• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.669-675
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• 2001

The objective of this study was to examine the effects of antioxidant vitamins on the formation of $AFB_{1}-DNA$ adduct and $AFB_{1}-inducing$ cellular oxidative damage. Intraperitoneal(i.p.)injections of 10 mg/kg vitamin C(VC) and 63.8 mg/kg vitamin E(VE) were repeatedly administrated 4 times with 2 days interval to 6 week old male ICR mice. After one hour of vitamin treatments, 0.4 mg/kg $AFB_1$ was injected in $AFB_1$ plus vitamin treated groups by same way. On the other hands, $AFB_1$ treated group was only injected with $AFB_1$ by the same method described above without vitamins. According to quantitative analysis of the $AFB_1$ in mice serum by indirect competitive ELISA, 12.28 and 18.78 ng/mL were detected in $AFB_1-treated$ groups, but 7.60 and 4.85 ng/mL in $AFB_1$ plus VC and VE treated groups, respectively. 23.78, 25.48 ng/mL of $AFB_1-DNA$ adduct were detected in mice liver of $AFB_1$treated groups, while 5.26, 7.81 ng/mL in $AFB_1$ plus VC and VE treated groups, respectively. Consequently, the differences in the concentrations of $AFB_1$ related materials between vitamin treated and non-treated groups were significant. Immunohistochemistry revealed brownish infiltration of $AFB_1$ around central vein and sinusoid in $AFB_1-treated$ group. This manifestation was distinctly reduced in $AFB_1$ plus VC and VE treated groups.

• Toxicological Research
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• v.11 no.2
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• pp.329-335
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• 1995

Incubation of aflatoxin $B_1$ $(AFB_1)$ with microsomes isolated from human liver number 110 yielded two metabolite peaks which were aflatoxin $Q_1$ $(AFQ_1)$ and $(AFB_1)$-exo-8, 9-epoxide (exo-epoxide) in high performance liquid chromatography. Production ratio of $AFQ_1$ to exo-epoxide was 2.43$\pm $0.04. Metabolism of $(AFB_1)$ to $(AFQ_1)$ and exo-epoxide was inhibited by troleandomycin in a same degree although troleandomycin was not activated as a mechanism-based inhibitor. The inhibitory effect was dependent upon either the incubation time with $(AFB_1)$ or the preincubation time before the addition of $(AFB_1)$. Incubation of troleandomycin and NADPH by the microsomes resulted in the formation of a cytochrome P 450 (P450)-metabollc intermediate (MI) complex and the level was approximately 80% of total P450 3A4 in the microsomes. This figure was similar to that of the inhibitory effect of troleandomycin on $AFB_1$ metabolism. Glutathione which was reported that it prevented the formation of MI complex in rat liver microsomes did not inhibit the formation of MI complex in human liver microsomes. These results suggested that the inhibitory effect of troleandomycin on $AFB_1$ metabolism is due to the formation of MI complex with P450 3A4. And the reaction mechanism of troleandomycin by human liver microsomes might be dlfferent from that one by rat liver microsomes.

• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.149-157
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• 1996

A procedure for the determination of Aflatoxins in food and grains which utilizes reversed phased liquid chromatographic (LC) analysis with postcolumn derivatization by an electrochemical cell and determination with a fluorescence detector has been evaluated. The LC mobile phase was water-acetonitrile-methanol (6+2+2) with 1mM KBr and 1 mM HNO3 which gave baseline separation for the four Aflatoxins (AfB1, AfB2, AfG1, AfG2). The electrochemical cell set at 7V, generated bromine and derivatized aflatoxins B1 and G1, The derivatives were detected by the fluorescence detector. The aflatoxins in naturally contaminated corn samples were isolated by three different cleanup procedures: the AOAC method I column(CB method), a rapid filtrate column (Romer's column), and an immunoaffinity column. The final extract were quantitated with fluordensitometric TLC and the LC postcolumn derivatization techniques. The results were quite similar, however the LC technique showed less interferences and could be automated. Samples of corn, raw peanuts, peanut butter and dried dates were also analyzed successfully with this procedure.

