Effects of deferoxamine on tissue superoxide dismutase and glutathione peroxidase levels in experimental head trauma

Neuroprotective effects of mildronate in a rat model of traumatic brain injury

OBJECTIVE

Traumatic brain injury (TBI) is one of the most common preventable causes of mortality and morbidity. Inflammation, apoptosis, oxidative stress, and ischemia are some of the important pathophysiological mechanisms underlying neuronal loss after TBI. Mildronate is demonstrated to be beneficial in various experimental models of ischemic diseases via anti-inflammatory, antioxidant, and neuroprotective mechanisms. This study aimed to investigate possible antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects of mildronate in a rat model of TBI.

METHODS

A total of 46 male rats were divided into three groups of control, saline-treated TBI, and mildronate-treated TBI. Both TBI groups were subjected to closed-head contusive weight-drop injuries followed by treatment with saline or mildronate (100 mg/kg) administered intraperitoneally. The forebrain was removed 24 h after trauma induction, the activities of myeloperoxidase (MPO) and caspase-3, levels of superoxide dismutase (SOD), luminol- and lucigenin-enhanced chemiluminescence were measured, and histomorphological evaluation of cerebral tissues was performed.

RESULTS

Increased MPO and caspase-3 activities in the vehicle-treated TBI group (p < 0.001) were suppressed in the mildronate-treated TBI group (p < 0.001). Similarly, increase in luminol and lucigenin levels (p < 0.001 and p < 0.01, respectively) in the vehicle-treated TBI group were decreased in the mildronate-treated TBI group (p < 0.001). Concomitantly, in the vehicle-treated TBI group, TBI-induced decrease in SOD activity (p < 0.01) was reversed with mildronate treatment (p < 0.05). On histopathological examination, TBI-induced damage in the cerebral cortex was lesser in the mildronate-treated TBI group than that in other groups.

CONCLUSION

This study revealed for the first time that mildronate, exhibits neuroprotective effects against TBI because of its anti-inflammatory, antiapoptotic, and antioxidant activities.

In search of antiepileptogenic treatments for post-traumatic epilepsy

Post-traumatic epilepsy (PTE) is diagnosed in 20% of individuals with acquired epilepsy, and can impact significantly the quality of life due to the seizures and other functional or cognitive and behavioral outcomes of the traumatic brain injury (TBI) and PTE. There is no available antiepileptogenic or disease modifying treatment for PTE. Animal models of TBI and PTE have been developed, offering useful insights on the value of inflammatory, neurodegenerative pathways, hemorrhages and iron accumulation, calcium channels and other target pathways that could be used for treatment development. Most of the existing preclinical studies test efficacy towards pathologies of functional recovery after TBI, while a few studies are emerging testing the effects towards induced or spontaneous seizures. Here we review the existing preclinical trials testing new candidate treatments for TBI sequelae and PTE, and discuss future directions for efforts aiming at developing antiepileptogenic and disease-modifying treatments.

Deferoxamine alleviates liver fibrosis induced by CCl4 in rats

Several chronic liver diseases can lead to the occurrence of hepatic fibrosis through the accumulation of iron, which causes induction of oxidative stress and consequently activation of fibrogenesis. The present study was designed to investigate the potential antifibrotic and anti-oxidant effects of deferoxamine (DFO), a well-known iron chelator in an experimental rat model of liver injury using carbon tetrachloride (CCl4 ). First, the potential effective dose of DFO was screened against CCl4 -induced acute hepatotoxicity. Then, rats were co-treated with DFO (300 mg/kg, i.p.) for 6 weeks starting from the third week of CCl4 induction of chronic hepatotoxicity. Liver function was assessed in addition to histopathological examination. Furthermore, oxidative stress and fibrosis markers were assessed. It was found that treatment of animals with DFO significantly counteracted the changes in liver function; histopathological lesions and hepatic iron deposition that were induced by CCl4 . DFO also significantly counteracted the CCl4 -induced lipid peroxidation increase and reduction in antioxidant activities of superoxide dismutase and glutathione peroxidase enzymes. In addition, DFO ameliorated significantly liver fibrosis markers including hydroxyproline, collagen accumulation, and the expression of the hepatic stellate cells (HSCs) activation marker; alpha smooth muscle actin and transforming growth factor-beta (TGF-β). Together, these findings indicate that DFO possesses a potent antifibrotic effect due to its antioxidant properties that counteracted oxidative stress and lipid peroxidation and restored antioxidant enzymes activities as well as reducing HSCs activation and fibrogenesis.

