Effect of resveratrol on pancreatic oxygen free radicals in rats with severe acute pancreatitis

AIM： To investigate the therapeutic effects of resveratrol （RESV） as a free radical scavenger on experimental severe acute pancreatitis （SAP）. METHODS： Seventy-two male Sprague-Dawley rats were divided randomly into sham operation group, SAP group, and resveratrol-treated group. Pancreatitis was induced by intraductal administration of 0.1 mL/kg 4% sodium taurocholate. RESV was given intravenously at a dose of 20 mg/kg body weight. All animals were killed at 3, 6, 12 h after induction of the model. Serum amylase, pancreatic superoxide dismutase （SOD）, malondialdehyde （MDA）, and myeloperoxidase （MPO） were determined. Pathologic changes of the pancreas were observed under optical microscope. RESULTS： The serum amylase, pancreatic MPO and the score of pathologic damage increased after the induction of pancreatitis, early （3, 6 h） SAP samples were characterized by decreased pancreatic SOD and increased pancreatic MDA. Resveratrol exhibited a protective effect against lipid peroxidation in cell membrane caused by oxygen free radicals in the early stage of SAP. This attenuation of the redox state impairment reduced cellular oxidative damage, as reflected by lower serum amylase, less severe pancreatic lesions, normal pancreatic MDA levels, as well as diminished neutrophil infiltration in pancreas. CONCLUSION： RESV may exert its therapeutic effect on SAP by lowering pancreatic oxidative free radicals and reducing pancreatic tissue infiltration of neutrophils.

Oxygen radical formation does not have an impact in the treatment of severe acute experimental pancreatitis using free cellular hemoglobin

AIM： Microcirculatory dysfunction and free oxygen radicals are important factors in the pathogenesis of severe acute pancreatitis. Additional oxygen delivery might enhance lipid peroxidation but may also improve pancreatic microcirculation. This study assesses the effect of free cellular bovine hemoglobin on the formation of oxygen radicals and microcirculation in a rodent model of severe acute pancreatitis. METHODS： Fifteen minutes after induction of acute pancreatitis Wistar rats received either 0.8 mL bovine hemoglobin （HBOC-200）, hydroxyethyl starch （HES） or 2.4 mL of normal saline to ensure normovolemic substitution. After 6 h of examination the pancreas was excised and rapidly processed for indirect measurement of lipid peroxidation products malondialdehyde （MDA） and reduced glutathione （GSH） in pancreatic tissue. RESULTS： The single application of HBOC-200 improved pancreatic microcirculation and reduced histopathological tissue damage significantly. Tissue concentration of MDA did not differ between the groups. Also no differences in GSH levels were detected.CONCLUSION： Though the single application of HBOC-200 and HES improve pancreatic microcirculation, no differences in lipid peroxidation products were detected. The beneficial effect of additional oxygen supply （HBOC-200） does not lead to enhanced lipid peroxidation.

Effect of Selenium Poisoning on Immune Function and Oxygen Free Radicals in Erythrocyte of Pig

[ Objective] This study was to investigate the effect of selenium（Se） on immune function and oxygen free radicals in erythrocyte of pig. [ Method] Fifteen weanling Landrace piglets as experimental animals were divided into three groups, two testing groups and one control group. For each group, Se content in whole blood, immune function of erythrocytes, activity of whole blood glutathione peroxidase（GSH-Px）, activity of blood plasma superoxide dismutase（SOD）, and blood plasma malondialdehyde（MDA） content were determined. [ Result] Compared with the control group, Se content in whole blood and blood plasma MDA content increased remarkably, while whole blood GSH-Px activity and blood plasma SOD activity decreased; RBC-C1 RR assumed a rise-fall trend, and RBC-ICR showed no obvious change. [Condusion] Se poisoning can reduce the activity of antioxidant enzymes, disturb the balance of oxygen free radicals metabolism, thereby inducing erythrooyte immune function in piglets.

