OBJECTIVETo study the combined toxic effects of fumonisin B(1) (FB(1)) and aflatoxin B(1) (AFB(1)) on Sprague-Dawley (SD) rats.

METHODAll 60 SD male rats were divided into five groups randomly according to the body weight (12 every group). They were given FB(1) (100 microg/kg bw), AFB(1) (100 microg/kg bw), FB(1) plus AFB(1) (100 microg/kg bw respectively), FB(1) plus AFB(1) (50 microg/kg bw respectively) and distilled water respectively by gavage. The experiment persisted 30 days to observe the changes of growth and development, the food used rate, the haematological indexes, the blood biochemical indexes and the viscera histopathology.

RESULTSAt the end of the experiment, the mean body weight increased in the FB(1) plus AFB(1) (100 microg/kg bw respectively) group was (164.9 +/- 19.8) g and the mean body weight increased in the control group was (203.7 +/- 17.1) g. And the food used rate in the FB(1) plus AFB(1) (100 microg/kg bw respectively) group was (25.3 +/- 1.6)% and the food used rate in the control group was (28.1 +/- 1.2)%. There were significant differences in the mean body weight increased and the food used rate between the FB(1) plus AFB(1) (100 microg/kg bw respectively) group and the control group (P < 0.05). While there were no significant differences of body weights and food used rates between controls and AFB(1), FB(1), and low dose AFB(1) + FB(1) groups (P > 0.05). The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutaminetransferase (gamma-GT) in serum of all of the treatment groups were increased, but the increasing extent was severe in the AFB(1) + FB(1) high dose group. At the same time the liver weight and kidney weight were decreased and the liver occurred with the remarkable histopathological lesions in the AFB(1) + FB(1) high dose group. The activity of superoxide dismutase (SOD) in serum was decreased and the level of malondialdehyde (MDA) in serum was elevated in treatment groups.

CONCLUSIONSThe combined toxic effects of AFB(1) and FB(1) existed in male SD rats. Our results provided the basic data for studying the combined effects on human exposed to these two mycotoxin at the same time.

Aflatoxin B1 ; toxicity ; Animals ; Fumonisins ; toxicity ; Male ; Mycotoxins ; toxicity ; Rats ; Rats, Sprague-Dawley ; Toxicity Tests

OBJECTIVETo understand the molecular mechanism and find out the responsible genes for liver cancer by exploring the regulation of gene expression during hepatocarcinogenesis in tree shrew induced by aflatoxin B1 (AFB1).

METHODSThe tissues from tree shrew of different stages during the pathogenesis and development of hepatocellular carcinoma (HCC), liver cancer tissue, para-cancerous tissues, pre-cancerous liver tissues, liver tissues of the same stage from normal controls and the liver tissues taken before AFB1-treatment were analyzed for gene expression by cDNA array.

RESULTSFour patterns of gene expression were observed during AFB1-induced hepatocarcinogenesis. They were: genes up-regulated in HCC tissue and para-cancerous tissue, especially in HCC tissues; genes with similar expressing level in both HCC tissue and para-cancerous tissue, but higher than that in pre-cancerous tissue; genes down-regulated in HCC tissue; genes up-regulated before HCC appeared but down-regulated after HCC appeared.

CONCLUSIONDynamic observation of gene expression will be beneficial to elucidate the mechanisms of AFB1- induced hepatocarcinogenesis and locate the responsible genes.

