Rifampicin prevents the aggregation and neurotoxicity of amyloid beta protein in vitro.

The aggregation and cerebral deposition of amyloid beta protein (A beta), which is a major component of senile plaques in Alzheimer's disease (AD) brains, is believed to be involved in the pathogenesis of AD. Inhibition of A beta aggregation would seem to be a promising strategy for the treatment of AD. Here, we show that rifampicin, which is an antibiotic widely used in the treatment of tuberculosis and leprosy, inhibited the aggregation and fibril formation of synthetic A beta 1-40 peptide in a dose-dependent manner at reasonable concentrations. Furthermore, rifampicin was found to prevent A beta 1-40-induced neurotoxicity on rat pheochromocytoma PC12 cells. Rifampicin may have therapeutic potential as an agent for inhibiting the initial step of amyloid formation in AD.