to hypoxia after cold stress at +4°C and oxygen. Pups in group 3 were injected intraperitoneally with ATRA (0.5 mg/kg body weight) once a day prior to each NEC procedure, beginning on postnatal day 1 and daily through postnatal day 4. The pups were killed on the 4th day and their intestinal tissues were harvested for biochemical and histopathological analysis. RESULTS: Mucosal injury scores and intestinal malondialdehyde levels in group 2 were found to be significantly higher than other groups (p < 0.05). Intestinal superoxide dismutase and glutathione peroxidase activities in group 3 were significantly higher than group 2 (p = 0.04 and p = 0.04, respectively). Intestinal tissue tumor necrosis factor-α levels were significantly reduced with ATRA treatment in group 3 compared to group 2 (p < 0.001). CONCLUSIONS: It is likely that oxidative stress and inflammatory mediators contributed to the pathogenesis of NEC and that ATRA had a protective effect on intestinal injury through its anti-inflammatory and antioxidant properties.

Protective effects of colchicine in an experimental model of necrotizing enterocolitis in neonatal rats.

BACKGROUND: The pathophysiology of necrotizing enterocolitis (NEC) includes the massive production of endogenous cytokines with exaggerated activation of inflammatory pathways. Colchicine has been used as an anti-inflammatory agent. The aim of this study was to investigate the possible beneficial effects of colchicine in a neonatal rat model of NEC. MATERIALS AND METHODS: We randomly divided rat pups into three groups: a control group, a saline-treated NEC group, and a colchicine-treated NEC group. We induced NEC by hyperosmolar enteral formula feeding and exposure to hypoxia/reoxygenation after cold stress. Intestinal samples were harvested for biochemical and histopathologic analyses. RESULTS: The grade of intestinal injury of pups in the saline-treated NEC group was significantly higher than in the control and colchicine-treated groups (P < 0.001 and 0.003, respectively). The median level of intestinal malondialdehyde was significantly higher in the saline-treated NEC group compared with the control group (P = 0.006) or the colchicine-treated NEC group (P = 0.015). We observed significantly higher activity levels of intestinal superoxide dismutase and glutathione peroxidase in the colchicine-treated NEC group compared with the saline-treated NEC group (P = 0.033 and 0.030, respectively). The tissue levels of tumor necrosis factor-α and interleukin-1ß were significantly higher in the saline-treated NEC group compared with the colchicine-treated NEC group (P < 0.001 and 0.003, respectively). CONCLUSIONS: We observed that in this model of NEC, colchicine had favorable effects on intestinal histologic and biochemical changes.

Effects of maternal smoking on fetal organs.

BACKGROUND: Unfavorable effects of in-utero smoke exposure have been shown in several studies. OBJECTIVES: In this experimental study, the authors aimed at showing detrimental effects of cigarette smoke on fetal tissues by assessing apoptosis that is detected by performing TUNEL staining. MATERIAL AND METHODS: Designed groups were smoke exposed rats before and during pregnancy and control groups. Rat offsprings were sacrificed when they were 12 days old. RESULTS: Lung, kidney, adrenal and gonad tissues were harvested for histopathologic analysis and assessed by TUNEL (Terminal dUTP Nick End Labeling) staining. CONCLUSIONS: Smoke exposure caused increased apoptotic activity in lung parenchyma of study groups.

Antioxidant effects of N-acetylcysteine in a neonatal rat model of necrotizing enterocolitis.

