• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.5
• /
• pp.502-508
• /
• 1986

Extracts of six seaweeds obtained from solvents such as water, methanol, hexane and ethyl ether have been tested for desmutagenic activities in the Salmonella typhimurium/microsome systems. Water extracts obtained from tangle, sea-tangle, and gompi were moderately effective on the mutagenicity of Trp-P-2 and aflatoxin $B_1$. Methanol extracts of sea-tangle and gompi were effective against Trp-p-2, and all samples of methanol extracts were very effective from 1.0mg to 2.0mg per plate on the mutagenicity of MeIQ and aflatoxin $B_1$. Hexane extracts of tangle, ses-tangle, gompi and sea-straghorn were very effective on the mutagenicity of Trp-p-2, MeIQ and aflatoxin $B_1$ except laver and green laver. Ethyl ether extracts of gompi and sea-straghorn were most effective from 1.0mg to 2.0mg per plate on the mutagenicity of Trp-P-2. Especially, ethyl ether extracts of all samples were great effective on the mutagenicity of MeIQ and aflatoxin $B_1$.

• Korean Journal of Microbiology
• /
• v.17 no.1
• /
• pp.16-24
• /
• 1979

In order to investigate the production of aflatoxin in various conditions such as pH, moisture and temperature, 27 smaples were inoculated with Aspergillus flavus, and in addition 3 smaples were inoculated with the mixture of Aspergillus flavus and Bacillus subtilis and cultured under the conditions such as $20^{\circ}C$ and 30% moisture contents. The following results were obtained : 1) Aflatoxin production was the highest at pH 5.0 and relatively high at pH 7.0. Its production was decreased significantly when pH reached 9.0. 2) The yield of aflatoxin was shown comparatively high level at 30% moisture contens. The higher moisture contents was, the lower aflatoxin production was. 3) The highest level of aflatoxin production was at $20^{\circ}C$, and comparatively high level was at $30^{\circ}C$. However, its production was fairly low at $40^{\circ}C$. 4) The highest crude aflatoxin production was 5,093ppm $(B_1,\;1.912\;ppm;\;B_2,\;0.521\;ppm;\;G_1,\;2.119\;ppm;\;G_2,\;0.541\;ppm)$ at 30% moisture, pH 5.0 and $20^{\circ}C$ and the lowest one 2.197 ppm $(B_1,\;0.793\;ppm;\;B_2,\;0.185\;ppm;\;G_1,\;0.102\;ppm;\;G_2,\;0.381\;ppm)$ at 63% moisture, pH 9.0 and $40^{\circ}C$ 5) When Aspergillus flavus and Bacillus subilis were cultured together under the conditions such as $20^{\circ}C$ and 30% moisture, aflatoxin production was decreased by 27% comparing with the culture of Aspergillus flavus alone.

• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.4
• /
• pp.379-385
• /
• 1995

Ninety Wistar male rats were used to study the effects of vitamin E and Se supplementation to diets containing aflatoxin $B_1$ on the contents of liver lipids and various blood parameters. Two levels of dietary aflatoxin (0 and 1 ppm), 3 levels of vitamin E (30, 60 and 120 IU/kg), and 3 levels of Se (0.1, 1 and 2 ppm) were used to design a $2{\times}3{\times}3$ factorial experiment. Rats, weighing about 200 g, were randomly allotted to 18 cages, 5 rats per cage. The aflatoxin significantly (p < .05) decreased growth rate, feed intake and feed efficiency. Aflatoxin increased the glucose level and decreased the cholesterol level in blood significantly. Levels of blood triglyceride, total protein, and albumin were not affected by aflatoxin, vitamin E or Se. Activities of blood alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased by aflatoxin; however, the glutathione peroxidase (GSH-Px) activity in the blood was decreased by aflatoxin even in the presence of Se. The vitamin E supplementation decreased the AST activity significantly, while GSH-Px activity increased significantly as the levels of dietary Se increased. The levels of total cholesterol and free cholesterol in the liver were significantly lower in rats receiving aflatoxin, while the extra vitamin E supplementation increased these hepatic cholesterol levels. It was concluded that the extra dietary vitamin E or Se supplementation might partially alleviate some of the harmful effects of aflatoxin in rats.

• Korean Journal of Food Science and Technology
• /
• v.17 no.4
• /
• pp.295-303
• /
• 1985

Aflatoxin $B_1$, $B_2$, $G_1$, and $G_2$were quantitatively detected by the high pressure liquid chromatography on a Micropak-CN column, with Hexane-THF-IPA-water, using a Lichrosorbpacked flowceil in the fluorometric detector. Under those conditions, the minimum detectable amount of aflatoxin $B_1$ was 0.2 ng. HPLC was used in determining amount of aflatoxins in the commercially manufactured soybean food and home-made Meju. Aflatoxin producing abilities of strains used in the industrially fermented soybean food were also studied with the HPLC technique. Although aflatoxin-like substances were detected in a few samples on TLC, they were not identified with the HPLC retention times of standard aflatoxins. The commercial fungal strains used in Korea had no aflatoxin producing abilities.

• Korean Journal of Food Science and Technology
• /
• v.21 no.5
• /
• pp.721-725
• /
• 1989

Aflatoxin accumulation by Aspergillus flavus in rice was inhibited by A. kawachii and A. Shirousamii so that the rate of toxin accumulation and the maximum concentration of accumulated aflatoxins were considerablly reduced, although the initiation of aflatoxin accumulation was not affected. The maximal accumulated aflatoxin $B_1$ in rice by A. flavus at $28^{\circ}C$ and 85% RH was $40{\mu}g/50g$ rice after 35 days. Under the same condition but the additional inoculation of A. kawachii, $25{\mu}g\;of\;aflatoxin\;B_1$ was accumulated maximally in 50g rice after 45 days. When A. shirousamii was inoculated simultaneously with A. flavus on rice, however, only trace levels of aflatoxins were detected throughout 60 days of storage. Aflatoxins added to rice were reduced by 97% with A. kawachii and by 98% with A. shirousamii after 7 days during rife koji preparation. They were also reduced after 48 Hours of incubation by 30-67%, with A. kawachii koji and by 16-75% with A. shirousamii koji.

