ABSTRACT
OBJECTIVE Calculate the dietary exposure and exposure risk of Chinese consumers to acephate,using the margin of exposure method.METHODS Determine the bench mark dose of acephate by 21 -day gavage experiment of rats.According to the data from the 2002 National Diet and Nutrition Survey,the 2000 -2006 national food conta mination monitoring program,the 2005 -2006 export monitoring data of customs,calculate the dietary exposure of Chinese consumers to acephate by probabilistic assessment.Estimate the exposure risk by co mparing the margin of exposure with 100. RESULTS The bench mark dose of acephate was 0.75 mg·kg -1 ,the BMDL was 0.51 mg·kg -1 .The exposure of children was higher than that of adults.The proportion at risk of group 1 -6 y,7 -17 y and 18 y or higher was 5%,1 % and 0.1 %,respectively.CONCLUSION So me consumers was of dietary exposure risk to acephate.The high exposure of children should be of great concern.
ABSTRACT
The present paper deals with the toxicity evaluation of pesticides acephate and chlorpyrifos by applying dominant lethal test (DLT) on mosquito Culex quinquefasciatus taken as an experimental model. For this, the adult male mosquitoes emerging from LC20 treated larval stock were allowed to crossmate with normal virgin females under controlled conditions of mosquito rearing laboratory along with the parallel controls, separately for each pesticide. The eggs obtained from such females were allowed to hatch after which they were examined under suitable magnification. The number of unhatched eggs was taken as the measure for calculating the dominant lethality caused by the pesticides and the data was analyzed statistically by applying Student's t-test. The statistical analysis of the results for acephate treated groups was 9.49±1.50 as against 3.92±0.41 in the control groups and chlorpyrifos treated groups gave the value 9.94±1.92 as against 4.26±0.35 in the control groups. The results indicated that these pesticides induced significant (p<0.05) dominant lethality.
ABSTRACT
Acephate (O,S-dimethyl acetyl phosphoramidothioate) is a racemic organophosphorus insecticide, and is effective against a wide range of insects and their larvae. The present study investigated the effect of acute sublethal dose of acephate on acetylcholine (ACh) levels and acetylcholinesterase (AChE) activity in different regions of rat brain, viz., cerebral cortex, hippocampus, cerebellum, and medulla oblongata. The LD50 of acephate (1080mg/kg) was evaluated by probit analysis method. Albino rats were divided into 4 groups with group I serving as control, while II, III and IV groups were given single, double, and multiple doses of acephate (1/5 LD50, i.e., 216mg/kg) orally, respectively. After a pre-determined time period, the rats were sacrificed by cervical dislocation, and the brain tissue was isolated in cold conditions to carry out estimations of ACh content and AChE activity. In contrast to increased AChE inhibition, ACh levels were elevated in all brain regions in a dose-dependent manner.
ABSTRACT
Acephate (Ace) is an organophosphate foliar spray insecticide of moderate persistence with residual systemic activity of about 10–15 days. This study was designed to evaluate the immunotoxic effect of oral subacute acephate exposure in 125-day old WLH Cockerel chicks for 28 days. The experimental birds were randomly divided into five groups (C1, C2, T1, T2 and T3), each comprising 25 birds. The birds of group C1 were given no treatment and served as control. Group C2 was administered groundnut oil (1ml/kg) and served as control (vehicle). Group T1 was given ALD50/40 (21.3 mg/kg), and Group T2 was put on ALD50/30 (28.4 mg/kg), while group T3 received ALD50/20 (42.6 mg/kg) of acephate suspended in groundnut oil. Experimental birds of all groups were vaccinated with New Castle disease vaccine at day 7. Blood was collected at two-week intervals for evaluation of humoral immune response. Parameters such as TLC, TP, antibody titre against ND vaccine, DNCB dye test, and histopathology of immune organs were studied to evaluate immunotoxicity. The results were statistically compared (p<0.05) with the control. Acephate produced decreased humoral immune response in terms of New Castle disease vaccine antibody titre, total protein, serum globulin, and serum albumin. Cell mediated immune response was checked with 1-chloro 2, 4 dinitrobenzene dye dermal sensitization test, and it did not reveal any significant differences. Lymphoid organs such as thymus, spleen, bursa, and liver were weighed during necropsy for calculation of organ weight: body weight ratio. After 28 days of acephate exposure, organ:body weight ratios of immune organs were significantly reduced except liver:body weight ratio on 14 days of exposure, which was increased in all treatment groups as compared to control groups. Histopathologically, bursa and spleen showed mild depletion of lymphocytes. To further identify the specific type of cell death as apoptotic or necrotic, DNA ladder assay was performed. DNA fragmentation assay detected ladder pattern (180bp) in DNA from hepatocytes and splenocytes of acephate-treated birds. It is concluded that acephate is immunotoxic, and exerts its immunotoxicity through induction of apoptosis and alteration of immunological parameters.
ABSTRACT
The influence of Acephate (an organophosphorous pesticide) on some red cell antioxydant enzymes was studied. Acephate of the doses of 20mg and 40mg/kg of body mass/day was administered on rabbit during 30 days continuously. The activity of superoxyde dismutase (SOD), glutathion peroxydase (GP2), glutathion reductase (TAS) in plasma was determined before and after the intoxication. Results showed a reduce of SOD, GR levels in the day 15 and 31 and a reverse to normal level in the day 45, SOD enzyme and GR enzyme levels reduced in day 15 and 31, while GPx activity increased. Total antioxydation was not varied.
Subject(s)
Rabbits , Antioxidants , Erythrocytes , Therapeutics , Organothiophosphorus CompoundsABSTRACT
Acephate with dose of oral 100mg/kilo weigh for 1 time made acute intoxication in rabbits and changes in activity clearly with some parameters: plasma ChE enzyme activity reduce about 41% after 3 to 6 hours intoxication, ability recover after 24 hours but after 48hours still hasn’t get medium level. MetHb rate increase highest at 6 hours and after reduce gradually to nomal level at 48 hours. There have change in acid-base balance, rabbits on infect alkali breathing at 3 hours, transform acid poisoning at 6 hours and infect combine alkali at 24hours and 48hours. Erythrocyte SOD enzyme activity reduce. Urea, glucoza, uric acid level increase significant after 3-6hours intoxication and back to normal nearly after 48hours