Synthesis and biological evaluation of scutellarein derivatives as neuroprotective agents via activating Nrf2/HO-1 pathway.

Oxidative stress has been considered as the main factor of neurodegenerative diseases. Activation of the Nrf2/HO-1 pathway, as one of the most crucial endogenous protection systems, was regarded as an effective strategy to against oxidative injury. Here, a series of phosphate esters or phosphonates of scutellarein derivatives were designed, synthesized and evaluated on SH-SY5Y cell lines to examine neuroprotective effects against H2O2 induced damage. Among them, compound 16d exhibited more potent cytoprotective effect than the lead compound scutellarin. Preliminary mechanism studies showed that compound 16d could prevent H2O2 induced neuronal apoptosis, significantly decrease ROS generation, elevate SOD and reduce MDA levels in a dose-dependent manner in SH-SY5Y cell lines. Furthermore, western blot assay disclosed that compound 16d could activate Nrf2, and increase the expression of its downstream genes HO-1 in a concentration-dependent manner, thus displaying potent neuroprotective activity. Overall, these findings demonstrated that compound 16d, as a promising neuroprotective agent, deserved further development.