Correlation between whole blood cholinesterase activity and cerebral cortex cholinesterase activity in rats treated with parathion

Coenzyme Q10, Biochanin A and Phloretin Attenuate Cr(VI)-Induced Oxidative Stress and DNA Damage by Stimulating Nrf2/HO-1 Pathway in the Experimental Model

Hexavalent chromium [Cr(VI)] has emerged as a prevailing environmental and occupational contaminant over the past few decades. However, the knowledge is sparse regarding Cr(VI)-induced neurological aberrations, and its remediation through natural bioactive compounds has not been fully explored. This study intended to probe the possible invigorative effects of nutraceuticals such as coenzyme Q10 (CoQ10), biochanin A (BCA), and phloretin (PHL) on Cr(VI) intoxicated Swiss albino mice with special emphasis on Nrf2/HO-1/NQO1 gene expressions. Mice received potassium dichromate (75 ppm) through drinking water and were simultaneously co-treated intraperitoneally with CoQ10 (10 mg/kg), BCA, and PHL (50 mg/kg) each for 30-day treatment period. The statistics highlight the elevated levels of lipid peroxidation (LPO) and protein carbonyl content (PCC) with a concomitant reduction in the superoxide dismutase (SOD), glutathione-S-transferase (GST), reduced glutathione (GSH), total thiols (TT), catalase (CAT), and cholinesterase activities in the Cr(VI)-exposed mice. The collateral assessment of DNA fragmentation, DNA breakages, and induced histological alterations was in conformity with the above findings in conjugation with the dysregulation in the Nrf2 and associated downstream HO-1 and NQO1 gene expressions. Co-treatment with the selected natural compounds reversed the above-altered parameters significantly, thereby bringing cellular homeostasis in alleviating the Cr(VI)-induced conciliated impairments. Our study demonstrated that the combination of different bioactive compounds shields the brain better against Cr(VI)-induced neurotoxicity by revoking the oxidative stress-associated manifestations. These compounds may represent a new potential combination therapy due to their ability to modulate the cellular antioxidant responses by upregulating the Nrf2/HO-1/NQO1 signaling pathway against Cr(VI)-exposed population. HIGHLIGHTS: Cr(VI)-associated heavy metal exposure poses a significant threat to the environment, especially to living organisms. Cr(VI) exposure for 30 days resulted in the free radical's generation that caused neurotoxicity in the Swiss albino mice. Natural compounds such as coenzyme Q10, biochanin A, and phloretin counteracted the neurotoxic effect due to Cr(VI) exposure in scavenging of free radicals by enhancing Nrf2/HO-1/NQO1 gene expressions in maintaining the cellular homeostasis.

Biomarker-based assessment of the toxicity of the antifungal clotrimazol to the microcrustacean Daphnia magna

Among the vast list of xenobiotics that may promote harmful effects in aquatic ecosystems, pharmaceuticals are currently a prominent class due to their ability to persist in these environments and also due to the lack of information regarding their effects on the different components of the aquatic biota. Antifungals in particular, despite their massive use, are not extensively studied in environbmental terms. The main objective of this study was to characterize the toxicity of the antifungal clotrimazole to the aquatic organism Daphnia magna. To attain this purpose, the effects of this compound were measured, focusing on the determination of acute lethality, and quantification of biomarkers, such as neurotoxicity (soluble cholinesterases, ChEs); and oxidative stress and metabolism (such as catalase, CAT; and glutathione-S-transferases, GSTs). The toxicity assessment with biomarkers was based on animals exposed to concentrations similar to those already found in surface waters in order to increase the ecological relevance of the obtained data. The results showed that exposure to clotrimazole was able to induce significant increases in both CAT amd GSTs activities. ChE activity was not significantly altered after clotrimazol exposure. In view of the above, it is concluded that the drug studied caused adverse effects in terms of oxidative stress, at an ecological relevant levels, showing that the presence of clotrimazol in the wild is not innocuous.

