Hyperbaric Oxygen Preconditioning Group Research Articles

Hyperbaric oxygen preconditioning attenuates brain injury after intracerebral hemorrhage by regulating microglia polarization in rats.

AimsHyperbaric oxygen preconditioning (HBOP) attenuates brain edema, microglia activation, and inflammation after intracerebral hemorrhage (ICH). In this present study, we investigated the role of HBOP in ICH‐induced microglia polarization and the potential involved signal pathway.MethodsMale Sprague‐Dawley rats were divided into three groups: SHAM, ICH, and ICH + HBOP group. Before surgery, rats in SHAM and HBOP groups received HBO for 5 days. Rats in SHAM group received needle injection, while rats in ICH and ICH + HBOP groups received 100 μL autologous blood injection into the right basal ganglia. Rats were euthanized at 24 hours after ICH, and the brains were removed for immunohistochemistry and Western blotting. Neurological deficits and brain water content were determined.ResultsIntracerebral hemorrhage induced brain edema, which was significantly lower in the HBOP group. The levels of MMP9 were also less in the HBOP group. HBO pretreatment resulted in less neuronal death and neurological deficits after ICH. Their immunoactivity and protein levels of M1 markers were downregulated, but the M2 markers were unchanged by HBOP. In addition, ICH‐induced pro‐inflammatory cytokine (TNF‐α and IL‐1β) levels and the phosphorylation of JNK and STAT1 were also lower in the HBOP rats.ConclusionsHBO pretreatment attenuated ICH‐induced brain injuries and MMP9 upregulation, which may through the inhibiting of M1 polarization of microglia and inflammatory signal pathways after ICH.

Injection of SVF combined with HBO2 improves viability of unfavorably designed flaps

Soft-tissue reconstruction is complicated by ischemia and reperfusion injury. Animal trials have documented the independent healing benefits of hyperbaric oxygen preconditioning (HBOP) and stem cell delivery in cutaneous flaps. We explored the role of HBOP and stem cell delivery in flap preconditioning and survival. We designed a randomized controlled trial to assess the effects of hyperbaric oxygen preconditioning and stromal vascular fraction (SVF) delivery on flap survival. Of the first 24 guinea pigs, six received neither HBOP nor injections, and six underwent HBOP without injections. Of the remaining 12 animals, six received SVF or saline injections in the absence of HBOP. The final six animals received autologous SVF injections or saline injections followed by four HBOP treatments. To enhance clinical relevance, a group of 6 animals underwent HBOP prior to SVF or saline injections. Thereafter, an unfavorably designed cutaneous flap was elevated and assessed via study-blinded observer, as well as by quantification of TUNEL-positive cells. Distal necrosis of the tissue flap was more extensive in the no-intervention group (45% of flap). Flaps treated with HBOP only and those treated with SVF injections demonstrated only 38.2% and 27.1% distal necrosis. The most significant difference occurred in the combination HBOP and SVF group, where distal necrosis was only 21.1% of the flap (p ≤ 0.05). SVF delivery immediately prior to flap elevation further minimized distal necrosis of the flap to 15.6%. These findings were mirrored by the TUNEL assay. Combining HBOP and SVF improves flap viability.

Analysis the effect of hyperbaric oxygen preconditioning on neuronal apoptosis, Ca2+ concentration and caspases expression after spinal cord injury in rats.

To investigate the effects of hyperbaric oxygen preconditioning (HBO-PC) on neuronal apoptosis, Ca2+ concentration, and Caspases expression after spinal cord injury (SCI) in rats. A total of 36 rats were randomly divided into control group (CON group), hyperbaric oxygen preconditioning group (HBO-PC group) and spinal cord injury group (SCI group), with 12 rats in each group. Rats in group HBO-PC were given HBO-PC intervention before modeling. SCI model was established by modified Allen method in group HBO-PC and group SCI. Basso-Beattie-Bresnahan (BBB) locomotor rating scale and motor evoked potential (MEP) examination were used to assess the neurological function. The expression of apoptosis gene caspase (3, 7, 8, 12) mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). The concentration of Ca2+ in spinal cord tissue of each group was detected. CON group, HBO-PC group, and SCI group were gradually diminishing in BBB score and potential value and amplitude of MEP, respectively. The differences between groups were statistically significant (p<0.05). The expressions of Caspase-3 and 7, 8 and 12 mRNA in SCI group were significantly higher than those in CON group and HBO-PC group, respectively (p<0.05). There was no significant difference between CON group and HBO-PC group (p>0.05). The concentrations of Ca2+ in the CON group, HBO-PC group and SCI group were gradually increased; differences between groups were statistically significant (p<0.05). HBO-PC can reduce the loss of motor function of SCI rats, which may inhibit the activation of endoplasmic reticulum pathway of neural apoptosis, and reduce the calcium overload through inhibiting the expressions of pro-apoptotic proteins (Caspase-3/7/8/12), thus reducing the cell apoptosis and protecting neurons.

