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Subchronic chlorpyrifos-induced clinical, hematological and biochemical changes in swiss albino mice: protective effect of vitamin e
Suleiman F. Ambali,Akanbi D O, Oladipo O O, Yaqub LS, Kawu MU
International Journal of Biological and Medical Research , 2011,
Abstract: Forty adult Swiss albino mice of either sex divided into 4 groups of 10 mice in each group were used to evaluate the ameliorating effect vitamin E on hematological and serum biochemical changes induced by subchronic chlorpyrifos (CPF) exposure. Group I (control~C/oil) and group II (VE) were administered corn oil (2 ml/kg) and vitamin E (75 mg/kg), respectively. Group III was administered CPF (21.3 mg/kg~ 1/5th LD50) only while group IV (VE + CPF) was pretreated with vitamin E (100 mg/kg) followed by CPF administration, 30 min later. The regimens were administered orally by gavage, every other week days for a period of ten weeks. The mice were evaluated for signs of toxicity and weekly body weight changes. At the end of the dosing period, blood samples collected were analyzed for packed cell volume, total red blood cell, white blood cell and total protein. The sera obtained from the blood samples were analyzed for the levels of Na+, K+, Cl-, total protein, urea, creatinine, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and malonaldehyde. The results showed that pretreatment with vitamin E ameliorated deficits in clinical, body weight, hematological and biochemical changes induced by repeated CPF administration in mice, partly due to its antioxidant properties.
Assessment of chlorpyrifos and lead acetate combination on neurobehavioral aspects in Wistar rats after subchronic dietary exposure  [PDF]
H Krishna,AV Ramachandran
Biology and Medicine , 2009,
Abstract: Organophosphorus insecticide, chlorpyrifos, and heavy metal, lead, were studied for their interactive effects onneurobehavioral aspects in Wistar rats when exposed for a period of 90 consecutive days through experimental diet.The tests used for the assessment of neurobehavioral changes were include functional observation battery, gripstrength measurement, foot splay measurement and motor activity. The study was designed using two different doselevels of chlorpyrifos and lead acetate and grouped into seven groups including concurrent controls. Neurobehavioralobservations were performed at the end of 4 and 13 weeks of exposure and after 4 weeks of recovery period.Repeated dietary exposure at a dose level of 10 ppm of chlorpyrifos (i.e., equivalent to 1mg/kg body weight/day) andin a combination of 10 ppm chlorpyrifos plus 500 ppm of lead acetate (i.e., equivalent to 44.0mg/kg body weight/day)to groups of animals revealed mild cholinergic symptoms and decreased rearing counts at the end of week 4. Inaddition, combination group animals (Chorpyrifos plus Lead) treated at the low dose level (Chlorpyrisfos-1ppm andlead-50 ppm) also revealed reduction in the vertical movements. The lack of persistence and/or cumulative effects ofthese changes after 13 weeks of exposure is due to tolerance induced by the chlorpyrifos. The rearing movementsmeasured in the open field are considered to be more indicative of exploratory behaviour and emotional tendenciesthan of general motor activity. A decrease in rearing counts of combination group animals (Chorpyrifos plus Lead)treated at the low dose level after week 4 was noticeable, irrespective of sex, suggests that even at low dose levels,the combination of chlorpyrifos and lead produces behavioral changes. However, many higher levels of tests fordetection of cognitive functions should also be considered. No other behavioral changes were noticed in the studiedbehavioral tests.
Hyperglycemia induced by subchronic co-administration of chlorpyrifos and lead in Wistar rats: Role of pancreatic lipoperoxidation and alleviating effect of vitamin C  [PDF]
SF Ambali
Biology and Medicine , 2011,
Abstract: Studies were conducted to evaluate the role of pancreatic lipoperoxidation on hyperglycemia induced by subchronicco-administration of chlorpyrifos (CPF) and lead (Pb) in Wistar rats and the ameliorative effect of vitamin C. Fortymale Wistar rats divided into 4 groups of 5 animals in each group were used for this study. Rats in group were dosedwith corn oil (2 ml/kg) while those in group II were dosed with vitamin C (100 mg/kg). Group III were co-administeredCPF ( 4.25 mg/kg~ 1/20th LD50) and Pb (250 mg/kg~1/20th LD50) while those in group IV were pretreated with vitaminC (100 mg/kg) and then co-administered with CPF (4.25 mg/kg) and Pb (250 mg/kg) 30 min later. The regimen wereadministered once daily by gavage for a period of 9 weeks. The rats were sacrificed and serum obtained from theblood samples were analyzed for glucose concentration. The liver and pancreas samples were analyzed for glycogenand malonaldehyde (MDA) concentrations, respectively. The study showed that co-administration of CPF and leadcaused increased glucose and MDA concentrations, and a reduced glycogen concentration. Pretreatment withvitamin C restored the concentrations of glucose, glycogen and MDA to apparently normal level. In conclusion,pretreatment with vitamin C restored the hyperglycemia and reduced glycogen concentration induced by coadministrationof CPF and Pb partly due to its antioxidant properties.
