RT Journal Article T1 Effect of natamycin on cytochrome P450 enzymes in rats A1 Martínez Caballero, María Aranzazu A1 Martínez Larrañaga, María Rosa A1 Castellano Santos, Víctor Jesús A1 Martínez Caballero, Marta A1 Ares Lombán, Irma A1 Romero Martínez, Manuel Alejandro A1 Anadón Navarro, Arturo Ramón AB Natamycin is a polyene macrolide antibiotic widely used in the food industry as a feed additive to prevent mold contamination of foods. There are many contradictory results on the genotoxic effects of macrolides which could suggest a potential risk for humans. In the present study, the effects of natamycin on the activities of some drug metabolizing enzymes in rat liver microsomes were determined in vivo. Rats were treated orally with natamycin at doses of 0.3, 1, 3 and 10 mg/kg body weight (bw)/day for 6 days. Determinations of cytochrome P450 (CYP) enzyme activities were carried out in hepatic microsomes isolated from rats treated. The activities of CYP2E1, CYP1A1/2 CYP2B1/2 and CYP4A1/2 enzymes significantly decreased after treatment with 1, 3 and 10 mg/kg bw/day, in a dose-dependent manner as compared to control. This effect was not observed after natamycin treatment at dose of 0.3 mg/kg bw/day. Our results suggest that natamycin may not potentiate the toxicity of many xenobiotics via metabolic activation and/or accumulation of reactive metabolites but also might affect the clearance of other xenobiotics detoxified by the studied CYP enzymes. PB Elsevier SN 0278-6915 YR 2013 FD 2013 LK https://hdl.handle.net/20.500.14352/98184 UL https://hdl.handle.net/20.500.14352/98184 LA eng NO Martínez MA, Martínez-Larrañaga MR, Castellano V, Martínez M, Ares I, Romero A, Anadón A. Effect of natamycin on cytochrome P450 enzymes in rats. Food Chem Toxicol. 2013 Dec;62:281-4. doi: 10.1016/j.fct.2013.08.075. Epub 2013 Aug 31. PMID: 24001439 NO Universidad Complutense de Madrid NO Comunidad de Madrid NO Ministerio de Educación y Ciencia (España) DS Docta Complutense RD 19 dic 2025