ASSESSMENT OF THE EMBRYOTOXIC POTENTIAL OF THE TOTAL HYDROLYSIS PRODUCT OF FUMONISIN B-1 USING CULTURED ORGANOGENESIS-STAGED RAT EMBRYOS

Aminopentol (AP1) is the total hydrolysis product of fumonisin BI (FBI ), the major and best characterized of the fumonisins, which are mycot oxins that are common contaminants of corn and corn meal. Some human p opulations expected to have significant exposure to API have a high in cidence of babies born with neural tube defects (NTD). The embryotoxic ity of API was evaluated in cultured rat embryos. Gestation day 9.5 em bryos were exposed to 0, 3, 10, 30, 100 or 300 mu M API throughout the entire 45-hr culture period. At 100 mu M AP1, growth and overall deve lopment were reduced significantly. There was also a significant incre ase in the incidence of abnormal embryos. 29% of the embryos had NTD, and 36% of the embryos had other abnormalities. At 300 mu M API, the i ncidence of NTD was 15%, and 85% of the embryos had other abnormalitie s. These findings suggest that API, at concentrations of 100 mu M and above, can induce NTD in organogenesis-stage cultured rat embryos. How ever, these NTD are in conjunction with significant overall retardatio n of growth and development as well as significant increases in the in cidence of other defects. These studies also showed, when compared wit h previous findings, that API is over 100-fold less toxic than FBI to cultured rat embryos. (C) 1997 Elsevier Science Ltd. All rights reserv ed.