Caffeic acid phenethyl ester (CAPE) protects brain against oxidative stress and inflammation induced by diabetes in rats

Diabetic patients reveal significant disorders, such as nephropathy, cardiomyopathy, and neuropathy. As oxidative stress and inflammation seem to be implicated in the pathogenesis of diabetic brain, we aimed to investigate the effects of caffeic acid phenethyl ester (CAPE) on oxidative stress and inflammation in diabetic rat brain. Diabetes was induced by a single dose of streptozotocin (45 mg kg⁻¹, i.p.) injection into rats. Two days after streptozotocin treatment 10 μM kg⁻¹ day⁻¹ CAPE was administrated and continued for 60 days. Here, we demonstrate that CAPE significantly decreased the levels of nitric oxide and malondialdehyde induced by diabetes, and the activities of catalase, glutathione peroxidase, and xanthine oxidase in the brain. However, glutathione levels were increased by CAPE. The mRNA expressions of tumor necrosis factor (TNF)-α and interferon (IFN)-γ, and inducible nitric oxide synthase (iNOS) were remarkably enhanced in brain by diabetes. CAPE treatments significantly suppressed these inflammatory cytokines (about 70% for TNF-α, 26% for IFN-γ) and NOS (completely). Anti-inflammatory cytokine IL-10 mRNA expression was not affected by either diabetes or CAPE treatments. In conclusion, diabetes induces oxidative stress and inflammation in the brain, and these may be contributory mechanisms involved in this disorder. CAPE treatment may reverse the diabetic-induced oxidative stress in rat brains. Moreover, CAPE reduces the mRNA expressions of TNF-α and IFN-γ in diabetic brain; suggesting CAPE suppresses inflammation as well as oxidative stress occurred in the brain of diabetic patients.     

Ameliorative role of genistein against age-dependent chronic arsenic toxicity in murine brains via the regulation of oxidative stress and inflammatory signaling cascades

Brain is highly prone to oxidative damage due to its huge lipid content and extensive energy requirements. Exogenous insult in brain via oxidative injury can lead to severe pathophysiological conditions. Age-dependent deterioration of normal brain functions is also noteworthy. Genistein, a polyphenolic isoflavonoid, obtained from the soy plant, is well known to protect against several diseased conditions. Here, in this study chronic brain toxicity model was developed using oral administration of arsenic for 90 days in adult and aged murines. We observed that intraperitoneal administration of genistein improved the arsenic induced behavioral abnormalities in the rats. It was also evident from the histopathological studies that the extent of tissue damage due to arsenic exposure was more in aged rats compared to the adults. Evaluation of different stress markers, intracellular ROS level and mitochondrial membrane potential revealed the involvement of oxidative stress and mitochondrial dysfunction in inducing brain damage in arsenic exposed murines. It was observed that genistein can significantly ameliorate the stressed condition in both the animal groups but the protective effect of genistein was more significant in the adult animals. The underlying signalling mechanism behind the cytotoxicity of arsenic was investigated and revealed that genistein exhibited neuroprotection significantly by modulating the JNK3 mediated apoptosis, ERK1/2 mediated autophagy and TNFα associated inflammatory pathways. Overall study infers that genistein has significant ameliorative effect of against age-dependent cytotoxicity of arsenic in murine brains.     

Heart protective effects and mechanism of quercetin preconditioning on anti-myocardial ischemia reperfusion (IR) injuries in rats

