Figure 4.

Icariin inhibits Aβ _25–35-induced cytotoxicity through the activation of PI3K/Akt signaling. After 1 h pretreatment with the PI3K inhibitor LY294002 (50 μM), PC12 cells were treated with 20 μM icariin for 1 h, followed by Aβ _25–35 treatment for 24 h. Phosphorylation of Akt was assessed by western blot. Densitometry values represent the mean ± S.D. of triplicate independent experiments. ^## P < 0.01 versus untreated control; ^** P < 0.01 versus Aβ _25–35 treatment; ^$$ P < 0.01 versus icariin treatment.