The effect of hyperbaric oxygen preconditioning on the expression of ICAM-1, VCAM-1, NF-κB and flap survival rate during ischemia-reperfusion injury in rat abdominal skin flap

To evaluate the effect of hyperbaric oxygen preconditioning on the expression of intercellular adhesion molecule-1 (ICAM-1),vascular cell adhesion molecule-1 (VCAM-1),NF-κB and flap survival rate during Ischemia-Reperfusion Injury in Rat Abdominal Skin Flap. 18 male adult SD rats were divided randomly into sham group (SH),ischemia-reperfusion group (IR) and hyperbaric oxygen preconditioning group (HBO),6 rats in each group. The rats in HBO group received regular hyperbaric oxygen treatment for three days (twice a day with an interval of 12 h) before operation. An abdominal skin flap pedicled with superficial epigastric artery was established. Ischemia lasted for 3 hours in the IR group and HBO group.On the third postoperative day,samples were taken to evaluate the expression of ICAM-1,VCAM-1 and NF-κB by immunohistochemistry staining and Western Blot. In the IR group, the flap survival rate and average blood perfusion were (22.38 ±4.35) ％ and (32.61 ±5.68) PU, while in the HBO group they were (45.34 ±3.15) ％ and (61.78 ±3.61) PU, showing significant difference between the two groups (P ＜0.01).The inflammatory cell infiltration condition in IR group was much higher than that in the HBO group from the HE staining observation. Compared with the HBO group,ICAM-1,VCAM-1 and NF-κB showed (+ + +) with higher positive cells in the IR group (P ＜ 0.01). Results of Western Blot showed similar conclusion. The relative expression of ICAM-1,VCAM-1 and NF-κB was much higher in the IR group than that in the HBO group (P ＜ 0.01). Hyperbaric oxygen preconditioning could decrease the expression of ICAM-1,VCAM-1,NF-κB and promote flap survival rate during the process of ischemia-reperfusion injury on a rat abdominal skin flap model.

Hyperbaric oxygen preconditioning ameliorates blood-brain barrier damage induced by hypoxia through modulation of tight junction proteins in an in vitro model.

AimTo explore the effects of hyperbaric oxygen preconditioning (HBOP) on the permeability of blood-brain barrier (BBB) and expression of tight junction proteins under hypoxic conditions in vitro.MethodsA BBB in vitro model was constructed using the hCMEC/D3 cell line and used when its trans-endothelial electrical resistance (TEER) reached 80-120 Ω · cm2 (tested by Millicell-Electrical Resistance System). The cells were randomly divided into the control group cultured under normal conditions, the group cultured under hypoxic conditions (2%O2) for 24 h (hypoxia group), and the group first subjected to HBOP for 2 h and then to hypoxia (HBOP group). Occludin and ZO-1 expression were analyzed by immunofluorescence assay.ResultsNormal hCMEC/D3 was spindle-shaped and tightly integrated. TEER was significantly reduced in the hypoxia (P = 0.001) and HBOP group (P = 0.014) compared to control group, with a greater decrease in the hypoxia group. Occludin membranous expression was significantly decreased in the hypoxia group (P = 0.001) compared to the control group, but there was no change in the HBOP group. ZO-1 membranous expression was significantly decreased (P = 0.002) and cytoplasmic expression was significantly increased (P = 0.001) in the hypoxia group compared to the control group, although overall expression levels did not change. In the HBOP group, there was no significant change in ZO-1 expression compared to the control group.ConclusionHyperbaric oxygen preconditioning protected the integrity of BBB in an in vitro model through modulation of occludin and ZO-1 expression under hypoxic conditions.

