Abstract
Locusts are esteemed as a traditional Chinese medicine, as well as tonic foods in Asian countries. While searching for natural anti-inflammatory agents in natural products, we isolated four novel locust cyclopeptides (LCPs) and the results show that [cyclo-(Trp-Leu-His-Thr)]∼LCP-3 has potent anti-inflammatory potency in RAW264.7 and HMC-1 cells under LPS (lipopolysaccharide) stimuli. Furthermore, mechanistic studies show that LCP-3 attenuates pro-inflammatory cytokine (TNF-α, IL-6, IL-1β, NO and PGE2) expression. Moreover, LCP-3 attenuates inflammatory damage associated with the direct inhibition of iNOS and COX-2 expression. LCP-3 also regulates the MAPK, PI3K/AKT and NF-κB pathways to attenuate LPS-induced damage. Of note, our study first reports the anti-inflammatory potency of LCPs and elucidates their underlying molecular mechanisms.