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The study investigated the potential neuroprotective effects of metformin (MET) on alcohol-induced neurotoxicity in adult Wistar rats. The animals were randomized in four groups (n = 10): control, alcohol (ALC), ALC + MET, and MET. ALC (2 g/kg b.w.) and MET (200 mg/kg b.w.) were orally administered for 21 days, once daily. For the ALC + MET group, MET was administered 2 h after ALC treatment. On day 22, the open field test (OFT) and elevated plus maze (EPM) were performed. MET improved global activity and increased the time spent in unprotected open arms, decreased oxidative stress, both in the frontal lobe and in the hippocampus, and increased neuroglobin expression in the frontal cortex. Histopathologically, an increased neurosecretory activity in the frontal cortex in the ALC + MET group was noticed. Thus, our findings suggest that metformin has antioxidant and anxiolytic effects and may partially reverse the neurotoxic effects induced by ethanol.

Diabetes mellitus and high-fat diets trigger the mechanisms that alter the walls of blood vessels. Gold nanoparticles, as new pharmaceutical drug delivery systems, may be used in the treatment of different diseases. In our study, the aorta was investigated via imaging after the oral administration of gold nanoparticles functionalized with bioactive compounds derived from Cornus mas fruit extract (AuNPsCM) in rats with a high-fat diet and diabetes mellitus. Sprague Dawley female rats that received a high-fat diet (HFD) for 8 months were injected with streptozotocin to develop diabetes mellitus (DM). The rats were randomly allocated into five groups and were treated, for one additional month with HFD, with carboxymethylcellulose (CMC), insulin, pioglitazone, AuNPsCM solution or with Cornus mas L. extract solution. The aorta imaging investigation consisted of echography, magnetic resonance imaging and transmission electron microscopy (TEM). Compared to the rats that received only CMC, the oral administration of AuNPsCM produced significant increases in aorta volume and significant decreases in blood flow velocity, with ultrastructural disorganization of the aorta wall. The oral administration of AuNPsCM altered the aorta wall with effects on the blood flow. [ABSTRACT FROM AUTHOR]

Cornus mas L. extract (CM) presents hypolipidemic, antioxidant and anti-inflammatory activity. Gold nanoparticles (AuNPs) are considered potent delivery systems and may be used to release pharmaceutical compounds at the level of injury. In our study, we used gold nanoparticles functionalized with bioactive compounds from Cornus mas L. (AuNPsCM) in an experimental model of a high-fat diet (HFD), and we assessed their effects on aorta wall but also in the serum, as compared to Cornus mas (CM) administration. Sprague Dawley female rats were fed for 9 months with an HFD. During the last month of the experiment, we randomly allocated the animals into three groups that received, by oral gavage: saline solution, CM solution (0.158 mg/mL polyphenols) or AuNPsCM solution (260 μg Au/kg/day), while a Control group received a standard diet and saline solution. At the end of the experiment, we performed an ultrasonography of the aorta and left ventricle and a histology and transmission electron microscopy of the aorta walls; we investigated the oxidative stress and inflammation in aorta homogenates and in serum and, in addition, the lipid profile. AuNPsCM presented better effects in comparison with the natural extract (CM) on lipid peroxidation (p < 0.01) and TNF-alpha (p < 0.001) in aorta homogenates. In serum, both CM and AuNPsCM decreased the triglycerides (p < 0.001) and C-reactive protein (CM, p < 0.01; AuNPsCM, p < 0.001) and increased the antioxidant protection (p < 0.001), in comparison with the HFD group. In intima, AuNPsCM produced ultrastructural lesions, with the disorganization of intima and subendothelial connective layer, whereas CM administration preserved the intima normal aspect, but with a thinned subendothelial connective layer. AuNPsCM oral administration presented certain antioxidant, anti-inflammatory and hypolipidemic effects in an experimental model of HFD, but with a negative impact on the ultrastructure of aorta walls, highlighted by the intima disorganization. [ABSTRACT FROM AUTHOR]