Effect of centchroman coadministration on the pharmacokinetics of metformin in rats  [cached]
Lal Jawahar,Jain Girish
Indian Journal of Pharmacology , 2010,
Abstract: Objectives : To study the effect of centchroman, a non-steroidal oral contraceptive, coadministration on the pharmacokinetics of metformin in rats. Materials and Methods : The pharmacokinetic interaction of metformin was studied in normal Sprague-Dawley female rats with and without centchroman coadministration. Blood samples were analyzed using a validated high-performance liquid chromatography method to generate the pharmacokinetic profile of metformin. The C max and t max were directly read from the concentration-time data. Other pharmacokinetic parameters were estimated using non-compartmental analyses. Results : Metformin was monitored up to 10 h, and it exhibited a double-peak phenomenon. The C max 1, 2.62 ± 0.32 μg/ml, and C max 2, 2.96 ± 0.65 μg/ml, occurred after 0.75 and 3 h post-dose, respectively. The mean residence time (MRT), AUC 0-4 h and volume of distribution (Vd/F) were 4.20 ± 0.30 h, 8.53 ± 1.89 μg.h/ml and 14.24 ± 5.42 L/kg, respectively. Following centchroman coadministration, metformin showed significantly (P < 0.05) higher C max (C max 1, 3.96 ± 0.55 μg/ml and C max 2, 5.21 ± 0.59 μg/ml), AUC 0-4 h (12.28 ± 0.73 μg.h/ml) and Vd/F (18.29 ± 1.19 L/kg), but lower MRT (3.19 ± 0.36 h) than the values obtained after metformin dosing alone. However, AUC0-t (17.74 ± 5.58 μg.h/ml) and clearance (3.76 ± 0.80 L/h/kg) remained unchanged. Conclusions : The results indicate that centchroman coadministration increases the rate but not the extent of absorption of metformin in rats. However, it does not seem to alter the pharmacokinetics of metformin to clinically significant levels.
PREDICTION OF BIOAVAILABILITY OF CHLORPYRIFOS RESIDUES IN SOIL TO EARTHWORMS
Wu,X.M; Yu,Y.L; Li,M; Long,Y.H; Fang,H; Li,S.N;
Journal of soil science and plant nutrition , 2011, DOI: 10.4067/S0718-95162011000100004
Abstract: an incubation test was conducted to investigate the effect of aging on bioavailability of chlorpyrifos in soil and to assess the feasibility of chemical extraction techniques for predicting bioavailability of chlorpyrifos in soil. chlorpyrifos was spiked into sterilized soil and aged in microcosms for up to 120 days. the earthworms were incubated in the spiked soils, at 0, 7, 14, 30, 60, and 120 days after spiking, for a period of 7 days. after exposure, chlorpyrifos concentrations in the earthworm tissues were determined. change in chemical extractability of soil-chlorpyrifos was measured using a several solvent systems including methanol, methanol-water (9:1), acetone-water (5:3), and water. the results show that chemical extractability and earthworm bioavailability of chlorpyrifos in soil decreased with aging. the amount of aged and unaged chlorpyrifos recovered from soil varied with the individual chemical extractant and extraction method. concentrations of chlorpyrifos in eisenia foetida were significantly higher than in allolobophora caliginosa, suggesting that the bioavailability of chlorpyrifos was a species-dependent process. the extractability of chlorpyrifos by chemical solvents was significantly correlated with bioavailability fraction of e. foetida and a. caliginosa, showing that these extraction techniques may be efficient for predicting bioavailability of chlorpyrifos in soil.
PREDICTION OF BIOAVAILABILITY OF CHLORPYRIFOS RESIDUES IN SOIL TO EARTHWORMS  [cached]
X.M Wu,Y.L Yu,M Li,Y.H Long
Journal of Soil Science and Plant Nutrition , 2011,
Abstract: An incubation test was conducted to investigate the effect of aging on bioavailability of chlorpyrifos in soil and to assess the feasibility of chemical extraction techniques for predicting bioavailability of chlorpyrifos in soil. Chlorpyrifos was spiked into sterilized soil and aged in microcosms for up to 120 days. The earthworms were incubated in the spiked soils, at 0, 7, 14, 30, 60, and 120 days after spiking, for a period of 7 days. After exposure, chlorpyrifos concentrations in the earthworm tissues were determined. Change in chemical extractability of soil-chlorpyrifos was measured using a several solvent systems including methanol, methanol-water (9:1), acetone-water (5:3), and water. The results show that chemical extractability and earthworm bioavailability of chlorpyrifos in soil decreased with aging. The amount of aged and unaged chlorpyrifos recovered from soil varied with the individual chemical extractant and extraction method. Concentrations of chlorpyrifos in Eisenia foetida were significantly higher than in Allolobophora caliginosa, suggesting that the bioavailability of chlorpyrifos was a species-dependent process. The extractability of chlorpyrifos by chemical solvents was significantly correlated with bioavailability fraction of E. foetida and A. caliginosa, showing that these extraction techniques may be efficient for predicting bioavailability of chlorpyrifos in soil.
