Oxidative stress, DNA damage and apoptosis induced by tebuconazole in the kidney of male Wistar rat.

Tebuconazole (TEB) is a broad-spectrum conazole fungicide that has been used in agriculture in the control of foliar and soil-borne diseases of many crops. The present study has investigated the adverse effects of subchronic exposure to TEB on the kidney of male rats. Animals were divided into four equal groups and treated with TEB at increasing doses 0.9, 9 and 27 mg/kg body weight for 28 consecutive days. The results showed that TEB induced oxidative stress in the kidney demonstrated by an increase in malondialdehyde (MDA), protein carbonyl (PC), advanced oxidation protein product (AOPP) levels and DNA damage, as compared to the controls. Furthermore, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities were increased in the renal tissue of treated rats. Moreover, significant decrease in reduced glutathione (GSH) content in TEB-treated rats was observed, while oxidized glutathione (GSSG) levels were increased, thus a marked fall in GSH/GSSG ratio was registered in the kidney. Glutathione reductase (GR) activity showed a significant increase after TEB exposure. Moreover, TEB down-regulated the expression of Bcl2 and up-regulated the expression of Bax and caspase 3, which triggered apoptosis via the Bax/Bcl2 and caspase pathway. Also, TEB administration resulted in altered biochemical indicators of renal function and varying lesions in the overall histo-architecture of renal tissues. Taken together, our findings brought into light the renal toxicity induced by TEB, which was found to be significant at low doses.

Effect of di(2-ethylhexyl) phthalate on Nrf2-regulated glutathione homeostasis in mouse kidney.

Environmental toxicants such as phthalate have been involved in multiple health disorders including renal diseases. Oxidative damage is implicated in many alterations caused by phthalate especially the di(2-ethylhexyl) phthalate (DEHP), which is the most useful phthalate. However, information regarding its mechanism of renal damage is lacking. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates gene expression implicated in free radical scavenging and cytoprotection including the antioxidant glutathione (GSH) pathway. The aim of this study was to assess whether DEHP affects the Nrf2 pathway and the GSH concentration. Mice were divided into four groups: a control group and three groups treated with DEHP at different concentrations (5, 50, and 200 mg/kg body weight) for 30 days. Our results showed that DEHP altered the normal levels of serum biochemical parameters creatinine (CREA), urea, and lactate dehydrogenase (LDH). This phthalate caused oxidative damage through the induction of lipid peroxidation and protein oxidation as marked by increase of protein carbonyl (PC) and loss of protein-bound sulfhydryls (PSH). Simultaneously, DEHP treatment decreased the protein level of Nrf-2, HO-1, and GCLC (responsible of GSH synthesis) and decreased the GSH level. Inhibition of the Nrf2 pathway is related to the activation of the mitochondrial pathway of apoptosis. This apoptotic process is evidenced by an upregulation of p53 and Bax protein levels in addition to a downregulation of Bcl-2. Collectively, our data demonstrated that depletion of Nrf2 and GSH was associated with the elevation of oxidative stress and the activation of intrinsic apoptosis in mouse kidney treated with DEHP.

Tebuconazole induced cardiotoxicity in male adult rat.

Tebuconazole is an effective systemic fungicide that belongs to the triazoles family. It has been widely used in both agricultural and medical sectors for the control of fungal diseases. Although TEB poses serious threats to mammals health, studies regarding its cardiotoxicity are very limited. Thus, we aimed to evaluate the effects of TEB on some biochemical parameters, the induction of apoptosis and DNA damage in the heart tissue. Male Wistar rats were treated with TEB at varied oral doses for 28 consecutive days. This study demonstrates that TEB decreased cardiac acetylcholinesterase, increased serum marker enzymes such as creatinine phosphokinase (CPK) and lactate dehydrogenase (LDH), and altered the lipid profile by increasing serum levels of total cholesterol (T-CHOL), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and reduced high-density lipoprotein cholesterol (HDL-C) levels. Furthermore, TEB increased levels of p53 and Bax/Bcl2 ratio, released the cytochrome c into the cytosol and activated caspase-9 and caspase-3. Besides, our results showed that TEB induced genotoxic effects. TEB induced DNA fragmentation and increased the frequency of micronucleated bone marrow cells. Moreover, TEB treatment developed fibrosis in the myocardium. Our results suggest that TEB exposure may affect myocardial cells normal functioning and triggers apoptosis.

