Anti-inflammatory effects of 18-nor-ent-pimara-9(11),15-diene-4β-ol isolated from the roots of Aralia continentalis on LPS-induced in RAW264.7 cells

Abstract

Abstract Aralia continentalis (A. continentalis) is a medicinal plant belonging to Araliaceae, it has been reported to exert anti-cancer, anti-bacterial, anti-inflammatory, anti-platelet and anti-oxidative activities. But the potential mechanism for the anti-inflammatory effect of compounds isolated from the roots of A. continentalis is still insufficient. So, we evaluated whether compounds isolated from the roots of A. continentalis exert anti-inflammatory effects and elucidated its potential mechanism in RAW264.7 cells. The concentrated residue was subsequently suspended in H2O and partitioned with n-hexane, methylene chloride (CH2Cl2), ethyl acetate (EtOAc) and n-butanol (n-BuOH). The fractions were subjected to sequential column chromatography over silica-gel, RP-18, MPLC, recycling and preparative HPLC to isolated the novel compound. The novel compound was identified as 18-nor-ent-pimara-9(11),15-diene-4β-ol and confirmed anti-inflammatory activity. The 18-nor-ent-pimara-9(11),15-diene-4β-ol dose-dependently blocked NO production and inhibited iNOS, COX-2, TNF-α and IL-1β expression in LPS-stimulated RAW264.7 cells. The 18-nor-ent-pimara-9(11),15-diene-4β-ol inhibited LPS-stimulated degradation of IκB-α and nuclear accumulation of p65, which resulted in the suppression of NF-κB activation in RAW264.7 cells. Also, the 18-nor-ent-pimara-9(11),15-diene-4β-ol attenuated the phosphorylation of p38 and ERK1/2 in LPS-induced RAW264.7 cells. These results suggest that the nor-ent-pimara-9(11),15-diene-4β-ol isolated from the roots of A. continentalis may have grate potential for the development of anti-inflammatory drugs.