Microglia are the resident macrophages in the central nervous system (CNS) and play essential roles in neuronal homeostasis and neuroinflammatory pathologies. Recently, microglia have been shown to contribute decisively to neuropathologic processes after
ischemic stroke. Furthermore, natural compounds have been reported to attenuate
inflammation and pathologies associated with
neuroinflammation.
Tryptanthrin (indolo[2,1-b]
quinazoline-6,12-dione) is a phytoalkaloid with known anti-inflammatory effects in cells. In present study, the authors confirmed
middle cerebral artery occlusion (MCAO) injury triggers the activation of microglia in brain tissue, and investigated whether
tryptanthrin influences the function of mouse murine BV2 microglia under LPS-induced inflammatory conditions in vitro. It was found
tryptanthrin protected BV2 microglia cells against LPS-induced
inflammation and inhibited the induction of M1 phenotype microglia under inflammatory conditions. In addition,
tryptanthrin reduced the production of pro-inflammatory
cytokines in BV2 microglia cells via nuclear factor erythroid 2-related factor 2 (Nrf2)/
heme oxygenase 1 (HO-1) signaling and NF-κB signaling. The authors suggest that
tryptanthrin might alleviate the progress of neuropathologies by controlling microglial functions under neuroinflammatory conditions.