N-benzylimidazole, a potent inducer of rat liver enzymes involved in mutagenic activation of various carcinogens

There and Back Again: A Perspective on 20 Years of CYP4Z1

Cytochrome P450 (CYP)4Z1, a highly expressed CYP gene in breast cancer, was one of the last CYPs to be identified in the human genome, some 20 years ago. CYP4 enzymes typically catalyze ω-hydroxylation and metabolize ω3 and ω6 polyunsaturated fatty acids to bioactive lipid metabolites that can influence tumor growth and metastasis. These attributes of CYP4Z1 make it an attractive target for new chemotherapeutic drug design, as a potential biomarker for selection of patients that might respond favorably to drugs and for developing enzyme inhibitors as potential therapeutic agents. This review summarizes the current state of knowledge regarding the advancing biochemistry of CYP4Z1, its role in breast cancer, and the recent synthesis of selective chemical inhibitors of the enzyme. We identify gaps that need to be filled to further advance this field and present new experimental data on recombinant CYP4Z1 expression and purification of the active catalytic form. SIGNIFICANCE STATEMENT: In breast cancer, an unmet need is the availability of highly effective therapeutic agents, especially for triple negative breast cancer. The relevance of the work summarized in this mini-review is that it identifies a new potential drug target, CYP4Z1, and discusses ways in which the gene product's catalytic activity might be modulated in order to combat this malignancy and limit its spread.

Genotoxic and aneugenic properties of an imidazole derivative

To contribute to a more accurate characterization of the mutagenic and aneugenic effects of thiabendazole (TBZ), a widely used antiparasitic and food preservative drug, the induction of sister chromatid exchanges (SCEs) and mitotic spindle anomalies as cytogenetic end-points were investigated. Studies were carried out in Chinese hamster ovary (CHO) cells and human peripheral blood lymphocytes. A significant dose-dependent increase in SCE frequency was observed in CHO cells with S9-Mix (P < 0.01) in the 50-100 microg ml(-1) dose-range, while in the absence of S9-Mix, an enhancement of the SCE frequency was exhibited at the highest dose (P < 0.01). In CHO-K1 cells a significant increase in mitotic spindle anomalies (P < 0.01) was observed with the highest concentration assayed reflecting the specific effect of TBZ formulation at the microtubule level. Cell proliferation kinetics (CPK) were not modified by the addition of this pharmaceutical product. In human lymphocyte cultures, exposure to 100 microg ml(-1) TBZ formulation resulted in a significant decrease of the mitotic index (MI) (P < 0.003) and changes in the replication index (RI) (P < 0.05).

Induction of cytochrome P450 enzymes by albendazole treatment in the rat

The anthelmintic drug albendazole (ABZ), methyl(5-(propylthio)-1H-benzimidazol-2-yl)carbamate, is a benzimidazole highly efficient in the treatment of neurocysticercosis. The effects of ABZ treatment (i.p. and p.o. administration) on the expression of several cytochrome P450 (CYP) enzymes were evaluated in rat liver in order to characterize the spectrum of altered CYP enzymes involved in the metabolism of environmental mutagens and carcinogens, after drug intake. Intraperitoneal administration of ABZ (50 mg/kg body weight/day/three days in corn oil) to rats, caused an induction of hepatic activities of CYP1A1-associated ethoxyresorufin O-deethylase (EROD) 65 fold, CYP1A2-associated methoxyresorufin O-demethylase (MROD) 6 fold, CYP2B1-associated penthoxyresorufin O-dealkylase (PROD) 4 fold, CYP2B2-associated benzyloxyresorufin O-dealkylase (BROD) 14 fold, as well as a partial reduction of CYP2E1-associated 4-nitrophenol hydroxylase (4-NPH) activity. CYP3A-associated erythromycin N-demethylase (END) activity was not modified under the same treatment conditions. Western blot analysis was conducted to explore if the increased catalytic activity was a result of an increased protein content; only CYP1A1/2 showed a visible increase in protein concentration after ABZ inoculation, therefore, the increased PROD and BROD activities could be attributed to the induction of CYP1A1/2. Results with the two main metabolites of ABZ (15 mg/kg body weight/day/three days, i.p.) indicated that ABZ sulfoxide (ABZSO) but not ABZ sulfone (ABZSO(2)) displayed the same pattern of CYP induction than ABZ. Oral administration of ABZ at the human therapeutic dose of 20 mg/kg body weight/day/three days, produced an increase in CYP1A1/2 protein content 24 h after the first intake. The protein level remained high during the treatment, and up to 72 h after the last administration; basal protein levels were almost recovered 48 h later.