The defensive effect of phellodendrine against AAPH-induced oxidative stress through regulating the AKT/NF-κB pathway in zebrafish embryos

Aims: This study is to investigate the effect of phellodendrine (PHE) against AAPH-induced oxidative stress and find out the biological mechanism of PHE by using the zebrafish embryo model.

Main methods: After treatments by AAPH or PHE, the mortality and heartbeat of zebrafish embryos were recorded and the production of Reactive Oxygen Species (ROS), lipid-peroxidation and the rate of cell death were detected by fluorescence spectrophotometry respectively. Whereafter, the pathways of PHE against AAPH-induced oxidative stress were screened by inhibitors to explore its biological mechanism. The related genes and proteins expressions were analyzed by real-time quantitative reverse-transcription polymerase-chain-reaction (qRT-PCR) and western blotting.

Key findings: The PHE obviously improved the decreased survival rate and abnormally elevated heart-beating rate of zebrafish embryos caused by AAPH. Especially 200μg/mL of PHE make the survival rate increased to 90.26±1.40% at 72hfp and the heartbeat back to normal. Besides, AAPH caused a significant increase in the production of Reactive Oxygen Species (ROS), lipid-peroxidation and cell death rate, all of which could be decreased after PHE treatment dose-dependently. And PHE exerted the protective activity against AAPH-induced oxidative stress through down-regulating Akt phosphorylation and NF-kB3 expression, which associate with modulation of IKK phosphorylation in zebrafish embryos.

Significance: The PHE showed a good antioxidant effect in vivo, and the mechanism has been stated that the PHE can down-regulating Akt, IKK, NF-kB phosphorylation and COX-2 expression induced by AAPH. Moreover, the PHE also ameliorated the ROS-mediated inflammatory response.