Gardenamide A attenuated cell apoptosis induced by serum deprivation insult via the ERK1/2 and PI3K/AKT signaling pathways.

Gardenamide A (GA) is a stable genipin derivative with neuroprotective properties. It rescued pheochromocytoma cell (PC12) sympathetic cultures and retinal neuronal cells from apoptosis insult induced by serum deprivation. GA attenuated the accumulation of intracellular reactive oxygen species (ROS) and the loss of mitochondrial membrane potential. Western blotting with specific phospho-antibodies indicated that GA increased the phosphorylation of both the protein kinase B (Akt) and the extracellular signal-regulated kinase (ERK1/2) in PC12 cells. The GA neuroprotective effect was inhibited by either the specific phosphoinositide 3-kinase (PI3K) inhibitor LY294002 or the mitogen-activated protein kinase (MAPK) pathway inhibitor PD98059. These results propose that the neuroprotective effect of GA on PC12 neuronal cell cultures was mediated through both the PI3K/Akt and ERK1/2 signaling pathways. Therefore, GA may serve as a pharmacological tool to investigate neuroprotective mechanisms of neurons afflicted by different insults.