Pelin Arda-Pirincci

Methiocarb-induced oxidative damage following subacute exposure and the protective effects of vitamin E and taurine in rats

Methiocarb, is used worldwide in agriculture and health programs. Besides its advantages in the agriculture, it causes several toxic effects. In this study, we aimed to investigate subacute effects of methiocarb on lipid peroxidation, reduced glutathione (GSH), antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) and histopathological changes in rat tissues. Moreover, we examined the possible protective effects of vitamin E and taurine on methiocarb-induced oxidative damage in rat tissues. Rats were randomly divided into six groups as follows; I-control group; II-methiocarb group; III-vitamin E group; IV-vitamin E+methiocarb group; V-taurine group and VI-taurine+methiocarb group. Methiocarb significantly increased lipid peroxidation in liver and kidney when compared to control groups. Levels of GSH and activities of SOD, CAT and GSH-Px were found to be decreased, while GSH-Rd remained unchanged in rat liver and kidney treated with methiocarb. Pretreatment of vitamin E and taurine resulted in a significant decrease on lipid peroxidation, alleviating effects on GSH and antioxidant enzymes. The degenerative histological changes were less in liver than kidney of rats treated with methiocarb. Pretreatment of vitamin E and taurine showed a protective effect on the histological changes in kidney comparing to the liver of rats treated with methiocarb.

Protective effects of ascorbic acid, DL-α-tocopherol acetate, and sodium selenate on ethanol-induced liver damage of rats

In this study, the effect of a combination of vitamin C (ascorbic acid), vitamin E (dl-α-tocopherol acetate), and selenium (sodium selenate) on ethanol-induced liver damage in rats was investigated, morphologically and biochemically. The ethanol-induced injury was produced by the administration of 1 mL of absolute ethanol to each rat. Animals received vitamin C (250 mg/kg), vitamin E (250 mg/kg), and selenium (0.5 mg/kg) (ViCESe) for 3 d 1 h prior to the administration of absolute ethanol. In the liver of the animals given ethanol, the degenerative changes such as extreme hyperemia, vacuolization in cells of portal areas, a dilation in sinusoids, mononuclear cell infiltration, a swelling in cisternae of granular endoplasmic reticulum and in mitochondrial cristae, an increase in smooth endoplasmic reticulum, many lipid vacuoles were observed both light and electron microscopically. A similar structure was usually distinguished when compared with control animals, in rats given ethanol+ViCESe. In this group, the findings indicating cellular damage were either not observed at all or were decreased. In the group administered ethanol, a reduction of the blood glutathione (GSH) level and increases in serum values of alanine aminotranserase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and γ-glutamyl transferase (GGT) activities were observed, whereas in the control group, the reverse was found to occur. On the other hand, in the group in which ethanol+ViCESe was administered, it was observed that the blood GSH value and serum ALP and ALT activities increased and serum AST, LDH, and GGT activities decreased. As a result, the present study indicates that ViCESe because of their antioxidant activity against ethanol damage have a protective effect on the liver.

The role of epidermal growth factor in prevention of oxidative injury and apoptosis induced by intestinal ischemia/reperfusion in rats

Intestinal ischemia/reperfusion is a major problem which may lead to multiorgan failure and death. The aim of the study was to evaluate the effects of epidermal growth factor (EGF) on apoptosis, cell proliferation, oxidative stress and the antioxidant system in intestinal injury induced by ischemia/reperfusion in rats and to determine if EGF can ameliorate these toxic effects. Intestinal ischemia/reperfusion injury was produced by causing complete occlusion of the superior mesenteric artery for 60 min followed by a 60-min reperfusion period. Animals received intraperitoneal injections of 150 μg/kg human recombinant EGF 30 min prior to the mesenteric ischemia/reperfusion. Mesenteric ischemia/reperfusion caused degeneration of the intestinal mucosa, inhibition of cell proliferation, stimulation of apoptosis and oxidative stress in the small intestine of rats. In the ischemia/reperfusion group, lipid peroxidation was stimulated accompanied by increased intestinal catalase and glutathione peroxidase activities, however, glutathione levels and superoxide dismutase activities were markedly decreased. EGF treatment to rats with ischemia/reperfusion prevented the ischemia/reperfusion-induced oxidative injury by reducing apoptosis and lipid peroxidation, and by increasing antioxidant enzyme activities. These results demonstrate that EGF has beneficial antiapoptotic and antioxidant effects on intestinal injury induced by ischemia/reperfusion in rats.