Resveratrol is a polyphenol with important antioxidant and antiinflammatory roles. Loratadine, as a selective inverse-agonist of peripheral receptor H1, is described as an anti-allergic substance with potential antiinflammatory effects. We aimed to assess the protective capacity of loratadine against oxidative stress produced by inflammation with carrageenan in comparison with a well-known antioxidant compound, resveratrol. Our results showed that resveratrol and loratadine had no protective anti-inflammatory effects in inflamed skin. As expected, resveratrol had antioxidant effects in serum and in liver. Loratadine developed oxidative stress in tegument and serum. In this experimental model, our results do not sustain the initial hypothesis that loratadine could have a protective effect in inflammation, and, in the contrary, is capable of increasing it, by producing an oxidative stress. [ABSTRACT FROM AUTHOR]

The aim of our study was to assess the hepatoprotective and antioxidant effects of chitosan as compared with vitamin E in experimental toxic liver injury induced by carbon tetrachloride. Blood and liver samples were collected in order to assess hepatocytolisis (AST, ALT), oxidative stress (MDA, carbonyl proteins, GSH, SH groups, SOD and CAT), and histopathology examination was performed in order to asses inflammation and fibrosis. Liver enzymes level showed a significant, progressive increase after repeated exposure to CCl4, first in liver tissue, then in the blood. Malondialdehyde and carbonyl proteins significantly increased, and GSH progressively decreased. Chitosan increased the GSH in the liver tissue to a value superior to that of the control group and decreased the AST and MDA level both in the liver and in the blood to values comparable to that of control group. Chitosan decreased carbonyl proteins level in the liver but slightly increased them in the blood. Vitamin E had similar effects concerning liver function and lipid peroxidation, but paradoxically, it induced protein peroxidation both in blood and in liver tissue. Histological modifications support the observed biochemical changes. [ABSTRACT FROM AUTHOR]

Solar ultraviolet radiation (UV) is a major cause of ocular injury contributing to photokeratitis, cataract and pterygium development. The aim of the study was to investigate the oxidant/antioxidant status of Wistar rat eyes after exposure to various doses of UVB in correlation with morphological and structural changes. Five groups of 8 animals each, randomly divided, were treated as follows: group 1: control, no UVB irradiation; group 2: a single UVB exposure to a dose of 45 mJ/cm²; group 3: a single UVB exposure to 90 mJ/cm²; group 4: a single UVB exposure to 180 mJ/cm²; group 5: a single UVB exposure to 360 mJ/cm². At 24 hrs after UVB irradiation the animals were anaesthetized and sacrificed by cervical dislocation. The rat eyes from 5 animals were extracted and used for biochemical determinations and from 3 animals were harvested and used for histopathological investigation. Our results demonstrated that a single UVB exposure at different doses disturbs the oxidant-antioxidant balance in the eye tissues by lipid peroxides generation, activation of CAT and SOD and adaptative increasing of GSH levels, particularly at high doses. Twenty hours following UVB irradiation the cornea showed significant lesions: inflammation, hemorrhage, superficial/deep ulcerous keratitis and epithelial exfoliation. Severity of injuries was dose-dependent. These data suggest that oxidative stress may be responsible for the corneal lesions induced by UVB irradiation. [ABSTRACT FROM AUTHOR]

Background. Protection from oxinitrosative stress can be provided by dietary antioxidants and the supplementation with various antioxidant preparations that under exercise conditions can contribute to the maintenance of exercise capacity and post-exercise recovery. We chose a preparation with a complex antioxidant formula: vitamins, fruit and plant extracts, patented lycopene, grape and olive extracts. Aims. The effect of antioxidant complex supplementation on the aerobic exercise capacity of rats was monitored. Methods. The groups were divided as follows: group I - exercise trained; group II - exercise trained and supplemented with an antioxidant complex; group III - loaded with 15% of weight and exercise trained; group IV - loaded with 15% of weight, exercise trained and supplemented with an antioxidant complex. Aerobic exercise capacity was measured using the running test. Results. Antioxidant supplementation and moderate intensity physical exercise cause a significant increase in aerobic exercise capacity compared to physical exercise of the same intensity without supplementation. Antioxidant supplementation and high intensity physical exercise induce a significant increase in aerobic exercise capacity compared to physical exercise of the same intensity without supplementation. Conclusions. Antioxidant supplementation and high intensity physical exercise determine a significant decrease in aerobic exercise capacity compared to moderate intensity physical exercise with and without antioxidant supplementation. [ABSTRACT FROM AUTHOR]