BACKGROUND/PURPOSE: Hypoxia and ischemia appear to play an important role in the pathogenesis of necrotizing enterocolitis (NEC), which may be related to oxygen-derived free radical formation. This study was designed to evaluate the role of oxidative stress and potentially beneficial effects of N-acetylcysteine (NAC) in a neonatal rat model of NEC. METHODS: Thirty Wistar albino rat pups were randomly divided into 3 groups: group 1, control; group 2, NEC and saline; and group 3, NEC and NAC treatment. Necrotizing enterocolitis was induced by hyperosmolar enteral formula feeding and exposure to hypoxia after cold stress at 4°C and oxygen. The pups were killed on the fourth day, and their intestinal tissues were harvested for biochemical and histopathologic analysis. RESULTS: Mucosal injury scores and intestinal malondialdehyde levels in group 2 were found to be significantly higher than that in other groups (P ≤ .05). Intestinal superoxide dismutase activities in group 3 were significantly higher than that in group 2 (P = .018). Intestinal tissue tumor necrosis factor α levels were significantly reduced with NAC treatment in group 3 compared with group 2 (P < .003). CONCLUSIONS: It is likely that oxidative stress and inflammatory mediators contribute to the pathogenesis of NEC and that NAC has a protective effect on intestinal injury through its antiinflammatory and antioxidant properties.

Colchicine protects against hyperoxic lung injury in neonatal rats.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is characterized by inflammation, fibrosis and mucosal necrosis, which leads to emphysematous coalescence of alveoli. OBJECTIVE: We tested whether prophylaxis with colchicine , an anti-inflammatory, antioxidant and antifibrotic drug, would decrease the severity of lung injury in an animal model of BPD. METHODS: Twenty-five rat pups were divided into three groups: control (n = 8), hyperoxia (n = 7), and hyperoxia + colchicine (n = 10). The hyperoxia groups were exposed to >95% oxygen from day 1 to 10 of life. On day 10, the animals were sacrificed and the lungs were processed for histology and biochemical analysis. Lung morphology was assessed by the mean linear intercept (MLI), a measure of alveolar size. The degree of lung inflammation and antioxidant capacity were assessed by quantifying lung homogenate tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. RESULTS: Colchicine significantly decreased lung damage as determined by the MLI in the hyperoxia groups (p < 0.01). The median level of lung MDA was significantly higher in the hyperoxia group compared with the control group (p < 0.05) and the colchicine-treated group (p < 0.05). Lung homogenate SOD and GSH-Px activities in the colchicine-treated group were significantly higher than in the hyperoxia group (p < 0.05). Furthermore, colchicine-treated pups had lower lung homogenate TNF-α and IL-1ß levels compared with the hyperoxia group (p < 0.05). CONCLUSIONS: Colchicine has favorable effects on alveolarization as well as inflammation and oxidative stress markers in an animal model of BPD.

Medical ozone therapy decreases postoperative uterine adhesion formation in rats.

PURPOSE: Various studies have been performed to find out novel treatment strategies to prevent postoperative adhesion formation. Ozone therapy (OT) is shown to reduce inflammation in several pathological conditions. Therefore, we aimed to evaluate the efficacy of OT in a rat model of experimental uterine adhesion (EUA). METHODS: Thirty female Wistar rats (200-250 g) were divided into three groups: sham, EUA and EUA+OT. EUA and EUA+OT groups were subjected to the postoperative adhesion procedure by bipolar coagulation on the uterine horns and corresponding pelvic sidewall parietal peritoneum. EUA+OT group received 0.7 mg/kg daily single dose for 3 days of ozone/oxygen mixture intraperitoneally after adhesion induction. All animals were killed on the 7th day and uterine adhesions were scored. Uterine tissues and peritoneal washing fluid were harvested for all analyses. RESULTS: Uterine malondialdehyde levels in the EUA group were significantly higher compared to the other groups. However, in the EUA group, uterine superoxide dismutase and glutathione peroxidase activities were lower than in other groups. Peritoneal fluid TNF-α levels were found to be significantly different for all groups (p < 0.001). Macroscopic total adhesion score was significantly higher in the EUA group compared to the other groups (p < 0.001). But, total score in the EUA+OT group was lower than in the EUA group (p = 0.006). CONCLUSIONS: Medical OT prevents postoperative uterine adhesions by modulating TNF-α levels and oxidative/antioxidative status in an experimental uterine adhesion model.

Role of cyclooxygenase 2 and endothelial nitric oxide synthetase in preclinical atherosclerosis.

