Geniposide Protects Primary Cortical Neurons against Oligomeric Aβ1-42-Induced Neurotoxicity through a Mitochondrial Pathway

Mitochondrial dysfunction plays a key role in the progression of Alzheimer's disease (AD). The accumulation of amyloid-beta peptide (Aβ) in the brains of AD patients is thought to be closely related to neuronal mitochondrial dysfunction and oxidative stress. Therefore, protecting mitochondria from Aβ-induced neurotoxicity is an effective strategy for AD therapeutics. In a previous study, we found that geniposide, a pharmacologically active compound purified from gardenia fruit, has protective effects on oxidative stress and mitochondrial dysfunction in AD transgenic mouse models. However, whether geniposide has a protective effect on Aβ-induced neuronal dysfunction remains unknown. In the present study, we demonstrate that geniposide protects cultured primary cortical neurons from Aβ-mediated mitochondrial dysfunction by recovering ATP generation, mitochondrial membrane potential (MMP), and cytochrome c oxidase (CcO) and caspase 3/9 activity; by reducing ROS production and cytochrome c leakage; as well as by inhibiting apoptosis. These findings suggest that geniposide may attenuate Aβ-induced neuronal injury by inhibiting mitochondrial dysfunction and oxidative stress.