• Journal of Food Hygiene and Safety
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• v.36 no.4
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• pp.316-323
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• 2021

A total of 106 samples (nuts, nut products, oilseeds, oilseed products, seed for beverage products) were simultaneously analyzed with LC/MS/MS method. The tested mycotoxins were aflatoxin (B₁, B₂, G₁, G₂), ochratoxin A, fumonisin (B₁, B₂), and zearalenone. Mycotoxins were detected in 37 of 106 samples (35%), and two or more mycotoxins were simultaneously detected in 9 of 106 samples (8.5%). Aflatoxin, ochratoxin A, fumonisin and zearalenone were detected at the range of 0.08-1.45 ㎍/kg, 17.29 ㎍/kg, 1.16-14.89 ㎍/kg and 0.12-12.69 ㎍/kg, respectively. The results revealed that the most frequently detected mycotoxin was zearalenone (23%), followed by aflatoxin (13%), fumonisin (8%) and ochratoxin A (1%). Detection rates of nuts and oilseeds were 35% and 33%, respectively, and detection rates of their processed foods were 44% and 46%, respectively. The detection rate of mycotoxins was 10% higher in processed foods than in nuts and oilseeds. Mycotoxins are physicochemically stable and can persist during food processing and cooking, making management of mycotoxins in raw materials a concern of high importance.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.75-82
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• 2013

The simultaneous analysis and monitoring of aflatoxin $B_1$, $G_1$, $B_2$, $G_2$ and ochratoxin A in foods were carried out by HPLC with fluorescence detection. The samples were extracted with methanol/water mixture. The extract was centrifuged, diluted with phosphate buffer saline (PBS), filtered, and applied to an immunoaffinity column containing antibodies specific to both aflatoxins and ochratoxin A. After washing the column with PBS and water, the toxins were eluted from the column with methanol, and quantified by HPLC, with a run time of approximately 30 min. The recoveries for aflatoxin $B_1$, $G_1$, $B_2$, $G_2$ and ochratoxin A in foods were 78.4~101.5%, 73.3~102.1%, 81.7~106.7%, 67.0~104.6% and 78.7~120.8%, respectively. The limits of detection of aflatoxins and ochratoxin A ranged from 0.05 to $0.18{\mu}g/kg$. According to monitoring result with the established method, aflatoxin $B_1$ and ochratoxin A were found in 13 of 151 domestic commercial foods. The contamination levels were $0.32{\sim}1.80{\mu}g/kg$ for aflatoxin $B_1$ and $0.97{\mu}g/kg$ for ochratoxin A. Therefore, this study showed all commercial foods monitored were safe under the Korean standards for aflatoxins and ochratoxin A.

• Journal of Food Hygiene and Safety
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• v.1 no.2
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• pp.171-176
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• 1986

ABSTRACT-In order to detect the aflatoxins in home-made Takju and peanut butter, the samples were collected in Chungbuk region and cleaned up Sep-pak silica cartridge. Aflatoxins were detected by thin layer chromatographic and high performance liquid chromatographic behavior. Determination was carried out by thin layer densitometer. The results were as follows; 1. Aflatoxin B, was detected in 78% of the home-made Takju, and the highest concentration was 1.2 ppb and average 0.36 ppb. 2. Aflatoxins were not detected in any peanut butter smaples. 3. Clean-up method by Sep-pak silica cartridge was more efficient and economical than column chromatography of AOAC method.method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.163-173
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• 2007

Lipid peroxidation is one of the main manifestations of oxidative damage and has been found to play an important role in the toxicity and carcinogenesis of many carcinogens. This study was carried out to determine the effects of vitamin C on lipid contents and fatty acid compositions of serum and liver in male rats treated with radiation or aflatoxin $B_1\;(AFB_1)$. Six week-old male Sprague-Dawley rats were randomly divided into 7 groups; control group, radiation exposed group, $AFB_1$ treated group, X-ray and $AFB_1$ co-treated group. Three groups, except control group, were each further divided into vitamin C administered group and not administered groups. For this study, vitamin C was injected with 10 mg/kg of body weight by intraperitoneal injection and 1 hr later, 0.4 mg/kg of $AFB_1$ was injected by the same method. These administrations were repeated every 3 days over a period of 15 days. Only one time, X-ray was irradiated on whole liver with 1,500 cGy. Then vitamin C and AFB1 were administered by the same level and same method described above. On the 16th day of treatments, the animals were sacrificed. From the analysis of the serum lipid patterns, significant decrease (p<0.01) in triglyceride (TG) and total cholesterol levels were observed in X-ray and $AFB_1$ co treated group administered with vitamin C (group 7). In liver lipids, the levels of free cholesterol and total cholesterol were also decreased in X-ray and $AFB_1$ co treated group administered with vitamin C (group 7). The levels of serum free cholesterol and hepatic TG were not significantly different among all groups according to vitamin C administrations. The high density lipoprotein (HDL)-cholesterol level of serum was significantly (p<0.01) increased while the low density lipoprotein (LDL)-cholesterol level was decreased in X-ray and $AFB_1$ co treated group administered with vitamin C (group 7). In the phospholipid fatty-acid compositions of serum and liver tissue, group 3, 5 and 7 showed an increase in polyunsaturated fatty-acid (PUFA) but a decrease in saturated fatty acid (SFA) when compared to the control group. The composition ratio of fatty acid varied according to vitamin C administration. These results suggested that vitamin C has partly suppressive effects on lipid contents and fatty acid composition of serum and liver in rats treated by radiation and $AFB_1$.

