Ahmet Koc

Protective agent, erdosteine, against cisplatin-induced hepatic oxidant injury in rats

Cisplatin, one of the most active cytotoxic agents against cancer, has several toxicities. Hepatotoxicity is one of them occurred during high doses treatment. The aim of this study was to determine the effects of erdosteine against cisplatin-induced liver injury through tissue oxidant/antioxidant parameters and light microscopic evaluation. The rats were randomly divided into three groups: control (n=5), cisplatin (10 mg/kg, n=6) and cisplatin+erdosteine (50 mg/kg/day oral erdosteine, n=8) groups. The rats were sacrificed at the 5th day of cisplatin treatment. The liver tissues were examined with light microscopy and oxidant/antioxidant biochemical parameters. The malondialdehyde (MDA) and nitric oxide (NO) levels were increased in the cisplatin group in comparison with the control and cisplatin+erdosteine groups (p<0.05). There was no significant difference in MDA and NO levels between control and cisplatin+erdosteine groups. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were higher in cisplatin+erdosteine group than cisplatin group (p<0.05). However, the CAT and GSH-Px activities were significantly lower in cisplatin group than in control group (p<0.05). The light microscopic examination revealed that cytoplasmic changes especially around cells of central vein were observed in cisplatin group. Hepatocellular vacuolization was seen in these cells. In the cisplatin plus erdosteine group, a decrease in cytoplasmic changes with the hepatocytes and sinusoidal dilatations around cells of central vein were noticed in as compared to cisplatin group. In the light of microscopic and biochemical results, it was concluded that cisplatin-induced liver damage in high dose and erdosteine prevented this toxic side effect by the way of its antioxidant and radical scavenging effects. (Mol Cell Biochem 278: 79–84, 2005)

Protective effects of thymoquinone against methotrexate-induced testicular injury

Thymoquinone is the major active component derived from Nigella sativa. Methotrexate is a folic acid antagonist widely used in clinic. Aim of this study was to investigate the possible protective role of thymoquinone on testicular toxicity of methotrexate. Experiments were performed on male C57BL/6 mice (6 weeks old, 20 ± 2 g). The animals were divided into four groups with six mice in each group. Equivalent volumes of saline were injected intraperitoneally (i.p.) in the control group. In the thymoquinone group, mice received thymoquinone i.p. with a dose of 10 mg/kg/day for 4 days. Mice in the methotrexate group received single dose of methotrexate i.p., with a dose of 20 mg/kg. Finally, in the methotrexate plus thymoquinone group, in the first and the following 3 days after methotrexate administration, thymoquinone was injected with a dose of 10 mg/kg/day, i.p. At the end of the experiment, the left testis was quickly removed and divided into two parts for histological examination and biochemical analysis. Methotrexate alone increased total antioxidant capacity and myeloperoxidase activity compared to the controls. Thymoquinone treatment decreased total antioxidant capacity and prevented the increase in the myeloperoxidase activity. Light microscopy showed in mice that receiving methotrexate resulted in interstitial space dilatation, edema, severe disruption of the seminiferous epithelium and reduced diameter of the seminiferous tubules. Administration of thymoquinone reversed histological changes of methotrexate significantly. We suggest that thymoquinone use may decrease the destructive effects of methotrexate on testicular tissue of patients using this agent.

The protective effect of erythropoietin and dimethylsulfoxide on ischemia-reperfusion injury in rat ovary

OBJECTIVES The aim of this study was to investigate the effects of erythropoietin and dimethylsulfoxide in the recovery from ischemia-reperfusion injury in an experimental rat adnexal torsion model. STUDY DESIGN Thirty-six Wistar-albino rats were divided into six groups. Except for the sham operation group, all groups were subjected to left unilateral adnexal torsion for 3h. Erythropoietin and dimethylsulfoxide were intraperitoneally administered 30min before the detorsion operation. Malondialdehyde and nitric oxide levels were detected from both the plasma and the tissue samples. The sections of the tissues were evaluated histologically. The results were analyzed by a one-way analysis of the variance (ANOVA) followed by the Duncan test for multiple comparisons using computer software, SPSS Version 15.0 for Windows. RESULTS This study demonstrated that dimethylsulfoxide and erythropoietin pretreatment attenuated ischemia-reperfusion-induced lipid peroxidation, prevented post-ischemic ovarian injury and helped to maintain the ovarian morphology. Malondialdehyde levels of plasma and ovary were higher in the torsion and detorsion groups than the sham group. This showed that ischemia-reperfusion had caused lipid peroxidation of the ovarian tissue, thus leading to oxidative damage. One of the major findings of this study is that malondialdehyde was significantly decreased in the plasma of rats who were pre-treated with dimethylsulfoxide and erythropoietin before detorsion. This suggests that dimethylsulfoxide and erythropoietin might prevent oxidative damage in ovarian ischemia-reperfusion injury. Histological examination confirmed that reperfusion caused more detrimental effects than only ischemia, which could be at least partially prevented by dimethylsulfoxide and erythropoietin administration prior to detorsion. CONCLUSION Erythropoietin and dimethylsulfoxide may have beneficial effects in ischemia-reperfusion injury in ovarian torsion.

