Effects of sulforaphane on TNF-α-induced proinflammatory cytokine production and reactive oxygen species generation in mouse brain endothelial cells

This study is to investigate the effects of sulforaphane (SFN) on TNF-α-induced proinflammatory cytokine production and reactive oxygen species (ROS) generation in bEnd.3 mouse brain endothelial cells. The bEnd.3 cells were stimulated with TNF-α, with or without SFN treatment, for 24 h. Interleukin-1β (IL-1β) and endothelin contents were detected by ELISA. ROS level was assessed by flow cytometry. The mRNA and protein expression levels of heme oxygenase (HO)-1 were detected by real-time PCR and Western blot, respectively. SFN (0-30 μg/mL) did not induce toxic effects on bEnd.3 cells. ELISA showed that, IL-1β and endothelin levels in bEnd.3 cells were significantly increased by the TNF-α treatment. However, SFN treatments significantly decreased the IL-1β and endothelin contents in these cells, in a dose dependent manner. Moreover, intracellular ROS level was significantly enhanced in TNF-α-treated bEnd.3 cells, which could be decreased by SFN treatments. Real-time PCR and Western blot showed that, the mRNA and protein expression levels of HO-1 were significantly increased by the TNF-α stimulation, which could be further elevated by SFN treatments. The reducing effects of SFN on IL-1β and endothelin production were enhanced by the activator of HO-1, while the effects of SFN were reversed by the inhibitor of HO-1, in TNF-α-treated bEnd.3 cells. SFN inhibits TNF-α-induced proinflammatory cytokine production and ROS generation in bEnd.3 cells, which might be mediated by the up-regulation of HO-1. Our findings may provide evidence for the application of SFN in the treatment of brain injuries caused by cerebral ischemia/reperfusion.