The physiological effects of DL-ethionine and related methionine analogs upon cellular protein synthesis and methyl group transfer to aflatoxin B1 in Aspergillus parasiticus were examined in growing and resting cell systems. The addition of DL-ethionine (0.02 M) to growing mycelia inhibits cellular growth some 37% after 120 h of development. Addition of ethionine before 50 h prevents any aflato...

Aflatoxin is a toxic secondary metabolite produced by different species of Aspergillus in food crops when stored under hot and humid conditions. Among the various aflatoxins produced by fungi aflatoxin B1 has been proved to have carcinogenic, mutagenic, teratogenic and immunosuppressive effects. They often contaminate human food, animal feed and agricultural produce. Rice straw acts as a common...

Twelve forms of human hepatic cytochrome P450 were expressed in hepatoma cells by means of recombinant vaccinia viruses. The expressed P450s were analyzed for their abilities to activate the potent hepatocarcinogen aflatoxin B1 to metabolites having mutagenic or DNA-binding properties. Five forms, P450s IA2, IIA3, IIB7, IIIA3, and IIIA4, activated aflatoxin B1 to mutagenic metabolites as assess...

Butylated hydroxytoluene pretreatment in the rat enhanced the total in vitro metabolism of aflatoxin B1 by the hepatic postmitochondrial fraction (S-9) and increased the formation of aflatoxin M1, aflatoxin Q1 and a metabolite tentatively identified as the aflatoxin-glutathione conjugate, the latter being the major metabolite produced. Addition of diethyl maleate, a glutathione depletor, to the...

This research investigated the optimal conditions of heat and chemical treatment for elimination aflatoxin. NaOH showed highest inhibition percentage (75.44%) Aspergillus flavus growth that was isolated from lowgrade maize. Low-grade maize contaminated with A. treated by varying three factors in levels: concentration (0, 2.5 5% w/v), temperature (25, 50 75°C) time (24, 48 72 h). Aflatoxin remov...

Whole-body autoradiography of 3H-labeled aflatoxin B1 in young pigs showed a localization of bound label in the nasal olfactory and respiratory mucosa, in the tracheo-laryngeal mucosa, and in the conjunctiva, in addition to the liver. Whole-body and microautoradiography also showed a labeling of pigmented tissues, which can be ascribed to a melanin binding of AFB1. In vitro experiments with mic...

Activation of ras proto-oncogenes occurs frequently in vivo in chemically induced rodent tumours, including rat hepatomas induced by aflatoxin B1. This study examines the in vitro activation of a human ras gene by this mycotoxin. A plasmid containing the human Ha-ras proto-oncogene, together with a neomycin resistance gene (pECneo), was incubated in vitro with a microsomal system generating afl...

An improved monoclonal antibody immunoaffinity chromatography/high-pressure liquid chromatography/ fluorescence detection method was developed to measure aflatoxin (AF) exposure by quantifying AFM1 in human and rat urine samples. Analysis of different amounts of various AF metabolites showed that the immunoaffinity resin was highly selective for aflatoxin B1 (AFB1), AFB2, and AFM1. Recovery of ...