Anti-inflammatory effect of Etlingera pavieana (Pierre ex Gagnep.) R.M.Sm. rhizomal extract and its phenolic compounds in lipopolysaccharide-stimulated macrophages

Abstract

BACKGROUND: (Pierre ex Gagnep.) R.M.Sm. showed potent inhibition on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced macrophages. However, the mechanism behind its inhibitory effect has not been yet explored, and little is known regarding its bioactive compounds responsible for the anti-inflammatory effect. OBJECTIVE: was evaluated for their inhibition on NO production and mechanism in LPS-stimulated macrophages. Active compounds responsible for such anti-inflammatory activity were identified. MATERIALS AND METHODS: Inhibitory activities on NO production were performed in LPS-stimulated RAW264.7 macrophage. Cytotoxicity of plant extracts was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, mRNA and protein expressions by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Anti-inflammatory compounds were isolated by activity-guided isolation technique using column chromatography. RESULTS: -coumaric acid (4), were obtained from bioactivity-guided isolation technique. CONCLUSIONS: rhizome extract and conferred through inhibition of iNOS expression, and NO formation provides scientific evidence and support for the development of new anti-inflammatory agents based on extracts from this plant. SUMMARY: ; NO: Nitric oxide (NO); LPS: Lipopolysaccharide; iNOS: Inducible nitric oxide synthase (iNOS); MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; NF-κB: Nuclear factor-kappa B; DMSO: Dimethyl sulfoxide; EtOAc: Ethylacetate; MeOH: Methanol; AG: Aminoguanidine; DCM: Dichloromethane; MCA: 4-methoxycinnamyl alcohol; MCD: trans-4-methoxycinnamaldehyde; MCC: 4-methoxycinnamyl p-coumarate; CM: p-coumaric acid.