Antioxidant and antiapoptotic effects of darbepoetin-α against traumatic brain injury in rats

INTRODUCTION

In this study, we tried to determine whether darbepoetin-α would protect the brain from oxidative stress and apoptosis in a rat traumatic brain injury model.

MATERIAL AND METHODS

The animals were randomized into four groups; group 1 (sham), group 2 (trauma), group 3 (darbepoetin α), group 4 (methylprednisolone). In the sham group only the skin incision was performed. In all the other groups, a moderate traumatic brain injury modelwas applied.

RESULTS

Following trauma both glutathione peroxidase, superoxide dismutase levels decreased (p < 0.001 for both); darbepoetin-α increased the activity of both antioxidant enzymes (p = 0.001 and p < 0.001 respectively). Trauma caused significant elevation in the nitric oxide synthetase and xanthine oxidase levels (p < 0.001 for both). Administration of darbepoetin-α significantly decreased the levels of nitric oxide synthetase and xanthine oxidase (p < 0.001 for both). Also, trauma caused significant elevation in the nitric oxide levels (p < 0.001); darbepoetin-α administration caused statistically significant reduction in the nitric oxide levels (p < 0.001). On the other hand, malondialdehyde levels were increased following trauma (p < 0.001), and darbepoetin α significantly reduced the malondialdehyde levels (p < 0.001). Due to the elevated apoptotic activity following the injury, caspase-3 activity increased significantly. Darbepoetin-α treatment significantly inhibited apoptosis by lowering the caspase-3 activity (p < 0.001). In the darbepoetin group, histopathological score was lower than the trauma group (p = 0.016).

CONCLUSIONS

In this study, darbepoetin-α was shown to be at least as effective as methylprednisolone in protecting brain from oxidative stress, lipid peroxidation and apoptosis.

Desferrioxamine effectively attenuates testicular tissue at the end of 3 h of ischemia but not in an equal period of reperfusion

OBJECTIVE

To investigate the effect of desferrioxamine (DFX) on ipsilateral and contralateral testis damage caused by experimental testis torsion and detorsion.

MATERIALS AND METHODS

Forty rats were divided into five groups (n = 8): control, torsion (T), torsion + desferrioxamine (T + DFX), torsion/detorsion (T/D), and torsion/detorsion + desferrioxamine (T/D + DFX). The right testes of the rats were subjected to torsion and detorsion for 3 h each. Thirty minutes before the application of torsion and detorsion, DFX (100 mg/kg) was administered intramuscularly. Blood samples and testicular tissues were examined using specific biochemical and histopathological methods.

RESULTS

Ipsilateral and contralateral testis tissue glutathione levels in the T group decreased compared with the control and T + DFX groups. Plasma glutathione peroxidase activity in the T, T/D, and T/D + DFX groups was lower than in the control group. Plasma catalase activity in the T and T/D groups decreased compared with the control group. Ipsilateral mean seminiferous tubule diameter of the T group was lower than that of the T + DFX group. The ipsilateral mean testis biopsy scores in the T and T/D groups were lower than in the control group.

CONCLUSION

The administration of DFX prior to torsion may be useful only for preventing ischemic damage in ipsilateral and contralateral testes.

The protective effect of 2-mercaptoethane sulfonate (MESNA) against traumatic brain injury in rats

BACKGROUND

The agent, 2-mercaptoethane sulfonate (MESNA), is a synthetic small molecule, widely used as a systemic protective agent against chemotherapy toxicity, but is primarily used to reduce hemorrhagic cystitis induced by cyclophosphamide. Because MESNA has potential antioxidant and cytoprotective effects, so we hypothesized that MESNA may protect the brain against traumatic injury.

METHOD

Thirty-two rats were randomized into four groups of eight animals each; Group 1 (sham), Group 2 (trauma), Group 3 (150 mg/kg MESNA), Group 4 (30 mg/kg methylprednisolone). Only skin incision was performed in the sham group. In all the other groups, the traumatic brain injury model was created by an object weighing 450 g falling freely from a height of 70 cm through a copper tube on to the metal disc over the skull. The drugs were administered immediately after the injury. The animals were killed 24 h later. Brain tissues were extracted for analysis, where levels of tissue malondialdehyde, caspase-3, glutathione peroxidase, superoxide dismutase, nitric oxide, nitric oxide synthetase and xanthine oxidase were analyzed. Also, histopathological evaluation of the tissues was performed.

