CONGO-RED PROTECTS AGAINST TOXICITY OF BETA-AMYLOID PEPTIDES ON RAT HIPPOCAMPAL-NEURONS

beta-AMYLOID peptides are neurotoxic when applied to primary cultures of hippocampal neurones from the embryonic rat. This neurotoxic effect can be inhibited completely by certain disazo dyestuffs. The most pot ent of these are Congo Red and Congo Rubin, whilst Direct Garnet and s odium 4-aminonaphthalene-1-sulphonate are inactive. Congo Red also inh ibits the neurotoxic effects of the human pancreatic amyloidogenic pep tide amylin. It is postulated that these dyes, by interacting with the beta-pleated sheet structure of amyloidogenic peptides, prevent aggre gation and hence neurotoxity.