Hyperbaric oxygen preconditioning attenuates neuroinflammation after intracerebral hemorrhage in rats by regulating microglia characteristics

Intracerebral Hemorrhage (ICH) results in a detrimental neurologic disorder with complicated secondary brain injury. Hyperbaric oxygen preconditioning (HBOP) may be a safe and effective therapeutic method for ICH victims. Our previous studies have demonstrated that HBOP induces neuroprotection in cerebral ischemia and traumatic brain injury. This study aimed to investigate whether HBOP could alleviate neuroinflammation by regulating changes in microglia characteristics in a rat model of ICH. ICH was induced by autologous arterial blood injection, and animals were sacrificed at 12, 24, and 72h post injury. We measured motor function and brain water content to evaluate the extent of inflammation. Fluoro-Jade C and TNF-α staining was used to characterize neuronal degeneration and neuroinflammatory cytokines, and immunofluorescence staining was performed for CD11b to show activated microglia and Iba-1 to show microglia. Our results indicate that motor dysfunction and brain water content are alleviated by HBOP, and Fluoro-Jade C staining demonstrates that neuron degeneration decreased in the HBOP group. The growth of Iba-1-positive microglia decreased in the HBOP group. Moreover, TNF-α was dynamically reduced in the HBOP group compared with the ICH group. CD11b-Iba-1 double staining demonstrated that the ratio of CD11b and Iba-1 was significantly decreased in the HBOP group. Overall, the data demonstrated that HBOP could significantly alleviate the ICH-induced neuroinflammation by regulating microglia characteristics changing. The phenomenon may propel the progress of the relation between microglia and HBOP and represent a novel target for ICH treatment.

Effect of hyperbaric oxygen preconditioning on peri-hemorrhagic focal edema and aquaporin-4 expression.

The aim of the present study was to investigate the effect of hyperbaric oxygen preconditioning (HBO-PC) on peri-hemorrhagic focal edema and aquaporin-4 (AQP-4) expression in an experimental intracerebral hemorrhage (ICH) rat model. Sixty-six Sprague Dawley® rats were divided into three groups: The sham-surgery group (SHG; n=6); the control group (A-ICH; n=30), in which the rats were injected with autologous blood; and the experimental HBO-PC group (P-HBO; n=30). The rats underwent brain edema and AQP-4 detection at 5 postoperative time-points (24, 48 and 72 h and 5 and 7 days). The water content in the brain tissues of the A-ICH animals was higher than that in the brain tissues of the SHG rats at each time-point (P<0.05), and the edema in the P-HBO was significantly more severe 24 and 48 h postoperatively than that at 7 days postoperatively (P<0.05). The difference between the P-HBO and A-ICH was significant at 48 and 72 h postoperatively (P<0.05). AQP-4 was expressed in the post-hemorrhagic rat brains of all groups; the SHG animals exhibited low expression, while the A-ICH animals exhibited an increased expression 24 h postoperatively. In the A-ICH, expression peaked at 48 h postoperatively and began to decrease gradually after 72 h. At the 7-day time-point, the expression level in the A-ICH was closer to but still higher than that of the SHG animals (P<0.05). The differences between the P-HBO and A-ICH animals at the postoperative 24-h, 48-h and 7-day time-points were statistically significant (P<0.05). In conclusion, HBO-PC may downregulate AQP-4 expression to reduce the intracerebral edema, thus strengthening tolerance to ICH and protecting the nerves.

Angiogenesis contributes to the neuroprotection induced by hyperbaric oxygen preconditioning against focal cerebral ischemia in rats

Ischemic stroke is one of the leading causes of mortality and disability worldwide. Previous studies have indicated that hyperbaric oxygen preconditioning (HBO-PC) can induce neuroprotection against focal cerebral ischemia. However, the underlying mechanisms are still not fully understood, and the optimal regimen for preconditioning must be confirmed. In the present study, we designed eight preconditioning regimens and compared their neuroprotective effects. Hyperbaric oxygen preconditioning every other day for there sessions exhibited the best neuroprotective effect; the infarct volume was reduced by almost 50% at 48 h after middle cerebral artery occlusion. We also found that HBO-PC significantly increased the microvessel density and the CD31-positive cells in the penumbra at 72 h after stroke. These results indicate that angiogenesis is involved in the neuroprotection induced by HBO-PC. Moreover, we explored the roles of HIF-1α and angiogenic factors in the angiogenesis process induced by HBO-PC. The results from western blotting demostrated that protein expression of Ang-2 in the HBO-PC group was significantly increased. In conclusion, HBO-PC reduced brain injury and improved neurological function after focal cerebral ischemia, as partly mediated by the increased microvessel density in the penumbra, and this effect may result from the upregulation of Ang-2.

