Suleiman F. Ambali

Taurine mitigates cognitive impairment induced by chronic co-exposure of male Wistar rats to chlorpyrifos and lead acetate

Organophosphate pesticides and heavy metals are ubiquitous environmental pollutants and neurotoxicants. We investigated the effects of taurine (an antioxidant; TA) on oxidative stress and cognition in male Wistar rats co-treated with chlorpyrifos (an organophosphate pesticide; CPF) and lead acetate (heavy metal; LA). The Wistar rats were divided into 5 groups of 10 rats each. The first two groups were administered with distilled water and soya oil respectively. The remaining three groups were administered with taurine (TA), 50 mg/kg body weight, CPF+LA group [CPF (4.25 mg/kg, 1/20 LD₅₀] and LA (233.25 mg/kg, 1/20 LD₅₀) and TA+CPF+LA group [TA (50 mg/kg), CPF (4.25 mg/kg) and LA (233.25 mg/kg)]. The xenobiotics were administered once daily by oral gavage for 16 weeks. The results showed reductions in the activities of brain antioxidant enzymes and acetylcholinesterase, increased lipoperoxidation and histopathological alterations of the cerebral cortex in the CPF+LA group. However, TA mitigated perturbations in the activities of the antioxidant enzymes and acetylcholinesterase, counteracted oxidative stress and brain lipoperoxidation and attenuated neuronal degeneration induced by joint CPF and LA-induced neurotoxicity. The results suggested that TA is neuroprotective following chronic co-exposure of rats to CPF and LA.

Erythrocyte osmotic fragility and lipid peroxidation following chronic co-exposure of rats to chlorpyrifos and deltamethrin, and the beneficial effect of alpha-lipoic acid

The present study aimed to evaluate the effect of chronic co-exposure to chlorpyrifos (CPF) and deltamethrin (DLT) on erythrocyte osmotic fragility, lipid peroxidation and the ameliorative effect of alpha-lipoic acid (ALA) on erythrocyte fragility. Thirty-six male Wistar rats divided into six groups of six rats each were used for the study. Groups I (S/oil) and II (ALA) were given soya oil (2 ml/kg) and ALA (60 mg/kg), respectively. Rats in group III (DLT) and IV (CPF) were exposed to DLT (6.25 mg/kg) and CPF (4.75 mg/kg) (1/20th of the previously determined LD50 of 125 mg/kg and 95 mg/kg, respectively, over a period of 48 h). Rats in group V (CPF + DLT) were co-exposed to CPF (4.75 mg/kg) and DLT (6.25 mg/kg), while those in group VI (ALA + CPF + DLT) were pretreated with ALA (60 mg/kg) and then co-exposed to CPF and DLT, 45 min later. The treatments were administered by gavage once daily for a period of 16 weeks. Blood collected at the end of the experimental period were analyzed for erythrocyte osmotic fragility and malondialdehyde (MDA) concentration. The study showed that chronic co-exposure to CPF and DLT resulted in an increase in erythrocyte fragility and MDA concentration which were ameliorated by supplementation with alpha-lipoic acid. The study concluded that repeated co-exposure to CPF and DLT elevated erythrocyte fragility probably due to increased lipid peroxidation, and pretreatment with alpha-lipoic acid ameliorated these alterations.

The protective role of alpha-lipoic acid on long-term exposure of rats to the combination of chlorpyrifos and deltamethrin pesticides

The study was aimed at evaluating the protective role of α-lipoic acid (ALA) on long-term exposure of rats to the combination of chlorpyrifos (CPF) and deltamethrin (DLT). Forty-two (42) male Wistar rats were divided into 6 exposure groups with 7 animals in each group: (I) soya oil (2 ml kg−1), (II) ALA (60 mg kg−1), (III) DLT (6.25 mg kg−1), (IV) CPF (4.75 mg kg−1), (V) (CPF + DLT) DLT (6.25 mg kg−1) and CPF (4.75 mg kg−1; 1/20th of the previously determined median lethal dose) and (VI) (ALA + CPF + DLT) pretreated with ALA (60 mg kg−1) and then co-exposed to CPF and DLT, 45 min later. The regimens were administered by gavage once daily for a period of 16 weeks. Sera obtained from blood collected at the end of the experimental period were used for the evaluation of serum glucose, total protein, albumin, urea, creatinine and the activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase and acetylcholinesterase. The liver homogenate was used to assay for the activities of superoxide dismutase and glutathione peroxidase and the concentrations of malondialdehyde, cytokine and tumour necrotic factor α. The result showed that the combination of CPF and DLT resulted in marked alterations of these biochemical parameters in most cases compared to either of the pesticides singly, supplementation with ALA ameliorated these alterations.

Co-treatment of chlorpyrifos and lead induce serum lipid disorders in rats Alleviation by taurine

The aim of this study was to investigate the effects of taurine (TA) on serum lipid profiles following chronic coadministration of chlorpyrifos (CP) and lead acetate (Pb) in male Wistar rats. Fifty rats randomly distributed into five groups served as subjects. Distilled water (DW) was given to DW group, while soya oil (SO; 1 mL kg−1) was given to SO group. The TA group was treated with TA (50 mg kg−1). The CP + Pb group was administered sequentially with CP (4.25 mg kg−1; 1/20th median lethal dose (LD50)) and Pb at 233.25 mg kg−1 (1/20th LD50), while the TA + CP + Pb group received TA (50 mg kg−1), CP (4.25 mg kg−1), and Pb (233.25 mg kg−1) sequentially. The treatments were administered once daily by oral gavage for 16 weeks. The rats were euthanised, and the blood samples were collected at the termination of the study. Sera obtained from the blood samples were analyzed for total cholesterol, high-density lipoprotein cholesterol, triglycerides, and malondialdehyde, and also the activities of serum antioxidant enzymes including superoxide dismutase, catalase and glutathione peroxidase were analyzed. The low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, and atherogenic index were calculated. The results showed that CP and Pb induced alterations in the serum lipid profiles and evoked oxidative stress. TA alleviated the disruptions in the serum lipid profiles of the rats partially by mitigating oxidative stress. It was concluded that TA may be used for prophylaxis against serum lipid disorders in animals that were constantly co-exposed to CP and Pb in the environment.