Cyclooxygenase-2 and endothelial nitric oxide (NO) synthase enzymes may have a role in developing preclinical atherosclerosis. Designed groups were as follows: smoke exposed rats before and during pregnancy, only before pregnancy, and controls. Cross-sectional samples of abdominal aorta were examined immunohistochemically. Cyclooxygenase-2 and eNOS expression was evaluated semi-quantitatively through staining extent (focal, diffuse) and staining intensity. Diffuse COX-2 expression was detected in study groups. Endothelial NO synthase expression was diffuse in study groups. COX-2 and eNOS may contribute to the formation of preatherosclerotic lesions in offspring of rats exposed to cigarette smoke through inflammatory response.

Passive smoke exposure of female rats caused aortic atherosclerotic precursor lesions in their offspring.

The aim of this study was to evaluate the presence and degree of preclinical atherosclerosis in pups of pregnant rats exposed to cigarette smoke. Abdominal aorta examined for atherosclerotic lesions and intimal medial thickness of the abdominal aorta was measured by image analysis. The study groups showed endothelial cellular losses, marked intimal injuries, elastic fiber damages, mononuclear cellular infiltration, and irregularities in internal elastic membrane, with pronounced damages as integrity losses and local fragmentations. The results provide evidence for development of an atherosclerotic process in the neonatal period, even in prenatal stage, long before the formation of smoke-related cardiovascular diseases.

Melatonin ameliorates necrotizing enterocolitis in a neonatal rat model.

INTRODUCTION: We designed the present study to evaluate the efficacy of melatonin (M) on the severity of necrotizing enterocolitis (NEC) in a neonatal rat model. MATERIALS AND METHODS: Immediately after birth, pups were weighed and randomized into 3 groups: NEC, NEC + M, and control. Necrotizing enterocolitis was induced by enteral formula feeding and exposure to hypoxia after cold stress at 4°C and oxygen. The NEC + M group received 10 mg/kg M daily for 3 days after the first day of the NEC procedure. The pups were killed on the fourth day, and their intestinal tissues were harvested for biochemical and histopathologic analysis. Blood samples were also obtained from the pups. RESULTS: The mortality rate and weight loss were highest in the NEC group. Malondialdehyde and protein carbonyl content were significantly increased, whereas superoxide dismutase and glutathione peroxidase were decreased in the NEC-treated pups. Melatonin prevented these changes, with these values being similar to control levels in the NEC + M group. Nitrate plus nitrite levels and serum tumor necrosis factor α and interleukin-1ß were increased in the NEC group, and histopathologic injury score in the NEC group was significantly higher than that in the NEC + M group. CONCLUSION: Melatonin significantly reduced the severity of NEC in our study.

Mercaptoethylguanidine attenuates caustic esophageal injury in rats: a role for scavenging of peroxynitrite.

INTRODUCTION: After ingestion of caustic material, tissue damage is caused by reactive oxygen species and reactive nitrogen species such as peroxynitrite. Mercaptoethylguanidine (MEG) is a well-known scavenger of peroxynitrite. This study was designed to determine whether MEG has a beneficial effect on caustic esophageal injury. MATERIALS AND METHODS: Forty-five rats were allocated into 3 groups: sham-operated, untreated, and treated groups. Caustic esophageal burn was created by instilling 15% NaOH in the distal esophagus. The rats were left untreated or treated with 10 mg/kg per day MEG intraperitoneally for 5 days. All rats were killed at 28 days. Efficacy of the treatment was assessed both histopathologically and biochemically. RESULTS: Of 15 rats, 6 (40%) died in the untreated group, and only 1 (7%) rat died in the treated group. The stenosis index (SI) and the histopathologic damage score were significantly lower in the MEG treatment group than the untreated group, which showed a correlation with tissue hydroxyproline level. In the untreated group, tissue oxidative stress parameters (malondialdehyde and protein carbonyl content) were significantly higher; and antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase) were significantly lower. Administration of MEG ameliorated oxidative stress parameters and antioxidant enzyme activities. Urinary nitrate and nitrite levels increased in the treated and untreated groups in the first 3 days, suggesting increased nitrosative stress; but at the fourth day, nitrate and nitrite level reached control values in the treated group. CONCLUSION: Peroxynitrites play an important role in the healing process of caustic esophagitis. As a peroxynitrites scavenger, MEG potentially might be a useful adjuvant agent in the treatment of esophageal caustic burn by modulating the antioxidant defense mechanism.