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.

Effect of black cumin (Nigella sativa) on heart rate, some hematological values, and pancreatic β-cell damage in cadmium-treated rats

This study was designed to investigate the effect of Nigella sativa (NS) on the heart rate, some hematological values, and pancreatic β-cell damage in cadmium (Cd)-treated rats. The rats were randomly grouped into one of three experimental groups: Control, Cd treated, and Cd+NS treated. Each group contained 10 animals. The Cd-treated and Cd+NS-treated groups were injected subcutaneously daily with CdCl2 dissolved in isotonic NaCl in the amount of 2 mL/kg for 30 d, resulting in a dosage of 0.49 mg Cd/kg/d. The control group was injected with only isotonic NaCl (2 mL/kg/d) throughout the experiment (for 30 d). Three days prior to administration of CdCl2, the Cd+NS-treated group received the daily intraperitoneal (ip) injection of 2 mL/kg NS until the end of the study; animals in all three groups were fasted for 12 h and blood samples were taken for the determination of the glucose and insulin levels, red blood cell (RBC) and white blood cell (WBC) counts, packet cell volume (PCV), and hemoglobin (Hb) concentration. The heart rates of rats were also measured by a direct writing electrocardiograph before the blood withdrawals. It was found that NS treatment increased the lowered insulin levels, RBC and WBC counts, PCV, and neutrophil percentage in Cd-treated rats. However, the WBC count of Cd-treated rats with NS treatment was still lower than those of control values. NS treatment also decreased the elevated heart rate and glucose concentration of Cd-treated rats. Pancreatic tissues were also harvested from the sacrificed animals for morphological and immunohistochemical examinations. Cd exposure alone caused a degeneration, necrosis, and weak degranulation in the β-cells of the pancreatic islets. In Cd+NS-treated rats, increased staining of insulin and preservation of islet cells were apparent. It is concluded that NS treatment might decrease the Cd-treated disturbances on heart rate, some hematological values, and pancreatic β-cell.

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.

The protective role of erdosteine on testicular tissue after testicular torsion and detorsion

Testicular torsion and detorsion are important clinical problems for infertile man and oxidative stress may have a role in this clinical situation. The aim of this study was to investigate the protective role of erdosteine, an antioxidant, on unilateral testicular reperfusion injury in rats. The rats were divided into four groups including seven rats in each group: control, torsion, torsion/detorsion and torsion/detorsion+erdosteine. Rats, except the sham operation group, were subjected to left unilateral torsion (720∘ rotation in the clockwise direction) without including the epididymis. The experiments were finished after sham operation time for control, 120 min torsion for torsion group and 120 min torsion and 240 min detorsion for torsion/detorsion groups. Bilateral orchiectomy was performed for all groups of rats. The ipsilateral and controlateral testis were divided into two pieces to analyse biochemical parameters and to investigate the light microscopic view.Malondialdehyde level of ipsilateral testis was increased in torsion and torsion/detorsion groups in comparison with the other groups (p < 0.05). Erdosteine treatment ameliorated lipid peroxidation after torsion/detorsion in ipsilateral testis (p < 0.05). Also, xanthine oxidase activity of ipsilateral testis was increased in torsion/detorsion group in comparison with the others (p < 0.05). Nitric oxide (NO) level of ipsilateral testis was higher in all experimental groups than sham operated control group (p < 0.05). Also, NO level of torsion group was increased in comparison with detorsion groups (p < 0.05). Erdosteine treatment caused increased glutathione peroxidase activity in comparison with torsion and torsion/detorsion groups and catalase activity in comparison with the other groups in ipsilateral testis (p < 0.05). Superoxide dismutase activity of ipsilateral testis was higher in torsion/detorsion and torsion/detorsion+erdosteine groups than control and torsion groups (p < 0.05). The biochemical parameters were not affected in controlateral testis in all groups. Torsion, torsion/detorsion and torsion/detorsion+erdosteine groups showed ipsilateral testicular damage in the histological examination, but the specimens from torsion/detorsion had a significantly greater histological injury than those from the other groups (p < 0.05). Control rats showed normal seminiferous tubule morphology. Rats in torsion group had slight-to-moderate disruption of the seminiferous epithelium. Rats in torsion/detorsion group displayed moderate-to-severe disruption of the seminiferous epithelium. In all animals from torsion/detorsion+erdosteine group, the testicular tissues were affected with slight-to-moderate degenerative changes of the seminiferous epithelium. Administration of erdosteine resulted in a significantly reduced histological damage associated with torsion of the spermatic cord compared with torsion/detorsion. In all groups, the contralateral testes were histologically normal.In conclusion, the results clearly displayed that erdosteine treatment may have a protective role on testicular torsion/detorsion injury. (Mol Cell Biochem xxx: 193–199, 2005)

