Aflatoxin B1 Cytotoxicity on Neurons in culture

Aflatoxin B-1(AFB(1)), a metabolite produced by Aspergillus flavus and Aspergillus parasiticus, is mainly known for its strong hepatotoxic and hepatocarcinogenic actions. Acute and reversible effects due to exposure to aflatoxin and the presence of aflatoxins in various human tissues and organs have also been reported. In particular, aflatoxin M(1) (a metabolite of AFB(1)) has been identified in human brain tissue, and a syndrome characterised by encephalopathy has been observed in humans poisoned by AFB(1). As a first approach to the study of the neurotoxicity of AFB(1), we used the human neuronal cell lines, SKNMC and SKNSH. The data reported show clearly that AFB(1) is capable of interacting directly with neuronal cells and causing a decrease in cell number following the addition of toxin to the culture. Decrease in cell survival is dependent on the toxin concentration, on time of exposure, and on cell density. The cytotoxic response of these cells has been compared to the effects of AFB(1) on hepatoma cells and spinal cord motor neurons. Postmitotic neurons are also susceptible to AFB(1) toxicity, although to a lower extent than proliferating cells. A non-proliferating state thus appears to lower, but not destroy, neuron sensitivity to the toxin.