Ameliorative influence of Urtica dioica L against cisplatin-induced toxicity in mice bearing Ehrlich ascites carcinoma.

Cisplatin (CP) is a widely used cytotoxic agent against cancer, and high doses of CP have been known to cause nephrotoxicity and hepatotoxicity. Some reports claim that antioxidants can reduce CP-induced toxicity. This study investigated the hepatoprotective, nephroprotective, and antioxidant activity of Urtica dioica L methanolic extract (UDME) against CP toxicity in Erhlich ascites tumor (EAT)-bearing mice. Levels of serum hepatic enzymes, renal function markers, and oxidant/antioxidant parameters of liver tissue were measured. Mice were inoculated with EAT on day 0 and treated with nothing else for 24 hours. After a single dose of CP administration on day 1, the extract was given at the doses of 50, 100, 200, and 400 mg/kg body weight daily during 6 days. Almost all doses of UDME performed a significant (P < 0.05) preventive role against CP toxicity by decreasing aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, blood urea nitrogen, creatinine, lipid peroxidation, protein oxidation levels, and myeloperoxidase activity, as well as increasing reduced glutathione content, superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase activities. This suggests that UDME has a protective capacity and antioxidant activity against CP toxicity in EAT-bearing mice, probably by promoting antioxidative defense systems.

Protective effects of selenium and vitamin E combination on experimental colitis in blood plasma and colon of rats.

Ulcerative colitis increases oxidative damage accompanied by production of free oxygen radicals. Selenium (Se) and vitamin E are two natural antioxidants. The present study was undertaken to investigate the possible protective role of Se and vitamin E combination in experimental colitis induced by acetic acid (AA) in rats. This study was carried out on three groups, namely the first (control), the second (experimental colitis group, 2 ml 5% acetic acid), and the third groups (2 ml 5% acetic acid, vitamin E (100 mg/kg body weight (bw)) plus Se (0.2 mg/kg bw)). The activities of catalase (CAT), prolidase (PRS), myeloperoxidase (MPO), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), total thiol (T-SH) were determined in plasma and colon samples. Macroscopic and microscopic damages in colon were increased by AA treatment (p < 0.01 and p < 0.01, respectively), whereas they were decreased by selenium and vitamin E treatment (p < 0.05 and p < 0.01, respectively). The activities of CAT and PRS in the plasma and colon were significantly affected (p < 0.05 and p < 0.01) by treatment of AA, Se, and vitamin E. MPO activity in colon was increased (p < 0.01) by AA treatment and decreased (p < 0.05) by Se and vitamin E administration. The values of TOS and OSI in plasma were increased (p < 0.5) by AA. The TAC and T-SH in colon were decreased (p < 0.05) by AA and increased (p < 0.05) by Se and vitamin E. Based upon these results, Se and vitamin E may play an important role in preventive indication of the oxidative damage associated by acetic acid caused inflammation.

Effects of selenium on histopathological and enzymatic changes in experimental liver injury of rats.

The most important antioxidant aspect of selenium is its function in the active site of selenoenzyme glutathione peroxidase. Glutathione peroxidase not only allows the removal of the toxic radicals but also permits the regeneration of lipid molecules through reacylation in the cellular membrane. Thus, GSHPx may prevent the harmful effects of free radicals and may reduce the formation of the reactive metabolites of carbon tetrachloride. Carbon tetrachloride is a hepatotoxic agent which generates haloalkane radicals during its biotransformation in the liver and is widely used to make the experimental model of hepatic damage. Therefore, the aim of the present study is to investigate the possible protective role of selenium on the experimental liver cirrhosis and some enzyme activities in blood plasma from rats. While the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were significantly increased (p < 0.05, p < 0.05 and p < 0.01, respectively), gamma-glutamyle transferase (GGT) activity was not statistically affected (p < 0.05) with carbon tetrachloride-injection. The levels of AST, ALT and GGT in carbon tetrachloride-group decreased to nearly the enzyme values in control-group after the selenium-injection but the ALP was increased (p<0.01). On the other hand, it was noticed that selenium significantly decreased the hepatic injury. In conclusion, our results showed that carbon tetrachloride caused an increase in the activities of liver enzymes in plasma and selenium application decreased the hepatic injury. Plasma levels of the liver enzymes were decreased after selenium-injections. Based upon these results, selenium may play an important role in the preventive indication of hepatic cellular injury inducted by carbon tetrachloride.