Di (2-ethylhexyl) phthalate induces cardiac disorders in BALB/c mice.

Because of the extensive use of phthalates for domestic, medical, and industrial applications, the evaluation of their toxic effects is of major concern to public health. The aim of the present study was to assess the propensity of di (2-ethylhexyl) phthalate (DEHP), one of the most used phthalates, to cause oxidative cardiac damage in mice. DEHP was administered intraperitoneally at doses of 5, 50, and 200 mg/kg body weight for 30 consecutive days in BALB/c mice. We assessed the effect of DEHP on cardiac injury using biochemical profile (such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatinine phosphokinase (CPK), total cholesterol (T-CHOL), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)), parameters related to myocardiac oxidative stress, such as malondialdehyde (MDA) level, protein carbonyl (PC) concentration, and DNA fragmentation. In addition, we evaluated antioxidant status; enzymatic (catalase (CAT) and superoxide dismutase (SOD) activities) and non-enzymatic (protein-bound sulfhydryl concentration (PSH)) antioxidants. Acetylcholinesterase (AChE) activity and histopathological changes were also assessed in heart mice treated with DEHP. Our results showed that DEHP induced an elevation of serum marker enzymes and perturbated the lipid profile. In addition, this phthalate increased lipid peroxidation, protein carbonyl levels, and DNA fragmentation in the heart in a dose-dependent manner. Antioxidant status was also perturbated by the increase of the CAT and SOD activities and the decrease of the protein-bound sulfhydryl concentration. AChE activity was also inhibited in the heart following the treatment with DEHP. These biochemical alterations were also confirmed by histopathological changes. Increased free radical production at various doses of DEHP would result in impairment of the redox status leading to an enhanced dose-dependent cardiotoxicity.

Acute triflumuron exposure induces oxidative stress responses in liver and kidney of Balb/C mice.

Triflumuron (TFM) is one of the most widely used insecticides over the world. It is a benzoylphenyl urea that belongs to the class of insect growth regulators. This insecticide acts by inhibiting insect's chitin synthesis and by consequences, making insect more susceptible to pathogens and malformations. TFM effects have been reported in mammalians and crops. However, studies that reveal its toxicity mechanisms are limited. In this line, the current study aimed to determine the implication of oxidative stress in the toxicity induced by TFM and particularly in the perturbation of biochemical parameters in male Balb/C mice. Male Balb/C mice were divided into three groups receiving TFM at doses of 250, 350, and 500 mg/kg bw respectively. The occurrence of oxidative stress in both kidney and liver tissues was monitored by measuring of oxidative stress markers. TFM caused an increase as protein carbonyls generation, malondialdehyde induction (MDA) and catalase (CAT), superoxide dismutase (SOD), glutathion peroxidase (Gpx), as well as glutathion S transferase (GST) activities. In the same conditions, we have evaluated the effect of TFM treatment on biochemical parameters. In response to the three TFM doses, we showed significant dose dependent inductions in all tested oxidative stress markers. However, TFM caused an increase in the liver enzyme activities as aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), g-glutamyltranspeptidase (GTT), and total bilirubin (BILT) in a dose-dependent manner. Equally, renal markers as urea, uric acid, albumin, and creatinine were increased in the same manner. We can conclude that oxidative damage seems to be a key determinant of TFM-induced toxicity in both liver and kidney of male Balb/C mice. Moreover, the oxidative stress is more pronounced in the liver than in the kidney. Thus, TFM may be considered as a hepatotoxic insecticide.

