Ahmet Nacar

Protective Effects of N-Acetylcysteine on Cyclosporine-A-Induced Nephrotoxicity

Objectives. Cyclosporine A (CsA) is used for the treatment of autoimmune and inflammatory disorders. However, CsA‐induced nephrotoxicity remains an important clinical problem, and oxidative stress has been implicated as a possible responsible mechanism. We assessed the protective ability of N‐acetylcysteine (NAC), an antioxidant, against CsA-induced nephrotoxicity. Materials and Methods. Wistar albino rats were randomly assigned into four groups. Group 1 rats were treated with sodium chloride as control, group 2 with CsA, group 3 with CsA and NAC, and group 4 with NAC alone. Animals were sacrificed and blood samples were analyzed for blood urea nitrogen (BUN), serum creatinine (Cr), malondialdehyde (MDA) and nitric oxide (NO) levels, and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. Kidney sections were analyzed for MDA and NO levels and SOD and GSH-Px activities, as well as histopathological changes. Results. Overall, the treatment of rats with CsA alone produced significant increases in NO and MDA levels and significant decreases in SOD and GSH-Px activities in serum and renal samples. Morphological changes, including tubular epithelial atrophy, vacuolizations, and cellular desquamations, were clearly observed in the rats treated with CsA alone. Concurrent NAC administration with CsA improved renal function, as indicated by lower BUN and Cr values. Moreover, NAC significantly reduced MAD and NO levels and increased SOD and GSH-Px activities in serum and renal tissue, as well as provided a histologically proven protection against CsA-induced nephrotoxicity. Conclusion. These results indicate that NAC produces a protective mechanism against CsA-induced nephrotoxicity and suggest a role for oxidative stress in pathogenesis.

Effects of Erdosteine on Acetaminophen-induced Hepatotoxicity in Rats

We investigated the effects of erdosteine on acetaminophen (APAP)-induced hepatotoxicity in rats. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), AST (aspartate aminotransferase), and ALT (alanine transaminase) activities, and malonyldialdehyde (MDA) and nitric oxide levels as oxidant/antioxidant biochemical parameters were investigated with light microscopic evaluation in adult female Wistar Albino rats. APAP administration produced a decrease in hepatic SOD, CAT, and GSH-Px activities, and coadministration of erdosteine (150 and 300 mg/kg) resulted in increases in the activities. MDA and NO levels increased in the APAP group, and erdosteine treatments prevented these increases. Significant elevations in serum AST and ALT levels were observed in the APAP group, and when erdosteine and APAP were coadministered, their serum levels were close to those in the control group. Light microscopic evaluation of livers showed that there were remarkable centrilobular (zone III) hepatic necrosis and mild to moderate sinusoidal congestion in the APAP group, whereas in the erdosteine group, cellular necrosis was minimal and the hepatocytes maintained a better morphology when compared to the APAP group. Erdosteine prevented APAP-induced liver injury and toxic side effects probably through the antioxidant and radical scavenging effects of erdosteine.

New perspective for the treatment of Alzheimer diseases: Liposomal rivastigmine formulations

The aim of this study was to determine the transportations of rivastigmine containing from various liposome formulations through Madin Darby Canine Kidney (MDCK) cells monolayer and to compare the in vitro test results with in vivo. There is no other liposome formulation of rivastigmine and the transportations of rivastigmine through MDCK cell monolayers or related study available in the literature. Cytotoxicity (MTT) test was used to determine cell viabilities. The effect of sodium-taurocholate or dimethyl-beta-cyclodextrine as penetration enhancer was also investigated. Characterization and stability studies for liposome formulations were performed. Permeation experiments of rivastigmine were performed through MDCK cells and dialysis membrane. The kinetic of release from liposomes was also investigated. The highest apparent permeability coefficient (log. values) was obtained with sodium-taurocholate liposomes for −1.15 ± 0.16 for MDCK cell. Rivastigmine liposomes and solutions were also administered to mice orally and intraperitonally. Acetylcholinesterase (AChE) activity was determined by Ellman method. AChE% inhibition values were calculated for both blood and brain after administration of rivastigmine solution and liposomes. The highest AChE inhibition was observed for rivastigmine-sodium-taurocholate liposomes. Histological observations of the mice’ brains were performed under transmission electron microscope (TEM). The histological results were also indicated and supported all these findings.

Ceftriaxone ameliorates cyclosporine A-induced oxidative nephrotoxicity in rat.