Protective Effect of Thymoquinone in Experimental Testicular Torsion

Objectives: To investigate the protective role of thymoquinone (TQ) on unilateral testicular ischemia-reperfusion (I/R) injury in mice. Materials and Methods: Experiments were performed on male C57BL/6 mice (8 weeks old, 20–25 g). The animals were divided into 3 groups including 6 mice in each group: control (sham), torsion/detorsion (TD) and TD+TQ. Mice, except the sham-operated group, were subjected to left unilateral torsion (720° rotation in the clockwise direction). The experiments were finished after sham operation time for controls, 120 min torsion and 240 min detorsion for the other groups. In the TD+TQ group 10 mg TQ was injected intraperitoneally 30 min before detorsion. Results: In the TD group total oxidative stress (TOS), oxidative stress index (OSI) and malondialdehyde (MDA) levels were higher than in the controls. TQ treatment decreased MDA, TOS and OSI values, but did not affect the total antioxidant capacity and myeloperoxidase activity in the TD+TQ group. Upon histological examination, mice in the TD group displayed moderate-to-severe disruption of the seminiferous epithelium. Treatment with TQ resulted in significantly reduced histological damage associated with I/R injury. Conclusion: Our results suggested that TQ treatment may have a protective effect on testicular I/R injury.

The protective role of topical propolis on experimental keratitis via nitric oxide levels in rabbits

The aim of this study was to investigate antioxidant, anti-inflammatory, and antibacterial properties of propolis in the treatment of experimental Staphylococcus aureus keratitis. Twenty young New Zealand white rabbits were used in this experiment. Staphylococcus aureus were given by intrastromal injection to 16 rabbits and 4 rabbits were used as control group (Group 1). Group 2 was treated with phosphate-buffered solution drops; Group 3 was administered ethanolic extract of propolis drops; Group 4 received topical ciprofloxacin drops; Group 5 was treated with topical ciprofloxacin drops along with ethanolic extract of propolis drops. The eyes were examined by slit lamp to assess corneal opacity. And then, corneas were removed to determine nitric oxide (NO) levels and count bacteria. Corneas were also evaluated histologically. Corneal NO concentration in gruop 5, treated with a combination of propolis and ciprofloxacin was determined significantly lower (10.0± 1.8 μmol/g wet tissue) than in Group 4, treated with ciprofloxacin (24.0± 3.1 μmol/g wet tissue), from Group 3, treated with propolis (15.6± 1.8 μmol/g wet tissue), and treated with PBS (44.7± 7.8 μmol/g wet tissue). There were significantly fewer bacteria in eyes that received propolis plus ciprofloxacin than in eyes treated with ciprofloxacin (p = 0.0001) or propolis (p = 0.0001) or eyes treated with PBS (p = 0.0001). The light microscopic examination revealed that the control group showed normal corneal morphology. In the nontreated group, sections of the stromal infiltration revealed the presence of inflammatory cells, which were diffusely distributed (p < 0.05). Administrations of ciprofloxacin plus propolis resulted in a significantly reduced histological damage with fewer bacterial inoculation of the corneal stroma in comparison with the other groups (p < 0.05). Based on these findings, we suggest that ethanolic extract of propolis has antioxidant, anti-inflammatory, and antibacterial properties for S. aureus keratitis in rabbits.

Beneficial effect of erdosteine on methotrexate-induced testicular toxicity in mice.

Methotrexate is used to treat certain types of cancer of the breast, skin, head and neck, or lung. Methotrexate can cause serious or life-threatening side effects on liver, lungs, kidneys, and immune system. Methotrexate chemotherapy causes testicular damage in humans. The aim of this study was to investigate the possible protective role of erdosteine on testicular toxicity of methotrexate in mice. Twenty-six male mice were divided into four groups as follows: group 1, control; group 2, erdosteine-treated; group 3, methotrexate-treated; and group 4, methotrexate + erdosteine treated. On the first day of experiment, a single dose of methotrexate was intraperitoneally administered to groups 3 and 4, although a daily single dose of erdosteine was orally administered to group 2 and 4 for 7 days. At the end of the experiment, the testes of the animals were removed and weighed. The levels of total antioxidant capacity and total oxidative stress, and myeloperoxidase activity in the methotrexate group were higher than the control group (p<0.05). Lipid peroxidation levels were not changed in methotrexate group compared with control group. In conclusion, erdosteine could effectively protect the testes in methotrexate-induced toxicity.