Afef Troudi

Antioxidant effect of vitamin E and selenium on hepatotoxicity induced by dimethoate in female adult rats

Acute exposure to pesticides can cause hepatotoxicity. Our study pertains to the potential ability of selenium and/or vitamin E, used as nutritional supplements, to alleviate oxidative stress induced by dimethoate. Female Wistar rats were randomly divided into seven groups of six each: group I served as controls; group II received in their drinking water dimethoate (2 g L(-1)); group III received both dimethoate and selenium (0.5 mg/kg of diet); group IV was treated with dimethoate and vitamin E (100 mg/kg of diet); group V received dimethoate+selenium+vitamin E and groups VI and VII received either selenium or vitamin E. The exposure of rats to dimethoate for 30 days promoted oxidative stress with an increase in malondialdehyde and a decrease in glutathione and non-protein thiol levels. A decrease in glutathione peroxidase, superoxide dismutase and catalase activities was also observed. While, plasma transaminases, lactate dehydrogenase activities and bilirubin levels increased. Co-administration of selenium and/or vitamin E through diet improved the biochemical parameters cited above. Liver histological studies confirmed biochemical parameters and the beneficial roles of selenium and vitamin E.

Hepatotoxicity induced by gibberellic acid in adult rats and their progeny.

Gibberellic acid (GA(3)), a plant growth regulator, was largely used in agriculture of many countries including Tunisia. However, its potential hazardous effects on human health were relatively unexplored. The purpose of this study was to investigate the effects of GA(3) on hepatic function in female rats and their pups. Animals were given daily 200 ppm GA(3) in drinking water from the 14th day of pregnancy until day 14 after delivery. It was found that GA(3) induced liver damages as evidenced by the elevation of plasma aminotransferases (ALT, AST), lactate dehydrogenase activities, bilirubin and albumin levels. Hepatotoxicity was objectified by the significant increase of malondialdehyde (MDA) level and a decrease of antioxidant enzyme activities such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione content in liver of suckling pups and their mothers. Impairment of hepatic function corresponded histologically. We have observed blood vessels congestion and leucocytes infiltration, which were more pronounced in hepatocytes of dams than those of suckling pups. Results of this current study suggest that exposure rats to GA(3) induces hepatotoxicity and histopathological changes in liver of female rats and their progeny.

Cardioprotective effects of selenium on chromium (VI)-induced toxicity in female rats.

Acute exposure to hexavalent chromium compounds can cause cardiotoxicity. Our study pertains to the protective effect of selenium against K(2)Cr(2)O(7)-induced cardiotoxicity. Female Wistar rats were divided into four groups of six each: group I served as controls which received standard diet; group II received in drinking water K(2)Cr(2)O(7) alone (700 ppm); group III received both K(2)Cr(2)O(7) and Se (0.5 Na(2)SeO(3) mg/kg of diet); group IV received Se (0.5 mg/kg of diet) for 3 weeks. The exposure of rats to chromium promoted oxidative stress with an increase in malondialdehyde levels and a decrease in antioxidant non-enzymatic levels such as glutathione, non-protein thiol and vitamin C, while, an increase in glutathione peroxidase, superoxide dismutase and catalase activities was observed. However, plasma transaminases, lactate dehydrogenase activities, cholesterol, triglycerides and low density lipoprotein-cholesterol levels increased, and high density lipoprotein-cholesterol decreased. Coadministration of Se restored the parameters cited above to near-normal values. The histopathological findings confirmed the biochemical results.

Protective effects of selenium on methimazole nephrotoxicity in adult rats and their offspring

This study aims to investigate the improving effects of selenium on methimazole-induced kidney impairments in adult rats and their pups. The animals were randomly divided into four groups of six each: group I served as control which received standard diet; group II received only methimazole in drinking water as 250 mg/l; group III received both methimazole (250 mg/l, orally) and selenium (0.5 mg/kg of diet); group IV served as a positive control and received selenium (0.5 mg/kg of diet) as sodium selenite (Na(2)SeO(3)). Treatments were started from the 14th day of pregnancy until day 14 after delivery. In the methimazole-treated group, body and absolute kidney weights decreased in pups and their mothers when compared to control. Daily urine volume, plasma creatinine levels were higher, while urinary levels were lower than in control. Besides, antioxidant enzyme activities, superoxide dismutase, catalase and glutathione peroxidase decreased. Lipid peroxidation recorded an increase revealed by high kidney malondialdehyde levels, while those of plasma and urinary uric acid showed a significant decline. Methimazole-treated rat kidneys exhibited leucocytic infiltrations, vascular congestion and narrowed Bowmans space. Co-administration of selenium through diet improved all the parameters cited above in adult rats and their progeny. Nevertheless, the distorted histoarchitecture in rat kidney was alleviated by selenium treatment. It can then be concluded that selenium is an important protective element that may be used as a dietary supplement against kidney impairments.

