Moreover, icariin (ICA), a natural compound derived from Herba Epimedii (39), showed neuroprotective effects on dopaminergic neurons in a PD mouse model, and the potential mechanisms might be related to phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways (40). This evidence concerns the gene AKT1 and Parkinson disease.