Icariin, a pharmacologically active component isolated from the Chinese herb Epimedium, has been shown to improve spatial learning and memory abilities in
Alzheimer's disease (AD) rats through inhibition of Aβ production and
tau protein hyperphosphorylation. However, the potential mechanism of
icariin-induced protective effects against
mitochondrial dysfunctions in AD still remains unclear. In the present study, we investigated the effect of
icariin on the modulation of mitochondrial transport and distribution in primary hippocampal cultures from triple-transgenic (3× Tg) AD mice. The results showed that
icariin enhanced mitochondrial motility and increased mitochondrial index and mitochondrial length and size in the diseased neurons. Additionally, the expression of the key mitochondrial
enzyme,
pyruvate dehydrogenase-E1α (PDHE1α), and the post synaptic density
protein 95 (PSD95), was preserved in AD neurons after
icariin treatment, accompanied by a downregulation of Aβ and phosphorylated tau expression in the corresponding areas. Further study showed that
icariin treatment resulted in a decrease in mitochondrial fission
protein dynamin-related
protein 1 (Drp1) and an increase in fusion
protein Mitofusin 2 (Mfn2). These data indicate that
icariin can promote mitochondrial transport, protect mitochondria against fragmentation and preserve the expression of mitochondrial and synaptic functional
proteins in AD neurons. Thus,
icariin may be a potential therapeutic
complement for AD and other mitochondrial malfunction-related neuronal degenerative diseases.