A growing body of evidence now suggested that cyclosporine A (CycA)‐induced nephrotoxicity is a crucial clinical problem and oxidative stress is importantly responsible for its toxicity. Ceftriaxone induced antioxidant effect in brain and neuronal tissues against oxidative damage although its antioxidant potential effect on kidney has not been clarified. The aim of this study was to evaluate whether ceftriaxone protects CycA‐induced oxidative stress kidney injury in rats. Twenty‐four rats were equally divided into four groups. First group was used as control. Ceftriaxone (200 mg/kg) and CycA (15 mg/kg) were administrated to second and third groups for 10 days, respectively. The ceftriaxone and CycA combination was given to rats constituting the fourth group for 10 days. Lipid peroxidation (LP), urea nitrogen and lactate dehydrogenase (LDH) levels were higher in CycA group than in control and ceftriaxone groups although LP, urea nitrogen and LDH levels were lower in ceftriaxone + CycA group than in control and ceftriaxone groups. Glutathione peroxidase and catalase activities were lower in CycA group than in control whereas their activities were increased in control and ceftriaxone groups. Superoxide dismutase activity did not change by the treatments. Ceftriaxone administration recovered also CycA‐induced atrophy, vacuolization and exfoliations of tubular epithelium and glomerular collapse in histopathological evaluation of kidney. In conclusion, we observed that ceftriaxone is beneficial on CycA‐induced oxidative stress in kidney of rats by modulating oxidative and antioxidant system. Copyright

Effects of erdosteine on cyclosporin-A-induced nephrotoxicity

Aim: In cyclosporin-A (CsA)-induced toxicity, oxidative stress has been implicated as a potential responsible mechanism. Therefore, we aimed to investigate the protective role of erdosteine against CsA-induced nephrotoxicity in terms of tissue oxidant/antioxidant parameters and light microscopy in rats. Materials and methods: Wistar albino rats were randomly separated into four groups. Group 1 rats treated with sodium chloride served as the control, group 2 rats were treated with CsA, group 3 with CsA plus erdosteine, and group 4 with erdosteine alone. Animals were killed and blood samples were analyzed for blood urea nitrogen (BUN), serum creatinine (Cr), uric acid (UA), total protein (TP), and albumin (ALB) levels. Kidney sections were analyzed for malondialdehyde (MDA) and nitric oxide (NO) levels and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities, as well as for histopathological changes. Results: In the CsA group, MDA, GSH-Px, BUN, and Cr levels were increased. The TP and ALB levels were decreased. These changes had been improved by erdosteine administration. Other biochemical parameters did not show any significant change. Conclusion: These results indicate that erdosteine produces a protective mechanism against CsA-induced nephrotoxicity and suggest a role of oxidative stress in pathogenesis.

Protective effect of ebselen on experimental testicular torsion and detorsion injury.

Ebselen is used as a drug in clinical trials against stroke, reperfusion injury with anti‐atherosclerotic and renoprotective effects. The aim of this study is to investigate the protective effect of ebselen, on torsion/detorsion (T/D)‐induced biochemical and histopathological changes in experimental testicular ischaemia/reperfusion injury. A total of 28 male Wistar Albino rats were divided into four groups: group 1(sham‐operated group, n = 7), group 2(ebselen group, n = 7), group 3(torsion/detorsion + saline, n = 7) and group 4(T/D + 10 mg kg−1 ebselen group, n = 7). The tissue homogenate samples were used for immediate nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase, catalase and glutathione measurement. Testes in all groups were evaluated for the biochemical assay and histopathological examinations. To evaluate spermatogenesis, Johnsen scoring system was used. Testicular tissue MDA and NO levels in group 3 were significantly higher than in group 1 and 4. In histological evaluation of the testicular tissues, ebselen administration improved tubular histology significantly compared with T/D group. Significant increase in histological score was observed in the testis of group 3 compared with group 1 and 2. Histological score in group 4 significantly decreased compared with group 3. Johnson score was significantly lower in T/D group compared with all other three groups, ebselen administration increased the score significantly compared with T/D group. Ebselen reduced oxidative biochemical and histopathological damage in our testicular T/D rat model.

The protective effects of omega-3 fatty acid against toluene-induced neurotoxicity in prefrontal cortex of rats.

Objective: Toluene is used as an organic solvent, and it has neurotoxic effects. Omega-3 is an essential fatty acid required for brain development. The aim of this study was to investigate the protective effects of omega-3 fatty acid against toluene-induced neurotoxicity in prefrontal cortex of rats. Materials and methods: A total of 21 male Wistar rats were divided into three groups with seven rats in each group. Rats in group I were the controls. Toluene was intraperitoneally injected into the rats of group II with a dose of 0.5 ml/kg. Rats in group III received omega-3 fatty acid with a dose of 0.4 g/kg/day while exposed to toluene. After 14 days, all the rats were killed by decapitation. Enzymatic activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the level of malondialdehyde (MDA) were spectrophotometrically studied in the prefrontal cortex of rats. Results: Enzymatic activities of SOD and GSH-Px were decreased, and MDA levels were significantly increased in rats treated with toluene compared with the controls. However, the increased SOD and decreased GSH-Px enzymatic activities and MDA levels were detected in the rats administered with omega-3 fatty acid while exposed to toluene. Conclusion: The results of this experimental study indicate that omega-3 fatty acid treatment can prevent toluene-induced neuronal damage in the prefrontal cortex of rats.

Effects of β-glucan pretreatment on acetylsalicylic acid-induced gastric damage: An experimental study in rats.

