Figure 5.

A scheme showing the mechanism by which melatonin protects human MSCs against oxidative stress-inhibited osteogenesis. Oxidative stress inhibits osteoblast differentiation of human MSCs by decreasing AMPK signaling. However, melatonin supplement alleviates oxidative stress-inhibited osteogenesis by restoring the in vitro differentiation potential of human MSCs through activation of AMPK-FOXO3a-RUNX2 axis. The proposed scheme suggests a therapeutic potential of melatonin in MSC-based bone regeneration and repair.