Rosuvastatin, a new generation 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitor, reduces ischemia/reperfusion-induced spinal cord tissue injury in rats.

BACKGROUND: Severe neurological injury still represents one of the most devastating complications occurring after surgical repair of thoracoabdominal aneurysms. We aimed to investigate the role of rosuvastatin (RSV) against ischemia/reperfusion injury in an experimental model of spinal cord ischemia in rats. METHODS: Experimental groups included control group (n = 8), ischemia/reperfusion group (n = 8) undergoing aortic occlusion without pharmacologic treatment, and RSV-treated group (n = 8) receiving 10 mg/kg/day of RSV orally for 3 days before spinal cord ischemia. Spinal cord ischemia was induced by occlusion of the abdominal aorta between the left renal artery and aortic bifurcation for 45 minutes, followed by reperfusion. Neurological status was assessed before spinal ischemia and at 48 hours postoperatively. Spinal cords were harvested for histopathologic examination with hematoxylin-eosin staining and biochemical analysis for tissue malondialdehyde, superoxide dismutase, and glutathione peroxidase levels. RESULTS: Decreased spinal cord tissue malondialdehyde levels (p = .01) and increased tissue superoxide dismutase (p = .01) and glutathione peroxidase (p = .09) levels were observed in the RSV-treated group, as compared with the ischemia group. Histopathologic analyses demonstrated typical changes of ischemic necrosis in the ischemia group; however, RSV attenuated tissue necrosis. Total injury score in the RSV-treated group was significantly decreased, as compared with the ischemia group (p < .05). The Tarlov scores at 48 hours postoperatively were higher in the RSV group as compared with the ischemia group. CONCLUSION: RSV administration before spinal cord ischemia reduces spinal cord tissue injury by increasing antioxidant enzyme levels and may reduce the incidence of associated neurological dysfunction.

Cilostazol, a type III phosphodiesterase inhibitor, reduces ischemia/reperfusion-induced spinal cord injury.

BACKGROUND: Spinal cord injury is still a devastating complication after surgical repair of thoracoabdominal aortic pathologies. In this study, we investigated the protective effect of cilostazol, a type III phosphodiesterase inhibitor, against ischemia/reperfusion (I/R)-induced spinal cord injury in rats. METHODS: Twenty-four rats were assigned to 3 experimental study groups: the control group (sham operation, n = 8); the ischemia group (nontreated, n = 8), which underwent aortic occlusion without pharmacologic intervention; and the cilostazol-treated group (n = 8), which received 20 mg/kg cilostazol per day orally for 3 days before spinal ischemia. All animals underwent a 45-minute period of spinal cord ischemia via clamping of the abdominal aorta between the left renal artery and the aortic bifurcation; removal of the aortic clamp was followed by reperfusion. Neurologic status was assessed before spinal ischemia and at 48 hours after the operation. All animals were sacrificed at 48 hours after the operation. Spinal cords were harvested for histopathologic examination and biochemical analyses for the malondialdehyde (MDA) level and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. RESULTS: Tarlov scores at postoperative hour 48 tended to be higher in the cilostazol-treated group than in the nontreated ischemia group (mean ± SD, 3.66 ± 0.40 versus 2.32 ± 0.80; P = .08). Spinal cord tissue MDA levels (per gram protein) were lower in the cilostazol-treated group than in the nontreated ischemia group (0.27 ± 0.01 mmol/g versus 0.33 ± 0.04 mmol/g, P = .026), and the cilostazol-treated group had higher activities of tissue SOD (519.6 ± 56.3 U/g versus 438.9 ± 67.4 U/g, P = .016) and GSH-Px (4.07 ± 1.37 U/g versus 3.21 ± 1.02 U/g, P = .47) than the nontreated ischemia group. Histopathologic analyses demonstrated that cilostazol treatment attenuated I/R-induced cellular damage. CONCLUSION: Administration of cilostazol before spinal cord ischemia reduced neurologic injury and produced clinical improvement by attenuating oxidative stress in this rat spinal cord I/R model.