Teduglutide, a glucagon-like peptide 2 analogue: a novel protective agent with anti-apoptotic and anti-oxidant properties in mice with lung injury.

Teduglutide is a long-acting synthetic analogue of human glucagon-like peptide-2 (GLP-2). GLP-2 regulates cell proliferation and apoptosis as well as normal physiology in the gastrointestinal tract. In the present study, possible cytoprotective and reparative effects of teduglutide were analyzed on a mouse model with lung injury induced by tumor necrosis factor-alpha (TNF-α) and actinomycin D (Act D). BALB/c mice were divided into six groups: control mice (I), mice injected intraperitoneally with 15 μg/kg TNF-α (II), 800 μg/kg Act D (III), Act D 2 min prior to TNF-α administration with the same doses (IV), mice injected subcutaneously with 200 μg/kg teduglutide every 12h for 10 consecutive days (V), and mice given Act D 2 min prior to TNF-α administration on day 11 after receiving teduglutide for 10 days (VI). The TNF-α/Act D administration made the lung a sensitive organ to damage. Mice lung subjected to TNF-α/Act D were characterized by the disruption of alveolar wall, induced pulmonary endothelial/epithelial cell apoptosis and expression of active caspase-3. These mice exhibited an increase in lipid peroxidation, glutathione levels, and activities of myeloperoxidase, superoxide dismutase, catalase, glutathione peroxidase and xanthine oxidase, as well as reduced tissue factor and sodium-potassium/ATPase activities. Teduglutide pretreatment regressed the structural damage, cell apoptosis and oxidative stress by reducing lipid peroxidation in mice received TNF-α/Act D. GLP-2 receptors were present on the cell membrane of type II pneumocytes and interstitial cells. Thus, teduglutide can be suggested as a novel protective agent, which possesses anti-apoptotic and anti-oxidant properties, against lung injury.

Effects of Zinc on Intestinal Injury and Some Serum Parameters in Ethanol-Administered Rats

This study was designed to determine the morphological and biochemical effects of zinc sulfate and the role of metallothionein in ethanol-induced intestinal injury. Rats received zinc sulfate (100 mg/kg/d) for 3 consecutive d, 2 h prior to the administration of ethanol by gavage. Ethanol administration caused intestinal injury as determined by increased serum lactate dehydrogenase activity, urea, creatinine, uric acid, and sialic acid levels, intestinal lipid peroxidation level, decreased serum catalase activity, intestinal glutathione level, and metallothionein expression. Zinc sulfate pretreatment of the ethanol group caused a decrease in histological damage, serum lactate dehydrogenase activity, urea, creatinine, uric acid, sialic acid levels, and intestinal lipid peroxidation level, but increases in serum catalase activity, intestinal glutathione level, and metallothionein expression. The present study indicates that zinc sulfate has a protective effect against ethanol-induced intestinal injury. In addition, the protective effect of zinc on ethanol-induced intestinal injury might be mediated by metallothionein, as well as having antioxidative potential.

The protective effect of an aqueous extract from Smilax excelsa l. against carbon tetrachloride-induced liver injury in rats

Background: Because reactive oxygen species (ros) contribute to the pathogenesis of various acute and chronic liver diseases, dietary antioxidants and drugs from herbal origins have been proved to be beneficial as therapeutic agents in reversing hepatotoxicity and oxidative stress. The objective of this study was to investigate the protective effect of an aqueous extract from smilax excelsa l. Shoots and leaves against acute ccl4-induced liver injury as well as the changes in antioxidative defense system in female wistar albino rats. Materials and Methods: S. Excelsa extract was administered orally in doses of 100, 200 and 400 mg/kg body weight, once daily for 9 days. Acute hepatic toxicity was induced by intraperitoneal injection of ccl4 (1 ml/kg) on the 10 day. 24 h after ccl4 intoxication, biochemical and histopathological analyses were undertaken on sera and liver tissues. Results: Ccl4 challenge caused significant increases in the activities of liver enzymes as well as the levels of bilirubin, malondialdehyde and nitric oxide, while total serum protein levels and antioxidant defense system parameters were reduced significantly compared to the normal group. Administration of s. Excelsa extract at a dose of 400 mg/kg resulted in a suppression of ccl4-induced lipid peroxidation and altered oxidative stress parameters to nearly normal values in comparison to ccl4-treated rats. Nevertheless the extract did not reduce the extent of ccl4-induced mild liver injury, as seen by the histopathology of liver damage. Conclusion: The results of this study suggest that s. Excelsa could protect the liver tissues against ccl4-induced oxidative stress probably by increasing antioxidative defense activities.