Search

Objectives: Alzheimer's disease is a neurodegenerative disorder characterized by progressive loss of memory followed by complete dementia. Furthermore it is the commonest form of dementia affecting older people. In this study we investigated the role of agmatine (Agm) on learning and memory and on parameters of oxidative stress in intracerebroventricular (i.c.v) streptozotocin (STZ) model of Alzheimer's disease in rats. Materials and Methods: We grouped rats as: naive control, sham operated, STZ and STZ+agmatine. Rats were injected bilaterally i.c.v STZ (3mg/kg) using stereotaxic frame on day 1 and 3 to induce experimental Alzheimer's disease. After 14 days from 1st STZ injection, learning and memory impairment of rats were observed in passive avoidance. Following this test, agmatine administered intraperitoneal (i.p.) 40mg/kg twice daily for 7 days. These animals were again subjected to these behavioral tests after 7 days agmatine treatment. On the 21st day after 1st STZ injection all groups were sacrificed by decapitation and brain tissues were collected for oxidative stress measurement. Malondialdehyde (MDA), glutathione (GSH) levels and myeloperoxidase (MPO) activity were measured for estimation of oxidative stress. Results: In this study it has been demonstrated that i.c.v STZ in Alzheimer model can cause disorder in cognitive functions and oxidative damage. Agmatine treatment is found to be effective to prevent both cognitive deficits as well as the oxidative damage. Conclusion: According to results of the current study agmatine, as an endogenous molecule, might be an important modulator in alzheimer's etiopathogenesis. [ABSTRACT FROM AUTHOR]

We investigated the protective effect of Nigella sativa against oxidative injury in the heart and kidney tissues of rats with renovascular hypertension (RVH). RVH model was induced by placing a renal artery clip (2-kidney-1-clip, 2K1C) in Wistar albino rats (n= 8), while sham rats (n= 8) had no clip placement. Starting on the 3rd week after the operation, rats received Nigella sativa (0.2 ml/kg/day, intraperitoneally) or vehicle for the following 6 weeks. Blood pressures (BP) were recorded at the beginning of the study and at the end of the 3rd and 9th weeks. Cardiac functions were assessed using transthoracic echocardiography before the rats were decapitated. Plasma samples were obtained to assay asymmetric dimethylarginine (ADMA), nitric oxide (NO), creatine kinase (CK) and lactate dehydrogenase (LDH) levels. Production of reactive oxidants was monitored by chemiluminescence (CL) assay in the cardiac and renal tissues. Moreover oxidative injury was examined through malondialdehyde (MDA) and glutathione (GSH) levels and Na+,K+-ATPase activity in these tissues. 2K1C caused increased BP and left ventricular (LV) dysfunction, while plasma ADMA, CK, and LDH levels were increased (p<0.05-0.001). Moreover, hypertension caused significant decreases in plasma NO levels, as well as in tissue Na+,K+-ATPase activities and GSH contents, while MDA levels in both tissues were increased (p<0.05-0.001). On the other hand, Nigella sativa treatment significantly reduced BP, attenuated oxidative injury and improved LV function. Nigella sativa protected against hypertension-induced tissue damage and improved cardiovascular function via its antioxidant and antihypertensive actions, suggesting a therapeutic potential of Nigella sativa in renovascular hypertension. [ABSTRACT FROM AUTHOR]

Objectives The putative protective effects of resveratrol against oxidative injury in the heart, kidney and brain tissues of rats induced with the two-kidney, one-clip (2K1C) hypertension model were investigated. Methods Wistar albino rats were divided into sham-operated ( n = 8) or 2K1C groups, in which rats received either resveratrol (10 mg/kg per day, i.p., n = 8), or saline ( n = 8) starting at Week 3 after the surgery and continuing for the following 6 weeks. Indirect blood pressure recordings and echocardiographic images were made to evaluate cardiac function. At the end of Week 9 the animals were decapitated and plasma, heart, kidney and brain were taken for biochemical assays, while aortic rings were prepared for vascular reactivity studies. Key findings 2K1C hypertension resulted in increased blood pressure, aortic hypercontractility and reduced left ventricular function, leading to increased lipid peroxidation and myeloperoxidase activity, concomitant with significant reductions in tissue glutathione, superoxide dismutase, Na+/K+-ATPase and catalase activities in the cardiac, renal and brain tissues, indicating the presence of oxidative tissue damage in peripheral target organs. Elevated plasma levels of lactate dehydrogenase, creatine kinase, as well as reduced plasma levels of antioxidant capacity and nitric oxide further verified the severity of oxidative injury. A 6-week treatment with resveratrol reversed all the measured parameters, ameliorated hypertension-induced oxidative injury in the target organs and improved cardiovascular function. Conclusions Resveratrol improved cardiovascular function through the augmentation of endogenous antioxidants and the inhibition of lipid peroxidation by maintaining a balance in oxidant/antioxidant status, which also ameliorated hypertension-induced oxidative injury in the cardiac, renal and cerebral tissues. [ABSTRACT FROM AUTHOR]