BACKGROUND NSAIDs have been found to induce gastrointestinal tract damage. Recently, it has been suggested that this might be mediated by lipid peroxidation. OBJECTIVE The aim of this study was to assess the potential protective effects of β-glucan against acetylsalicylic acid (ASA-induced gastric damage by means of its antioxidant capacity in an experimental rat model. METHODS Thirty-two male Wistar albino rats (200-250 g) were randomized into 4 groups consisting of 8 rats each. The β-glucan group received 50 mg/kg β-glucan once a day for 10 days and 30 minutes before anesthesia. The ASA group received saline once a day for 10 days and 300 mg/kg (20 mg/mL) ASA as a single dose, 4 hours before anesthesia. The ASA+β-glucan group was administered 50 mg/kg β-glucan once a day for 10 days and 30 minutes before anesthesia. Additionally, 300 mg/kg (20 mg/mL) ASA was administered as a single dose, 4 hours before anesthesia. The control group received saline once a day for 10 days and 30 minutes before anesthesia. All medications were administered by intragastric gavage. The stomach from each rat was dissected and divided into 2 parts for histologic and biochemical analysis. Gastric tissue malondialdehyde (MDA), nitric oxide (NO) levels, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were determined for oxidative parameter analysis. RESULTS The gastroprotective and antioxidant effects of β-glucan appeared to attenuate the ASA-induced gastric tissue damage. Compared with the control group, MDA and NO levels and CAT and GSH-Px activities were significantly increased in the stomachs of ASA-treated rats (MDA, 4.12 [0.44] to 13.41 [1.05] μmol/L; NO, 8.04 [7.25-9.10] vs 30.35 [22.34-37.95] μmol/g protein; CAT, 0.050 [0.004] to 0.083 [0.003] k/g protein; GSH-Px, 0.57 [0.42-0.66] to 1.55 [1.19-1.76] U/L; all, P < 0.001), whereas SOD activity was significantly decreased in the same group (291 [29] to 124 [6] U/mL; P < 0.001). In the ASA+β-glucan group, MDA and NO levels and CAT and GSH-Px activities were found to be significantly lower, while SOD activity was found to be significantly higher, in comparison with the ASA-treated group (all, P < 0.001). CONCLUSION β-Glucan appeared to attenuate the gastric damage caused by ASA in these rats.

Letrozole induces hepatotoxicity without causing oxidative stress: the protective effect of melatonin

Aim. The aim of this study was to determine the effects of letrozole (LTZ), an aromatase inhibitor (AI), and melatonin (MLT) on hepatic function and oxidative stress in female rats. Material and methods. A total of 32 female rats were divided equally into four groups (n = 8). Control group received saline (0.5 ml/day, oral gavage). LTZ was administered to rats by daily oral gavage at 1 mg/kg dose. LTZ + MLT group was given LTZ (1 mg/kg, oral gavage) plus MLT (0.5 mg/kg/day, s.c.). MLT group was given MLT (0.5 mg/kg/day) by s.c. injection. The activities of superoxide dismutase (SOD) and catalase (CAT) and malondialdehyde (MDA) levels were measured in liver tissue. Total antioxidant capacity (TAC), total oxidant status (TOS), ALT, AST, GGT, ALP, LDH, bilirubin, BUN, creatinine, total cholesterol (TC), high-density lipoprotein (HDL) and triglyceride (TG) were assayed in serum samples. Results. The oxidative stress parameters did not differ between groups. LTZ administration increased hepatic function parameters such as AST, LDH, ALP, bilirubin and MLT improved the disturbances of hepatic function. LTZ caused minimal histological changes in liver tissue and MLT treatment reversed those dejenerations. Discussion. LTZ may cause hepatotoxicity without inducing oxidative stress and MLT restores hepatic activity.

N-Acetylcysteine prevents doxorubucine-induced cardiotoxicity in rats

This study is designed to observe the effects of N-acetylcysteine (NAC) on doxorubucine-induced cardiac toxicity in rats both histologically and biochemically. Totally 32 rats divided equally into four groups were studied. The first group received only 200 mg/kg NAC intraperitoneal (i.p.) once every 24 h for 5 days (group 1); the second group received 20 mg/kg doxorubucine (DOX) i.p. single dose plus NAC 200 mg/kg i.p. once every 24 h for 5 days (group 2); the third group received DOX 20 mg/kg DOX i.p. single dose (group 3) and the fourth group, which is also the control group, received saline (group 4). Following 24 h of the final dose, blood samples were drawn from a portal vein and heart tissue were obtained. Tissue thiobarbituric acid reactive substance (TBARS) and nitric oxide (NO) levels were highest in the DOX group. In the DOX-treated rats, serum TBARS, NO, aspartate transaminase, lactate dehydrogenase and creatine kinase levels were highest when compared with other groups. Except for serum superoxide dismutase levels, all other parameters differed significantly between the DOX plus NAC group and the DOX group. In the DOX plus NAC group, general architecture was preserved better than the DOX group and myofibril loss was minimal compared with the DOX group. NAC demonstrated, both biochemically and histologically, to be effective in the prevention of DOX-induced cardiotoxicity in rat models. Evaluation of NAC’s effect on DOX toxicity warrants further clinical trials on cancer patients.