title: Comparative study of in vitro prooxidative properties and genotoxicity induced by aflatoxin B1 and its laccase-mediated detoxification products.
abstract: In this paper, the enzymatic detoxification of aflatoxin B1 (AFB1) by laccase was studied, and the prooxidant properties and mutagenicity of the detoxification products were compared with those of AFB1. The optimal enzymatic reaction occurred in 0.1M of citrate buffer containing 20% DMSO at 35 °C, a pH of 4.5, and a laccase activity of 30 U mL(-1). After 2 d, sixty-seven percent of the toxic substrate was removed. The prooxidative properties of the detoxified products (27% versus 86%) and the mutagenicity were significantly decreased in comparison with the parent toxin. Unlike AFB1, which promoted metabolism-dependent genetic mutations by base-pair substitution, the detoxified products did not induce genotoxicity. Comparison of the Km values for AFB1 and riboflavin, a valuable food nutrient, indicated that laccase showed greater affinity for the toxin than for riboflavin.
authors: Department of Pharmacology and Toxicology, Faculty of Pharmacy and Toxicology and Poisoning Research Centre, Tehran University of Medical Sciences, Tehran 1417614411, Iran.
authors: Hamed
authors: H
authors: Zeinvand-Lorestani
authors: Department of Pharmacology and Toxicology, Faculty of Pharmacy and Toxicology and Poisoning Research Centre, Tehran University of Medical Sciences, Tehran 1417614411, Iran. Electronic address: omid@tums.ac.ir.
authors: Omid
authors: O
authors: Sabzevari
authors: Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences, Tehran 1417614411, Iran.
authors: Neda
authors: N
authors: Setayesh
authors: Department of Medicinal Chemistry, Faculty of Pharmacy and Drug Design and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Mohsen
authors: M
authors: Amini
authors: Department of Pharmacology and Toxicology, Faculty of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran.
authors: Amir
authors: A
authors: Nili-Ahmadabadi
authors: Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences, Tehran 1417614411, Iran. Electronic address: faramarz@tums.ac.ir.
authors: Mohammad Ali
authors: MA
authors: Faramarzi
mesh_terms: D016604:Aflatoxin B1 / Q000633:toxicity*; D004249:DNA Damage; D008658:Inactivation, Metabolic; D042845:Laccase / Q000378:metabolism*; D009153:Mutagens; D009154:Mutation
chemical_list: D009153:Mutagens; D016604:Aflatoxin B1; D042845:Laccase
keywords: Aflatoxin B1; Enzyme affinity; Laccase; Mutation; Prooxidant