I. Cetin Ozturk

Carbon tetrachloride-induced nephrotoxicity and protective effect of betaine in Sprague-Dawley rats.

OBJECTIVES To observe the changes in the antioxidative defense enzymes and to detect the alterations of renal microscopy after carbon tetrachloride (CCl4) administration in rats and to investigate the possible protective effects of betaine against CCl4-induced renal damage. METHODS Thirty-two adult Sprague-Dawley rats were divided into four groups as follows: control group, betaine group, CCl4 group, and CCl4 + betaine group. CCl4 was given subcutaneously at 1 mL/kg. In the CCl4 + betaine group, rats were pretreated with betaine, then exposed to CCl4 at the same dose. Betaine group rats received concentrated betaine solution. The rats were killed and the kidneys taken for enzyme analyses and histologic examination. Glutathione peroxidase, superoxide dismutase, and catalase activities were measured in right kidney homogenates. Left kidneys were processed for light microscopic evaluation. RESULTS In the CCl4-treated group, significant increases in kidney superoxide dismutase and catalase activities and significant decrease in glutathione peroxidase activity were observed (P <0.01). These changes were found to be normalized in the CCl4 + betaine group. Betaine did not change the enzyme activities. Exposure to CCl4 resulted in glomerular and tubular alterations in the renal cortex. These alterations were found to be prevented by betaine pretreatment. CONCLUSIONS These results indicate that exposure to CCl4 leads to renal damage in rats and betaine exerts an improvement on nephrotoxic effects of CCl4.

Protective Effect of Β-Carotene on Methotrexate-Induced Oxidative Liver Damage

In this study, the authors aimed to investigate the role of oxidative stress on the hepatic damage caused by methotrexate (MTX) and the possible protective effects of β-carotene against this damage. The rats were divided into four groups as control, MTX (20 mg/kg ip), β-carotene (10 mg/kg/day ip) + MTX, and β-carotene. Histopathologic alterations were evaluated for defining the liver damage. The tissue, malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GP-x) contents and serum aspartate aminotransferase (AST) and alanine aminotranferase (ALT) activities were also examined. Histopathologic damage for each group score findings have been determined as control: 0.66 ± 0.33; MTX: 7.0 ± 0.68; β-carotene + MTX: 3.3 ± 0.42; and β-carotene: 0.5 ± 0.3. In the MTX-treated group, MDA, AST, and ALT values were increased, while SOD and GP-x values were decreased compared with the control group. In the β-carotene + MTX-treated group, AST and ALT values significantly decreased, while all other parameters were similar to the control group. This study shows that β-carotene has a protective effect on MTX-induced oxidative hepatic damage. Consequently, it seems that an antioxidant agents like β-carotene may be useful in decreasing the side effects of chemotherapy.

Protective effect of apricot (Prunus armeniaca L.) on hepatic steatosis and damage induced by carbon tetrachloride in Wistar rats.

The present study was planned to investigate the protective effect of 10 % and 20 % apricot-containing feed on carbon tetrachloride (CCl4)-induced hepatic steatosis and damage. Adult male Wistar rats (n 42) were divided into six groups of seven each, as follows: control group; CCl4 group; CCl4+10 % apricot group; CCl4+20 % apricot group; 10 % apricot group; 20 % apricot group. All apricot groups were fed with 10 % or 20 % apricot-containing feed for 5 months. CCl4 injections were applied to the CCl4 groups at the dose of 1 mg/kg for 3 d at the end of 5 months. In the CCl4 group, vacuolated hepatocytes and hepatic necrosis were seen, especially in the centrilobular area. Hepatocytes showed an oedematous cytoplasmic matrix, large lipid globules and degenerated organelles. The area of liver injury was found significantly decreased with apricot feeding. Malondialdehyde and total glutathione levels and catalase, superoxide dismutase and glutathione peroxidase activities were significantly changed in the CCl4 group and indicated increased oxidative stress. Apricot feeding decreased this oxidative stress and ameliorated histological damage. We concluded that apricot feeding had beneficial effects on CCl4-induced liver steatosis and damage probably due to its antioxidant nutrient (beta-carotene and vitamin) contents and high radical-scavenging capacity. Dietary intake of apricot can reduce the risk of liver steatosis and damage caused by free radicals.

Comparison of plasma malondialdehyde, glutathione, glutathione peroxidase, hydroxyproline and selenium levels in patients with vitiligo and healthy controls

Background: The etiology and pathophysiologic mechanism of vitiligo are still unclear. The relationship between increased oxidative stress due to the accumulation of radicals and reactive oxygen species and the associated changes in blood and epidermal component of vitiliginous skin have been reported many times. We investigated the possible changes of plasma malondialdehyde, glutathione, selenium, hydroxyproline and glutathione peroxidase activity levels in patients with vitiligo in order to evaluate the relationship between oxidative stress and etiopathogenesis of vitiligo. Materials and Methods: Plasma malondialdehyde, glutathione, hydroxyproline and glutathione peroxidase activity levels were measured by spectrophotometric methods, and HPLC was used for measurement of selenium concentrations. Results: Our results showed increased malondialdehyde, hydroxyproline and glutathione peroxidase activity levels in plasma of vitiligo group (P < 0.05). Conclusion: Support of antioxidant system via nonenzymatic antioxidant compounds and antioxidant enzymes may be useful to prevent of melanocyte degeneration which occur due to oxidative damage in vitiligo.

The effect of melatonin on 7,12-dimethyl- benz[a]anthracene injury in comparison with vitamin E + selenium in mouse kidneys

The aims of this study were to observe the changes in antioxidative defense enzymes and renal morphology after 7,12‐dimethyl‐benz[a]anthracene (7,12‐DMBA) administration in mice and to investigate the possible protective effects of melatonin against 7,12‐DMBA‐induced renal damage in comparison with vitamin E + selenium (vit E + Se). Forty female mice were divided into four groups: control, DMBA, DMBA + vit E + Se and DMBA + melatonin. In the DMBA group, mice were given injections of 7,12‐DMBA (20 mg/kg). DMBA + vit E + Se group mice received injections of 7,12‐DMBA + vit E + Se (20 mg/kg + 90 mg/kg + 1.8 μg/kg). In the melatonin group, mice were given injections of 7,12‐DMBA + melatonin (20 mg/kg + 4.2 mg/kg). The experiment lasted for 21 days. Mice were killed and the kidneys were taken for enzyme analyses and histologic examination. Catalase (CAT) and glutathione peroxidase (GSH‐Px) activities were found significantly decreased in the DMBA group and in the DMBA + vit E + Se group when compared with the control group (P < 0.05), whereas CAT and GSH‐Px activities were found significantly elevated in the DMBA + melatonin group when compared with the control (P < 0.05) and the DMBA group (P < 0.01). Exposure to DMBA resulted in tubular alterations in renal cortex. Morphometric analysis revealed proximal and distal tubular damage (P < 0.05). These alterations were found to be prevented by melatonin but not with vit E + Se administration. These results reveal that melatonin stimulates CAT and GSH‐Px activities and prevents renal injury better than vit E + Se combination in mice kidneys.