Osteopontin Mediates Hyperbaric Oxygen Preconditioning-Induced Neuroprotection Against Ischemic Stroke.

Neurosurgical operations may result in surgical injury which would lead to postoperative neurological deficits. Hyperbaric oxygen preconditioning (HBO-PC) may be beneficial for such people. However, the exact mechanism underlying HBO-PC is not well known yet. The aim of this study is to explore the role of osteopontin (OPN) in HBO-PC-induced neuroprotection. The study consisted of two experiments. In experiment 1, Sprague Dawley (SD) rats were divided into four groups: sham group, HBO-PC sham group, stroke group, and HBO-PC group (HBO-PC + stroke). The animals in the second experiment were randomly assigned to one of two groups: OPN small interfering (siRNA) group (HBO-PC + stroke + OPN siRNA) and control siRNA group (HBO-PC + stroke + negative control siRNA). Neurological outcome in HBO-PC group was better than that of stroke group. After OPN siRNA was administered, neurological function aggravated compared with control siRNA group. Brain morphology and structure seen by light microscopy was diminished in stroke group and OPN siRNA group, while fewer pathological injuries occurred in HBO-PC and control siRNA group. The infarct volume in HBO-PC group was the lowest, followed by OPN siRNA group and stroke group, respectively. Preconditioning with HBO promoted expression of OPN, which reduced the expression of interleukin (IL)-1β/nuclear factor-κ-gene binding (NFκB) and augmented protein kinase B (Akt). OPN siRNA reversed these changes. OPN plays an important role in the neuroprotection elicited by HBO-PC. Pretreatment with HBO may be beneficial for people going to undertake brain surgery.

Hemeoxgenase-1 mediates the protective effect of hyperbaric oxygen preconditioning against the brain edema after experimental hemorrhage in rats

Objective To investigate the role of Heme oxygenase-1 in the effect of hyperbaric oxygen preconditioning (HBOP) against the brain edema formation after experimental intracerebral hemorrhage in rats.Methods The study was carried out by animal experiment in two steps by using 54 Spradgue-Dawley rats weighting from 300-350 g.In the first step,rats were treated with HBOP (HBOP group,n =3) or with sham pre-conditioning (Sham pre-conditioning group,n =3).All the rats were sacrificed 24 h after the preconditioning,and basal ganglion of brain tissue was taken for detect HO-1 level by using western blot analysis.In the second step,rats were divided into 4 groups (n =12 in each group):HBOP +ZnPP group,in which rats had a micro-pump intra-peritoneally implanted containing a specific HO-1 inhibitor ZnPPⅨ (Zinc protoporphyrin IX,0.01 mg/kg),Sham pre-conditioning + Znpp group,HBOP + DMSO group,in which rats with a intra-peritoneal micro-pump containing 2 mL Dimethyl sulfoxide (DMSO,a solvent vehicle) and Sham pre-conditioning + DMSO group before HBOP.At 24 hours after the pre-conditioning,rats received an infusion of 100 μL autologous blood into the caudate nucleus to form a simulated intracerebrum hemorrhage (ICH),and were sacrificed 72 h later for brain water content measurements.All data were analyzed by using Stata 7.0 software and statistical analyses were carried out by two-tailed Student t test.Results Compared with the Sham pre-conditioning group,the HBOP group had significant higher level of HO-1.Compared with the Sham pre-conditioning + DMSO group,the HBOP + DMSO group had a significant lower level of water content in the ipsilateral basal ganglion [(81.4 ± 0.9) ％ vs.(82.6 ± 0.8) ％ (P ＜ 0.05)],however,peritoneal infusion of ZnPP Ⅸ before HBOP abolished HBOP-induced protection against brain edema formation after experimental ICH [(82.8 ± 0.9) ％ vs.(82.6 ± 0.7) ％ (P ＞ 0.05)].Conclusions Hyperbaric oxygen preconditioning attenuate brain edema formation after experimental ICH in rats,and this protection is attributed to the activation of HO-1. Key words: Hyperbaric oxygen ; Preconditioning; Rat; Intracerebral hemorrhage ; Brain edema; Heme oxygenase-1 ; Zinc protoporphyrin