Protective effect of taurine in chlorpyrifos and lead-induced hematological alterations in Wistar rats

Chlorpyrifos (CPF) and lead (Pb) are common contaminants that evoke hematotoxicity in rodents and humans. Taurine (TA) is an amino acid with bioprotective properties. The purpose of the study was to investigate the role of TA on hematological parameters in rats co-exposed to CPF and Pb. Fifty rats were divided into five groups of 10 rats each. The distilled water (DW) group received distilled water while the soya oil (SO) group received soya oil (1 mL kg−1). The TA group was given taurine (50 mg kg−1), while the chlorpyrifos + lead (CPF + Pb) group was co-administered with CPF (4.3 mg kg−1, ∼5% LD50) and Pb (233 mg kg−1, ∼5% LD50). The TA + CPF + Pb group was co-treated with TA, CPF, and Pb. The treatments were administered daily by oral gavage for four months. Hematological parameters were evaluated after the termination of the study. The results showed reductions in packed cell volume, hemoglobin concentration, red blood cell count, erythrocyte indices, total white blood cell, lymphocyte and platelet counts following co-exposure of the rats to CPF and Pb. The neutrophil counts, neutrophil/lymphocyte ratio and erythrocyte osmotic fragility were increased in the CPF + Pb group. It is speculated that TA mitigated hematotoxicity in the rats through its cytoprotective, osmoregulatory, and membrane stabilization properties.

Pancreatic function and histoarchitecture in Wistar rats following chronic exposure to Bushfire®: the mitigating role of zinc

Objectives To assess the toxicopathologic effects of chronic exposure to the glyphosate-based herbicide Bushfire® on the pancreas of Wistar rats and the protective role of zinc. Methods We exposed the rats to daily doses of 14.4 to 750 mg/kg body weight of the glyphosate-based herbicide Bushfire® and to 50 or 100 mg/kg zinc, and measured blood glucose levels and serum insulin levels. Tissue samples were evaluated for histopathological alterations. Results Levels of both blood glucose and serum insulin increased in glyphosate-exposed rats, and moderate to severe degenerative changes were observed in both glandular pancreatic acinar cells and islets of Langerhans in all rats exposed to glyphosate. These effects were prevented by pretreatment with zinc. Conclusion Chronic exposure to glyphosate can alter pancreatic function and histoarchitecture, but zinc supplementation can mitigate these toxicopathologic effects.

Chronic co-exposure to chlorpyrifos and deltamethrin pesticides induces alterations in serum lipids and oxidative stress in Wistar rats: mitigating role of alpha-lipoic acid

The study evaluated the effect of combination of chlorpyrifos (CPF) and deltamethrin (DLT) on serum lipid profiles and oxidative stress in rats, and the mitigating role of alpha-lipoic acid (ALA). Thirty male rats were used for the 120-day study. Serum samples obtained at termination were evaluated for the levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), malondialdehyde (MDA), and the activities of antioxidant enzymes. The levels of low-density lipoprotein-cholesterol (LDL), very low-density lipoprotein-cholesterol (VLDL), and atherogenic index (AI) were calculated. The pesticide combination elevated the levels of TG, TC, LDL, VLDL, AI, and MDA, and decreased HDL level, and activities of CAT, SOD, and GPx. The alterations induced by CPF and DLT were alleviated by ALA, partly through its antioxidant properties. In conclusion, co-exposure to DLT and CPF altered serum lipids and increased oxidative stress changes in the rats, which were ameliorated by ALA.

Dyslipdemia induced by chronic low dose co-exposure to lead, cadmium and manganese in rats: the role of oxidative stress

Lead (Pb), cadmium (Cd) and manganese (Mn) have many potential adverse health effects in vitro and in animal models of clinical toxicity. The current study investigated the dyslipidaemic and oxidative stress effects of chronic low-dose oral exposure to Pb, Cd and Mn and the combination (Pb+Cd+Mn) in rats for 15 weeks. Chronic exposure to the metals did not significantly (P>0.05) alter serum lipid profiles. However, the atherogenic index decreased by 32.2% in the Pb+Cd+Mn group, relative to the control. The triglyceride/high-density lipoprotein cholesterol ratio decreased by 39.4% in the Pb+Cd+Mn group, relative to the control, and elevated by 81.8, 94.8 and 20.8%, relative to the Pb, Cd and Mn groups, respectively. While the serum concentrations of malondialdehyde significantly increased in the Mn and Pb+Cd+Mn groups, that of glutathione peroxidase-1 decreased in the Pb+Cd+Mn group, and metallothionein-1 and zinc concentrations markedly decreased in all the metal treatment groups. The results suggest that long-term exposure of rats to Pb+Cd+Mn may result in hypolipidaemia, mediated via oxidative stress and metal interactions. Individuals who are constantly exposed to environmentally relevant levels of the metals may be at risk of hypolipidaemia.