Ozone therapy and hyperbaric oxygen treatment in lung injury in septic rats.

Various therapeutic protocols were used for the management of sepsis including hyperbaric oxygen (HBO) therapy. It has been shown that ozone therapy (OT) reduced inflammation in several entities and exhibits some similarity with HBO in regard to mechanisms of action. We designed a study to evaluate the efficacy of OT in an experimental rat model of sepsis to compare with HBO. Male Wistar rats were divided into sham, sepsis+cefepime, sepsis+cefepime+HBO, and sepsis+cefepime+OT groups. Sepsis was induced by an intraperitoneal injection of Escherichia coli; HBO was administered twice daily; OT was set as intraperitoneal injections once a day. The treatments were continued for 5 days after the induction of sepsis. At the end of experiment, the lung tissues and blood samples were harvested for biochemical and histological analysis. Myeloperoxidase activities and oxidative stress parameters, and serum proinflammatory cytokine levels, IL-1ß and TNF-α, were found to be ameliorated by the adjuvant use of HBO and OT in the lung tissue when compared with the antibiotherapy only group. Histologic evaluation of the lung tissue samples confirmed the biochemical outcome. Our data presented that both HBO and OT reduced inflammation and injury in the septic rats' lungs; a greater benefit was obtained for OT. The current study demonstrated that the administration of OT as well as HBO as adjuvant therapy may support antibiotherapy in protecting the lung against septic injury. HBO and OT reduced tissue oxidative stress, regulated the systemic inflammatory response, and abated cellular infiltration to the lung demonstrated by findings of MPO activity and histopathologic examination. These findings indicated that OT tended to be more effective than HBO, in particular regarding serum IL-1ß, lung GSH-Px and histologic outcome.

Efficacy of melatonin, mercaptoethylguanidine and 1400W in doxorubicin- and trastuzumab-induced cardiotoxicity.

Doxorubicin (DOX) and Trastuzumab (TRAST) are effective agents for the treatment of many neoplastic diseases. Cardiotoxicity is a major side effect of these drugs and limit their use. In this study, the possible protective effects of melatonin (MEL), mercaptoethylguanidine (MEG), or N-(3-(aminomethyl) benzyl) acetamidine (1400W) against the cardiotoxicity of DOX and TRAST were tested. Male Sprague-Dawley rats received an injection of DOX (20 mg/kg) alone or in combination with TRAST (10 mg/kg) to induce cardiotoxicity; daily treatments with MEL (10 mg/kg × 2), MEG (10 mg/kg × 2), or 1400W (10 mg/kg × 2) were begun 36 hr before and continued for 72 hr after DOX and TRAST administration. Oxidant/antioxidant indices of the cardiac tissue, namely, malondialdehyde, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as serum levels of creatine phosphokinase (CK-MB) were measured. Additionally, the injury scores were evaluated histopathologically. Malondialdehyde levels were significantly higher, while SOD and GSH-Px activities were significantly reduced in rats with DOX- or DOX+TRAST-induced cardiotoxicity compared to normal values. All three treatment agents significantly reversed oxidative stress markers. Serum CK-MB levels were significantly increased after treatment with DOX and DOX+TRAST; these changes were also reversed by each of the treatments and resulted in near normal levels. Both the DOX- and DOX+TRAST-treated rats presented similar histopathologic injuries; in the animals treated with the protective agents, histologic protection of the cardiac tissue was apparent. These results suggested that MEL, MEG, as well as 1400 W are effective in preventing DOX- or DOX+TRAST-induced cardiotoxicity.