In this study, we investigated the effects and mechanism of quercetin preconditioning on anti-myocardial ischemia reperfusion (IR) injuries in vivo. Meanwhile, their potential anti-oxidative stress and anti-inflammation effect were assessed. SD rats were orally given quercetin 250 mg/kg. Myocardium apoptosis was determined with TUNEL staining. The biomarkers related to myocardial ischemia injury were determined. Simultaneously, hemodynamic parameters were monitored as left ventricular systolic pressure (LVSP), LV end-diastolic pressure (LVEDP) and maximal rate of increase and decrease of left ventricular pressure (dP/dtmax). The oxidative stress indicators and inflammatory factors were also evaluated. Western blot method was used for analysis of PI3K, Akt, p-Akt, Bax and Bcl-2 protein expressions. The results showed that quercetin significantly reduced apoptosis rate, improved cardiac function, decreased levels of creatine kinase (CK), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH). Quercetin also restrained the oxidative stress related to myocardial ischemia injury as evidenced by decreased malondialdehyde (MDA), and elevated GSH, superoxide dismutase (SOD), catalase (CAT), glutathione-peroxidase (GSH-Px), glutathione reductase (GR) activity. Meanwhile, the inflammatory cascade was inhibited as evidenced by decreased cytokines such as tumor necrosis factor-α (TNF-α), C-reactive protein (CRP) and interleukin-1β (IL-1β). Our results still showed that quercetin pretreatment significantly inhibited the apoptosis by decreasing the number of apoptotic cells, decreasing the level of cleaved Bax, and increasing the level of Bcl-2 in rats subjected to I/R injury. Simultaneously, quercetin pretreatment markedly increased the phosphorylation of Akt. Blockade of PI3K activity by LY294002, dramatically abolished its anti-apoptotic effect and lowered Akt phosphorylation level. It can be concluded that quercetin pretreatment was protected against myocardium IR injury by decreasing oxidative stress, repressing inflammatory cascade, inhibiting apoptosis in vivo and PI3K/Akt pathway involved in the anti-apoptotic effect.     

Sevoflurane reduces ischemic brain injury in rats with diet and streptozotocin-induced diabetes

Abstract

To investigate the role of S100B, oxidative stress and the apoptosis signaling pathways in the sevoflurane induced neuroprotective effect on stroke. The brain injury, molecular and cellular damage, and functional recovery were investigated upon ischemic brain injury followed by sevoflurane treatment. Longa rodent stroke scales was used to quantify neurological deficits. TTC staining was used to measure infarct volume of brain tissue. Absolute brain water content was measured by wet/dry weight method. The neuronal morphological change was assessed by H and E staining. The spatial learning and memory ability were measured by water maze test. Serum proteins including S100B, GSH-PX, SOD, Bcl-2, Bax, Caspase-3 were measured by ELISA. The level of NOS and NO in serum was determined by colorimetric method. Compared with control, the serum proteins including S100B, Bax, NO, Caspase-3, and NOS activity in cerebral infarction rats increased significantly while SOD, GSH-PX, and Bcl-2 decreased significantly. Diabetic mellitus complicated with cerebral infarction rats showed more dramatic increase for S100B, Bax, NO, Caspase-3, and NOS activity and dramatic decrease for SOD, GSH-PX, and Bcl-2. Interestingly, sevoflurane reduced the changes significantly. The S100B level positively correlated with brain damage, NO, Bax, caspase-3, and NOS activity but negatively correlated with SOD, Bax, and GSH-PX. Brain damage in sevoflurane groups decreased while behavior outcomes including Longa neurologic score, learning, and memory increased significantly. The neuroprotective effect of sevoflurane is associated with defense mechanisms against free radical-induced oxidative stress and inhibition of apoptosis. S100B protein correlated with oxidative stress and the apoptosis signaling pathways.     