Aflatoxin B1 ; toxicity ; Animals ; Gene Expression Profiling ; Liver Neoplasms, Experimental ; chemically induced ; genetics ; Oligonucleotide Array Sequence Analysis ; methods ; Tupaiidae

Aflatoxins, found in contaminated food, are potent hepatocarcinogen. The aflatoxin-detoxiczyme (ADTZ) isolated from the edible fungus Armillariella sp., detoxifies aflatoxin B1 (AFB1). This paper reports on the characterization of immobilized ADTZ using a hydrophobic adsorption method. The ADTZ was isolated from cryo-homogenated fungus, previously cultivated at 24 - 28 degrees C for 20 - 30 days, using n-alkyl amino-agar beads. Various adsorption conditions of the enzyme to n-alkyl or n-octyl amino-agar beads were carried out. The effects of enzyme immobilization on different alkyl amino-agar beads, at different pH values (5.5 - 7.5), at different temperature (20 - 40 degrees C) and at different salt concentrations were investigated. The enzyme activity was measured at OD360 by reacting 133.3 ng/mL of AFB1 at 30 degrees C for 30 min with the immobilized ADTZ. The Km value of the immobilized enzyme, determined using Schematic Linewearver-Burk plot, is 3.308 x 10(-3) mol/L, lower than that of free enzyme, which is 2.16 x 10(-6) mol/L. This indicated the affinity of the detoxiczyme to AFB1 decreased after immobilization. The immobilized enzyme activity in oil-phase (n-hexane) was also studied with different concentration of water. After the treatment of the immobilized ADTZ, the toxin no longer causes liver toxicity in the rat toxicity test, no longer causes mutagenicity in Ames test and is no longer toxic in the chicken embryo test. Results also indicated that the pH stability, the thermostability and the freezing stability of ADTZ were improved after the immobilization.
Absorption ; Aflatoxin B1 ; metabolism ; toxicity ; Animals ; Chickens ; Enzyme Stability ; Enzymes, Immobilized ; chemistry ; metabolism ; Hydrogen-Ion Concentration ; Hydrophobic and Hydrophilic Interactions ; Multienzyme Complexes ; chemistry ; metabolism ; Rats ; Temperature ; Toxicity Tests

Aflatoxin B1 ; toxicity ; Animals ; Carcinoma, Hepatocellular ; chemically induced ; metabolism ; Cell Transformation, Neoplastic ; Liver ; pathology ; Male ; Rats ; Rats, Sprague-Dawley ; beta Catenin ; metabolism

This study aimed to discover potential biomarkers for dioxynivalenol (DON) intoxication. B6C3F1 male mice were rally exposed to 0.83, 2.5 and 7.5 mg/kg body weight (bw) DON for 8 days and the differential protein expressions in their blood plasma were determined by SELDI - Time-of-Flight/Mass Spectrometry (TOF/MS) and the immunoglobulins (Igs) G, A, M and E in the serum were investigated. 11.7 kDa protein was significantly highly expressed according to DON administration and this protein was purified by employing a methyl ceramic HyperD F column with using optimization buffer for adsorption and desorption. The purified protein was identified as a haptoglobin precursor by peptide mapping with using LC/Q-TOF/MS and MALDI-TOF/MS and this was confirmed by western blotting and ELISA. IgG and IgM in serum were decreased in a dose-dependent manner and IgA was decreased at 7.5 mg/kg bw DON administration, but the IgE level was not changed. To compare the expressions of haptoglobin and the Igs patterns between aflatoxin B1 (AFB1), zearalenone (ZEA) and DON intoxications, rats were orally administered with AFB1 1.0, ZEA 240 and DON 7.5 mg/kg bw for 8 days. Haptoglobin was increased only at DON 7.5 mg/kg bw, while it was slightly decreased at ZEA 240 mg/kg bw and it was not detected at all at AFB1 1.0 mg/kg bw. IgG and IgA were decreased by DON, but IgG, IgA, IgM and IgE were all increased by AFB1. No changes were observed by ZEA administration. These results show that plasma haptoglobin could be a diagnostic biomarker for DON intoxication when this is combined with examining the serum Igs.
Aflatoxin B1/toxicity ; Animals ; Blood Proteins/drug effects/*metabolism ; Enzyme-Linked Immunosorbent Assay ; Haptoglobins/drug effects/*metabolism ; Immunoglobulins/*blood/drug effects ; Male ; Mass Spectrometry ; Mice ; Mice, Inbred Strains ; Rats ; Rats, Wistar ; Trichothecenes/*toxicity ; Zearalenone/toxicity