2,4-Dichlorophenoxyacetic acid effects on nephrotoxicity in rats during late pregnancy and early postnatal periods

2,4-Dichlorophenoxyacetic acid (2,4-D) is largely used as a selective herbicide in Tunisia. The purpose of this study was to investigate the effects of 2,4-D on the kidneys of adult rats and their suckling pups. Female Wistar rats were divided into two groups: the controls and the treated rats that received 600 mg/L of 2,4-D in their drinking water from the 14th day of pregnancy until day 14 after delivery. Exposure to 2,4-D induced nephrotoxicity as evidenced by an increase in thiobarbituric acid reactive substances and protein carbonyl levels and a decrease in antioxidant enzyme activities such as catalase, superoxide dismutase, glutathione peroxidase in the kidneys of suckling pups and their mothers. In addition, a significant decline in kidney glutathione, non-protein thiol and vitamin C levels was also observed. Histological changes, seen in the kidney of mothers and their pups treated with 2,4-D are characterized by a narrowed Bowmans space, tubular epithelial cells degeneration, widened tubular lumen and vascular congestion.

Dimethoate-induced oxidative damage in erythrocytes of female adult rats: possible protective effect of vitamin E and selenium supplemented to diet

Pesticide hazards have been accentuated by the sharp rise in their agricultural, industrial and domestic use. Acute exposure to pesticides can cause oxidative damage. Our study investigated the potential ability of selenium (Se) and/or vitamin E, used as nutritional supplements, to alleviate erythrocyte oxidative damage induced by dimethoate (DM), an organophosphate pesticide. Female Wistar rats were exposed to DM (0.2g/L−1 of drinking water), DM + Se (0.5 mg/kg of diet), DM + vitamin E (100 mg/kg of diet), or DM + Se + vitamin E. Rats exposed to DM for 30 days showed an increase in malondialdehyde levels, superoxide dismutase and glutathione peroxidase activities in their erythocytes, while Na+,K+-ATPase and catalase activities, glutathione, non-protein thiol, vitamin E and vitamin C levels decreased. We also noted an increase in lactate dehydrogenase activity, marker of haemolysis and a decrease in acetylcholinesterase, the principal mode of organophosphorus action. Co-administration of Se or vitamin E to the diet of DM-treated rats ameliorated the biochemical parameters cited above. But the combined effect of Se and vitamin E was more powerful in antagonizing DM-induced oxidative stress. Therefore, our investigation revealed that both Se and vitamin E were useful elements in preventing DM-induced erythrocytes damage.

Dimethoate Induced Oxidative Damage and Histopathological Changes in lung of Adult rats: Modulatory Effects of Selenium and/or Vitamin E

OBJECTIVE To determine the efficiency of selenium and/or vitamin E to alleviate lung oxidative damage induced by dimethoate, an organophosphorus compound. METHODS Adult Wistar rats were exposed during 30 days either to dimethoate (0.2 g/L of drinking water), dimethoate+selenium (0.5 mg/kg of diet), dimethoate+vitamin E (100 mg/kg of diet), or dimethoate+selenium+vitamin E. RESULTS Exposure to dimethoate caused oxidative stress in lung evidenced by an increase of malondialdehyde, protein carbonyl groups and advanced oxidation protein products. An increase in glutathione peroxidase, superoxide dismutase, catalase and a decrease in acetylcholinesterase and butyrylcholinesterase activities, glutathione, non-protein thiols and vitamins C levels were observed. Histopathological changes in lung tissue were noted as emphysema, hemorrhages and hemosiderin deposits. Co-administration of selenium or vitamin E to the diet of dimethoate treated rats ameliorated the biochemical parameters as well as histological impairments. The joint effect of these elements was more powerful in antagonizing dimethoate-induced lung oxidative damage. CONCLUSION We concluded that selenium and vitamin E ameliorated the toxic effects of this pesticide in lung tissue suggesting their role as potential antioxidants.