Functional recovery in rat spinal cord injury induced by hyperbaric oxygen preconditioning

Background: It is a common belief that neurosurgical interventions can cause inevitable damage resulting from the procedure itself in surgery especially for intramedullary spinal cord tumors. The present study was designed to examine if hyperbaric oxygen preconditioning (HBO-PC) was neuroprotective against surgical injuries using a rat model of spinal cord injury (SCI).Methods: Sprague–Dawley rats were randomly divided into three groups: HBO-PC group, hypobaric hypoxic preconditioning (HH-PC) control group, and normobaric control group. All groups were subjected to SCI by weight drop device. Rats from each group were examined for neurological behavior and electrophysiological function. Tissue sections were analyzed by using immunohistochemistry, TdT-mediated dUTP-biotin nick end labeling, and axonal tract tracing.Results: Significant neurological deficits were observed after SCI and HBO-PC and HH-PC improved neurological deficits 1 week post-injury. The latencies of motor-evoked potential and somatosensory-evoked potential were significantly delayed after SCI, which was attenuated by HBO-PC and HH-PC. Compared with normobaric control group, pretreatment with HBO and hypobaric hypoxia significantly reduced the number of TdT-mediated dUTP-biotin nick end labeling-positive cells, and increased nestin-positive cells. HBO-PC and HH-PC enhanced axonal growth after SCI.Conclusions: In conclusion, preconditioning with HBO and hypobaric hypoxia can facilitate functional recovery and suppress cell apoptosis after SCI and may prove to be a useful preventive strategy to neurosurgical SCI.

Hyperbaric oxygen preconditioning attenuates hyperglycemia enhanced hemorrhagic transformation after transient MCAO in rats

BackgroundHemorrhagic transformation (HT) can be a devastating complication of ischemic stroke. Hyperbaric oxygen preconditioning (HBO-PC) has been shown to improve blood-brain barrier (BBB) permeability in stroke models. The purpose of this study is to examine whether HBO-PC attenuates HT after focal cerebral ischemia, and to investigate whether the mechanism of HBO-PC against HT includes up-regulation of antioxidants in hyperglycemic rats.MethodsMale Sprague-Dawley rats (280-320 g) were divided into the following groups: sham, middle cerebral artery occlusion (MCAO) for 2 h, and MCAO treated with HBO-PC. HBO-PC was conducted giving 100% oxygen at 2.5 atm absolute (ATA), for 1 h at every 24 h interval for 5 days. At 24 h after the last session of HBO-PC, rats received an injection of 50% glucose (6 ml/kg intraperitoneally) and were subjected to MCAO 15 min later. At 24 h after MCAO, neurological behavior tests, infarct volume, blood-brain barrier permeability, and hemoglobin content were measured to evaluate the effect of HBO-PC. Western blot analysis of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was evaluated at multiple time-points before and after MCAO.ResultsHBO-PC improved neurological behavior test, and reduced infarction volume, HT and Evans blue extravasation in the ipsilateral hemisphere at 24 h after MCAO. Western blot analysis failed to demonstrate up-regulation of Nrf2 in HBO-PC group before and after MCAO. Paradoxically, HBO-PC decreased HO-1 expression at 24 h after MCAO, as compared with htMCAO group.ConclusionsHBO-PC improved neurological deficits, infarction volume, BBB disruption, and HT after focal cerebral ischemia. However, its mechanism against focal cerebral ischemia and HT may not include activation of Nrf2 and subsequent HO-1 expression.

Hyperbaric oxygen preconditioning attenuates brain edema induced by infra-cerebral hemorrhage in the experimental rate