Anti-apoptotic and Anti-oxidative Roles of Quercetin After Traumatic Brain Injury

Experimental studies have demonstrated significant secondary damage (including cell apoptosis, blood–brain barrier disruption, inflammatory responses, excitotoxic damage, and free radical production) after traumatic brain injury (TBI). Quercetin is a natural flavonoid found in high quantities in fruits and vegetables, and may be a potential antioxidant and free radical scavenger. The purpose of this study was to determine the effects of quercetin on TBI-induced upregulation of oxidative stress, inflammation, and apoptosis in adult Sprague–Dawley rats. Animals were subjected to Feeney’s weight-drop injury, thus inducing the parietal contusion brain injury model. Quercetin was administered (30 mg/kg intraperitoneal injection) 0, 24, 48, and 72 h after TBI. Quercetin reduced cognitive deficits, the number of TUNEL- and ED-1-positive cells, the protein expressions of Bax and cleaved-caspase-3 proteins, and the levels of TBARS and proinflammatory cytokines, and increased the activity of antioxidant enzymes (GSH-Px, SOD, and CAT) at 1 week after TBI. Our results suggest that in TBI rats, quercetin improves cognitive function owing to its neuroprotective action via the inhibition of oxidative stress, leading to a reduced inflammatory response, thereby reducing neuronal death.     

RETRACTED ARTICLE: Effect of preischemic treatment with fenofibrate,a peroxisome proliferator-activated receptor-α ligand,on hepatic ischemia–reperfusion injury in rats

Liver ischemia/reperfusion (I/R) injury is a serious clinical problem. The reactive oxygen species (ROS) and tumor necrosis factor alpha (TNF-α) are important mediators in liver I/R injury. This study was designed to investigate the effect of preischemic treatment with fenofibrate (Peroxisome proliferator-activated receptor- α agonist) on the oxidative stress and inflammatory response to hepatic I/R injury in rats. Hepatic I/R was induced by clamping the blood supply of the left lateral and median lobes of the liver for 60 min, followed by reperfusion for 4 h. Each animal group was pretreated with a single dose of fenofibrate (50 mg/kg body weight) intraperitoneally 1 h before ischemia. At the end of reperfusion, blood samples and liver tissues were obtained to assess serum alanine aminotransferase (ALT), TNF-α, hepatic malondialdehyde (MDA) and superoxide dismutase activity (SOD). Liver specimens were obtained and processed for light and electron microscopic study. Hepatic I/R induced a significant elevation of serum ALT and TNF-α with significant elevation of hepatic MDA and reduction of SOD activity. Histopathological examination revealed hepatic inflammation, necrosis and apoptosis. Preischemic treatment with fenofibrate at a dose of 50 mg/kg significantly attenuated the biochemical and structural alterations of I/R-induced liver injury.     

Lanthanum chloride suppresses oxysterol-induced ECV-304 cell apoptosis via inhibition of intracellular Ca<Superscript>2+</Superscript> concentration elevation,oxidative stress,and activation of ERK and NF-κB signaling pathways

Experimental studies have demonstrated that oral administration of lanthanum chloride (LaCl₃) inhibits the development of atherosclerosis, but the related mechanism has not been fully elucidated. Oxysterols are toxic to the vascular endothelial cells which are important in preventing the formation and progression of atheromatous plaque. In this study, we examined the effect of LaCl₃ on oxysterol cholestane-3β,5α,6β-triol (Triol)-induced apoptosis and the related mechanisms in ECV-304 cells, a presumptive endothelial cell line. Incubation with Triol resulted in apoptosis of ECV-304 cells, as determined by Hoechst 33342 staining, fluorescein isothiocyanate labeled annexin V/propidium iodide double staining, and the loss of mitochondrial membrane potential. Triol activated extracellular-signal-regulated kinase (ERK) and nuclear factor κB (NF-κB), and inhibition of Triol-activated ERK and NF-κB signaling by specific inhibitors attenuated apoptosis induction by Triol in ECV-304 cells. Pretreatment with LaCl₃ (1 μM) for 12 h before exposure to Triol decreased Triol-mediated apoptosis as well as activation of ERK and NF-κB. In addition, Triol induced oxidative stress in ECV-304 cells, manifested by the increase of intracellular reactive oxygen species generation and malondialdehyde level, and the reduction of the content of total protein thiols and the activity of antioxidant glutathione peroxidases; LaCl₃ pretreatment significantly reversed these effects. Finally, LaCl₃ pretreatment significantly inhibited the increases of intracellular Ca²⁺ concentration induced by Triol. Our study suggests that Triol induced ECV-304 cell apoptosis, and LaCl₃ could suppress this effect probably by inhibiting intracellular Ca²⁺ concentration elevation, oxidative stress, as well as activation of ERK and NF-κB signaling pathways.     