In this study the role of free radicals in naphthalene-induced toxicity and the protection by erdosteine are investigated. Female Sprague-Dawley rats were treated with a single oral dose of 1100 mg naphthalene/kg in corn oil. Erdosteine was given 50 mg/kg/day orally for 3 days before naphthalene treatment and rats were decapitated 24 hours after naphthalene administration. Liver and kidney tissue samples were taken for determination of malondialdehyde (MDA), glutathione (GSH), Na+, K+-ATPase and myeloperoxidase (MPO) activities. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine levels and lactate dehydrogenase (LDH) activity were measured in the serum samples, while TNF-α, IL-1β, IL-6, 8-hydroxy-2'-deoxyguanosine (8- OHdG) and total antioxidant capacity (AOC) were assayed in plasma samples. Naphthalene administration caused a significant decrease in tissue GSH levels, Na+, K+-ATPase activity and plasma AOC levels, which was accompanied with significant increases in tissue MDA levels and MPO activity. Moreover the pro-inflammatory mediators (TNF-α, IL-β, IL-6), 8- OHdG, LDH activity, AST, ALT, creatinine and BUN levels were significantly increased in the naphthalene group. On the other hand erdosteine treatment prevented all these biochemical changes induced by naphthalene. In conclusion, it seems likely that erdostein protects tissues by inhibiting neutrophil infiltration, balancing the oxidant-antioxidant status and regulating the generation of inflammatory mediators. [ABSTRACT FROM AUTHOR]

The protective effect of resveratrol against nicotine induced oxidative damage on urogenital tissues was evaluated by biochemical, histological and functional studies. Wistar Albino rats were injected with either nicotine hydrogen bitartarate (0.6 mg/kg/day, ip) or saline. Resveratrol (10 mg/kg, po) was administered along with saline or nicotine injections for 28 days. After decapitation, the urinary bladder, corpus cavernosum and kidney tissues were excised. Corpus cavernosum and bladder tissues were used for in vitro contractility studies, or stored at -80 ºC along with kidney tissue for the measurement of malondialdehyde (MDA), glutathione (GSH), and luminol-lucigenin chemiluminescence (CL) levels. Tissue samples were also examined histologically. Chronic nicotine administration caused a significant decrease in GSH levels and increases in MDA levels, and luminol-lucigenin CL in kidney, urinary bladder and corpus cavernosum tissues, suggesting oxidative organ damage, which was also verified histologically. In serum samples increased blood urea nitrogen (BUN), creatinine, proinflammatory cytokines (TNF-α and IL-1β), lactate dehydrogenase (LDH) activity, oxidative DNA damage (8-OHdG) and decreased antioxidant capacity (AOC) due to nicotine administration were reversed with resveratrol. Furthermore, chronic nicotine administration impaired the contractile activity of the bladder and corpus cavernosum strips while resveratrol supplementation to nicotine-treated animals reversed these effects in both tissues. Resveratrol treatment to the nicotine group restored the endogenous GSH levels and decreased oxidative damage parameters in all studied tissues. These data suggest that resveratrol supplementation effectively counteracts the deleterious effect of chronic nicotine administration on bladder, corpus cavernosum and kidney functions and attenuates oxidative damage possibly by its antioxidant effects. [ABSTRACT FROM AUTHOR]

The effect of melatonin was investigated in an angiotensin II-dependent renovascular hypertension model in Wistar albino rats by placing a renal artery clip (two-kidney, one-clip; 2K1C), while sham rats did not have clip placement. Starting either on the operation day or 3 wk after the operation, the rats received melatonin (10 mg/kg/day) or vehicle for the following 6 wk. At the end of the nineth week, after blood pressure (BP) and echocardiographic recordings were obtained, plasma samples were obtained to assay lactate dehydrogenase (LDH), creatine kinase (CK), antioxidant capacity (AOC), asymmetric dimethylarginine (ADMA), and nitric oxide (NOx) levels. In the kidney, heart and brain tissues, malondialdehyde (MDA) and glutathione (GSH) levels, superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO) and Na+-K+ ATPase activities were determined. 2K1C caused an increase in BP and left ventricular (LV) dysfunction. In hypertensive animals LDH, CK, ADMA levels were increased in plasma with a concomitant reduction in AOC and NOx. Moreover, hypertension caused a significant decrease in tissue SOD, CAT, and Na+, K+-ATPase activities and glutathione content, while MDA levels and MPO activity were increased in all studied tissues. On the other hand, both melatonin regimens significantly reduced BP, alleviated oxidative injury and improved LV function. In conclusion, melatonin protected against renovascular hypertension-induced tissue damage and improved cardiac function presumably due to both its direct antioxidant and receptor-dependent actions, suggesting that melatonin may be of therapeutic use in preventing oxidative stress due to hypertension. [ABSTRACT FROM AUTHOR]

