Anti-inflammatory effects and chemical study of a flavonoid-enriched fraction from adlay bran

Abstract

Anti-inflammation-guided fractionation and purification were used to evaluate the bioactivity and components of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) bran. Results showed that the fraction with high phenolic and flavonoid contents from the ethanol extracts of adlay bran suppressed LPS-stimulated IL-6 and TNF-α secretions in a concentration-dependent manner in RAW 264.7 cells and murine peritoneal macrophages. Fifteen compounds, including a novel aurone derivative, two chromones, one dihydrochalcone, one chalcone, four flavanones, five flavones and one isoflavone, were isolated from the active fraction. The structure of the new compound was elucidated by spectroscopic methods, including 1D and 2D NMR and MS. All of the isolates are reported for the first time from adlay except naringenin. LC/MS was also provided as an analytical platform. Our results suggest that flavonoids in adlay bran, partially at least, contribute to its anti-inflammatory effect. Thus, adlay bran may be beneficial to the health of consumers.

Keywords: Adlay bran; Anti-inflammation; Flavonoids; LC/MS; New aurone derivative.