Crocin protects the liver and kidney from patulin-induced apoptosis in vivo.

Patulin (PAT) is a mycotoxin mainly produced by Aspergillus, Penicillium, and Bissochlamys. Given the high risk associated with this mycotoxin, its potential effects have been investigated by many studies. It is known to be teratogenic, mutagenic, and genotoxic, and it has been shown to induce damages in several organs in experimental animals. Our aim was to investigate the preventive effect against PAT-induced apoptosis in vivo using natural carotenoid, Crocin (CRO). Mice were divided into six groups: a control group, a "PAT alone" group, a "CRO alone" group, and a "PAT plus CRO" groups (pre-treatment conditions). Our results showed that CRO restored the normal levels of biochemical parameters in the liver and kidney. The analysis of the protein expression in these organs revealed that PAT-induced toxicity promotes the induction of apoptosis via the increase in P53, Bax, and cytochrome C and the decrease in Bcl2 expressions. We also found that PAT triggered caspase 3 activation and DNA fragmentation. However, pre-treatment with CRO demonstrated a reduction in the induction of apoptosis via the regulation of all tested biomarkers demonstrating that CRO is effective in the protection against PAT hazards. This could be relevant, particularly with the emergent demand for natural products which may counteract the detrimental toxic effects and therefore prevents multiple human diseases.

The potential effect of patulin on mice bearing melanoma cells: an anti-tumour or carcinogenic effect?

Mycotoxins are bioactive compounds that are noxious to human. Their effects on oncogenesis have been satisfactorily elucidated, and some of mycotoxins have been classified as carcinogenic to humans. Nevertheless, patulin (PAT) is considered by the International Agency of Research on Cancer as 'not carcinogenic to humans'. The present study was designed to understand the effect of this mycotoxin on melanoma cells (B16F10) by measuring cell proliferation and assessing the anti-tumour effect in vivo in Balb/c mice. Our results revealed that intraperitoneally administration of PAT for 20 days significantly induces tumour regression in B16F10 cell-implanted mice. This effect was evidenced by the activation of apoptosis which is supported by the increase in p53 and Bax expressions, the downregulation of the protein levels of Bcl2, and the increase in caspase-3 activity. Moreover, systemic toxicity analysis demonstrated that there is no potential toxicity following PAT treatment unlike untreated melanoma mice which suffer from anaemia, inflammation and liver dysfunction. Remarkably, this is the first published report demonstrating the therapeutic efficacy of PAT in vivo models.

Neuropsychological Effects of Mercury Exposure Among Dentists in Monastir City.

AIMS: The aim of this study is to assess the neuropsychological manifestations of mercury exposure in dentists. METHODS: A cross-sectional study was carried out including 64 dentists matched to a control group according to age and gender. This study protocol included a neurological evaluation, a questionnaire assessing the study groups' general characteristics and personal factors that may affect mercury urinary excretion in both groups. EUROQUEST questionnaire and Hospital Anxiety and Depression scale (HADS) were used to evaluate the neuropsychological symptoms reported during the last 12 months. In both groups, mercury impregnation was assessed by monitoring urinary mercury. RESULTS: In the exposed group, scores of neurological symptoms, memory disturbances and anxiety were found to be significantly higher than those in controls (p < 0.01). Mean scores of HAD Depression's scale were higher in the exposed group than in controls. Most of the neurotoxic manifestations were correlated to the levels of urinary mercury excretion in the exposed group. Mean levels of urinary mercury were significantly higher in the dentists group than in controls, with respective values of 21.1 ± 19.6 µg/g of creatinine and 0.05 ± 0.9 µg/g of creatinine. In nine dentists having urinary mercury levels higher than 35 µg/g of creatinine, neurological examination showed a bilateral and symmetric intentional tremor in both upper limbs. In the exposed group, the neuropsychological manifestations and levels of urinary mercury were found to be significantly correlated. CONCLUSION: Increased levels of urinary mercury observed in dentists suggest that exposure to mercury vapour emissions adversely affects dental professionals, therefore prevention measures should be strengthened, with a special medical supervision program of dentists exposed to mercury vapours should be implemented. We have also outlined some relevant patents in this article.