The influence of ultraviolet blood irradiation and oxygenation on oxygen free radicals metabolism in rabbits with soman intoxication

Objective: To investigate the effect of ultraviolet blood irradiation and oxygenation (UBIO) on the metabolism of oxygen free radicals in rabbits with acute soman intoxication. Methods: One hundred rabbits were randomly divided into 5 groups: normal control group, intoxication group, routine therapy group. UBIO therapy group and combined therapy group. After 14 d, the concentration of malondiadehyde(MDA) and activity of superoxide dismutase(SOD), glutathionperoxidase(GSH-Px), catalase (CAT) and total antioxidative capacity (T-AOC) in serum were determined respectively. Results: Compared with the normal control group, the concentration of MDA and activity of CAT in the intoxication group were significantly higher (P < 0. 05). but SOD. GSH-Px activity and T-AOC were significantly lower (P<0. 05). After UBIO or combined therapy, serum MDA level was significantly lower in comparison with intoxication group (P<0. 05). but the activity of SOD. GSH-Px, CAT and T-AOC were higher than intoxication group(P<0. 05). Conclusion: There is an obvious oxygen free radical injury in rabbits with a-cute soman intoxication. UBIO can improve the antioxidation ability of rabbits and may be applied to treat acute soman intoxication as adjunctive therapy.

THE ACTION OF CAPTOPRIL ON SCAVENGING OXYGEN FREE RADICALS

The protective effect of captopril on ischemic myocardium was studied in 40 patients with congenital heart disease accompanied with pulmonary hypertention.Twenty of these patients received captopril 50 mg b.i.d.for three months preoperatively (Group A).The other 20 patients without pretreatment with captopril were used as controls (Group B).In Group A,the cardiac output increased and the pulmonary pressure decreased significantly in the first 24 hours postoperatively,indicating a high cardiac output with a low vascular resistance.The differences or CPK,CPKMB,LDH release between Group A and Group B were highly significant or siguificant from the end of operation to 24 hours postoperatively. Myocardial protection in the reduction of the release of CPK, CPK-MB, LDH might be attributed to action on scavenging oxygen free radicals.

Direct Measurement of Oxygen Free Radicals of the Liver Tissue Following Shock/Reperfusion and Its Significance

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EFFECT OF ACUPUNCTURE ON BLOOD OXYGEN FREE RADICAL AND NO LEVELS IN TREATMENT OF APOPLECTIC SEQUELAE

Objective: To observe the effect of acupuncture on blood oxygen free radical (OFR) and nitric oxide (NO) levels in the treatment of apoplectic sequelae. Methods: A total of 61 cases of apoplectic patients were subjected into this study and randomly divided into "JIN San Zhen" group (n=30) and control group (n=31). Blood lipid peroxidase (LPO), superoxide dismutase (SOD), glutathione peroxidase(GSH Px) and nitric oxide (NO) contents before and after acupuncture treatment were determined with radioimmunoassay. In both groups, acupuncture was given once daily, six times a week, with 4 weeks being a therapeutic course and with the interval between two weeks being a week, 3 courses all together. In "JIN San Zhen" group, acupoints of "JIN San Zhen" were used predominately, while in control group, scalp point Motor Sensory Area (MS 8) was used as the main point. Results: Self comparison showed that after 3 courses of treatment, in both groups, LPO and NO levels decreased significantly (P<0.05-0.01), SOD and GST Px values increased considerably (P<0.05-0.01). Comparison between two groups indicated that the effects of "JIN San Zhen" group are significantly superior to those of control group in raising blood SOD and GST Px levels (P<0.05-0.01) and in lowering blood NO content (P<0.01). Analysis on the correlation between the restoration of neural function and the changes of LPO, SOD and GST Px levels suggested that the effect of acupuncture in improving neural function may be related to changes of the aforementioned indexes. Conclusion: Acupuncture therapy can significantly lower blood LPO and NO levels and evidently raise blood SOD and GST Px levels in stroke patients.