Objective: This study aimed to explore the protective effect of procyanidin B2 (PCB2) on acute liver injury induced by aflatoxin B (AFB ) in rats. Methods: Forty Sprague Dawley rats were randomly divided into control, AFB , AFB + PCB2, and PCB2 groups. The latter two groups were administrated PCB2 intragastrically (30 mg/kg body weight) for 7 d, whereas the control and AFB groups were given the same dose of double distilled water intragastrically. On the sixth day of treatment, the AFB and AFB + PCB2 groups were intraperitoneally injected with AFB (2 mg/kg). The control and PCB2 groups were intraperitoneally administered the same dose of dimethyl sulfoxide (DMSO). On the eighth day, all rats were euthanized: serum and liver tissue were isolated for further examination. Hepatic histological features were assessed by hematoxylin and eosin-stained sections. Weight, organ coefficient (liver, spleen, and kidney), liver function (serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, and direct bilirubin), oxidative index (catalase, glutathione, superoxide dismutase, malondialdehyde, and 8-hydroxy-2'-deoxyguanosine), inflammation factor [hepatic interleukin-6 (IL-6) mRNA expression and serum IL-6], and bcl-2/bax ratio were measured. Results: AFB significantly caused hepatic histopathological damage, abnormal liver function, oxidative stress, inflammation, and bcl-2/bax ratio reduction compared with DMSO-treated controls. Our results indicate that PCB2 treatment can partially reverse the adverse liver conditions induced by AFB . Conclusion Our findings indicate that PCB2 exhibits a protective effect on acute liver injury induced by AFB .
Aflatoxin B1 ; toxicity ; Animals ; Biflavonoids ; administration & dosage ; pharmacology ; Catechin ; administration & dosage ; pharmacology ; Chemical and Drug Induced Liver Injury ; drug therapy ; etiology ; Male ; Poisons ; toxicity ; Proanthocyanidins ; administration & dosage ; pharmacology ; Protective Agents ; administration & dosage ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo explore the association of the Thr241Met polymorphism of X-ray cross-complementing group 3 (XRCC3) gene with genetic susceptibility to aflatoxin B1(AFB-1)-related hepatocellular carcinoma (HCC)in Guangxi population.

METHODSWe conducted a hospital-based case-control study, including 257 HCC cases and 711 controls without cancers or liver diseases. The XRCC3 Thr241Met polymorphism was analyzed by PCR.

RESULTSThe XRCC3 genotypes XRCC3-Thr/Met or XRCC3-Met/Met were related with an elevated risk of HCC. The risk of HCC was associated with the number of mutant Met copies (adjusted OR were 2.20 and 8.56 for XRCC3-Thr/Met and Met/Met, respectively); moreover, there seemed to be combined effects for HCC risk between the variant genotypes and AFB1-DNA adduct levels from peripheral blood leukocytes (adjusted OR was 2.34 to 20.44, P < 0.01).

CONCLUSIONThese results suggested that XRCC3 polymorphism may be associated with the risk of AFB1- related HCC among the Guangxi population, and interacts with AFB1 exposure in the development of HCC induced by AFB1.

Aflatoxin B1 ; toxicity ; Carcinoma, Hepatocellular ; chemically induced ; genetics ; Case-Control Studies ; China ; DNA-Binding Proteins ; genetics ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Polymorphism, Restriction Fragment Length ; genetics

OBJECTIVETo detect the expression and variation of p53 gene during tree shrews' hepatocarcinogenesis induced by hepatitis B virus (HBV) and aflatoxin B1 (AFB1).