Evaluation of ameliorative effect of curcumin on imidacloprid-induced male reproductive toxicity in wistar rats

This study was undertaken to investigate the toxic effects of imidacloprid (IM) on male reproductive system and ameliorative effect of curcumin (CMN) in male Wistar rats. For this purpose, IM (45 and 90 mg/kg, body weight) and CMN (100 mg/kg, body weight) were administered orally to the rats either alone or in combinations for a period of 28 days. At the end of experiment, male reproductive toxicity parameters (total sperm count and sperm abnormalities), testosterone level, steroidal enzymatic activity [3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-HSD], and oxidative stress indicators were estimated in testis and plasma. IM treatments resulted in significant decrease (p < 0.05) in total epididymal sperm count, sperm motility, live sperm count, and increase (p < 0.05) in sperm abnormalities. Activities of gamma-glutamyl transpeptidase, lactate dehydrogenase-x, and sorbitol dehydrogenase were significantly increased (p < 0.05), while, 3β-HSD and 17β-HSD enzymatic activity along with testosterone concentration in testis and plasma were decreased significantly (p < 0.05) in IM-treated rats. IM exposure resulted in significant increase (p < 0.05) in LPO and decrease (p < 0.05) in GSH level along with decreased activities of CAT, SOD, GPx, and GST. IM-treated rats showed histopathological alterations in testis and epididymis. However, the reproductive toxicity parameters, oxidative stress indicators, and histopathological changes were minimized and functional restorations were noticed by co-administration of CMN in IM-treated rats. The results of this study suggest that IM-induced male reproductive toxic effects could be ameliorated by CMN supplementation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1250-1263, 2016.

Biomarkers of environmental stress in gills of Pinna nobilis (Linnaeus 1758) from Balearic Island

In aquatic environments, bivalve molluscs are used as sentinel species for environmental biomonitoring. In this study Pinna nobilis specimens, the biggest Mediterranean bivalve, were collected in the Magaluf bay (Mallorca), a touristic location and in a pristine area of the Cabrera National Park as the control location. Histological and histochemical analysis in gills of specimens sampled from Magaluf exhibited evident tissue alterations with high presence of haemocytes. Lower acetylcholinesterase (AChE) activity and protein expression were also found in the gills of specimens collected from Magaluf compared with the control area. The determination of antioxidant enzyme activities, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, showed a higher activities of these antioxidant enzymes and total glutathione content in samples from Magaluf bay than in Cabrera. In conclusion, the present study demonstrated that human activities result in morphological tissue alterations and a reduced AChE activity in gills of P. nobilis. Moreover, these stressful environmental conditions induced an adaptive response in P. nobilis as evidenced by increased antioxidant defences and a decreased AChE activity.

CAPSULE

The human activities induce oxidative stress in P. nobilis as evidenced by increased antioxidant defences and a decreased acetylcholinesterase activity.

Acute Toxicity and Cholinesterase Inhibition in Chicks Dosed Orally with Organophosphate Insecticides

Acute toxic effects of three commonly used insecticidal preparations of the organophosphates chlorpyrifos, diazinon, and dichlorvos were examined in mixed breed broiler chicks, and cholinesterase activity in plasma and brain were measured. The acute (24 h) oral median lethal doses (LD50) of chlorpyrifos, diazinon, and dichlorvos were 10.79 mg kg-1, 6.32 mg kg-1, and 6.30 mg kg-1, respectively, as determined by the up-and-down method in chicks. Signs of cholinergic toxicosis in the chicks appeared within two hours after dosing, and they included salivation, lacrimation, gasping, frequent defecation, drooping of wings, tremors, convulsions, and recumbency before death. Halving the oral LD50 of chlorpyrifos (5 mg kg-1), diazinon (3 mg kg-1), and dichlorvos (3 mg kg-1) caused immobility and wing drooping, but not the clinical signs of cholinergic toxicity. However, at full LD50 doses of these insecticides, chicks showed clinical signs of cholinergic toxicity similar to those seen in the LD50 experiments. Two out of six chicks died within two hours after treatment with LD50 doses of chlorpyrifos and dichlorvos, whereas LD50 dosing with diazinon caused death in three out of six chicks. Compared to control values, the insecticides reduced plasma and whole brain cholinesterase activities by 29 % to 84 % and 18 % to 77 %, respectively, depending on the dose. The decrease in plasma cholinesterase correlated well (r = 0.82) with that of the brain. These data suggest that organophosphate insecticides administered orally at LD50 doses induce clinical signs of cholinergic poisoning and concurrently reduce brain and plasma cholinesterase activities in chicks.