Purpose: many studies in experimental models have evidenced the presence of inflammation in venous vascular dysfunction and the implication of TNF-α in vascular pathology, through its prooxidant and proinflammatory effect. Starting from these studies, we experimentally investigated the effect of treatment with a TNF-α inhibitor, etanercept, on the oxidant/antioxidant balance in rats, with the partial obstruction of the common femoral vein. Methods: the researches were carried out in 7 groups of animals (n=10 rats/group), 6 groups undergoing surgery and a control group. In 3 groups, the ligation of the common femoral vein was performed (groups 1, 2, 3), 3 groups underwent the ligation of the common femoral vein and received etanercept (groups 4, 5, 6), in a dose of 1 mg/kg, one dose per week, according to data found in literature. The serum indicators of the O/AO balance were determined: indicators for oxidative stress (malondialdehyde (MDA), protein carbonyls (PC)), indicators for non-enzymatic AO defense (thiol groups (SH), hydrogen donors (HD ), glutathione (GSH)) at weeks 1, 2 and three. Results and Conclusions: chronic venous insufficiency with and without anti-TNF-α treatment induced changes in the oxidant/antioxidant balance compared to the control group; after the administration of the anti-TNF-α preparation, oxidative stress was maintained on account of MDA that increased significantly, and decreased significantly on account of PC compared to the untreated groups; after the administration of the anti-TNF-α preparation, at two and three weeks there was an insignificant increase in antioxidant defense on account of HD and GSH compared to the untreated groups; the administered anti-TNF-α preparation had late and insignificant effects in chronic venous insufficiency. [ABSTRACT FROM AUTHOR]

Chronic stress is a major factor that contributes to several disorders. A common animal model, performed in order to evaluate the environmental experimentally-induced-stress is hypothermia. L-Carnitine is a natural substance required in the energetic metabolism of the mammals, which also has an antioxidant function. The aim of the present study was to evaluate the effect of chronic hypothermic stress on oxidant/antioxidant balance in the serum and tissues, (liver and muscle), on rats with and without carnitine supplementation. Rats were divided randomly into four groups often rats each: control group (I); hypothermic stress (II) - exposed to cold stress; supplemented with carnitine (HI) supplemented with carnitine and exposed to hypothermic stress (TV). Our experimental results showed that chronic hypothermic stress increases the oxidative stress (OS) indicators in serum and tissues and decreased those of antioxidant (AO) defense. Carnitine supplementation in chronic hypothermic stress conditions had benefic effects on OS and AO defense indicators, this compound being likely to have favorable effects in an experimental hypothermic stress model. [ABSTRACT FROM AUTHOR]

Myringosclerosis is a common sequel of the ventilation tube treatment of otitis media. Recent studies have established the relationship between reactive oxygen species (ROS) and myringosclerosis.The aim of this experimental study was to investigate the temporal change of oxidants/antioxidants balance at 6, 12, 24, and 48 hours after the myringotomy. Fifty healthy adult male Wistar albino rats, weighing approximate 250-300 g, were randomly separated into five groups (n = 10 rats/group): first group ,of control, nonmyringotimized and four groups myringotimized unilaterally on the left ear. The tympanic membranes were collected from sacrificed rats for biochemical evaluation of parameters of oxidants/antioxidants balance from 1st group and in 6 hours from 2nd group, in 12 hours from 3rd group, in 24 hours from 4th group and in 48 hours from 5th group. The index oxidants were malondialdehyde and carbonyl proteins and the index antioxidants were hydrogen donor ability and sulfhydril groups. Results and conclusions: The changes of oxidants/antioxidants balance and oxidative stress appear after myringotomy in 6 hours and increase in 12, 24, and 48 hours. Myringosclerosis develops promptly after myringotomy. [ABSTRACT FROM AUTHOR]

