Submitted to: Journal of Toxicology and Environmental Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 17, 1996
Publication Date: N/A
Interpretive Summary: Fusaric acid is a common toxin produced by several molds and is found along with other toxins in corn, corn based foods and feeds, wheat, barley, and other cereal grains toxic to domestic animals. Fusaric acid exhibits low to no acute toxicity, and its overall toxic effects in animals have not been determined. Fusaric acid affects two important neurochemicals of the brains that are associated with the processes of growth, maturation, and reproduction. A major hormone, melatonin, also related to these and other physiological processes, is indirectly affected by fusaric acid since its production is dependent on these neurochemicals. Scientists at TMRU/RRC determined the effects of fusaric acid on these two neurochemicals in rats nursed on milk from mothers receiving fusaric acid diets, by measuring the levels of melatonin. The effects of fusaric acid on melatonin production was also measured in a specific rat tissue culture. It was discovered that fusaric acid was passed to nursing offspring. Further, the concentrations of melatonin in the nursing offspring were altered. The effects of fusaric acid on rat cell cultures were the same as those observed in rats. These scientists were the first to document an increase in melatonin levels in blood serum of nursing animals, suggesting that although the effects of fusaric acid is not acutely toxic, fusaric acid may be important in the physiology of the animal relative to long term or chronic exposure because of its effects on two important neurochemicals and a hormone.
Technical Abstract: Fusaric acid (FA) is produced by several Fusarium species that commonly infect cereal grains and other agricultural commodities. FA in the feed of nursing dams is lactationally transferred to the suckling offspring and alters serotonin (SER) and tyrosine (TYR) in the pineal gland of the neonate rats. SER, and TYR indirectly, are involved in melatonin (MEL) production by the pineal gland. MEL is a hormone important in reproduction and seasonality in animals. Therefore, the effects of FA on MEL in the serum and pineal gland of weanling rats from dams on a FA diet were studied. MEL was measured by enzyme-linked immunosorbent assay (ELISA) which was standardized for directly measuring MEL in rat serum and pineal homogenates. FA at 200 ppm in the diet of nursing dams increased pineal and serum MEL (P<0.05) in male and female 21-day-old weanling rats. Results obtained from ELISA were supported by HPLC analysis with fluorescence detection. Analogously, in pineal cell monolayer cultures, FA at 1 uM and 100 uM increased MEL in a dose dependent manner. This is the first report that FA increases MEL both in vivo and in vitro and suggests that FA contamination of diets may affect mechanisms involving MEL synthesis.