METHODSTree shrews were divided into four groups: the tree shrews were infected with HBV and fed with AFB1 in group A, only infected with HBV in group B, fed with AFB1 alone in group C, and normal control in group D. All the tree shrews were performed liver biopsy every 15 weeks. The tissues of liver and tumor were detected by immunohistochemistry and molecular biotechnologies.

RESULTS(1) The incidence of hepatocellular carcinoma (HCC) in group A (66.7%) was higher than that in Group B and C (30%). HCC appearance in group A was earlier than that in group C (120.0 weeks +/-16.6 weeks vs 153.3 weeks +/-5.8 weeks, t = 3.336, P<0.01). (2) Mutated p53 protein was not found before the 75th week of the experiment in each group. (3) At the 105th week, the expression rates of mutated p53 protein were 78.6%, 60% and 71.4% in group A, B and C respectively, which were much higher than that (10%) in group D (x2 > or = 5.03, P<0.05). An abnormal band of p53 gene was detected in both group A and C. (4) The mutation points of p53 gene in liver cancer of tree shrew were at codon 275, 78 and 13. The nucleotide sequence and amino acids sequence of tree shrew's wild-type p53 showed 91.7% and 93.4% homology with those of human p53 respectively.

CONCLUSIONSThere is a remarkable synergistic effect between HBV and AFB1 on HCC. Mutated p53 protein is expressed before HCC occurrence, which promotes the development and progress of HCC. HBV and AFB1 may synergistically induce p53 gene mutation.

Aflatoxin B1 ; toxicity ; Animals ; Carcinoma, Hepatocellular ; genetics ; Cocarcinogenesis ; Gene Expression Regulation, Neoplastic ; Genetic Variation ; Hepatitis B ; virology ; Hepatitis B virus ; Liver Neoplasms, Experimental ; genetics ; Point Mutation ; RNA, Neoplasm ; analysis ; Tumor Suppressor Protein p53 ; genetics ; Tupaiidae

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

OBJECTIVETo study the association between susceptibility to aflatoxin B1 (AFB1)-related hepatocellular carcinoma(HCC) and the null genotypes of detoxication gene gstM1 and gstT1.

METHODSPeripheral blood white blood cells DNA samples were obtained from all the subjects including 140 HCC cases and 536 controls from AFB1 high risk area Guangxi. gstM1 and gstT1 polymorphisms were detected by polymerase chain reaction technique.

RESULTS(1) gstM1- and gstT1-present were associated with decreasing risk of HCC. gstM1- and gstT1-null were associated with the increasing risk of HCC [adjusted OR (95 % CI) = 2.07 (1.20-3.57) and 1.44 (0.85-2.45), respectively]; (2) The appearance of both gstM1- and gstT1-null genotypes were more susceptible to HCC than either one of them(adjusted OR and 95% CI are 2.43 and (1.19-4.97); (3) From low/median to high level of AFB1 exposure, both gstM1- and gstTl-null genotypes were associated with significantly conspicuous increasing risk of HCC [adjusted OR(95% CI) = 12.76(5.38-30.24) and 7.82(3.61-16.90) respectively].

CONCLUSIONIt was suggested that: genetic polymorphisms of gstM1 and gstT1 were susceptible to HCC; individuals who were gstM1- or gstT1-null would have an increasing risk of developing HCC while individuals with both nulls were more susceptible. There was evidence of interaction between gstM1- and gstT1-null and the level of AFB1 exposure which was associated with the increasing risk of HCC.

Adult ; Aflatoxin B1 ; toxicity ; Aged ; Alleles ; Asian Continental Ancestry Group ; genetics ; Carcinoma, Hepatocellular ; complications ; etiology ; genetics ; Case-Control Studies ; China ; Environmental Exposure ; adverse effects ; Female ; Genetic Predisposition to Disease ; Genotype ; Glutathione Transferase ; genetics ; Hepatitis B ; complications ; Humans ; Liver Neoplasms ; complications ; etiology ; genetics ; Male ; Middle Aged ; Polymorphism, Genetic