Osthole Antagonizes Microglial Activation in an NRF2-Dependent Manner.

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 Aß-overexpressing fruit flies, and silencing NRF2 abolishes OST's antagonism. Furthermore, OST treatment rescued survival, climbing, and the learning ability of Aß-overexpressing fruit flies and relieved oxidative stress. In conclusion, we proved that OST antagonizes microglial activation induced by either LPS or Aß and that NRF2 is necessary for OST's antagonism.

Design, synthesis of novel C-3'-N-sulfonyl modified taxane analogues from 1-deoxybaccatin VI and their impact on anti-HCC activity.

A new series of C-3'-N-sulfonyl paclitaxel analogs were designed and synthesized from 1-deoxybaccatin VI and their structures were confirmed by 1H NMR, 13C NMR and high resolution MS. The synthesized compounds were evaluated for their in vitro anti-Hepatocellular carcinoma (HCC) activity against human hepatoma (HepG2) cell line. Bioassay results showed that compounds 17c, 17d and 17f exhibited more potent inhibitory activity against HepG2 cell line in comparison with paclitaxel. It is suggested that paclitaxel analogs containing the C-3'-N-sulfonyl could be considered as a precursor structure for further synthesis of more potent analogues.