Background. Thyroid gland is susceptible to oxidative stress. It uses hydrogen peroxide for hormone synthesis and the removal of thyroid tissue may trigger the increase of pro-oxidant processes. Aims. We investigated the antioxidant effects of quercetin and curcumin on the oxidative stress parameters in rats with hemithyroidectomy. Methods. Male albino Wistar rats with hemithyroidectomy were used. The animals were randomly allocated in the following groups: group CMC -received carboxymethyl cellulose (CMC) 1%; Que 20 group -quercetin 20 mg/kg/day; Que 40 group-quercetin 40 mg/kg/day; group Euthyrox -1.3 μg/kg/day of sodium levothyroxine; Curcumin 15 group -15 mg/kg/day of curcumin; Curcumin 30 group -revived 30 mg/kg/day of curcumin. The parameters of the oxidative stress were investigated in serum and thyroid homogenate. Thyroxine (T4) and TSH levels were also evaluated. Results. Quercetin 40 mg/kg/day or Curcumin 30 mg/kg/day administration produced significant modifications: in serum, decreased malondialdehyde (MDA) and increased catalase level; in thyroid gland, decreased MDA, increased glutathione (GSH) and catalase levels. Thyroxine and TSH levels were not modified significantly. Conclusions. Quercetin and curcumin protected against oxidative stress by decreasing the lipid peroxidation and increasing the antioxidant protection. Curcumin presented the best effects. [ABSTRACT FROM AUTHOR]

Background. Oxidative stress, the result of the oxidant/antioxidant imbalance, is involved in the pathogenesis of different diseases associated with inflammation. Aims. The study aimed to investigate the effects of orally administered gold nanoparticles phytoreduced with ellagic acid (AuNPs-EA) on oxidative stress in carrageenan-induced paw oedema, in Wistar rats. Methods. Paw oedema and oxidative stress parameters were investigated in rats after intraplantar carrageenan injection (0.2 ml 1% solution). Prior to this, the animals, randomly allocated into four groups, received, for 15 days, vehicle (1% carboxymethyl cellulose –CMC) (group C), 1 mg/kg/day indomethacin (group I), 40 mg/kg/day ellagic acid (group II) or 0.3 mg/kg/day AuNPs-EA (group III). The paw oedema was evaluated through plethysmometry before and at 2, 6 and 24 hours after carrageenan injection and blood samples, paw tissues and kidneys fragments were collected for oxidative stress investigation. Results. AuNPs-EA and indomethacin administration produced significant decreases of the paw oedema, compared to the control group. Lipid peroxidation was reduced significantly by the tested medication in the paw tissues, but it was increased significantly by AuNPs-EA in the kidneys. The antioxidant protection, evaluated through the GSH/GSSG ratio, was amplified significantly in all rats that received AuNPs-EA and indomethacin, in paw tissues and in serum. Ellagic acid provided antioxidant protection only in the serum. In the kidneys, only indomethacin administration increased significantly GSH/GSSG ratio. Conclusions. AuNPs-EA reduced the paw oedema and oxidative stress in inflamed tissue and in serum, in carrageenaninduced inflammation model. [ABSTRACT FROM AUTHOR]

Aims: The influence of acute ozone (O3) exposure on the tissue oxidant/antioxidant (O/AO) balance in the brain, myocardium, lungs and striated muscles was studied at rest and during exercise. Material and Methods: The research was performed in 3 groups of white male Wistar rats with a weight of 280-300 g: Group I - control group, sedentary rats under normoxia conditions; Group II - sedentary rats, acutely exposed to O3; Group III - animals acutely exposed to O3, followed by exercise under normoxia conditions. The rats were exposed to ozone for 3 days, 5 min/day. Group III was trained daily for 3 days under normoxia conditions by the swimming test. In order to determine the indicators of the oxidant/antioxidant balance, tissue samples from the brain, myocardium, lungs and quadriceps muscle of the anesthetized animals were taken. On the third day the following were measured: malondialdehyde (MDA), protein carbonyls (PC), hydrogen donor capacity (HD) and total sulfhydryl (thiol) group content (SH). Results: Between the indicators of the tissue O/AO balance, significant correlations were evidenced in the brain, myocardium, lungs and muscles. Conclusions: Acute combined stress through O3 pre-exposure and exercise causes OS on account of PC in the brain, myocardium and muscles, a decrease in AO defense capacity on account of HD in the brain, lungs and muscles, and an increase in AO defense capacity in the myocardium. [ABSTRACT FROM AUTHOR]

