Fig. 7

Hypothetical mechanisms of NGF and 6-shogaol neuritogenesis in PC-12 cells. Nerve growth factor induced neuritogenesis via binding to its high affinity TrkA receptor and leads to the activation of two major signaling pathways, the MEK/ERK1/2 and PI3K/AKT. Addition of Trk inhibitor (K252a), MEK/ERK1/2 inhibitors (U0126, PD98059) and PI3K/AKT inhibitor (LY294002) inhibited NGF-induced neuritogenesis in PC-12 cells. In the present study, the neuritogenic activity of 6-shogaol was inhibited by U0126, PD98059 and LY294002, but only partially inhibited by K252a. Therefore, based on the present findings, both the TrkA-dependent and TrkA-independent initiated MEK/ERK1/2 and PI3K/AKT signaling pathways were involved in 6-shogaol-induced neuritogenesis in PC-12 cells