Granulocyte colony-stimulating factor increases extracellular glutamic acid uptake and suppresses free radicals in an experimental model of amyotrophic lateral sclerosis

Excitatory amino acid toxicity and free radical damage play important roles in amyotrophic lateral sclerosis. Granulocyte colony-stimulating factor （G-CSF） protects nerve cells exposed to high-concentrations of glutamic acid, suggesting positive effects in the treatment of amyotrophic lateral sclerosis. The present study induced in vitro motor neuron injury using glutamic acid excitotoxicity, and the biochemical effects of G-CSF on glutamic acid concentration were determined. In addition, the effects of G-CSF on superoxide dismutase, glutathione peroxidase activity in motor neurons, and malondialdehyde and nitric oxide contents were analyzed. Immunohistochemistry was performed to measure neuronal survival. Results revealed that G-CSF significantly suppressed free radical activity, inhibited excitotoxicity, and reduced apoptosis and loss of motor neurons in the anterior horn of the spinal cord.

The Maturation and Senescence in Relation to Ca^2+,CaMContent and Ca^2+-ATPase Activity and Active OxygenMetabolism in Strawberry Fruits

The changes in content of Ca2 + and CaM, Ca2 + -ATPase activity and active oxygen metabolism during strawberry (Fragaria ananassa Duch. cv. Chunxing) fruits maturation and senescence were investigated in this study. The results showed that the soluble Ca2+ content and SOD activity in fruits tended to decline and O2 production rate to increase, the Ca2 + -ATPase activity peaked at first and then declined during fruits maturation and senescence. There were the highest CaM content at white stage in preharvest fruits and at marked senescence stage in postharvest ones. The above biochemical changes in fruits stored at low temperature (4℃)were slower than those stored at normal temperature(25℃). Thus, it indicated that the stimulation of calcium messenger system and accumulation of active oxygen free radical were closely related to fruits maturation and senescence.

The effect of reactive oxygen species of inducing apoptosis on the hepatocacinoma in the rabbits

Objective:To study the effect of reactive oxygen species of inducing apoptosis on the heptocacinoma tissues following ischemia and reperfusion and perfusion hyperoxia liquid of hepatocarcinoma. Methods: The hepatocarcinoma animal models ware established by implantation of VX2 tumor constitution mass into the left middle lobe of liver of rabbits. The animals were subjected to 60 min clamp-induced ischemia of hepatic artery distributing in the left middle lobe followed by reperfusion at 1 h, 1 d, 3 d and 7 d, respectively, and perfusion hyperoxia liquid (partial pressure of oxygen, PO2>80 kPa) at the same time with reperfusion beginning. The concentration of MDA and NO ware tested. Apoptotic changes in the hepatocarcinoma and normal hepatic tissues were observed by means of HE staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Results:The concentration of MDA in normal hepatic tissues and hepatocarcinoma tissue increased followed ischemia and reperfusion especially for reperfusion 1 h (4.61±0.40, 3.10±0.23) and restored to normal level at reperfusion 7 d in normal hepatic tissues but still kept high concentration in the hepatocarcinoma tissue. Even though concentration of MDA in normal hepatic tissues is higher than that of before ischemia and reperfusion, no difference have been found after perfusion of hyperoxia liquid, and in the hepatocarcinoma tissue, the increasing of concentration of MDA was obvious after simply ischemia and reperfusion at reperfusion 1 d (4.25±0.45). The concentration of NO in normal hepatic tissues increased for reperfusion 3 d and 7 d(18.17±0.13, 17.45±0.23),while that of hepatocarcinoma tissue decreased at reperfusion 3 d(15.95±043). After perfusion of hyperoxia liquid, the concentration of NO in normal hepatic tissues kept increasing and that decreased in the hepatocarcinoma tissues in all time point and reached the lowest level at reperfusion 1 d(14.62±0.45).The result demonstrated the changes of concentration of NO and MDA in the hepatocarcinoma tissues ware more obvious than that of normal hepatic tissues(P<0.01). Conclusion:Perfusion of hyperoxia liquid from hepatic portal vein can intensify ischemia and reperfusion injury but less so for normal hepatic tissues.

