APP and Parkinson disease: For example, metformin significantly reduces the levels of phosphorylated α-synuclein, a modified form of the protein that is more frequently present in Parkinson’s disease (PD) [184,185], whereas resveratrol promotes the clearance of β-amyloid protein, the core component of the senile plaque found in AD, in HEK293 cells expressing the amyloid precursor protein [186], thus demonstrating the efficacy of this approach.