Nahla S. El-Shenawy

Effects of insecticides fenitrothion, endosulfan and abamectin on antioxidant parameters of isolated rat hepatocytes.

Fenitrothion, endosulfan and abamectin are insecticides that affect various organs in humans and animals. The present study was conducted to investigate their cytotoxicity in isolated male rat hepatocytes. The study suggests that incubation of hepatocytes with 10 or 100 microM of each insecticide for 2h significantly decreased the cell viability. Increased leakage percentage of lactate dehydrogenase (LDH), alanine transaminase (ALT) and aspartate aminotranferase (AST) were detected in hepatocytes due to the same dose of insecticide exposure confirmed membrane damage of hepatocytes. Fenitrothion (100 microM) increased the cellular lipid peroxidation (LPO) levels more than the other insecticides. The activities of the antioxidant enzymes like superoxide dismutase (SOD), glutathione peroxidise (GSH-Px) and glutathione-S-transferase (GST) were decreased by fenitrothion incubation more than endosulfan and abamectin. The same treatment reduced the level of antioxidant glutathione (GSH) and increased the level of LPO. The activities of glutathione-S-transferase (GST) and gamma glutamyl transpeptidase (gamma-GT) were more affected by fenitrothion and endosulfan, respectively, indicating an oxidative stress. There was negative correlation coefficient among GSH, GST and gamma-GT. A significant correlation was also found between gamma-GT and cell viability. The present study revealed that fenitrothion showed varying pathological signs depending on the dose; high dose caused marked damage of isolated hepatocytes in the oxidative and antioxidant parameters. Endosulfan induced cell membrane damage of the hepatocytes more than abamectin and fenitrothion as indicated by increasing the leakage percentages of LDH, ALT, AST and gamma-GT. Therefore, hepatotoxicity of insecticides increased in a time and dose-dependent manner and depended on the class of the insecticide.

Using the enzymatic and non-enzymatic antioxidant defense system of the land snail Eobania vermiculata as biomarkers of terrestrial heavy metal pollution.

The present study aimed to investigate the efficacy of antioxidant defense system of the land snail Eobania vermiculata as biomarkers for terrestrial heavy metal pollution. For this reason, a set of biomarkers was performed on land snails E. vermiculata collected from polluted and non-polluted areas in the field. The biomarkers used were lactate dehydrogenase activity, level of lipid peroxidation, activities of catalase, glutathione peroxidase, glutathione-S-transferase, gamma-glutamyl transferase and content of glutathione, metalothionines, total proteins and total lipid in the digestive gland tissue. The correlation between the bioaccumulation of heavy metal in gland tissue and all the biomarkers in the digestive gland was determined. The results revealed appreciable alterations in the biomarker values in field, accompanied by significant correlations among the biomarkers. Therefore, this study suggests E. vermiculata is a suitable sentinel organism and the selected biomarkers show efficacy for terrestrial heavy metal biomonitoring.

Oxidative stress and antioxidant responses of liver and kidney tissue after implantation of titanium or titanium oxide coated plate in rat tibiae

Coating with titanium oxides is a promising method to improve the blood compatibility of materials to be used for medical implants. However, biodegradation of the coating can result in microparticles that subsequently cause oxidative stress. Therefore, the present study was carried out to throw some light on the mechanisms affecting the reaction of tissue surroundings Ti implants either in the form of titanium oxide or not in tibiae of rats. The serum collected twice from animals during the period of study and rats were sacrificed after two months of implantation. The complete blood picture, total proteins content and the activities of some serum enzymes were determined as liver biomarker. Kidney function was examined by measuring the levels of serum creatinine and uric acid. The level of lipid peroxidation and the activities of superoxide dismutase, catalase and glutathione S-transferase as well as glutathione content in liver and kidney tissue were evaluated. It has been indicated that the lipid peroxidation is one of the molecular mechanisms involved in Ti-plate induced cytotoxicity however; the TiO2-plate did not. The biodegradation of Ti-plate was very slow that could explain why the all enzymatic and non-enzymatic antioxidant not affected by implantation of Ti-plate. The total antioxidant level in serum was better in rats had TiO2/Ti-plate than those animals that had Ti-plate. The coating of titanium implants with titanium oxide leads to attaining of reduced the oxidative state in the cells, which enhance the healing process in comparison with the uncoated implants.