Middle Molecular Weight Heparinyl Amino Acid Derivatives (MHADs) Function as Indirect Radical Scavengers in Vitro

We conducted the novel synthesis of middle molecular weight heparinyl amino acid derivatives (MHADs) to reduce the adverse effect of heparin (HE) based on its anticoagulant activity. Subsequently, we investigated the radical scavenging effects of 12 kinds of MHAD on cultured human umbilical vein endothelial cells (HUV-ECs) damaged by oxygen free radicals using xanthine and xanthine oxidase in vitro. As a result, middle molecular weight heparinyl phenylalanine, middle molecular weight heparinyl leucine, and middle molecular weight heparinyl tyrosine showed significant protective effects on HUV-ECs. In conclusion, these three HE derivatives might be candidates for therapeutic agents to treat diseases attributed to peroxidation.

Highly efficient catalytic scavenging of oxygen free radicals with graphene-encapsulated metal nanoshields

Normal levels of oxygen free radicals play an important role in cellular signal transduction, redox homeostasis, regulatory pathways, and metabolic processes. However, radiolysis of water induced by high-energy radiation can produce excessive amounts of exogenous oxygen free radicals, which cause severe oxidative damages to all cellular components, disrupt cellular structures and signaling pathways, and eventually lead to death. Herein, we show that hybrid nanoshields based on single-layer graphene encapsulating metal nanoparticles exhibit high catalytic activity in scavenging oxygen superoxide （·O2^-）, hydroxyl （·OH）, and hydroperoxyl （HO2·） free radicals via electron transfer between the single-layer graphene and the metal core, thus achieving biocatalytic scavenging both in vitro and in vivo. The levels of the superoxide enzyme, DNA, and reactive oxygen species measured in vivo dearly show that the nanoshields can efficiently eliminate harmful oxygen free radicals at the cellular level, both in organs and circulating blood. Moreover, the nanoshields lead to an increase in the overall survival rate of gamma ray-irradiated mice to up to 90%, showing the great potential of these systems as protective agents against ionizing radiation.

Direct detection of oxygen free radicals produced in the viscera of burned rats using electron paramagnetic resonance spectroscopy

To detect superoxide anion (O - 2 ) signals in the heart, liver, lung and kidney tissues after burns. Methods: Twenty four male rats were randomized into 4 groups. The rats of experimental groups were immersed in 100℃ water for 15 seconds and 25% third degree burn was created. Thoracotomy or laparotomy was performed at 5, 10, 15, 20 and 30 minutes after burn, and specimens of the heart, lung, liver kidney were obtained for burned rats. The specimens were then preserved in liqu id nitrogen for cryo preservation and detected immediately using EPR. Results: The signals of superoxide O radical appeared in the he art, lung, 1iver and kidney specimens 10 15 minutes after burn. Conclusions: There is a direct evidence of oxygen free radicals (OFRs) injury to viscera of burned rats between 10 15 minutes after burn.

Role of oxygen free radicals in the proliferation of myofibroblasts induced by AngII

Previous studies have demonstrated the important role of angiotension II(AngII)in promoting proliferation of myofibroblasts(myoFbs)and myocardial fibrosis.However,the underlying mechanisms and the role of oxygen free radicals in the proliferation of myofibroblasts induced by AngII are unclear.The present study was designed to shed light on this issue through exploration of AngII signaling pathways via in vitro experiments.Primary cultures of neonatal rat myoFbs were divided into five groups which were treated with AngII(10^(-8) to 10^(-6) M),AngII with the antioxidant N-acetyl-L-cysteine(NAC),or normal culture medium.We observed the proliferation of myoFbs as induced by AngII at different concentrations with MTT.Reactive oxygen species(ROS)levels in myoFbs were detected by monitoring the fluorescence of 2',7'-dichlorofluorescein.The contents and levels of oxygen free radicals(OH·)in the three groups were detected by spectrophotometer,immunocytochemical staining,and confocal fluorescence.Western blot and image analysis were used to measure membrane translocation and expression of phospho-protein kinase Ca.MyoFbs incubated with AngII(10^(-8) to 10^(-6) M)for 24 h increased their rate of proliferation,the content of OH·,and expression of ROS(P<0.01 vs.control group),whereas these parameters decreased in the presence of NAC.Immunocytochemistry,confocal fluorescence staining and image analysis showed that AngII could promote the translocation and expression of p-PKCα in membrane,and the antioxidant NAC blocked this increase(P<0.01).Western blot results also showed that NAC could inhibit the expression of p-PKCα.