The possible protective effects of resveratrol (RVT) against cardiotoxicity were investigated in Wistar albino rats treated with saline, saline+doxorubicin (DOX; 20 mg/kg) or RVT (10 mg/kg)+DOX. Blood pressure and heart rate were recorded on the 1st week and on the 7th week, while cardiomyopathy was assessed using transthoracic echocardiography before the rats were decapitated. DOX-induced cardiotoxicity resulted in decreased blood pressure and heart rate, but lactate dehydrogenase, creatine phosphokinase, total cholesterol, triglyceride, aspartate aminotransferase and 8-OHdG levels were increased in plasma. Moreover, DOX caused a significant decrease in plasma total antioxidant capacity along with a reduction in cardiac superoxide dismutase, catalase and Na+,K+-ATPase activities and glutathione contents, while malondialdehyde, myelopreoxidase activity and the generation of reactive oxygen species were increased in the cardiac tissue. On the other hand, RVT markedly ameliorated the severity of cardiac dysfunction, while all oxidant responses were prevented; implicating that RVT may be of therapeutic use in preventing oxidative stress due to DOX toxicity. [ABSTRACT FROM AUTHOR]

Abstract: Objective: This investigation confirms the role of free radicals in naphthalene-induced toxicity and elucidates the mechanism of resveratrol (RVT). Methods: Both male and female BALB-c mice were administered with naphthalene (100mg/kg, i.p.) for 30 days, either along with saline or along with RVT (10mg/kg, orally). At the end of the experiment, following treatment and sacrifice of animals by decapitation, lung, liver and kidney tissue samples were taken for histological examination or determination of malondialdehyde (MDA), glutathione (GSH), myeloperoxidase (MPO) activity and collagen contents. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine levels and lactate dehydrogenase (LDH) activity were measured in the serum samples, while TNF-α, IL-β, IL-6 and total antioxidant capacity (AOC) were assayed in plasma samples. Results: Naphthalene administration caused a significant decrease in tissue GSH and plasma AOC, which was accompanied with significant increases in tissue MDA and collagen levels and MPO activity. Moreover, the pro-inflammatory mediators (TNF-α, IL-β, IL-6), LDH activity, AST, ALT, creatinine and BUN levels were significantly increased in the naphthalene group. On the other hand, RVT treatment reversed all these biochemical indices as well as histopathological alterations induced by naphthalene. Conclusions: Oxidative mechanisms play an important role in naphthalene-induced tissue damage, and RVT, by inhibiting neutrophil infiltration, balancing oxidant–antioxidant status, and regulating the generation of inflammatory mediators, ameliorates oxidative organ injury due to naphthalene toxicity. [Copyright &y& Elsevier]

Abstract: Mechanisms of burn-induced skin and remote organ injury involve oxidant generation and the release of pro-inflammatory cytokines. In this study the possible antioxidant and anti-inflammatory effects of ghrelin were evaluated in a rat model of thermal trauma. Wistar albino rats were exposed to 90°C bath for 10s to induce thermal trauma. Ghrelin, was administered subcutaneously (10ng/kg/day) after the burn injury and repeated twice daily. Rats were decapitated at 6h and 48h after burn injury and blood was collected for the analysis of pro-inflammatory cytokines (TNF-α and IL-1β), lactate dehydrogenase (LDH) activity and antioxidant capacity (AOC). In skin, lung and stomach tissue samples malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) and Na+–K+-ATPase activity were measured in addition to the histological analysis. DNA fragmentation ratio in the gastric mucosa was also evaluated. Burn injury caused significant increase in both cytokine levels, and LDH activity, while plasma AOC was found to be depleted after thermal trauma. On the other hand, in tissue samples the raised MDA levels, MPO activity and reduced GSH levels, Na+–K+-ATPase activity due to burn injury were found at control levels in ghrelin-treated groups, while DNA fragmentation in the gastric tissue was also reduced. According to the findings of the present study, ghrelin possesses a neutrophil-dependent anti-inflammatory effect that prevents burn-induced damage in skin and remote organs and protects against oxidative organ damage. [Copyright &y& Elsevier]