Flavonoids casticin and chrysosplenol D from Artemisia annua L. inhibit inflammation in vitro and in vivo.

Background: The aim of our experiments was to investigate the anti-inflammatory properties of casticin and chrysosplenol D, two flavonoids present in Artemisia annua L.

Methods: Topical inflammation was induced in ICR mice using croton oil. Mice were then treated with casticin or chrysosplenol D. Cutaneous histological changes and edema were assessed. ICR mice were intragastrically administrated with casticin or chrysosplenol D followed by intraperitoneal injection of lipopolysaccharide (LPS). Mouse Raw264.7 macrophage cells were incubated with casticin or chrysosplenol D. Intracellular phosphorylation was detected, and migration was assessed by trans-well assay. HT-29/NFκB-luc cells were incubated with casticin or chrysosplenol D in the presence or absence of LPS, and NF-κB activation was quantified.

Results: In mice, administration of casticin (0.5, 1 and 1.5μmol/cm(2)) and chrysosplenol D (1 and 1.5μmol/cm(2)) inhibited croton oil-induced ear edema (casticin: 29.39-64.95%; chrysosplenol D: 37.76-65.89%, all P<0.05) in a manner similar to indomethacin (0.5, 1 and 1.5μmol/cm(2); 55.63-84.58%). Casticin (0.07, 0.13 and 0.27mmol/kg) and chrysosplenol D (0.07, 0.14 and 0.28mmol/kg) protected against LPS-induced systemic inflammatory response syndrome (SIRS) in mice (all P<0.05), in a manner similar to dexamethasone (0.03mmol/kg). Casticin and chrysosplenol D suppressed LPS-induced release of IL-1 beta, IL-6 and MCP-1, inhibited cell migration, and reduced LPS-induced IκB and c-JUN phosphorylation in Raw264.7 cells. JNK inhibitor SP600125 blocked the inhibitory effect of chrysosplenol D on cytokine release.

Conclusions: The flavonoids casticin and chrysosplenol D from A. annua L. inhibited inflammation in vitro and in vivo.