Effect of Radix Salviae Miltiorrhizae on Production of Lung Oxygen Free Radical Products during Cardiopulmonary Bypass Operation

Objective: The effect of Radix Salviae Miltiorrhizae (RSM) on production of lung oxygen freeradical products during cardiac operations was researched. Methods: Thirty cases of heart valve replacementwere randomly divided into two groups: RSM treatment group (RSM group ) and control group. Blood sampleswere taken from before (right atrium, RA) and after (left atrium, LA) pulmonary circulation before cardiopulmonary bypass operation and 10 minutes, 45 minutes, 2 hours, 6 hours after the aortic crossclamp removal toobserve the level of peroxidation product and the changes in leucocyte count. Results: The number of leucocytesin LA was smaller than that in RA and the amount of peroxidation product in LA was higher than that in RA(P＜0. 01～0. 05 ) during the early phase of lung reperfusion in the control group. There was no significant difference (P＞0. 05) in the amount of peroxidation product and the leucocyte count between LA and RA in theRSM group. Conclusions: RSM could markedly prevent the lung leucocyte aggregation and reduce the production of lung free radical products. It suggested that the effect of RSM of reducing the lung oxygen free radicalproducts was related to its effect of preventing the lung leucocyte aggregation.

The Prevenlive-Therapeutic Effects of Reduqing (热毒清)on Endotoxin-Induced DIC in Rabbits (Continued)Protection of Hepatocytic Microsomes, Maintenance of CalciumHomeostasis and Reduction of Oxygen Free Radicals

Disseminated intravascular coagulation (DIC) model of rabbits was made by the injectionof endotoxin. Cytochrome P-450 content and aniline hydroxylase activity in hepatocytic microsomes in DICrabbits were significantly reduced. The microviscosity of mitochondrial membrane was elevated, whilethe fluidity of the membrane, and the activities of calcium-magnesium-adenosine triphosphatase and calci-um-adenosine triphosphatase were reduced. Lipid peroxide and xanthine oxidase activities were in-creased. while superoxide dismutase and glutathione peroxidase activities were significantly decreased(P<0.05 or <0. 01) . The changes in the Reduqing test group were not prominent. and the parameters ofthe test group were close to those of the control group. This study suggests that in endotoxin induced DICrabbits the hepatocytic microsomes are injured. calcium homeostasis is disturbed and oxygen free radicalsare notably accumulated. Whereas Reduqing may have a protective effect on hepatocytic microsomestrom the injury, maintain calcium homeostasis and reduce oxygen free radicals in DIC rabbits.

Mechanisms of Inhibitory Effects of Breviscapine on Lipid Peroxidation in Rat Brain Mitochondria

The mechanisms by which breviscapine (Bre) inhibits the lipid preoxidation in rat brain mitochondria were investigated. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. The chelating activities of Bre for Fe 2+ were tested by differential spectrum. Superoxide anion (O 2)from xanthine xanthine oxidase (Xan XO) system and hydroxyl radical (·OH) from FeSO 4 H 2O 2 system were determined with spectrophotometry. It was found that Bre could effectively inhibit the lipid peroxidation of brain mitochondria induced by free radicals driven from Xan XO and FeSO 4 H 2O 2 system. The IC 50 of Bre were 93 01 μmol·L -1 for Xan XO system and 62 18 μmol·L -1 for FeSO 4 H 2O 2 system. Bre also scavenged O 2 and ·OH produced by Xan XO and FeSO 4 H 2O 2 systems. The IC 50 of Bre were 32 63 μmol·L -1 for O - 2 and 20 22 μmol·L -1 for ·OH. Furthermore, the chelating Fe 2+ activity of Bre was shown. It may be concluded that Bre inhibited lipid peroxidation at different stages of the reaction of oxygen free redial with the mitochondria membrane: (1) the formation of ·OH; (2) the initiation of the lipid peroxidation, by chelating Fe 2+ and scavenging O 2 as well as ·OH. The scavenging oxygen free radicals and chelating iron are the mechanisms of inhibitory effect of Bre on lipid peroxidation.