Bioactivation of Chlorpyrifos in the Riceland Prawn, Macrobrachium lanchesteri
W. Tongbai,P. Damrongphol
Journal of Biological Sciences , 2011,
Abstract: Metabolic activation of chlorpyrifos to chlorpyrifos-oxon via cytochrome-P450 (CYP450) in the riceland prawn Macrobrachium lanchesteri was examined. Direct effects of chlorpyrifos-oxon on Acetylcholinesterase (AChE) activity was studied in vitro by exposing M. lanchesteri supernatants to chlorpyrifos-oxon. And the role of CYP450 in the bioactivation was investigated in vivo by treating M. lanchesteri with piperonyl butoxide, a potent CYP450 inhibitor, prior to chlorpyrifos exposure. The study indicated that chlorpyrifos-oxon was a more potent AChE inhibitor than chlorpyrifos. However, chlorpyrifos concentrations which did not inhibit AChE activity in vitro exerted AChE inhibition in vivo. CYP450 played an important role in the bioactivation of chlorpyrifos since M. lanchesteri pretreated with 500 g L-1 piperonyl butoxide for 24 h prior to 1.5 g L-1 chlorpyrifos exposure for 96 h significantly attenuated the inhibition of AChE activity caused by chlorpyrifos. Nevertheless, pretreatment with piperonyl butoxide did not alter the effects of chlorpyrifos in reducing catalase activity, increasing lipid peroxidation as evidenced by increased thiobarbituric acid reactive substance levels and inducing histopathological changes such as swelling of the gills and degeneration of the hepatopancreatic cells. In conclusion, chlorpyrifos was bioactivated to chlorpyrifos-oxon in M. lanchesteri via CYP450. Chlorpyrifos-oxon was a strong AChE inhibitor but did not alter the effects of chlorpyrifos in inducing oxidative stress and histopathological changes.
Dissipation of chlorpyrifos on pakchoi inside and outside greenhouse
YU Yun-long,FANG Hu,WANG Xiao,YU Jing-quan,FAN De-fang,
YU Yun-long
,FANG Hu,WANG Xiao,YU Jing-quan,FAN De-fang

环境科学学报(英文版) , 2005,
Abstract: The dissipation of chlorpyrifos on pakchoi inside and outside greenhouse was studied. The decline curve of chlorpyrifos on pakchoi could be described as first-order kinetic. The experimental data showed that both the hermetic environment of greenhouse and season affected dissipation rates of chlorpyrifos on pakchoi. Chlorpyrifos declined faster outside greenhouse than inside greenhouse. Chlorpyrifos residues at pre-harvest time were below the maximum residue limits(MRLs) fixed in China, whereas the values inside greenhouse were higher than those outside greenhouse by almost 50%. The recommended pre-harvest time established under conditions of open field might not always fit to greenhouse production.
Reactivation of acetycholinesterase inhibited by the pesticide chlorpyrifos
Veronika Racakova,Daniel Jun,Veronika Opletalova,Kamil Kuca
Journal of Applied Biomedicine , 2006,
Abstract: Organophosphorus pesticides such as parathion or chlorpyrifos are substances used worldwide foragricultural purposes. These compounds are able to inhibit an enzyme acetylcholinesterase (AChE; EC3.1.1.7) by phosphorylation in its active site. AChE reactivators and anticholinergics are generally used asantidotes in the case of intoxication by these agents. In this work, the reactivation potency of ninestructurally different AChE reactivators was tested in vitro. Chlorpyrifos was chosen as an appropriatemember of the pesticide family. The result is that bisquaternary reactivators with two oxime groups inposition four at the pyridinium rings (trimedoxime and K074) seem to be the most potent reactivators ofchlorpyrifos-inhibited AChE.
Effect of chlorpyrifos on soil microbial populations and enzyme activities
SHAN Min,FANG Hua,WANG Xiao,FENG Bo,CHU Xiao-qiang,YU Yun-long,
SHAN Min
,FANG Hu,WANG Xiao,FENG Bo,CHU Xiao-qiang,YU Yun-long

环境科学学报(英文版) , 2006,
Abstract: Chlorpyrifos is an organophosphate pesticide that acts as an insecticide-acaricide by ingestion, contact, and inhalation, and is now widely used in greenhouse for the control of pests. The dissipation of chlorpyrifos in crops such as orange fruit (Martinez-Vidal et al., 1998), tomatoes(Aysal et al., 1999), soil and its effects on soil microbial characteristics (Singh et al., 2002) has been reported frequently. However, little information is available to describe impacts of chlorpyrifos on soil microbial population and enzyme activity in greenhouse. In this study, the effect of chlorpyrifos on soil bacteria, fungi, actinomycetes, and soil enzyme activity was investigated.
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