Induction of hemeoxygenase-1 reduces glomerular injury and apoptosis in diabetic spontaneously hypertensive rats

Induction of hemeoxygenase-1 (HO-1) lowers blood pressure and reduces organ damage in hypertensive animal models; however, a potential protective role for HO-1 induction against diabetic-induced glomerular injury remains unclear. We hypothesize that HO-1 induction will protect against diabetes-induced glomerular injury by maintaining glomerular integrity and inhibiting renal apoptosis, inflammation, and oxidative stress. Diabetes was induced with streptozotocin in spontaneously hypertensive rats (SHR) as a model where the coexistence of hypertension and diabetes aggravates the progression of diabetic renal injury. Control and diabetic SHR were randomized to receive vehicle or the HO-1 inducer cobalt protoporphyrin (CoPP). Glomerular albumin permeability was significantly greater in diabetic SHR compared with control, consistent with an increase in apoptosis and decreased glomerular nephrin and α(3)β(1)-integrin protein expression in diabetic SHR. CoPP significantly reduced albumin permeability and apoptosis and restored nephrin and α(3)β(1)-integrin protein expression levels in diabetic SHR. Glomerular injury in diabetic SHR was also associated with increases in NF-κB-induced inflammation and oxidative stress relative to vehicle-treated SHR, and CoPP significantly blunted diabetes-induced increases in glomerular inflammation and oxidative stress in diabetic SHR. These effects were specific to exogenous stimulation of HO-1, since incubation with the HO inhibitor stannous mesoporphyrin alone did not alter glomerular inflammatory markers or oxidative stress yet was able to prevent CoPP-mediated decreases in these parameters. These data suggest that induction of HO-1 reduces diabetic induced-glomerular injury and apoptosis and these effects are associated with decreased NF-κB-induced inflammation and oxidative stress.     

Alterations in antioxidant enzymes and oxidative damage in experimental diabetic rat tissues: Effect of vanadate and fenugreek (Trigonella foenum graecum)

With the premise that oxygen free radicals may be responsible for the severity and complications of diabetes, the level of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as the oxidative damage were examined in the tissues of control, diabetic and treated rats. After three weeks of diabetes, the activity of CAT was significantly increased in heart in diabetes (about 6-fold) but decreased in liver. The SOD activity decreased significantly in liver but increased in brain. The activity of GPx decreased significantly in liver and increased in kidney. A significant increase was observed in oxidative damage in heart and kidney and a small increase in brain with decrease in liver and muscle. Vanadate and fenugreek (Trigonella foenum graecum) administration to diabetic animals showed a reversal of the disturbed antioxidant levels and peroxidative damage. Results suggest that oxidative stress play a key role in the complications of diabetes. Vanadate and fenugreek seeds showed an encouraging antioxidant property and can be valuable candidates in the treatment of the reversal of the complications of diabetes.     

