Hirsutella sinensis mycelium suppresses interleukin-1β and interleukin-18 secretion by inhibiting both canonical and non-canonical inflammasomes

Cordyceps sinensis is a medicinal mushroom used for centuries in Asian countries as a health supplement and tonic. Hirsutella sinensis—the anamorphic, mycelial form of C. sinensis—possesses similar properties, and is increasingly used as a health supplement. Recently, C. sinensis extracts were shown to inhibit the production of the pro-inflammatory cytokine IL-1β in lipopolysaccharide-treated macrophages. However, the molecular mechanism underlying this process has remained unclear. In addition, whether H. sinensis mycelium (HSM) extracts also inhibit the production of IL-1β has not been investigated. In the present study, the HSM extract suppresses IL-1β and IL-18 secretion, and ATP-induced activation of caspase-1. Notably, we observed that HSM not only reduced expression of the inflammasome component NLRP1 and the P2X(7)R but also reduced the activation of caspase-4, and ATP-induced ROS production. These findings reveal that the HSM extract has anti-inflammatory properties attributed to its ability to inhibit both canonical and non-canonical inflammasomes.