Suppressive effects on the biosynthesis of inflammatory mediators by Aralia elata extract fractions in macrophage cells

The aim of this study is to elucidate the anti-inflammatory effects of Aralia elata extract fractions (AEEFs). A. elata-ethyl acetate fraction (AEEF) had the strongest antioxidant activity. A. elata-chloroform fraction (AECF) and A. elata-butanol fraction (AEBF) inhibited potently LPS-induced nitrite production from RAW 264.7 macrophage cells. The inhibition of nitric oxide (NO) production by AEEFs was partially due to chemical scavenge of NO and the suppression of inducible NOS (iNOS) transcription level in LPS-induced macrophage cells. In addition, AEEFs inhibited significantly the biosynthesis of Prostaglandin E2 (PGE2), and cyclooxygenase-2, which regulates the synthesis of PGE2, was attenuated partially by the treatment of AEEFs in LPS-induced macrophage cells. Also, A. elata-methanolic extract (AEME) suppressed remarkably IL-1β and IL-6 level to the basal (more than 99% inhibition) in concentration-dependant manners. Its anti-inflammatory actions might be related with inhibition of NF-κB activation in LPS-stimulated macrophage cells. It is concluded that AEEFs may be useful as a functional food material and an alternative medicine for the relief and retardation of immunological inflammatory responses.