RESUMO
AIMS: To verify the effects of several 5,8-dimethoxy-1,4-naphthoquinone (DMNQ) derivatives on LPS-induced NO production, cellular ROS levels and cytokine expression in BV-2 microglial cells. MAIN METHODS: An MTT assay and FACS flow cytometry were performed to assess the cellular viability and apoptosis and cellular ROS levels, respectively. To examine the expression of pro-inflammatory cytokines and cellular signaling pathways, semi-quantitative RT-PCR and Western blotting were also used in this study. KEY FINDINGS: Among the six newly synthesized DMNQ derivatives, 2-cyclohexylamino-5,8-dimethoxy-1,4-naphthoquinone (R6) significantly inhibited the NO production, cellular ROS levels and the cytokines expression in BV-2 microglial cells, which stimulated by LPS. Signaling study showed that compound R6 treatment also significantly down-regulated the LPS-induced phosphorylation of MAPKs (ERK, JNK and p38) and decreased the degradation of IκB-α in BV2 microglial cells. SIGNIFICANCE: Our findings demonstrate that our newly synthesized compound derived from DMNQ, 2-cyclohexylamino-5,8-dimethoxy-1,4-naphthoquinone (R6), might be a therapeutic agent for the treatment of glia-mediated neuroinflammatory diseases.
RESUMO
It has previously been reported that 16α, 17α-epoxypregnenolone-20-oxime (EPREGO) exerts an inhibitory effect on nitric oxide (NO) production and inducible NO synthase (iNOS) expression in microglia. The present study aimed to investigate the effects of EPREGO on the lipopolysaccharide (LPS)induced inflammatory response in RAW264.7 macrophage cells, and to determine the underlying molecular mechanisms using western blot analysis, enzymelinked immunosorbent assays and fluorescenceactivated cell sorting. The present study demonstrated that LPSinduced production of NO and interleukin (IL)-6, and the protein expression levels of iNOS, were reduced by EPREGO in a dose and timedependent manner, whereas, EPREGO did not affect tumor necrosis factorα production. In addition, EPREGO suppressed LPSinduced cellular reactive oxygen species production and phagocytosis. Furthermore, EPREGO significantly inhibited the LPSinduced activation of mitogenactivated protein kinases and inhibitor of κB α degradation in LPSstimulated RAW264.7 cells, thus resulting in modulation of the production of NO and IL6. Taken together, these results suggest that EPREGO exhibits anti-inflammatory activity in macrophages, thus validating the hypothesis that EPREGO may be useful as a therapeutic agent for the treatment of macrophage-mediated inflammation.