Effect of coumaphos on cholinesterase activity, hematology, and biochemical blood parameters of bovines in tropical regions of Mexico

To assess the effect of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] exposure on physiological responses during bovine production, acetylcolinesterase (AChE) and butyrylcholinesterase (BuChE) activities were measured in whole blood, erythrocytes, and plasma of healthy male steers (Bos Taurus x Bos indicus) sprayed with coumaphos at a non-lethal dose of 1 mg kg(- 1) body weight per day once every 14 (in vivo group) or 21 days (southern and central groups). Coumaphos topically administered at 1 mg/kg body weight per day to cattle under normal management practices in tropical areas produced a significant inhibition in erythrocyte (RBC) AChE and BuAChE activities when compared to baseline levels. RBC-AChE activity for the in vivo group decreased 71.3% (P < 0.05) and BuChE activity 59.1% (P < 0.05); RBC-AChE activity decreased 55.1% (P < 0.05) (southern group) and 43.4% (P < 0.05) (central group). Compared to the control specimens, steers from in vivo, southern, and central groups after 150 days of exposure had lower (P < 0.05) leukocyte count, absolute lymphocyte, erythrocyte, and platelet counts. Decreases in RBC-AChE activities correlated with decreased lymphocyte (r = 1.000, p = 0.01), erythrocyte (r = 1.000, p = 0.003), and platelet counts (r = 0.841, p = 0.036). Significantly increased BUN levels (P < 0.05) correlated with the decrease in RBC-AChE activities (r = - 0.997, p = 0.047) and with the decrease in absolute red blood cell (r = - 0.883, p = 0.020) and lymphocyte (r = - 0.825, p = 0.043) counts; increased (P < 0.05) total plasma protein levels correlated with the decrease in RBC-AChE activities (r = -0.998, p = 0.043), absolute red blood cell (r = - 0.998, p = 0.040), lymphocyte (r = - 0.893, p = 0.017), and platelet (r = -0.855, p = 0.030) counts. The physiological responses correlated with the erythrocyte acetylcholinesterase inhibition could be considered as early indicators or warning responses of bovine exposures to organophosphorus pesticides (OPs).

Protective effect of polyurethane immobilized human butyrylcholinesterase against parathion inhalation in rat

Organophosphates (OP) are used in large quantities around the world as agricultural insecticides. Exposure to these toxic chemicals is a serious global health problem. Human plasma butyrylcholinesterase is known to be a good scavenger of organophosphorus pesticides and chemical warfare agents. In this study, purified human plasma butyrylcholinesterase (HuBChE) from pooled outdated human plasma, was immobilized onto the polyurethane foam. The immobilized enzyme showed greater stability at and above room temperature (up to 55°C), compared to the enzyme in solution. Scavenger properties of immobilized enzyme were tested in vitro with parathion and its active metabolite paraoxon. In, in vitro experiments polyurethane foam with immobilized active enzyme removed 40% of parathion and 50% of paraoxon inhibitory effect (based on cholinesterase inhibition). In, in vivo experiments groups of rats inhaled parathion through filters with immobilized active enzyme (Group I), immobilized inactivated enzyme (Group II), and control group (Group III) inhaled solvent only without any parathion or filter. In the Group II animals, activity of plasma and red blood cells cholinesterase was significantly decreased (30 and 28%, respectively) compared to Groups I and III animals. In other tissues such as brain, skeletal muscle and lung, activity of the acetylcholinesterase (AChE) in the Group II animals, was decreased significantly (29, 28, and 22%, respectively). There was no significant differences between Groups I and III animals enzyme activities. In conclusion, immobilized butyrylcholinesterase (BChE) may be useful in scavenging and detoxifying organophosphate compounds both for medical protection and decontamination procedures.

Effect of diplodiatoxin (Stenocarpella maydis) on some enzymatic profiles in male and female rats

Acute and subacute effects of diplodiatoxin were monitored with special reference to biochemical target enzymes like acid phosphatase (AcP), alkaline phosphatase (AkP), and acetylcholinesterase (AChE) in male and female rats. For acute toxicity study the rats were treated with single oral dose of 5.7 mg/kg of diplodiatoxin, whereas for subacute toxicity study the rats were orally treated with 0.27 mg/kg/day for 21 days. Diplodiatoxin caused loss in body weight and feed intake with other clinical symptoms. Due to the acute and subacute treatment of diplodiatoxin significant decreases were observed in serum AcP and AkP and also in liver AkP, whereas liver AcP increased in both male and female treated rats. Further, significant inhibition of brain AChE was observed in acute and subacute treated animals, indicating its effect on nerve synapsis. Sexual dimorphism was recorded when the activity of male rats was compared with female rats. The values were near those of controls on Day 7 (posttreatment), indicating recovery in the altered enzymes once the treatment was ceased. These results suggest that diplodiatoxin is toxic and has potential to affect the normal functioning of individuals and can cause changes in vital tissues such as liver.