Gambogic acid protects from endotoxin shock by suppressing pro-inflammatory factors in vivo and in vitro.

Gambogic acid (GBA) targeted Heat shock protein 90 (Hsp90) and prohibited TNF-α/NF-κB signaling pathway. It can be inferred that the anti-inflammatory activity of GBA results from inhibiting the cytokine production via NF-κB signaling pathway. We used the RAW264.7 cell line and the endotoxin shock mouse model to confirm the hypothesis that GBA protects mice from endotoxin shock by suppressing cytokine synthesis. RAW264.7 cells were cultured and the endotoxin shocked mice model was constructed. ELISA was employed to evaluate the change of cytokine secretion levels. The effects of GBA on the activation of NF-κB signaling pathway were also determined by western blot and immune-fluorescent analysis. Cell viability was determined by MTT assay, and the cell migration was tested by wound healing assay. Our results demonstrated that GBA significantly inhibited the LPS-induced release of pro-inflammatory factors both in cell lines and mice serum, thereby protecting mice from endotoxin shock. Furthermore, we observed that the reduction of inflammatory cytokines interleukin 1-beta, interleukin 6 and TNF-α resulted from the Hsp90's client protein IKK degradation and the suppression of NF-κB pathway. Moreover, GBA suppressed the migration of LPS-induced RAW264.7 cells. Our results indicate that GBA has a potential both as an antitumor and anti-inflammatory therapeutic agent.