• Toxicological Research
• /
• v.8 no.1
• /
• pp.83-94
• /
• 1992

The influences of dietary aflatoxin B1 on performance, on hematologic, pathologic and immunologic changes in broiler chickens were studied. One hundred and fifty hatched broiler chickens were fed with diet containing aflatoxin B1 (1.0 ppm and 2.5 ppm) fot three weeks. Blood samples, serum, and immune organs were obtained to investigate hematological, clinico-chemical, and histopathologial changes. Body weight gain and feed intake were significantly decreased. The liver and kidney were increased, whereas the bursa of Fabricius, spleen and thymus were decreased.

• The Korean Journal of Mycology
• /
• v.9 no.1
• /
• pp.1-6
• /
• 1981

The effect of gamma irradiation on production and accumulation of aflatoxin on natural substrate (barley) by Aspergillus parasiticus NRRL 2999 has been studied in some detail. Gamma irradiation at five doses, 0, 50, 100, 200 and 400 Krad was applied to the grain either soon after moisture equilibration (3 days after inoculation) or 10 days later (13 days after inoculation). And the results were as in the followings. 1. Increase in moisture content from 17% to 25% greatly increased the aflatoxin concentration, especially at zero irradiation dose. 2. Prolongation of the incubation period prior to irradiation from 3 to 13 days resulted in greater accumulation of aflatoxin. 3. Two hundreds Krad applied 13 days after inoculation on barley stored at 25% moisture (100% RH) and $25^{\circ}C$ led to higher aflatoxin production than 100 Krad or even 50 Krad. 4. The relative proportion of the principal aflatoxins in relation to irradiation showed that aflatoxin G was elaborated at a significantly higher rate than aflatoxin B.

• Journal of Environmental Health Sciences
• /
• v.31 no.2 s.83
• /
• pp.127-133
• /
• 2005

This study was performed to investigate the competitive effect of Leuconostoc mesenteroides and Lactobacillus plantarum on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus. Leu. mesenteroides and Lac. plantarum were grown with A. parasiticus in a modified APT broth at $28^{\circ}C$ for 9 days. It was observed that the growth of A. parasiticus got lower when the two bacteria were inoculated simultaneously than when the mold grew alone. The pH of mixed culture of Leu. mesenteroides and Lac. plantarum showed significantly lower value than the pH of the pure culture of A. parasiticus (p<0.05). The acidity of the mixed culture group significantly increased compared with the control group (A. parasiticus alone group) (p<0.05). The aflatoxin $B_1$ production was significantly decreased in the mixed culture group than in the A. parasiticus alone group (p<0.05). Leu. mesenteroides showed the more efficient effect than Lac. plantarum. These results indicate that the two lactic acid bacteria have inhibitory effect on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus.

• Korean Journal of Veterinary Research
• /
• v.15 no.2
• /
• pp.263-269
• /
• 1975

한국산(韓國産) aflatoxin $G_1$의 독성(毒性)을 비교구명(比較究明)하기 위하여, 한국산(韓國産) aflatoxin $G_1$과 표준(標準) Aflatoxin $G_1$을 各各 1포(圃)씩 오리병아리에 경구투여(經口投與)해서 얻은 결과(結果)는 다음과 같다. 1. Aflatoxin $G_1$의 독성(毒性)에 의(依)하여 유발(誘發)되서 간장(肝臟)에 나타난 병리조직학적(病理組織學的) 병변(病變)은 출혈(出血), 지방변성(脂肪變性) 및 경(輕)한 담관세포(膽管細胞)의 증식등(增殖等)이었다. 2. 출혈(出血)은 $75{\mu}g$의 한국산(韓國産) aflatoxin $G_1$의 투여(投與)로 폐사한 오리에서 가장 현저하였다. 담관세포(擔管細胞)의 증식(增殖)은 $75{\mu}g$과 $50{\mu}g$의 aflatoxin $G_1$을 투여(投與)한 경우에 경(輕)하게 나타났다. 3. 독량(毒量)이 같은 경우에도 Aflatoxin $B_1$에 비(比)해 Aflatoxin $G_1$의 병변(病變)이 훨씬 가볍게 나타났다. 4. 한국산(韓國産) aflatoxin $G_1$을 투여해서 발생(發生)된 병변(病變)은 표준(標準) aflatoxin $G_1$을 투여해서 발생(發生)된 병변(病變)과 유사(類似)하였으며, 그 정도(程度)도 비슷하였다.

• Biomolecules & Therapeutics
• /
• v.4 no.2
• /
• pp.190-195
• /
• 1996

Aflatoxin B1 (AFB1) has been reported to directly suppress the immune responses. In the present study, the effect of AFB1 on immune functions was investigated. Splenic lymphocytes were treated with various doses of the mitogens (lipopolysaccharide, concanavalin A) in the presence of AFB1. AFB1 pretretment decreased the number of plaque forming cells (PFC) in a dose-dependent manner. Antibody production of IgM and IgG class was significantly decreased in AFB1-treated splenic cells. In addition, when animals were exposed to AFB1, the susceptibility of bacterial infection as well as the growth of tumor cells was increased. These data suggest that AFB1 affected the immune function and humoral immunity impaired by AFB1 treatment contributed to pathological process.