New lathyrane diterpenoid hybrids have anti-inflammatory activity through the NF-κB signaling pathway and autophagy

In our ongoing work on the identification of potent anti-inflammatory agents, we designed and synthesized three series of lathyrane diterpenoid hybrids in which the lathyrane diterpenoid skeleton was hybridized with other anti-inflammatory pharmacophores. Unexpectedly, lathyrane diterpenoid/3-hydroxyflavone hybrids showed more potent anti-inflammatory activity in RAW264.7 cells than did the corresponding parent compounds. Compound 8d1 exhibited potent anti-inflammatory activity with low cytotoxicity (IC50 = 1.55 ± 0.68 μM), and downregulated LPS-induced expression of iNOS and COX-2, as well as IκBα phosphorylation. This compound also inhibited the expression and nuclear translocation of NF-κB, and stimulated autophagy induction. Thus, 8d1’s anti-inflammatory mechanism is associated with inhibition of the NF-κB signaling pathway and increasing autophagy. This compound may serve as a promising anti-inflammatory agent.