Objective: Endothelial disorders of the veins are considered to play a role in the pathogenesis of primary varicose veins and oxidative stress is implicated in these disorders. With this aim, we investigated the levels of metabolic markers of oxidative stress after creating partial venous obstruction on an experimental animal model. Methods: Chronic venous hypertension was produced by partial ligation of the superficial and common femoral vein in Wistar rats ( 2 groups: group 1- ligation of the superficial femoral vein, n=30 animals,10 animals/lot; group 2 - ligation of the common femoral vein, n=30 animals,10 animals/lot). At specified intervals blood was collected from the retroorbital sinus of the animals. We investigated the levels of malondialdehyde, carbonilated proteins, glutathion, hydrogen donors and thiol radicals in the study groups and compared the results with a control group. Results: There was statistically significant difference between the study groups and the control group concerning the levels of oxidative stress markers. Plasma levels of malondialdehyde and carbonilated proteins were found higher than in control group at each time point for both study groups.Total antioxidant capacity of the blood was found at decreasing levels compared with controls. Conclusions: The current model of induced venous hypertension demonstrates early changes in the oxidative status of study animals not only in the local area but also in the sistemic circulation. [ABSTRACT FROM AUTHOR]

Background. Carrageenan-induced inflammation implies the release of inflammatory cytokines and also, oxidative stress, with high amounts of reactive oxygen species (ROS) production. Aims. The present study aimed to investigate the effects of a unique dose of chlorogenic acid, orally administered at one hour after a paw inflammation was produced. Methods. The paw edema and oxidative stress parameters in rats that were injected with 0.2 ml carrageenan solution 1% for paw inflammation production were investigated, and after 1 hour they received a single dose of either chlorogenic acid (100 mg/kg or 150 mg/kg) or indomethacin (1 mg/kg), by oral gavage. The paw edema was investigated using the plethysmometer test (at 2, 6 and 24 hours after carrageenan injection) and oxidative stress by spectrophotometry. Malondialdehyde (MDA), glutathione (GSH) and oxidized glutathione (GSSG) levels were investigated from blood samples, paw inflamed skin and kidneys. Results. The present study showed that chlorogenic acid (both doses) and indomethacin produced significant decreases of inflamed paw volume, compared to the control group (rats without treatment). Lipid peroxidation was reduced significantly and the antioxidant protection investigated through the GSH/GSSG ratio was increased significantly in all rats that received medication, in all the tested samples: inflamed skin, serum, kidneys. Conclusions. Chlorogenic acid may reduce efficiently oxidative stress and edema if it is administered during the first phase of carrageenan-induced inflammation. [ABSTRACT FROM AUTHOR]

Background. The beneficial cellular protective and antioxidative effects of melatonin and chitosan, by limiting the molecular destruction, could stimulate the peripheral nerve regeneration and exert a neuroprotective action. Aims. In this study we proposed to investigate the influence of melatonin and chitosan on the functional neuromotor recovery, by measuring the sciatic functional index (SFI) in rats with peripheral nerve injuries. Material and methods. The sciatic nerve was acutely injured by crush lesion in 3 groups of white Wistar rats, male (n=10 animals/group). The experimental groups were: control group, group I - treated with 0,01 mg/kgc melatonin (day 1-28); group II - treated with 1,5 mg/kgc chitosan (day 1-28). SFI was determined in all groups in days 1 and 28. Results. During the recovery period, administration of melatonin and chitosan improved significantly the functional recovery. SFI was significantly better in melatonin treated group than in chitosan treated group. Conclusions. 1) Administration of melatonin and chitosan improves motor function in peripheral nerve lesion recovery. 2) Melatonin has favorable effects on nerve regeneration even in low-doses. 3) The beneficial antioxidative effects of melatonin treatment after sciatic nerve crush injury could persist for the whole time length of peripheral nerve recovery. [ABSTRACT FROM AUTHOR]

