Osthole Antagonizes Microglial Activation in an NRF2-Dependent Manner

Abstract

Microglia are neuroglia in the brain with an innate immune function and participate in the progress of neurodegenerative diseases. Osthole (OST) is a coumarin derivative extracted from Cnidium monnieri and bears a microglia-antagonizing ability. However, the underlying mechanism of the antagonism is not clear. The lipopolysaccharides-induced microglial BV2 cell line and amyloid-overexpressing fruit fly were used as models to study OST treatment. We found that OST treatment is sufficient to evoke NRF2 cascade under an LPS-induced inflammatory environment, and silencing NRF2 is sufficient to abolish the process. Moreover, we found that OST is sufficient to antagonize microglial activation in both LPS-induced BV2 cells and Aβ-overexpressing fruit flies, and silencing NRF2 abolishes OST’s antagonism. Furthermore, OST treatment rescued survival, climbing, and the learning ability of Aβ-overexpressing fruit flies and relieved oxidative stress. In conclusion, we proved that OST antagonizes microglial activation induced by either LPS or Aβ and that NRF2 is necessary for OST’s antagonism.

Dendrobium nobile Polysaccharide Attenuates Blue Light-Induced Injury in Retinal Cells and In Vivo in Drosophila

“…While in vitro studies offer a controlled environment for investigating cellular mechanisms, in vivo models provide a more realistic representation of the whole organism. Despite the differences between these two approaches, there is growing evidence that results obtained from in vitro cell lines can be consistent with those from in vivo Drosophila models [43,[62][63][64]. Our results showed that exposure to blue light caused injury not only to the ARPE-19 and 661W cells but also to Drosophila's phototransduction (Figures 7 and 8).…”