Protective and rescuing abilities of IGF-I and some putative free radical scavengers against β-amyloid-inducing toxicity in neurons

beta-Amyloid (A beta) peptides are most likely involved in the neurodegenerative process occurring in Alzheimer's Disease (AD) and are enriched in senile plaques, The mechanisms of A beta toxicity are not clear but likely involve free radicals and apoptosis. Much interest is currently aiming at developing effective approaches to block A beta toxicity in order to slow down disease progression. In that context, we are particularly interested in studying the role of insulin like growth factors, particularly IGF-I and purported free radical scavengers including a Gingko biloba extract (EGb761) as blocker of A beta toxicity in a simple irt vitro model of hippocampal primary cultures, We observed that both IGF-I and EGb761 are unique in that they are able not only to protect but even to rescue neurons against A beta toxicity. These results are summarized here and possible mechanisms of action are discussed to explain the protective properties of these two classes of agents.