Gastroprotective effect of leptin in indomethacin-induced gastric injury

This study investigated the involvement of neutrophil infiltration, disturbances in nitric oxide (NO) generation and oxidative stress in indomethacin-induced gastric ulcer, and the possible gastroprotective potentials of leptin, known for its angiogenic effect. Male Wistar albino rats (180–220 g) were allocated into a normal control group, ulcer control group (received a single dose of indomethacin 40 mg/kg p.o.) and an ulcer group pretreated with leptin (10 μg/kg i.p. 30 min before ulcer induction). The animals were killed 6 h after indomethacin administration and their gastric juice, serum and mucosal tissue were used for gastric injury evaluation. Indomethacin produced multiple lesions in glandular mucosa, evidenced by marked increase in gastric ulcer index (GUI) accompanied by significant increases in gastric juice acidity, tissue myeloperoxidase (MPO) activity, serum NO and tissue conjugated diene (CD), and marked decreases in tissue NO and glutathione (GSH) as well as glutathione reductase (GR) and superoxide dismutase (SOD) activities, while gastric juice mucin and tissue glutathione peroxidase (GPx) were not affected. Leptin exerted significant gastroprotection as evidenced by significantly decreased GUI and attenuated neutrophil infiltration. Leptin significantly increased mucin and tissue NO, restored GR and SOD activities and up-regulated GPx activity. It failed to affect acidity, serum NO, GSH and CD. These results suggest that leptin confers significant gastroprotection against indomethacin-induced injury through interfering with neutrophil infiltration, NO production and oxidative stress.     

The anti-inflammatory and anti-apoptotic effects of nesfatin-1 in the traumatic rat brain

Nesfatin-1 has been demonstrated to possess anti-inflammatory and anti-apoptotic effects in the rat brain with subarachnoid hemorrhage. The study was designed to investigate the influence of nesfatin-1 on inflammatory responses and neuronal cell apoptosis after traumatic brain injury. Wistar rats were subjected to 5, 10 or 20 μg/kg of nesfatin-1 at designed time points (0.5, 2, 4 or 8h after head trauma) intraperitoneally. Rats were sacrificed at hours 2, 6 and 12, as well as day 1, 2, 3 and 5 after head trauma. The administration of 10 or 20 μg/kg of nesfatin-1 at hour 0.5 after head trauma could significantly suppress gene expressions of nuclear factor kappa-B, lessen concentrations of tumor necrosis factor-alpha, interleukin-1beta and interleukin-6, diminish caspase-3 activity as well as reduce number of apoptotic neuronal cells in traumatic rat brain tissues (P<0.05), but the administration of 5 μg/kg of nesfatin-1 not (P>0.05). Moreover, 20 μg/kg nesfatin-1 also significantly suppressed the inflammation and neuronal cell apoptosis when applied 2, 4 or 8h after head trauma. However, a clear concentration-response or time-response relationship was not found. These findings suggest that nesfatin-1 may inhibit nuclear factor kappa-B-dependent inflammatory responses, and lessen caspase-3-mediated neuronal cell apoptosis after traumatic brain injury in rats.     

Chronic hydrogen-rich saline treatment reduces oxidative stress and attenuates left ventricular hypertrophy in spontaneous hypertensive rats

In hypertensive animals and patients, oxidative stress represents the primary risk factor for progression of left ventricular hypertrophy. Recently, it has been demonstrated that hydrogen, as a novel antioxidant, can selectively reduce hydroxyl radicals and peroxynitrite anion to exert therapeutic antioxidant activity. In the current study, we explored the effect of chronic treatment with hydrogen-rich saline (HRS) on left ventricular hypertrophy in spontaneously hypertensive rats (SHR). The 8-week-old male SHR and age-matched Wistar-Kyoto rats (WKY) were randomized into HRS-treated (6 ml/kg/day for 3 months, i.p.) and vehicle-treated groups. HRS treatment had no significant effect on blood pressure, but it effectively attenuated left ventricular hypertrophy in SHR. HRS treatment abated oxidative stress, restored the activity of antioxidant enzymes including GPx, GST, catalase, and SOD, suppressed NADPH oxidase activity and downregulated Nox2 and Nox4 expression in left ventricles of SHR. HRS treatment suppressed pro-inflammatory cytokines including IL-1β, IL-6, TNF-α, and MCP-1, and inhibited NF-κB activation through preventing IκBα degradation in left ventricles of SHR. HRS treatment preserved mitochondrial function through restoring electron transport chain enzyme activity, repressing ROS formation, and enhancing ATP production in left ventricles of SHR. Moreover, HRS treatment suppressed ACE expression and locally reduced angiotensin II generation in left ventricles of SHR. In conclusion, HRS treatment attenuates left ventricular hypertrophy through abating oxidative stress, suppressing inflammatory process, preserving mitochondrial function, in which suppression of HRS on angiotensin II in left ventricles locally might be involved.     

