Spirulina maxima extract prevents activation of the NLRP3 inflammasome by inhibiting ERK signaling

Sci Rep. 2020 Feb 7;10(1):2075. doi: 10.1038/s41598-020-58896-6.


The blue-green alga Spirulina maxima is a microscopic filamentous cyanobacterium. Spirulina was recently reported to elicit beneficial effects such as reducing cholesterol and inducing weight loss; however, its effects on inflammation are unknown. To determine the effect of S. maxima extract (SME) on innate immunity, we investigated the NLRP3 inflammasome activation, which is a multiprotein scaffolding complex that plays important roles in innate immune responses to many pathogenic infections in macrophages. SME suppressed lipopolysaccharide (LPS)-induced upregulation of the pro-inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-12, IL-1β, and IL-18 in RAW264.7 cells. In addition, SME attenuated LPS-induced NLRP3 inflammasome activation, and thus pro-IL-1β could not be cleaved to IL-1β by activated caspase-1, which is activated by the NLRP3 inflammasome in RAW264.7 cells. Moreover, SME inhibited LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK) in RAW264.7 cells, and attenuated the generation of ERK1 induced-reactive oxygen species (ROS), resulting in decreased expression of NF-κB. These findings suggest that SME suppresses the effects of the NLRP3 inflammasome via regulation of extracellular signal-regulated kinase (ERK). In summary, we demonstrated that SME prevents activation of the NLRP3 inflammasome by inhibiting ERK signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Blotting, Western
  • Cytokines / metabolism
  • Humans
  • Inflammasomes / drug effects*
  • Inflammasomes / metabolism
  • Interleukin-18 / metabolism
  • Interleukin-1beta / metabolism
  • MAP Kinase Signaling System / drug effects*
  • Mice
  • Mice, Inbred C57BL
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism*
  • RAW 264.7 Cells / drug effects
  • RAW 264.7 Cells / metabolism
  • Reactive Oxygen Species / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Spirulina / chemistry*
  • THP-1 Cells / drug effects
  • THP-1 Cells / metabolism


  • Anti-Inflammatory Agents
  • Cytokines
  • Inflammasomes
  • Interleukin-18
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • NLRP3 protein, human
  • Nlrp3 protein, mouse
  • Reactive Oxygen Species