AFLATOXIN B-1 CYTOTOXICITY IN NEURONS IN CULTURE

Aflatoxin B-1(AFB(1)), a metabolite produced by Aspergillus flavus and Aspergillus parasiticus, is mainly known for its strong hepatotoxic a nd hepatocarcinogenic actions. Acute and reversible effects due to exp osure to aflatoxin and the presence of aflatoxins in various human tis sues and organs have also been reported. In particular, aflatoxin M(1) (a metabolite of AFB(1)) has been identified in human brain tissue, a nd a syndrome characterised by encephalopathy has been observed in hum ans poisoned by AFB(1). As a first approach to the study of the neurot oxicity of AFB(1), we used the human neuronal cell lines, SKNMC and SK NSH. The data reported show clearly that AFB(1) is capable of interact ing directly with neuronal cells and causing a decrease in cell number following the addition of toxin to the culture. Decrease in cell surv ival is dependent on the toxin concentration, on time of exposure, and on cell density. The cytotoxic response of these cells has been compa red to the effects of AFB(1) on hepatoma cells and spinal cord motor n eurons. Postmitotic neurons are also susceptible to AFB(1) toxicity, a lthough to a lower extent than proliferating cells. A non-proliferatin g state thus appears to lower, but not destroy, neuron sensitivity to the toxin.