Antioxidant and Anti-Inflammatory Activities of a Natural Compound, Shizukahenriol, through Nrf2 Activation.

Imbalance in the antioxidant defense system leads to detrimental consequences, such as neurological disorders. The Nrf2 signaling is known as a main pathway involved in cellular defense system. Nrf2 is a transcription factor that regulates oxidative stress response by inducing expression of various antioxidant enzyme genes. In this study, we screened several pure natural compounds for Nrf2 activator. Among them, shizukahenriol (SZH), isolated from Chloranthus henryi, activated Nrf2, and induced expression of the Nrf2-dependent antioxidant enzymes HO-1, GCLC, and GCLM in BV-2 microglial cells. This natural compound was also effective in suppressing production of inflammatory molecules NO, TNF-α, and inhibition of NF-κB p65 translocation to the nucleus in a dose-dependent manner. We also examined whether SZH rescued the microglial cells from oxidative stress-induced cell death. Pretreatment with SZH dose-dependently attenuated H₂O₂-induced cytotoxicity in BV-2 microglial cells. These results suggested SZH as a potential neuroprotective agent for neurological disorders.