OBJECTIVES: Aflatoxin M1 (AFM1)-contaminated dairy products pose serious human health risks, causing liver and renal failure if consumed. They are also related to decreased milk and egg production in infected animals. This study investigated the AFM1 contamination levels in cheeses sold in Isfahan province, Iran, by enzyme-linked immunosorbent assay (ELISA). METHODS: A total of 100 white cheese samples were randomly collected from supermarkets in Isfahan province and after extraction using dichloromethane were prepared for the ELISA. RESULTS: Of the 100 samples, 52 (52%) were contaminated by AFM1, at levels ranging from 50.2 to 424.4 ng/kg. The remaining 48% of the samples had undetectable AFM1 levels (< 50 ng/kg). Based on the standard limit set by the European Commission and Iran, 8% (8/100) of the AFM1-positive samples (with concentrations between 250.2 and 424.4 ng/kg) had levels higher than the permissible value of 250 ng/kg. CONCLUSION: Although the percentage of cheese samples in Isfahan province with AFM1 levels exceeding the national permissible limit was low, the examination of cheeses and the milk used for their production is nevertheless important for ensuring public health. Furthermore, optimum storage conditions of animal feed should be ensured, and livestock nutrition must be monitored for the presence of AFM1 and other aflatoxins.
Aflatoxin M1* ; Aflatoxins* ; Animal Feed ; Animals ; Cheese* ; Dairy Products ; Enzyme-Linked Immunosorbent Assay ; Humans ; Iran* ; Liver ; Livestock ; Methylene Chloride ; Milk ; Ovum ; Public Health ; Renal Insufficiency

AIMTo study the effect of antihepatitis drug, dimethyl diphenyl bicarboxylate (DDB) on the metabolism and hepatotoxicity of aflatoxin B1(AFB1) in rats.

METHODSRats were given orally DDB 300 mg.kg-1.d-1 for 3 days and then injected intraperitioneally with AFB1 1.5 mg.kg-1. Serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were examined 16 hours after the injection of AFB1. The in vitro metabolism of AFB1 by DDB-pretreated rat liver microsome was investigated by HPLC assay.

RESULTSDDB (300 mg.kg-1) pretreatment provided significant protection against AFB1 hepatotoxicity as evidenced by the decrease of AFB1-elevated serum marker enzymes in rats. Pretreatment with DDB was shown to slightly increase the level of AFM1, the less toxic metabolite. DDB significantly increased the liver cytochrome P450 content, P450 isozyme 2B1-mediated 7-pentoxyresorufin O-dealkylase (PROD) activity, cytosolic glutahione (GSH) level and GSH S-transferase (GST) activities. In addition, DDB slightly increased P450 isozymes, 3A-mediated erythromycin-demethylase and 1A-mediated 7-ethoxyresorufin O-deethylase (EROD) activities.

CONCLUSIONThe results indicate that DDB protected rats against AFB1 hepatotoxicity by increasing the detoxifying metabolism of AFB1 in the liver.

Aflatoxin B1 ; pharmacokinetics ; toxicity ; Aflatoxin M1 ; metabolism ; Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Biotransformation ; Chemical and Drug Induced Liver Injury ; etiology ; metabolism ; prevention & control ; Cytochrome P-450 Enzyme System ; metabolism ; Dioxoles ; therapeutic use ; Disease Models, Animal ; Male ; Microsomes, Liver ; metabolism ; Protective Agents ; therapeutic use ; Rats