Evaluation of in vitro and in vivo toxic effects of newly synthesized benzimidazole-based organophosphorus compounds

• Published in: Ecotoxicology and environmental safety 2013-01, Vol.87 (1), p.23-32
• Main Authors: Güngördü, Abbas, Sireci, Nihat, Küçükbay, Hasan, Birhanli, Ayşe, Ozmen, Murat
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase; Acetylcholinesterase - metabolism; alanine transaminase; Animal, plant and microbial ecology; Animals; Applied ecology; aspartate transaminase; Azinphosmethyl - pharmacology; Benzimidazoles - toxicity; Biocompatibility; Biological and medical sciences; Biomarker; biomarkers; Biomedical materials; carboxylesterase; Carboxylesterase - antagonists & inhibitors; Carboxylesterase - metabolism; Cholinesterase Inhibitors - pharmacology; Ecotoxicology, biological effects of pollution; eel; Electric Conductivity; Electric eel; Enzyme Activation - drug effects; enzyme activity; exposure duration; Fundamental and applied biological sciences. Psychology; General aspects; Glutathione; glutathione peroxidase; glutathione transferase; Glutathione Transferase - metabolism; glutathione-disulfide reductase; Hydrogen-Ion Concentration; In vitro testing; In vivo testing; In vivo tests; Inhibition; lactate dehydrogenase; Larva - drug effects; Larva - enzymology; lethal concentration 50; Lethal Dose 50; Organophosphorus compounds; Organophosphorus Compounds - chemical synthesis; Organophosphorus Compounds - toxicity; Oxygen - analysis; Surgical implants; tadpoles; Techniques; Temperature; toxicity; Xenopus laevis
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2012.10.007

This paper reports the toxic properties of eight newly synthesized benzimidazole-based organophosphorus (OP) compounds in Xenopus laevis in both in vivo and in vitro conditions. For both experiments, a commercial solution of azinphos methyl (AzM, Gusathion M WP25) was used as a reference compound. The 24-h median lethal concentrations (LC50) of all tested compounds were determined for 46th stage tadpoles in the range of 9.54–140.0μM. For evaluation of the lethality of the compounds, the activity of the enzyme biomarkers acetylcholinesterase (AChE), carboxylesterase, glutathione S-transferase (GST), glutathione peroxidase, glutathione reductase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase were determined in vivo in X. laevis tadpoles exposed to three concentrations (LC50, LC50/2, and LC50/4) of tested compounds. All exposure concentrations of AzM and seven of eight tested compounds caused CaE inhibition in in vivo conditions. Furthermore, the AChE inhibition capacity of tested compounds in commercial electric eel AChE and in X. laevis homogenates and also CaE inhibition capacity in only X. laevis homogenates were assayed for a 30-min in vitro exposure period. Eight OP compounds did not inhibit AChE activity more than 23 percent, but AzM exposure inhibited AChE activity by 26 percent for X. laevis homogenates and 97 percent for electric fish AChE in in vitro conditions. Also, CaE inhibition levels in X. laevis tadpole homogenates were 46 percent for AzM and between 8 percent and 33 percent for other compounds in in vitro conditions. [Display omitted] ► Biological activities of newly synthesized benzimidazole-based OP compounds were investigated. ► The mechanisms of toxic action were evaluated in comparison with azinphos methyl. ► Tested compounds did not cause death through inhibition of AChE. ► However, AzM and seven of eight tested compounds caused to CaE inhibition. ► Some of these compounds that may be useful as pesticide, should be tested with further studies for their toxic properties.