Mycologists, medical and related scientists have collaborated since the first investigation into the “yellow rice” problem, which occurred in Taiwan in 1937. Together they have elucidated the toxic fungi involved and characterised their toxins. For collaborative studies to succeed and for the scientists to benefit from such collaboration it is important for the scientists to be of a high calibre. The Japanese Association for Mycotoxicology was founded by scientists who have undertaken important collaborative studies which has contributed to the development of this Association. As a member of this Association, who has been involved in such collaborative studies, I would like to emphasize the importance of “horizontal research” together with “vertical research” into the mycotoxins themselves, according to the individual interests of member scientists. This approach has contributed much to enhancing the results of their research. In conclusion, I would like to give my very special thanks to Dr. Hiroshi Tsunoda who has pioneered research in this area and who has generously supplied a vast amount of research material to other scientists in support of their research.
Aflatoxin B1, contamination was surveyed in Virginia, large-type, (5,595 lots) and Spanish-Runner, small-type (19,863 lots), raw shelled peanuts, imported to Japan during September 1972 to December 1991. The regulation level of aflatoxin B1 in food is 10 ppb in Japan. Aflatoxin B1 was detected in 0.4% (24 lots of 5,595) of large-type raw shelled peanut samples, and 0.1% (5 lots) of the samples were rejected as having above the regulation level of aflatoxin B1. Aflatoxin B1 contamination of small-type raw shelled peanuts was detected in exports from 20 of 31 countries. Aflatoxin B1 was detected in 3.4% (670 of 19,863 lots) of small-type raw shelled peanut samples and 1.4% (269 lots) were rejected as having above the regulation level of aflatoxin B1. The mean aflatoxin B1 levels for large-and small-type raw shelled peanuts were 56 ppb (range 0.3-608 ppb) and 202 ppb (range 0.1-8,065 ppb), respectively.
In order to find serological marker(s) of rubratoxin B′s toxicity, the effects of rubratoxin B on serum transaminases, glucose, triglyceride, cholesterol, interleukin (IL) -1β, IL-6 and tumor necrosis factor (TNF) -α levels in mice were investigated. Serum transaminase levels of 24-hr rubratoxin B-treated C3H/HeN mice were much higher than controls, indicating that rubratoxin B brought about hepatic injury. However, rubratoxin B-caused elevation was not remarkable in BALB/cAnN mice. Rubratoxin B decreased serum glucose level in mice of both strains. Again, rubratoxin B was less effective in BALB/cAnN mice. Serum triglyceride and cholesterol levels were not affected by rubratoxin B. We observed drastic elevation of serum IL-6 level in 24-hr rubratoxin B-treated C3H/HeN mice. On the other hand, we detected virtually no serum IL-6 in BALB/cAnN mice. In addition, serum IL -1β and TNF -α were not detected in mice of both strains. Taken together the above results, rubratoxin B exerted more toxicity and induced much more serum IL-6 in C3H/HeN mice than in BALB/AnN mice. It is likely that IL-6 is an excellent serological marker of the toxicity of rubratoxin B. Our results suggest that rubratoxin B can serve as a good model of drug-induced hepatic injury.
We introduce an approach to measuring the toxicity of mycotoxins using co-culture systems with human intestinal cells and target calls. The system is a simple method of interfacing Using chambers systems with commercially available filter supports on which epithelial monolayers can be grown. Bing cultured target calls of mycotoxin, such as lymphocyte, neuro cells, hepatocyte etc., can be cultured under the grown epithelial monolayer cells, and the responses of target cells are examined when the epitheilal cell was exposed to contaminants on the apical side of intestinal epithelial cells. As an application of this system, we examined the toxicity of deoxynivalenol (DON) on limphocytes through intestinal epithelial cells, Caco-2 cells. We found here that the exposure of intestinal epithelial cells to DON in production of cytokines (IL-10 and IL-12) on lymphocytes.
The detection of fungi and the analysis of mycotoxins in grain and other commodities traditionally require considerable time, expertise and often, sophisticated equipment. This leads to expensive and time-consuming methods, which do not lend themselves for ‘real-time’ measurement or ‘field’ type applications. To overcome these problems, work is in progress to develop antibodies, which can be incorporated into immunoassays and other rapid formats, for the specific and general detection of fungi and some of their associated mycotoxins. This paper describes the development of a ‘general mould’ reagent set, based on several monoclonal antibodies raised towards groups of serologically related fungi, including many which are potentially toxigenic, and also the development of a single monoclonal to the fungal membrane lipid, ergosterol. Applications for assays incorporating these antibodies, as well as their suitability for use in lateral flow devices for ‘on-site’ detection of fungi and mycotoxins, are discussed
In attempting to improve upon existing screening assays for mycotoxins a number of biosensors and imaging systems in a variety of instrument platforms have been developed. The biosensor platforms that have been examined range from hand-held devices to benchtop instruments and use technology as diverse as fiber optics, liposomes, small particles (beads), surface plasmon resonance, and microcapillaries. Several of these devices show substantial promise as rapid, sensitive, methods for measuring mycotoxins. The imaging systems that have been developed are presumptive tests for fungal, and by extension mycotoxin, contamination. These systems have used principles as varied as color, fluorescence, and infrared spectroscopy and have been successfully used to indicate fungal contamination. The utility of the techniques for indirectly reducing toxin levels, by removal of product contaminated with fungi, has also been demonstrated. Studies by multiple laboratories to validate the newer biosensor and imaging systems would contribute significantly to their more widespread acceptance, and will hopefully be conducted in the near future.
Scientific activities of the Japanese Association of Mycotoxicology since its establishment in 1974 were briefly overviewed. These acitivities included 49 annual meetings with 21 symposia and 8 workshops, international symposia in 1983 (IMC 3, Tokyo), 1988 (IUPAC, Tokyo) and 1999 (ISMYCO ′99, Chiba), technical seminars, publication of the journal “Mycotoxins”, opening the home-page, and international co-operations. In addition, author′s personal opinions regarding the following issues were mentioned in expectation of the future development of the Association: dynamics of fungi/mycotoxin-contamination and its effects, challenges to the discovery of new mycotoxins, the risk assessment and management of mycotoxins in Japan, and so on.