Inhibitory Effects of Chemical Compounds Isolated from the Rhizome ofSmilax glabraon Nitric Oxide and Tumor Necrosis Factor-αProduction in Lipopolysaccharide-Induced RAW264.7 Cell

Abstract

The rhizome ofSmilax glabrahas been used for a long time as both food and folk medicine in many countries. The present study focused on the active constituents from the rhizome ofS. glabra, which possess potential anti-inflammatory activities. As a result, nine known compounds were isolated from the rhizome ofS. glabrawith the bioassay-guiding, and were identified as syringaresinol (1), lasiodiplodin (2), de-O-methyllasiodiplodin (3), syringic acid (4), 1,4-bis(4-hydroxy-3,5-dimethoxyphenyl)-2,3-bis(hydroxymethyl)-1,4-butanediol (5), lyoniresinol (6),trans-resveratrol (7),trans-caffeic acid methyl ester (8), and dihydrokaempferol (9). Among these compounds,2and3were isolated for the first time fromS. glabra. In addition, the potential anti-inflammatory activities of the isolated compounds were evaluatedin vitroin lipopolysaccharide- (LPS-) induced RAW264.7 cells. Results indicated that4and7showed significant inhibitory effects on NO production of RAW264.7 cells, and1,2,3, and5showed moderate suppression effects on induced NO production.1,7, and5exhibited high inhibitory effects on TNF-αproduction, with the IC50values less than 2.3, 4.4, and 16.6 μM, respectively. These findings strongly suggest that compounds1,2,3,4,5,7, and9were the potential anti-inflammatory active compositions ofS. glabra.