Aims. The influence of acute O3 and hypobaric hypoxia exposure on tissue redox reactivity during rest and exercise conditions was studied in the brain, myocardium, lungs and striated muscles. Material and methods. The investigation was performed in 3 groups of white male Wistar rats: group I - control group, sedentary rats under normoxia conditions; group II - sedentary rats exposed to acute combined stress: acute O3 + hypobaric hypoxia; group III - animals exposed to acute combined stress, followed by exercise. Exposure was simulated in the hypobaric chamber for 3 days, 20 hours a day, at 2500 m. Ozone exposure was performed for 3 days, 5 min daily. Group III was trained daily for 3 days under normoxia conditions, by the swimming test. In order to measure the indicators of the oxidant/antioxidant (O/AO) balance, on day 3 tissue samples were taken from the brain, myocardium, lungs and femoral quadriceps muscle. Results. Animals undergoing physical exercise after acute combined stress exposure have a significant increase in oxidative stress (OS) in the lungs compared to controls. In the myocardium and striated muscle, there are OS changes similar to those found in sedentary animals exposed to combined stress. In the brain, there is a significant decrease in OS simultaneously with a significant decrease in AO defense compared to both the control group and the sedentary group exposed to combined stress. Conclusions. Physical exercise performed after acute O3 and hypobaric hypoxia exposure induces significant changes in the O/AO balance in pulmonary, myocardial and brain tissue. Major adaptive changes occur in the lungs, where OS and AO defense increase simultaneously. [ABSTRACT FROM AUTHOR]

Background. Antioxidant supplementation can influence histological changes in myocardial and nerve tissues, after altitude exposure and physical exercise, conditions under which oxidative stress occurs. Aims. To study the histopathological changes induced in the myocardium and the encephalon by physical exercise and antioxidant supplementation after exposure to hypobaric hypoxia. Methods. The research was performed using the Hi-Lo model, in 4 groups of white male Wistar rats, under laboratory conditions corresponding to the altitude of 364 m, O2 = 20.93%: group I - sedentary controls, kept under normoxia conditions; group II - sedentary animals, kept under normoxia conditions and supplemented with an antioxidant complex daily, for 28 days; group III - animals exposed to hypobaric hypoxia corresponding to a 5500 m altitude for 28 days, followed by exercise under normoxia conditions; group IV - animals exposed to hypobaric hypoxia for 28 days, followed by the administration of an antioxidant complex and daily exercise. Groups II and III received a complex of antioxidants - Antioxidant Optimizer, produced by the Jarow company (2010 Jarow Formulas, Los Angeles), distributed by Secom, in a dose of 45 mg/kg body weight, by oral gavage, daily, before exercise. The histopathological study was performed on the myocardium and 3 encephalic areas: hippocampus (Ammon's horn), thalamus and cerebral cortex. Results. Hypobaric hypoxia exposure followed by exercise has beneficial effects on the heart, with a reduction in the number of the foci of chronic progressive cardiomyopathy, and on the nervous system, with the reduction in the number of apoptotic necrotic neurons. The administration of an antioxidant complex does not influence the cardioprotective and neuroprotective effects of hypoxic preconditioning, followed by physical exercise. Conclusions. The Hi-Lo model involving the association of severe chronic intermittent hypobaric hypoxia and aerobic physical exercise under normoxia conditions has favorable cardioprotective and neuroprotective effects. [ABSTRACT FROM AUTHOR]

Background. Immobilization is a stressful agent used in order to induce experimental laboratory stress. The controversies regarding the effects of carnitine administration on motility and emotivity in sportsmen, determined us to perform experimental studies. Aims. The study evaluated the effects of restraint stress on spontaneous motility and emotivity in carnitine supplemented rats. Methods. The study was made on four groups of male rats, adult (n=10 animals/group) Wistar breed, kept for 3 days in standard laboratory temperature (18-20°C): Group I - control, group II - exposed to anakinetic stress, group III - supplemented with carnitine, group IV - supplemented with carnitine and exposed to anakinetic stress. Spontaneous motility and emotivity was evaluated by Open Field Test. Results. The restraint stress determined significant decreases of the spontaneous motility (movement and rearings) and significant increases of the emotivity (defecations and micturitions). Carnitine supplementation in acute restraint stress exposed animals induces significant spontaneous motility decrease and significant emotivity increase as compared to the control group. Conclusions. Acute anakinetic stress with and without carnitine supplementation induces hypomotility and hiperemotivity. [ABSTRACT FROM AUTHOR]

