Anti-inflammatory constituents from Perilla frutescens on lipopolysaccharide-stimulated RAW264.7 cells

Perilla frutescens (L.) Britt. (Lamiaceae) is a traditionally medicinal herb in East Asian countries to treat various diseases. In present study, the low-polarity constituents of the aerial parts of P. frutescens were investigated and their anti-inflammatory effect on lipopolysaccharide (LPS)-stimulated RAW264.7 cells were assayed. Three new furanoid monoterpenoids, named as frutescenones A - C (1-3), together with thirteen known compounds (4-16) were isolated and identified on the basis of extensive spectroscopic analysis and a single-crystal X-ray diffraction study. Among these components, 1 is an unusual monoterpenoid with 2,3'-bifuran skeleton, and 3 is a rare perillaketone-adenine hybrid heterodimer, while the revised NMR arrangements of 4 were reported at the first time. Furthermore, monoterpenoid 4 and alkaloid 15 showed remarkably inhibitory effect on the production of inflammatory mediator (NO) and pro-inflammatory cytokines (TNF-alpha and/or IL-6) in LPS-stimulated RAW264.7 cells.