Sulforaphane induces Nrf2 target genes and attenuates inflammatory gene expression in microglia from brain of young adult and aged mice

• Sulforaphane (SFN) activated Nrf2 in BV2 cells and increased antioxidant genes.
• SFN reduced proinflammatory cytokines in LPS-stimulated BV2 microglia.
• SFN increased expression of antioxidant genes in adult and aged microglia.
• SFN reduced LPS-induced proinflammatory cytokines in adult and aged microglia.
• SFN is a potential therapeutic supplement for aging-related neuroinflammation.

Increased neuroinflammation and oxidative stress resulting from heightened microglial activation are associated with age-related cognitive impairment. The objectives of this study were to examine the effects of the bioactive sulforaphane (SFN) on the nuclear factor E2-related factor 2 (Nrf2) pathway in BV2 microglia and primary microglia, and to evaluate proinflammatory cytokine expression in lipopolysaccharide (LPS)-stimulated primary microglia from adult and aged mice. BV2 microglia and primary microglia isolated from young adult and aged mice were treated with SFN and LPS. Changes in Nrf2 activity, expression of Nrf2 target genes, and levels of proinflammatory markers were assessed by quantitative PCR and immunoassay. SFN increased Nrf2 DNA-binding activity and upregulated Nrf2 target genes in BV2 microglia, while reducing LPS-induced interleukin (IL-)1β, IL-6, and inducible nitric oxide synthase (iNOS). In primary microglia from adult and aged mice, SFN increased expression of Nrf2 target genes and attenuated IL-1β, IL-6, and iNOS induced by LPS. These data indicate that SFN is a potential beneficial supplement that may be useful for reducing microglial mediated neuroinflammation and oxidative stress associated with aging.