Pathogenesis of pancreatic encephalopathy in severe acute pancreatitis

BACKGROUND: Pancreatic encephalopathy (PE) is a serious complication of severe acute pancreatitis (SAP). In recent years, more and more PE cases have been reported worldwide, and the onset PE in the early stage was regarded as a poor prognosis sign of SAP, but the pathogenesis of PE in SAP still has not been clarified in the past decade. The purpose of this review is to elucidate the possible pathogenesis of PE in SAP. DATA SOURCES: The English-language literature concerning PE in this review came from the Database of MEDLINE (period of 1991-2005), and the keywords of severe acute pancreatitis and pancreatic encephalopathy were used in the searching. RESULTS: Many factors were involved in the pathogenesis of PE in SAP. Pancreatin activation, excessive release of cytokines and oxygen free radicals, microcirculation abnormalities of hemodynamic disturbance, ET-1/NO ratio, hypoxemia, bacterial infection, water and electrolyte imbalance, and vitamin B1 deficiency participated in the development of PE in SAP. CONCLUSIONS: The pathogenesis of PE in SAP has not yet been fully understood. The development of PE in SAP may be a multi-factor process. To find out the possible inducing factor is essential to the clinical management of PE in SAP.

Neuroprotective effect of penehyclidine hydrochloride on focal cerebral ischemia-reperfusion injury

Penehyclidine hydrochloride can promote microcirculation and reduce vascular permeability. However, the role of penehyclidine hydrochlodde in cerebral ischemia-reperfusion injury remains unclear. In this study, in vivo middle cerebral artery occlusion models were established in experimental rats, and penehyclidine hydrochloride pretreatment was given via intravenous injection prior to model establishment. Tetrazolium chloride, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling and immunohistochemical staining showed that, penehyclidine hydrochloride pretreatment markedly attenuated neuronal histopathological changes in the cortex, hippocampus and striatum, reduced infarction size, increased the expression level of BcI-2, decreased the expression level of caspase-3, and inhibited neuronal apoptosis in rats with cerebral ischemia-reperfusion injury. Xanthine oxidase and thiobarbituric acid chromogenic results showed that penehyclidine hydrochloride upregulated the activity of superoxide dismutase and downregulated the concentration of malondialdehyde in the ischemic cerebral cortex and hippocampus, as well as reduced the concentration of extracellular excitatory amino acids in rats with cerebral ischemia-reperfusion injury. In addition, penehyclidine hydrochloride inhibited the expression level of the NR1 subunit in hippocampal nerve cells in vitro following oxygen-glucose deprivation, as detected by PCR. Experimental findings indicate that penehyclidine hydrochloride attenuates neuronal apoptosis and oxidative stress injury after focal cerebral ischemia-reperfusion, thus exerting a neuroprotective effect.

Oxidative stress disturbs energy metabolism of mitochondria in ethanol-induced gastric mucosa injury

AIM: To study the role of mitochondrial energy disorder in the pathogenesis of ethanol-induced gastric mucosa injury. METHODS: Wistar rats were used in this study. A gastric mucosal injury model was established by giving the rats alcohol. Gross and microscopic appearance of gastric mucosa and ultrastructure of mitochondria were evaluated. Malondiadehyde (MDA) in gastric mucosa was measured with thiobarbituric acid. Expression of ATP synthase (ATPase) subunits 6 and 8 in mitochondrial DNA (mtDNA) was determined by reverse transcription polymerase chain reaction (RT- PCR). RESULTS:The gastric mucosal lesion index was correlated with the MDA content in gastric mucosa. As the concentration of ethanol was elevated and theexposure time to ethanol was extended, the content of MDA in gastric mucosa increased and the extent of damage aggravated. The ultrastructure of mitochondria was positively related to the ethanol concentration and exposure time. The expression of mtDNA ATPase subunits 6 and 8 mRNA declined with the increasing MDA content in gastric mucosa after gavage with ethanol. CONCLUSION: Ethanol-induced gastric mucosa injury is related to oxidative stress, which disturbs energy metabolism of mitochondria and plays a critical role in the pathogenesis of ethanol-induced gastric mucosa injury.