Phenthoate induced-oxidative stress in fresh isolated mice hepatocytes: Alleviation by ascorbic acid

This study was conducted to determine the protective role of ascorbic acid (AA) against cytotoxicity of the phenthoate (PTA) on hepatocytes. Lipid peroxidation (LPO), nitric oxide (NO), antioxidant enzymes like superoxide dismutase, catalase, glutathione peroxidase, gamma glutamyl transferase and glutathione-S-transferase activities were measured. Non-enzymes antioxidant levels of reduced glutathione (GSH), ferric reducing antioxidant power (FRAP), AA and total proteins (TP) were determined. The results were demonstrated that the 2 hr-LC50 obtained for PTA value was 79.94 mM. LPO and NO were increased in hepatocytes-treated with PTA. PTA-induced oxidative stress in the isolated hepatocytes by decreasing the levels of some antioxidant enzymes. GSH levels were also diminished in PTA treated-hepatocytes as compared to DMSO hepatocytes. FRAP, AA and total protein were also decreased following treatment with PTA. These findings suggest that cytotoxicity of PTA is mediated by increasing free radical formation and decreasing the antioxidants. PTA hepatotoxicity increased in a time- and concentration-dependent manner. The AA can be very effective in perhaps reducing the extent of injury and in overcoming oxidant damage caused by PTA.

The beneficial effects of ascorbic acid during chlorpyrifos-induced oxidative stress and histopathological changes in Oreochromis spilurus

This study was aimed to evaluate the oxidative stress and histopathological changes of chlorpyrifos (CPF; Dursban 48) on sub-adult Oreochromis spilurus as well as the protective role of vitamin C supplementation. The fish were divided into four groups (10 fish/each). The feeding rate was 3% of body weight for fish of each aquarium and the diets were given twice daily for 14 days as follows; aquarium I: free basal diet (untreated group), aquarium II: basal diet with 100 mg/kg of Vit C, aquarium III: basal diet with 1/4 LC50-96 hr of CPF and aquarium IV: basal diet with pesticide as in group III and Vit C. The biochemical changes induced by CPF stress is due to disturbed metabolism manifested as inhibition of enzymes, total proteins, total lipid, enzymatic and non-enzymatic antioxidant. The biochemical alternation was associated with histopathological changes in liver, kidney and muscles tissues. The calculated 96-hr LC50 value of CPF to sub-adults tilapia, O. spilurus was 6.48 μM. The lipid peroxidation levels in CPF and Vit C group were decreased by 0.68-, 0.59- and 0.53-fold in liver, kidney and muscle tissues as compared to CPF group, respectively. Vit C treatment for CPF-intoxicated fish raised the activity of superoxide dismutase by 1.24-, 1.44- and 1.07-fold for liver, kidney and muscles as compared to CPF group, respectively. The supplementation of Vit C in the food with CPF treated-fish had improved the oxidative/antioxidant status and the histological architecture of the fish.

Decreasing the diabetic complication by vanadyl(VO) 2+ /vitamin B 6 complex in alloxan-induced diabetic mice

The scope of this work was to synthesize a novel bifunctionalized vanadyl(VO)2+/vitamin B6 complex. The diabetic therapeutic efficacy of the new complex was investigated in alloxan-induced diabetic mice. The results suggested that vanadyl(VO)2+/vit B6 complex has an anti-diabetic potency, improved the lipid profile and liver and kidney functions. The new complex possesses an antioxidant activity. The current results support the therapeutic potentiality of vanadyl(VO)2+/vitamin B6 complex for the management of diabetes.