Objective To investigate the effects of hyperbaric oxygen preconditioning (HBOP) on brain edema, inflammatory reaction and neuronal cell apoptosis induced by experimental hemorrhage in rats. Method Eighteen male Spraque-Dawley rats, weighing 300 - 350 g,received five successive sessions of HBOP with 3 atmosphere absolute pressure and 100% O2 one hour daily for five successive days, and other eighteen rats received five successive sessions of pretreatment with one atmosphere absolute pressure, air, one hour daily for five successive days. Twenty-four hours after the final pre-conditioning, rats received an infusion of 100 μL autologous blood into the basal ganglion. Seventy-two hours later, rats were sacrificed for brain edema measurements in 12 rats of each group. The histopathological changes around the hematoma were observed microscopically, and the neuronal cell apoptosis was detected by using the terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) in six rats of each group. Data of brain water content were analyzed by using Stata 7.0 software and statistical analysis was carried out by two-tailed Student t -test. Results Compared with the control group, HBOP significantly attenuated brain edema 72 hours after intra-cerebral hemorrhage in experimental rats (81. 6± 0. 7% vs. 82. 8± 0.9%, P < 0.01). Inflammatory cell infiltration and neuronal cell apoptosis were also significantly decreased in the HBOP group. Conclusions HBOP protects the rats against brain edema formation, and quells inflammatory reaction and neuronal cell apoptosis following intra-cerebral hemorrhage in experimental rats. Key words: Hyperbaric oxygen; Preconditioning; Rat; Intracerebral hemorrhage; Brain edema; Inflammatory reaction; Apoptosis; Animal model

Amelioration of rCBF and PbtO2 following TBI at high altitude by hyperbaric oxygen pre-conditioning

Objectives: Hypobaric hypoxia at high altitude can lead to brain damage and pre-conditioning with hyperbaric oxygen (HBO) can reduce ischemic/hypoxic brain injury. This study investigates the effects of high altitude on traumatic brain injury (TBI) and examines the neuroprotection provided by HBO pre-conditioning against TBI.Methods: Rats were randomly divided into four groups: HBO pre-conditioning group (HBOP, n = 10), high altitude group (HA, n = 10), plain control group (PC, n = 10) and plain sham operation group (sham, n = 10). All groups were subjected to head trauma by weight drop device except for the sham group. Rats from each group were examined for neurological function, regional cerebral blood flow (rCBF) and brain tissue oxygen pressure (PbtO2) and were killed for analysis by transmission electron microscope.Results: The score of neurological deficits in the HA group was highest, followed by the HBOP group and the PC group, respectively. Both rCBF and PbtO2 were the lowest in the HA group. Brain morphology and structure seen via the transmission electron microscope was diminished in the HA group, while fewer pathological injuries occurred in the HBOP and PC groups.Conclusions: High altitude aggravates TBI significantly and HBO pre-conditioning can attenuate TBI in rats at high altitude by improvement of rCBF and PbtO2. Pre-treatment with HBO might be beneficial for people traveling to high altitude locations.

Effect of hyperbaric oxygen and ozone preconditioning on oxidative/nitrosative stress induced by tourniquet ischemia/reperfusion in rat skeletal muscle

The aim of the study was to investigate the effect of hyperbaric oxygen-preconditioning (HBO-PC) and ozone-preconditioning (O3-PC) on oxidative/nitrosative stress induced by tourniquet ischemia/reperfusion (I/R) in rat skeletal muscle. Thirty-two Wistar-Albino-type male rats included in the study were divided into four groups of equal number: 1) sham operation, 2) I/R, 3) I/R+HBO-PC, or 4) I/R+O3-PC. One session of 3-4 L/min 100% oxygenation for 60 min at 3 absolute atmosphere (ATA) was defined as one dose of HBO; in total, 7 doses of HBO-PC were administered before ischemia. One dose of O3 comprised 0.7 mg/kg ozone/oxygen mixture, administered intraperitoneally; a total of 4 doses of O3-PC were administered before ischemia. The I/R model was performed in anesthetized rats by clipping right femoral artery to induce 2 h ischemia followed by 22 h of reperfusion. The right gastrocnemius muscle and venous blood samples were harvested. Tissue was assayed for levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Serum was assayed to measure the level of nitrite-nitrate (NOx). Tissue MDA level, SOD activity, and serum NOx level were increased, whereas GSHPx was decreased in the I/R group. MDA and NOx levels were decreased, whereas GSH-Px activity was increased in both the I/R+HBO-PC and I/R+O3-PC groups. SOD activity was increased in the I/R+O3-PC group, but did not change significantly in the I/R+HBO-PC group. iNOS staining score and intensity were lower in the I/R+HBO-PC and I/R+O3-PC groups than I/R group. Both O3-PC and HBO-PC reduced tissue lipid peroxidation, NOx levels, and iNOS staining scores in the experimental I/R model. Our data suggest that HBO-PC and O3-PC protect against oxidative/nitrosative stress induced by I/R in rat skeletal muscle.