RESULTS

After head trauma, tissue malondialdehyde levels increased; these levels were significantly decreased by MESNA administration. Caspase-3 levels were increased after trauma, but no effect of MESNA was determined in caspase-3 activity. Following trauma, both glutathione peroxidase and superoxide dismutase levels were decreased; MESNA increased the activity of both these antioxidant enzymes. Also, after trauma, nitric oxide, nitric oxide synthetase and xanthine oxidase levels were increased; administration of MESNA significantly decreased the levels of nitric oxide, nitric oxide synthetase and xanthine oxidase, promising an antioxidant activity. Histopathological analysis showed that MESNA protected the brain tissues well from injury.

CONCLUSIONS

Although further studies considering different dose regimens and time intervals are required, MESNA was shown to be at least as effective as methylprednisolone in the traumatic brain injury model.

Neuroprotective Effects of N-acetylcysteine on Experimental Closed Head Trauma in Rats

N-acetylcysteine (NAC) is a precursor of glutathione, a potent antioxidant, and a free radical scavenger. The beneficial effect of NAC on nervous system ischemia and ischemia/reperfusion models has been well documented. However, the effect of NAC on nervous system trauma remains less understood. Therefore, we aimed to investigate the therapeutic efficacy of NAC with an experimental closed head trauma model in rats. Thirty-six adult male Sprague-Dawley rats were randomly divided into three groups of 12 rats each: Group I (control), Group II (trauma-alone), and Group III (trauma+NAC treatment). In Groups II and III, a cranial impact was delivered to the skull from a height of 7 cm at a point just in front of the coronal suture and over the right hemisphere. Rats were sacrificed at 2 h (Subgroups I-A, II-A, and III-A) and 12 h (Subgroups I-B, II-B, and III-B) after the onset of injury. Brain tissues were removed for biochemical and histopathological investigation. The closed head trauma significantly increased tissue malondialdehyde (MDA) levels (P < 0.05), and significantly decreased tissue superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities (P < 0.05), but not tissue catalase (CAT) activity, when compared with controls. The administration of a single dose of NAC (150 mg/kg) 15 min after the trauma has shown protective effect via decreasing significantly the elevated MDA levels (P < 0.05) and also significantly (P < 0.05) increasing the reduced antioxidant enzyme (SOD and GPx) activities, except CAT activity. In the trauma-alone group, the neurons became extensively dark and degenerated into picnotic nuclei. The morphology of neurons in the NAC treatment group was well protected. The number of neurons in the trauma-alone group was significantly less than that of both the control and trauma+NAC treatment groups. In conclusion, the NAC treatment might be beneficial in preventing trauma-induced oxidative brain tissue damage, thus showing potential for clinical implications.

Screening for the formation of reactive oxygen species and of NO in muscle tissue and remote organs upon mechanical trauma to the mouse hind limb

BACKGROUND

Until now, no systematic surveys exist in the literature on the early local and systemic generation of reactive oxygen species and of nitric oxide in response to muscle crush injury. Therefore, this study aims to evaluate the formation of reactive oxygen species and nitric oxide in different tissues (injured and contralateral muscle, liver, kidney, spleen and blood) that is induced by closed muscle trauma.

METHODS

5, 45 and 180 min after induction of blunt trauma to the mouse gastrocnemius muscle, animals were sacrificed, tissues harvested and homogenized, and analyzed for their content of glutathione, nitrate and thiobarbituric acid-reactive substances.

RESULTS

The local formation of reactive oxygen species in the injured muscle started immediately upon induction of the mechanical trauma as indicated by changes in the glutathione redox balance. Liver and kidney did not show any response to trauma; however, a marked and immediate increase in the splenic nitrate content was detected, thus suggesting a specific nitric oxide-dependent response of splenic cells to injury.