Malathion-induced hepatotoxicity in male Wistar rats: biochemical and histopathological studies.

The increasing use of organophosphorus pesticides in the environment constitutes an ecotoxicological hazard especially for humans and non-target animals. Hereby, we analyzed the toxic effects of malathion on the histological structure of liver and biochemical parameters in male rats. Three groups received daily different amounts of malathion: 1/1000, 1/100, and 1/10 LD50 for 30 days. The weights of treated rat's liver have increased. Analyzed tissues showed centrilobular and sinusoidal congestion, hepatocyte hypertrophy, cellular vacuolization, anucleated hepatocytes, depletion of organelles affecting the majority of cells, and presence of necrotic foci into the hepatic parenchyma. Histological sections of the liver showed important hepatocyte glycogen storage. We conclude that malathion stimulates the filing of glycogen in a dose-dependent manner. Biochemical parameters showed that alanine transaminase (ALT), aspartate transaminase (AST), gamma glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) levels increased in the treated groups when the level of total protein decreased in intoxicated groups.

Crocin Prevents Patulin-Induced Acute Toxicity in Cardiac Tissues via the Regulation of Oxidative Damage and Apoptosis.

Patulin (PAT) is a mycotoxin produced by several species of the genera of Penicillium, Aspergillus, and Byssochlamys principally by Penicillium expansum. This mycotoxin is suspected to affect several organs including kidney and liver. However, its toxic effect on heart remains unknown. The present study investigated for the first time the cardiotoxic effect of PAT in mice. We demonstrated that PAT increased creatinin phosphokinase (CPK) level, induced lipoperoxydation and protein oxidation, and triggered the antioxidant enzymes such as superoxide dismutase and catalase activities. We also demonstrated that acute administration of PAT triggers apoptosis via P53 overexpression and caspase 3 activation. We further investigated the antioxidant efficiency of crocin (CRO), a carotenoid pigment, against PAT-induced cardiotoxicity. We found that pretreatment with CRO prevents cardiac impairment by reducing CPK levels, restoring the redox statute and suppressing apoptosis. Collectively, our data provide new preventive effect of CRO toward PAT-induced cardiotoxicity in mice.

Influence of hypercalcic and/or hyperoxalic diet on calcium oxalate renal stone formation in rats.

OBJECTIVE: To test whether increasing dietary calcium intake prevents calcium oxalate stone formation when the diet is oxalate-rich. Material and methods. Four groups, eight rats in each, were subjected to a lithogenic diet by the addition of 0.5% ethylene glycol to drinking water for 3 weeks. The first group, used as a control, simultaneously received a standard diet. The second group was supplemented with calcium at 500 mg/100 g of diet and the third group with oxalate at 3 g/100 g of diet. The diet given to the last group was supplemented with similar doses of calcium and oxalate. One day before the end of treatment, each animal was placed in a metabolic cage to collect 24-h urine samples and determine urinary parameters. The kidneys were removed to determine calcium oxalate deposits and for histological examination. RESULTS: The number of calcium oxalate crystals in renal tissue was highest in the oxalate group and calcium oxalate deposits were also found to be elevated in this group. Hyperoxaluria and hypocitraturia, induced by a oxalate-rich diet, seemed to be the major causes contributing to aggravated renal stone formation. The protective effect of dietary calcium supplementation, which was clear in the calcium + oxalate group, was probably due to intestinal binding of oxalate by calcium, thereby reducing urinary oxalate excretion. CONCLUSION: Increased dietary calcium intake can prevent calcium oxalate stone formation only when the diet is oxalate-rich.