The influence of intrauterine hypobaric hypoxia on prooxidant/antioxidant balance of occipital cortex, corpus callosum and retina of 40 Wistar offspring rats was investigated. Malondialdehyde, thyol groups and reduced glutathione levels were assessed accordingly to each experimental group, as follows: control group - pregnant rats unexposed to hypobaric hypoxia and unprotected with α-lipoic acid; pregnant rats exposed to hypobaric hypoxia; pregnant rats exposed to hypobaric hypoxia and protected with α-lipoic acid; pregnant rats unexposed to hypobaric hypoxia but protected with α-lipoic acid. It was noticed a significant increase (p<0.01) in malondialdehyde levels in group exposed to hypobaric hypoxia as compared to control and to hypobaric hypoxia and α-lipoic acid treated group. Thyol groups had a lower concentration in hypobaric hypoxia group as compared to control group. Also, it was noticed a significant difference between hypobaric hypoxia group and hypobaric hypoxia and α-lipoic acid treated group in all analyzed tissues. On the other hand, glutathione level registered significant differences between hypobaric hypoxia group as compared to control group (p<0.01) and hypobaric hypoxia group as compared to α-lipoic acid treated group (p<0.05) in all analyzed tissues. Hypobaric hypoxia led to an increase in malondialdehyde levels and to a decrease of antioxidant defense (thyol groups and reduced glutathione) in occipital cortex, corpus callosum and retina. α-lipoic acid administration, previously to hypobaric hypoxia exposure, protected thyol groups and reduced glutahione. [ABSTRACT FROM AUTHOR]

Background. Myringosclerosis is a common sequel of ventilation tube treatment of otitis media. Recent studies have established the relationship between reactive oxygen species and myringosclerosis. Objectives. The objective of this study was to investigate the possible effect of topically applied A and C vitamin well know antioxidant agents on prevention of experimentally induced myringosclerosis in rats. Methods. 40 healthy adult Wistar albino rats, weighing approximate 250-300 g, were randomly separated into 4 groups: 1st group control (n=10), nonmyringotomized; 2nd group (n=10) myringotomized unilaterally on the left ear; 3rd group (n=10) myringotomized unilaterally and A vitamin applied to the left ear and 4th group (n=10) myringotomized unilaterally and C vitamin applied to the left ear. The tympanic membranes were collected for biochemical evaluation of parameters of oxidants/antioxidants balance from 1st group and on the 48 hours of the experiment from 2nd, 3rd and 4th groups. Results. Pretreatment with A and C vitamin increases formation of carbonyl proteins and reduces malondialdehyde and antioxidants activities (hydrogen donor ability and sulfhydril groups) in rat tympanic membrane. Conclusion. Topically applied A and C vitamin was found to be no effective in prevention of oxidative stress and development of myringosclerosis. [ABSTRACT FROM AUTHOR]

Sleep apnea, due to the induced hipoxia, leads to severe sleep disturbances and has negative consequences on the physical and psychological health status. The oxidative stress is involved in the pathogenic mechanism of this syndrome. Natural antioxidant supplementation equilibrates the oxidants/antioxidants balance and reduces the effects of the reactive oxygen species. We used 40 male Wistar rates divides into four equal groups. Two of them (I, II) had been kept in atmospheric air, while the other two (III, IV) had been exposed to chronic intermittent hypoxia. Two groups (II, IV) received a daily supplement of polyphenols extracted from grape seeds. After 14 days the spatial learning capacity of all the animals was tested using Morris water maze; then serum and brains samples have been taken in order to asses the parameters of the oxidative stress. We identified an increase in the oxidative stress parameters and a decreased learning ability in the rats exposed to hypoxia. The polyphenols extract improved both the biochemical and the cognitive parameters. [ABSTRACT FROM AUTHOR]

Increased oxidative stress has been described previously in models of hyperthyroidism and in human subjects with Basedow disease. In this study, the influence of a diet enriched in soy on reactive oxygen species production and on antioxidant defence in hepatic tissue was explored. Soy products are attractive because of their beneficial effects on chronic diseases such as cardiovascular diseases, atherosclerosis, and type II diabetes. [ABSTRACT FROM AUTHOR]