In vivo and in vitro effects of deltamethrin on cytochrome p450 monooxygenase activity in carp (cyprinus carpio L.) liver

Abstract

The in vivo and in vitro effects of the insecticide deltamethrin (DM) on hepatic cytochrome P450 (Cyt P450) monooxygenase were examined in adult carp. The in vivo experiments were carried out with 0.2 microgram/l DM at 20 degrees C. The changes in the hepatic microsomal Cyt P450 content and the Cyt P450-dependent monooxygenase activities were studied in DM-treated fish. Although there were no changes in the Cyt P450 content during the exposure time, after treatment for 24 h all the investigated isoenzyme activities (para-nitrophenetole-O-deethylase, p-NPOD; aminopyrene-N-demethylase, APND; ethylmorphine-N-demethylase, EMND; 7-ethoxycoumarin-O-deethylase, ECOD; and ethoxyresorufin-O-deethylase, EROD) were significantly inhibited. After 72 h, all the activities were still lower than in the control animals. In vitro incubation of liver microsomes with DM led to a concentration-dependent decrease in total microsomal Cyt P450 content. A complete loss of Cyt P450 occurred after a 5-min incubation with 60 microM DM. The maximum in the difference spectra of microsomes was shifted to higher wavelength, showing the strong interaction of DM with Cyt P450. EROD and ECOD activities were inhibited by DM. The in vitro kinetic results on ECOD revealed that the inhibition was of non-competitive type, with K1 = 9.8 +/- 2.3 microM. This study indicates important biochemical effects of DM in fish liver, and suggests that exposure to DM may cause loss of the Cyt P450-dependent metabolism in fish.

In vitro biotransformation of surfactants in fish. Part II – Alcohol ethoxylate (C16EO8) and alcohol ethoxylate sulfate (C14EO2S) to estimate bioconcentration potential

“…ECOD activities of microsomes from carp and trout were greater than carp homogenates (data in Dyer et al, 2008). The ECOD activity in trout was similar to that reported by Banka et al (1997).…”

Transcriptional responses in the hepatopancreas of Eriocheir sinensis exposed to deltamethrin

“…We found that the expression levels of CYP450 and glutathione metabolism genes were downregulated, which means that CYP450 and glutamathione are relevant to deltamethrin metabolism. Our results were consistent with those of previous studies: Banka et al [ 59 ] found that CYP450 enzymes were inhibited by deltamethrin in vivo and in vitro, and Abdel-Daim et al [ 60 ] revealed that deltamethrin could induce lipid peroxidation and glutathione reduction. However, Erdogan et al [ 61 ] found a significant increase in CYP450 in the muscle of rainbow trout exposed to deltamethrin, and Olsvik et al [ 62 ] reported that the levels of non-enzymatic antioxidant glutathione were increased in all the tissues exposed to deltamethrin.…”

The effects of epoxiconazole and α‐cypermethrin on Daphnia magna growth, reproduction, and offspring size

“…However, cis-permethrin and fenpropathrin were reported to be inhibitors of CYP1A measured on rat liver microsomes in vitro [47]. Moreover, deltamethrin was found to inhibit several hepatic cytochrome P450 activities in a fish (Cyprinus carpio L.) at a concentration equal to 0.2 mg/L during 72-h exposure and fish-liver microsome (ECOD) activity [48]. Thus it cannot be excluded that the initial a-cypermethrininduced decrease in measured ECOD activity may be caused by inhibition, resulting in lower measurable activity.…”

“…Inhibition of cytochrome P450 activity caused by pyrethroids has not been extensively studied. Moreover, deltamethrin was found to inhibit several hepatic cytochrome P450 activities in a fish (Cyprinus carpio L.) at a concentration equal to 0.2 mg/L during 72-h exposure and fish-liver microsome (ECOD) activity [48]. Moreover, deltamethrin was found to inhibit several hepatic cytochrome P450 activities in a fish (Cyprinus carpio L.) at a concentration equal to 0.2 mg/L during 72-h exposure and fish-liver microsome (ECOD) activity [48].…”