Inhibition of inflammation and oxidative stress by an imidazopyridine derivative X22 prevents heart injury from obesity

Inflammation and oxidative stress plays an important role in the development of obesity‐related complications and cardiovascular disease. Benzimidazole and imidazopyridine compounds are a class of compounds with a variety of activities, including anti‐inflammatory, antioxidant and anti‐cancer. X22 is an imidazopyridine derivative we synthesized and evaluated previously for anti‐inflammatory activity in lipopolysaccharide‐stimulated macrophages. However, its ability to alleviate obesity‐induced heart injury via its anti‐inflammatory actions was unclear. This study was designed to evaluate the cardioprotective effects of X22 using cell culture studies and a high‐fat diet rat model. We observed that palmitic acid treatment in cardiac‐derived H9c2 cells induced a significant increase in reactive oxygen species, inflammation, apoptosis, fibrosis and hypertrophy. All of these changes were inhibited by treatment with X22. Furthermore, oral administration of X22 suppressed high‐fat diet‐induced oxidative stress, inflammation, apoptosis, hypertrophy and fibrosis in rat heart tissues and decreased serum lipid concentration. We also found that the anti‐inflammatory and anti‐oxidative actions of X22 were associated with Nrf2 activation and nuclear factor‐kappaB (NF‐κB) inhibition, respectively, both in vitro and in vivo. The results of this study indicate that X22 may be a promising cardioprotective agent and that Nrf2 and NF‐κB may be important therapeutic targets for obesity‐related complications.     

alpha-Phenyl-n-tert-butyl-nitrone reduces lipopolysaccharide-induced white matter injury in the neonatal rat brain

Lipopolysaccharide (LPS)-induced white matter injury in the neonatal rat brain is at least partially associated with oxidative stress. alpha-Phenyl-n-tert-butyl-nitrone (PBN) (100 mg/kg) significantly attenuated LPS (1 mg/kg)-induced brain injury, as indicated by the reduction in bilateral ventricular enlargement, apoptotic cell death of oligodendrocytes (OLs), and the loss of OL immunoreactivity in the neonatal rat brain. Protection of PBN was linked with the attenuated oxidative stress induced by LPS, as indicated by the decreased elevation of 8-isoprostane content and by the reduced number of 4-hydroxynonenal or malondialdehyde positive OLs following LPS exposure. Interestingly, while LPS exposure elevated, rather than depleted, levels of the reduced glutathione (GSH) and the GSH/GSSG (oxidized form) ratio, LPS exposure significantly suppressed glutathione peroxidase activity in the rat brain. PBN attenuated LPS-induced alterations in glutathione homeostasis in the rat brain. Additionally, the inflammatory responses were also reduced in the PBN-treated brain, as indicated by the decreased number of activated microglia following LPS exposure and by the consequently decreased elevation of interleukin1-beta and tumor necrosis factor-alpha contents in the rat brain. The overall results suggest that antioxidant PBN, more than a straightforward free radical scavenger, may also involve anti-inflammatory and anti-apoptotic properties in protection of the neonatal rat brain from LPS-induced injury.     

