Inhibitor Report for: Benfuracarb

Benfuracarb is a carbamate insecticide used to control insect pests in vegetables and it has anti-acetylcholinesterase activity lower than other carbamates. Cytotoxic effects of benfuracarb were evaluated by using root growth inhibition (EC50), mitotic index (MI), and mitotic phase determinations on the root meristem cells of Allium cepa and mutagenic effects were determined in Salmonella typhymurium Ames test by TA98 and TA100 strains with and without metabolic activation. In Allium test, 1 % DMSO was used as negative control group and 10 ppm MMS was used as positive control group. 75 ppm concentration of benfuracarb was found as EC50. In MI and mitotic phases determination study, 37.5, 75 and 150 ppm doses of benfuracarb were used. Dose-dependent cytotoxic activity was found by root growth inhibition and MI studies. It was identified that mitotic inhibition activity of benfuracarb was higher than 10 ppm MMS. In Ames test, mutagenic activity was not observed and over 200 microg/plate of benfuracarb was determined as cytotoxic to S. typhymurium strains. Benfuracarb can be called as "mitotic inhibitor" but not called as mutagen.

Blatta germanica is the more prevalent cockroach species in Algeria. In the present study, we tested the effect on reproduction in B. germanica of two insect growth regulators, RH-0345, a benzoylhydrazine analogue that mimics the action of 20-hydroxyecdysone, and methoprene, one of the most commercially important juvenile hormone analogues, and a novel carbamate insecticide, benfuracarb. The compounds were applied topically (10 and 20 microg/insect for RH-0345, and 1 and 10 microg/insect for methoprene) or orally administrated (at 2% for benfuracarb) on newly emerged females and evaluated on reproductive events during the adult life (2, 4 and 6 days). Treatment with RH-0345 and benfuracarb reduced significantly the number of oocytes, the size and the volume of the basal oocyte during the experimental period. Methoprene distorted the ovarian development since it caused a significant reduction in the number of oocytes at 2, 4 and 6 days for the two tested doses, and an increase in oocyte size at 2, 4 and 6 days with 1 microg and a decrease with 10 microg. In a second series of experiments, the effects of these compounds were assayed on the ovarian proteins. Data from biochemical analysis revealed that RH-0345 and benfuracarb reduced the ovarian amounts of proteins, while treatment with methoprene increased it during the sexual maturation.

The antidotal action of atropine sulfate and 2-pyridine aldoxime methiodide (2-PAM) against poisoning attributable to the new procarbamate insecticide benfuracarb [(ethyl N-[2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio]-N-isopropyl-beta-alaninate] was compared utilizing rats as our experimental model. Both the intraperitoneal and oral administrations of these antidotes were examined after five, ten, fifteen and thirty minutes exposure periods, following treatment with benfuracarb at dose levels approximating LD50 and LD100. The results obtained demonstrate that both the intraperitoneal and oral administrations of atropine sulfate blocked or significantly reduced the toxic effects of benfuracarb and protected the animals from death. The intraperitoneal administration route appears to be more effective than was the oral route. In addition, the administration of atropine sulfate after the shorter period (up to 15 minutes), following exposure to benfuracarb, improved antidotal action, particularly with the LD100 dose of benfuracarb. It is suggested that atropine sulfate antagonizes benfuracarb poisoning by blocking acetylcholine (ACh) receptors, as many other carbamate insecticides, since benfuracarb was an in vivo cholinesterase (ChE) inhibitor and the toxic effect of benfuracarb was reduced by atropine sulfate. 2-PAM, however, did not significantly block or reduce the toxic effects of benfuracarb.

Benfuracarb is a carbamate insecticide used to control insect pests in vegetables and it has anti-acetylcholinesterase activity lower than other carbamates. Cytotoxic effects of benfuracarb were evaluated by using root growth inhibition (EC50), mitotic index (MI), and mitotic phase determinations on the root meristem cells of Allium cepa and mutagenic effects were determined in Salmonella typhymurium Ames test by TA98 and TA100 strains with and without metabolic activation. In Allium test, 1 % DMSO was used as negative control group and 10 ppm MMS was used as positive control group. 75 ppm concentration of benfuracarb was found as EC50. In MI and mitotic phases determination study, 37.5, 75 and 150 ppm doses of benfuracarb were used. Dose-dependent cytotoxic activity was found by root growth inhibition and MI studies. It was identified that mitotic inhibition activity of benfuracarb was higher than 10 ppm MMS. In Ames test, mutagenic activity was not observed and over 200 microg/plate of benfuracarb was determined as cytotoxic to S. typhymurium strains. Benfuracarb can be called as "mitotic inhibitor" but not called as mutagen.

BACKGROUND: In intensive agriculture, the use of pesticides and soil fumigants is necessary to produce economically viable crops worldwide. However, this practice may involve undesirable effects on human health and the environment. In 1995, methyl bromide was restricted by the Montreal Protocol because of possible ozone depletion. The objective of this study was to compare intrinsic environmental and toxicological properties of 11 active substances with nematicidal properties, some of them recognized as methyl bromide alternatives. RESULTS: Four groups of active substances were discriminated by a series of principal component analyses (PCAs): (a) high toxicity to non-target fauna, humans and animals and medium persistence in the environment (cadusafos, ethoprophos and fenamiphos); (b) high toxicity to humans, animals and non-target fauna and high persistence (carbofuran and fosthiazate); (c) low toxicity to non-target fauna, humans and animals and low persistence (carbosulfan, benfuracarb and oxamyl); (d) low toxicity to humans, animals and non-target fauna and medium persistence in the environment (1,3-dichloropropene, chloropicrin and methyl bromide). CONCLUSION: Evaluating the multiple aspects of toxicological and environmental properties of active substances through PCA is proposed as a helpful tool for initially comparing the complex toxicological behaviour of active substances as plant protection products.