• Journal of Food Hygiene and Safety
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• v.23 no.2
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• pp.108-112
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• 2008

A survey of total aflatoxin levels was conducted on 158 samples (nuts, fermented foods and their processed products) collected in local markets in Gyeonggi-do and Domestic Internet Site. The total aflatoxins were quantified by the immunoaffinity column clean-up method followed by high performance liquid chromatography (HPLC)-fluorescence detector (FLD). Aflatoxins were found in 45(28.5%) samples including 34 nuts and nut products, 7 soybean pastes, 1 meju, 1 bean product and 2 corn snacks with a range of $0.02{\sim}3.96\;{\mu}g/kg$. These results show that the contamination level of aflatoxin in foods consumed in Korea is low compared with the standard in Korea Food Code($10\;{\mu}g/kg$ as aflatoxin $B_1$). Aflatoxin $B_1$ content was increased in peanuts and com snacks during storage but it was decreased in doenjang (soybean paste).

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.288-294
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• 1986

The effects of ginseng saponin and its related materials on aflatoxin production by Aspergillus parasiticus NRRL2999 in yeast extract sucrose (YES) medium were studied. Maximal production of aflatoxins by the mold in the medium occurred after 9 days at $28^{\circ}C$. When various concentrations of ginseng saponin were added to the medium aflatoxin productions were significantly reduced (p<0.05) compared to the control after 9 days at $28^{\circ}C$. 0.05% of saponin in the medium greatly decreased aflatoxin synthesis, and no aflatoxins were synthesized by the mold in the medium contained 5.0% of saponin. When various concentrations of saponin diol and triol were added to the medium both ingibitory and sitimulatory effects on alfatoxin production were resulted. Saponin fraction numbers of 1, 2, 4, 5 and 6 decreased aflatoxin production, however the numbers of 3 and 7 stimulated the toxin production. 0.05% of adenosine, guanosine, caffeine and xanthosine in the media inhibited aflatoxin production (p<0.05), but adenine and cytosine increased the production. When 5.0% of saponin was added to the medium aflatoxins were not synthesized at all, but total lipid synthesis and mold growth were highly stimulated. Both the synthesis of total lipid and mold growth were reduced in case of aflatoxin synthesis stimulated.

• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.37-53
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• 1993

F. moniliforme MRC 826, a common fungal contaminant of com, has been known to produce a group of mycotoxins, the fumonisins. By thin layer chromatography, fumonisin $B_{1}$ was detected in the F. moniliforme MRC 826 com culture material(CM) extracts. This study was performed to compare the toxicity and carcinogenicity of F. moniliforme MRC 826 CM with those of aflatoxin $B_1(AFB_1)$ in rats. The toxicity was tested over a period of 7 days in ten female Sprague-Dawley (SD) rats. Treatment group were fed a 1 : 1 mixture(wt/wt) of ground CM and basal diet in powder form, while other negative control group were given basal diet alone. The principal pathological changes in rats treated with 50% CM were hepatocellular hydropic degeneration and renal tubular necrosis. The cancer-promoting activity of CM was evaluated in the rat liver diethylnitrosamine-two thirds partial hepatectomy(DEN-PH) model for carcinogenesis. 70 male SO rats(ca. 170 g) were randomized into 5 groups. Group I served as the positive controls and received the basal diet containing 2 ppm $AFB_{1}$ group 2 received 5% CM, group 3 received 2.5% CM, group 4 received 5% normal com and group 5 received 2.5% normal com. 5% treated group showed cancer promoting activity in rat liver using DEN as initiator and the induction of glutathione S-transferase placental form positive foci as an end point after 6 weeks of promotion.