Catalase Activity and Thiobarbituric Acid Reactive Substances (TBARS) Production in a Rat Model of Diffuse Axonal Injury. Effect of Gadolinium and Amiloride

This study evaluated the effect of mechanogated membrane ion channel blockers on brain catalase (CAT) activity and thiobarbituric acid reactive substances (TBARS) production after traumatic brain injury (TBI). A weight drop trauma model was used. Controls were sham-operated and received no weight drop. Gadolinium (GAD) or amiloride (AMI) were administered to control and experimental rats (30 min after TBI). Brain CAT activity and TBARS production were measured. When blood vessels were washed out with saline perfusion brain CAT activity significantly increased up to 6 h after trauma, decreasing significantly by 24 h; GAD or AMI administration preserved CAT activity 24 h after TBI. TBARS production increased after trauma, this effect being significantly reversed by GAD or AMI administration. GAD significantly decreased TBARS production in control animals. Mechanogated membrane ion channels may be involved in the genesis of the ionic disruption leading to oxidative stress and other secondary injury processes in head trauma.     

Modulation of autophagy in traumatic brain injury

Traumatic brain injury (TBI) is defined as a traumatically induced structural injury or physiological disruption of brain function as a result of external forces, leading to adult disability and death. A growing body of evidence reveals that alterations in autophagy-related proteins exist extensively in both experimentally and clinically after TBI. Of note, the autophagy pathway plays an essential role in pathophysiological processes, such as oxidative stress, inflammatory response, and apoptosis, thus contributing to neurological properties of TBI. With this in mind, this review summarizes a comprehensive overview on the beneficial and detrimental effects of autophagy in pathophysiological conditions and how these activities are linked to the pathogenesis of TBI. Moreover, the relationship between oxidative stress, inflammation, apoptosis, and autophagy occur TBI. Ultimately, multiple compounds and various drugs targeting the autophagy pathway are well described in TBI. Therefore, autophagy flux represents a potential clinical therapeutic value for the treatment of TBI and its complications.     

The circadian nuclear receptor RORα negatively regulates cerebral ischemia–reperfusion injury and mediates the neuroprotective effects of melatonin

Disruptions of the circadian rhythm and reduced circulating levels of the circadian hormone melatonin predispose to ischemic stroke. Although the nuclear receptor RORα is considered as a circadian rhythm regulator and a mediator of certain melatonin effects, its potential role in cerebral ischemia-reperfusion (CI/R) injury and in the neuroprotective effects of melatonin remain undefined. Here, we observed that CI/R injury in RORα-deficient mice was associated with greater cerebral infarct size, brain edema, and cerebral apoptosis compared with wild-type model. In contrast, transgenic mice with brain-specific overexpression of RORα versus non-transgenic controls exerted significantly reduced infarct volume, brain edema and apoptotic response induced by CI/R. Mechanistically, RORα deficiency was found to exacerbate apoptosis pathways mediated by endoplasmic-reticulum stress and mitochondria and aggravate oxidative/nitrative stress after CI/R. Further studies revealed that RORα deficiency intensified the activation of nuclear factor-κB signaling induced by CI/R. Given the emerging evidence of RORα as an essential melatonin activity mediator, we further investigated the RORα roles in melatonin-exerted neuroprotection against acute ischemic stroke. Melatonin treatment significantly decreased infarct volume and cerebral apoptosis; mitigated endoplasmic reticulum stress and mitochondrial dysfunction; and inhibited CI/R injury-induced oxidative/nitrative stress and nuclear factor-κB activation, which was eradicated in RORα-deficient mice. Collectively, current findings suggest that RORα is a novel endogenous neuroprotective receptor, and a pivotal mediator of melatonin's suppressive effects against CI/R injury.     

Tenoxicam Modulates Antioxidant Redox System and Lipid Peroxidation in Rat Brain

We investigated effects of two doses of Tenoxicam, a type 2 cyclooxygenase inhibitor, administration on lipid peroxidation and antioxidant redox system in cortex of the brain in rats. Twenty-two male Wistar rats were randomly divided into three groups. First group was used as control. 10 and 20 mg/kg body weight Tenoxicam were intramuscularly administrated to rats constituting the second and third groups for 10 days, respectively. Both dose of Tenoxicam administration resulted in significant increase in the glutathione peroxidase activity, reduced glutathione and vitamins C and E of cortex of the brain. The lipid peroxidation levels in the cortex of the brain were significantly decreased by the administration. Vitamin A and β-carotene concentration was not affected by the administration. There was no statistical difference in all values between 10 and 20 mg Tenoxicam administrated groups. In conclusion, treatment of brain with 10 and 20 mg Tenoxicam has protective effects on the oxidative stress by inhibiting free radical and supporting antioxidant redox system.     