CONCLUSION

We conclude that immediately after the induction of trauma a formation of reactive oxygen species takes place at the site of crush injury. This might constitute the basis of further damage to the injured tissue by free radical-dependent mechanisms. The immediate formation of nitric oxide within the spleen upon muscle crush appears to represent a specific signalling mechanism of the body in response to distant organ injury.

Antioxidant properties of propofol and erythropoietin after closed head injury in rats

Reactive oxygen species play a role during brain injury due to closed head trauma. Enzymatic or nonenzymatic antioxidants may protect brain tissue against oxidative damage. The present study was performed to assess the changes of endogenous indices of oxidative stress in serum from rats subjected to head trauma and whether treatment with propofol and/or erythropoietin (EPO) modifies the levels of endogenous indices of oxidative stress. For these purposes, female Wistar Albino rats were divided into five groups: non-traumatic sham group, trauma performed control, trauma with propofol (i.p.), trauma with EPO (i.p.) and trauma with propofol and EPO performed study groups. At the end of the experimental procedure, blood was taken by cardiac puncture to determine superoxide dismutase (SOD) and xanthine oxidase (XO) activities as well as malondialdehyde (MDA) and nitric oxide (NO) levels in serum. Serum MDA level of control traumatic brain injury (TBI) group was significantly higher than sham operation group (p<0.012). Serum MDA levels in propofol, EPO and propofol+EPO groups were found to be decreased in comparison with control group (p<0.039, p<0.030 and p<0.018, respectively). Serum NO level was found to be increased in TBI group, but difference was not statistically significant when compared to sham-operated group (p=0.092). Propofol, EPO and propofol+EPO administration efficiently reduced serum NO levels to reach sham-operated group (p<0.002, p<0.001 and p<0.015, respectively). These results suggested that acute administration of both propofol and EPO altered the indices of oxidative stress similarly against brain injury due to trauma.

Deferoxamine-induced attenuation of brain edema and neurological deficits in a rat model of intracerebral hemorrhage

OBJECT

Previous studies undertaken by the authors have indicated that iron accumulation and oxidative stress in the brain contribute to secondary brain damage after intracerebral hemorrhage (ICH). In the present study the authors investigate whether deferoxamine, an iron chelator, can reduce ICH-induced brain injury.

METHODS

Male Sprague-Dawley rats each received an infusion of 100 microl of autologous whole blood into the right basal ganglia and were killed 1, 3, or 7 days later. Iron distribution was examined histochemically (enhanced Perls reaction). The effects of deferoxamine on ICH-induced brain injury were examined by measuring brain edema and neurological deficits. Immunohistochemical analysis was performed to investigate 8-hydroxyl-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, and Western blot analysis was performed to measure the amount of apurinic/apyrimidinic endonuclease/redox effector factor-1 (APE/Ref-1), a repair mechanism for DNA oxidative damage. Iron accumulation was observed in the perihematomal zone from 1 day after ICH. Deferoxamine attenuated brain edema, neurological deficits, and ICH-induced changes in 8-OHdG and APE/Ref-1.

CONCLUSIONS

Deferoxamine and other iron chelators may be potential therapeutic agents for ICH. They may act by reducing the oxidative stress caused by the release of iron from the hematoma.

Deferoxamine-induced attenuation of brain edema and neurological deficits in a rat model of intracerebral hemorrhage

Object

In the authors' previous studies they found that brain iron accumulation and oxidative stress contribute to secondary brain damage after intracerebral hemorrhage (ICH). In the present study they investigated whether deferoxamine, an iron chelator, can reduce ICH-induced brain injury.

Methods

Male Sprague–Dawley rats received an infusion of 100 μl of autologous whole blood into the right basal ganglia and were killed 1, 3, or 7 days thereafter. Iron distribution was examined histochemically (enhanced Perl reaction). The effects of deferoxamine on ICH-induced brain injury were examined by measuring brain edema and neurological deficits. Apurinic/apyrimidinic endonuclease/redox effector factor–1 (APE/Ref-1), a repair mechanism for DNA oxidative damage, was quantitated by Western blot analysis.

Iron accumulation was observed in the perihematoma zone beginning 1 day after ICH. Deferoxamine attenuated brain edema, neurological deficits, and ICH-induced changes in APE/Ref-1.

Conclusions

Deferoxamine and other iron chelators may be potential therapeutic agents for treating ICH. They may act by reducing the oxidative stress caused by the release of iron from the hematoma.