Blatta germanica is the more prevalent cockroach species in Algeria. In the present study, we tested the effect on reproduction in B. germanica of two insect growth regulators, RH-0345, a benzoylhydrazine analogue that mimics the action of 20-hydroxyecdysone, and methoprene, one of the most commercially important juvenile hormone analogues, and a novel carbamate insecticide, benfuracarb. The compounds were applied topically (10 and 20 microg/insect for RH-0345, and 1 and 10 microg/insect for methoprene) or orally administrated (at 2% for benfuracarb) on newly emerged females and evaluated on reproductive events during the adult life (2, 4 and 6 days). Treatment with RH-0345 and benfuracarb reduced significantly the number of oocytes, the size and the volume of the basal oocyte during the experimental period. Methoprene distorted the ovarian development since it caused a significant reduction in the number of oocytes at 2, 4 and 6 days for the two tested doses, and an increase in oocyte size at 2, 4 and 6 days with 1 microg and a decrease with 10 microg. In a second series of experiments, the effects of these compounds were assayed on the ovarian proteins. Data from biochemical analysis revealed that RH-0345 and benfuracarb reduced the ovarian amounts of proteins, while treatment with methoprene increased it during the sexual maturation.

Four insecticides, carbofuran, chlormephos, terbufos and benfuracarb, currently used on maize (Zea mays) at sowing, were tested for their compatibility with Azospirillum lipoferum strain CRT1 used as an inoculant to improve maize growth and yield. The growth or survival of A lipoferum was studied in the presence of the insecticides: (1) in liquid and solid cultures of the bacteria, (2) when a commercial inoculant (Azogreen-m, Liphatech, Meyzieu, France) was inoculated directly on insecticide granules, (3) when inoculated Azogreen-m granules were mixed with insecticide granules and (4) when inoculated Azogreen-m granules were delivered separately to the seed bed. Of the four insecticides tested, only terbufos had a slight effect on growth of A lipoferum in solid cultures. All the insecticides decreased the survival of A lipoferum when the bacteria were inoculated directly on to the granules, or when inoculated Azogreen-m granules were mixed with an insecticide. We hypothesize that the discrepancies between bacterial culture tests and survival studies might be explained by the conditions of desiccation encountered during inoculation of the granules. Desiccation stress could increase the toxic effect of the insecticides. We therefore suggest including desiccation stress in the biotest used to assess inoculant-pesticide compatibility.

Residues of benzoylphenylurea insecticides (diflubenzuron, hexaflumuron, and flufenuxuron), carboxamide acaricides (hexythiazox), and carbamate insecticides (benfuracarb) were determined in 150 orange fruit samples from September 1998 to June 1999, to estimate exposure of the Valencian population to oranges contaminated with these newly developed pesticides. The method for monitoring these residues is based on matrix solid-phase dispersion and liquid chromatography with UV or atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) detection. Orange samples representing 11 varieties were collected from an agricultural cooperative and examined for the 5 pesticides. In 74.6% of all analyzed samples, the pesticide residues were below detection limits, which ranged from 0.002 to 0.05 mg/kg. Residues were detected in 25.4% of the samples, with higher incidences of diflubenzuron, flufenuxuron, hexythiazox, and benfuracarb; hexaflumuron residues were detected only occasionally. Two different pesticides exceeded maximum residue limits (MRLs) in 4 (2.7%) of the orange samples. Diflubenzuron surpassed 1 mg/kg MRL in 3 samples and flufenuxuron exceeded the 0.3 mg/kg MRL in 3 samples. The estimated daily intake of the 5 pesticide residues during the period was 0.077 microg/kg body weight per day. This value is much lower than the total admissible daily intake proposed by the Food and Agricultural Organization and the World Health Organization.

The antidotal action of atropine sulfate and 2-pyridine aldoxime methiodide (2-PAM) against poisoning attributable to the new procarbamate insecticide benfuracarb [(ethyl N-[2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio]-N-isopropyl-beta-alaninate] was compared utilizing rats as our experimental model. Both the intraperitoneal and oral administrations of these antidotes were examined after five, ten, fifteen and thirty minutes exposure periods, following treatment with benfuracarb at dose levels approximating LD50 and LD100. The results obtained demonstrate that both the intraperitoneal and oral administrations of atropine sulfate blocked or significantly reduced the toxic effects of benfuracarb and protected the animals from death. The intraperitoneal administration route appears to be more effective than was the oral route. In addition, the administration of atropine sulfate after the shorter period (up to 15 minutes), following exposure to benfuracarb, improved antidotal action, particularly with the LD100 dose of benfuracarb. It is suggested that atropine sulfate antagonizes benfuracarb poisoning by blocking acetylcholine (ACh) receptors, as many other carbamate insecticides, since benfuracarb was an in vivo cholinesterase (ChE) inhibitor and the toxic effect of benfuracarb was reduced by atropine sulfate. 2-PAM, however, did not significantly block or reduce the toxic effects of benfuracarb.