Oxidative Burst of Circulating Neutrophils Following Traumatic Brain Injury in Human

Besides secondary injury at the lesional site, Traumatic brain injury (TBI) can cause a systemic inflammatory response, which may cause damage to initially unaffected organs and potentially further exacerbate the original injury. Here we investigated plasma levels of important inflammatory mediators, oxidative activity of circulating leukocytes, particularly focusing on neutrophils, from TBI subjects and control subjects with general trauma from 6 hours to 2 weeks following injury, comparing with values from uninjured subjects. We observed increased plasma level of inflammatory cytokines/molecules TNF-α, IL-6 and CRP, dramatically increased circulating leukocyte counts and elevated expression of TNF-α and iNOS in circulating leukocytes from TBI patients, which suggests a systemic inflammatory response following TBI. Our data further showed increased free radical production in leukocyte homogenates and elevated expression of key oxidative enzymes iNOS, COX-2 and NADPH oxidase (gp91^phox) in circulating leukocytes, indicating an intense induction of oxidative burst following TBI, which is significantly greater than that in control subjects with general trauma. Furthermore, flow cytometry assay proved neutrophils as the largest population in circulation after TBI and showed significantly up-regulated oxidative activity and suppressed phagocytosis rate for circulating neutrophils following brain trauma. It suggests that the highly activated neutrophils might play an important role in the secondary damage, even outside the injured brain. Taken together, the potent systemic inflammatory response induced by TBI, especially the intensively increase oxidative activity of circulating leukocytes, mainly neutrophils, may lead to a systemic damage, dysfunction/damage of bystander tissues/organs and even further exacerbate secondary local damage. Controlling these pathophysiological processes may be a promising therapeutic strategy and will protect unaffected organs and the injured brain from the secondary damage.     

Neuroprotective Effect of Hydrogen-Rich Saline in Global Cerebral Ischemia/Reperfusion Rats: Up-Regulated Tregs and Down-Regulated miR-21, miR-210 and NF-κB Expression

Recently, it has been suggested that molecular hydrogen (H₂) can selectively reduce the levels of hydroxyl radicals (.OH), and ameliorate oxidative and inflammatory injuries to organs in global cerebral ischemia reperfusion models. Global cerebral ischemia/reperfusion (I/R) can induce a sudden activation of inflammatory cytokines and later influence the systemic immunoreactivity which may contribute to a worse outcome. Regulatory T cells (Tregs) are involved in several pathological aspects of cerebral I/R. In addition, miRNA took part in the processes of cellular response to hypoxia. Since the expression of a specific set of miRNA called “hypoxamirs” is upregulated by hypoxia. Therefore, the aim of this study was to analyze the effect of HRS on I/R inducing cerebral damage, Tregs, and specific miRNA. Our results showed that rats undergone global cerebral I/R and treated with HRS have milder injury than I/R animals without HRS treatment. miR-210 expression in the hippocampus of the I/R group at 6, 24 and 96 h after reperfusion was significantly increased at each time point, while its expression in the group treated with HRS was significantly decreased. In addition, Tregs number in group I/R was decreased at each time points, while its number in the group treated with HRS was increased at 24 and 96 h after reperfusion. We focus on the relationship among Tregs, TGF-β1, TNF-α and NF-κB at 24 h, and we found that there is a high correlation among them. Therefore, our results indicated that the brain resuscitation mechanism in the HRS-treated rats may be related with the effect of upregulating the number of Treg cells.