Protective effects of selenium on methimazole-induced anemia and oxidative stress in adult rats and their offspring

The present study investigates the potential ability of selenium, considered as an antioxidant with pharmacological property to alleviate oxidative stress and hematological parameter disorders induced by methimazole, an antithyroid drug. Pregnant Wistar rats were randomly divided into four groups of six each: group I served as negative control and received a standard diet; group II received 250 mg/L of methimazole in drinking water and a standard diet; group III received both methimazole (250 mg/L, orally) and selenium (0.5 mg/kg of diet) supplemented to the standard diet; group IV served as positive control and received a supplement of selenium in the diet (0.5 mg/kg of diet) as sodium selenite (Na2SeO3). Treatment was started from the 14th day of pregnancy until day 14 after delivery. Methimazole reduced the number of red blood cells, hemoglobin concentration and hematocrit in mothers and their pups. Besides, plasma iron, vitamins B9, B12, C and E levels were reduced. Lipid peroxidation increased, objectified by high malondialdehyde levels and lactate dehydrogenase activity in plasma, while glutathione, glutathione peroxidase, superoxide dismutase and catalase activities showed a significant decline. Co-administration of selenium through diet improved all the parameters cited above. It can be concluded that the administration of selenium alleviates methimazole-induced toxicity, thus demonstrating its antioxidant efficacy.

Protective effects of vitamin E and selenium against dimethoate‐induced cardiotoxicity in vivo: Biochemical and histological studies

There is considerable interest in the study of free radical‐mediated damage to biological systems due to pesticide exposure. However, there is a lack of consensus as to which determinations are best used to quantify future risks arising from xenobiotic exposure and natural antioxidant interventions. Our study investigated the potential ability of selenium and/or vitamin E, used as nutritional supplements, to alleviate cardiotoxicity induced by dimethoate. Female Wistar rats were exposed for 30 days either to dimethoate (0.2 g L−1 of drinking water), dimethoate+selenium (0.5 mg kg−1 of diet), dimethoate+vitamin E (100 mg kg−1 of diet), or dimethoate+selenium+vitamin E. The exposure of rats to dimethoate promoted oxidative stress with a rise in malondialdehyde, advanced protein oxidation, and protein carbonyl levels. An increase of glutathione peroxidase, superoxide dismutase, and catalase activities was also noted. A fall in acetylcholinesterase and Na+K+‐ATPase activities, glutathione, nonprotein thiols, vitamins C and E levels was observed. Plasma levels of cholesterol, triglycerides, and low density lipoprotein‐cholesterol increased and those of high density lipoprotein‐cholesterol decreased. Coadministration of selenium or vitamin E to the diet of dimethoate‐treated rats ameliorated the biochemical parameters cited above. The histopathological findings confirmed the biochemical results and the potential protective effects of selenium and vitamin E against cardiotoxicity induced by dimethoate.

Neurotoxicity and oxidative stress induced by gibberellic acid in rats during late pregnancy and early postnatal periods: Biochemical and histological changes

Gibberellic acid (GA(3)) is an endogenous plant growth regulator used worldwide in agriculture; however, little is known about its biochemical and physiological effects on mammals. This study investigated possible neurotoxic effects of GA(3) on the cerebrum and cerebellum of suckling rats. Female Wistar rats were given daily 200 ppm GA(3) in drinking water from the 14th day of pregnancy until day 14 after delivery. Acetylcholinesterase activity in both cerebellum and cerebrum was inhibited after treatment with GA(3). Neurotoxicity was demonstrated by a significant increase in malondialdehyde level and a decrease in the antioxidant enzyme activities of catalase, superoxide dismutase, glutathione peroxidase in the cerebrum and cerebellum of suckling pups. A significant decline of glutathione content and vitamin C was also observed. The biochemical parameters were correlated histologically with an abnormal development of the external granular layer and a loss of Purkinje cells in the cerebellum of GA(3)-treated suckling rats.