Inhibitory Effects of Chemical Compounds Isolated from the Rhizome of Smilax glabra on Nitric Oxide and Tumor Necrosis Factor-α Production in Lipopolysaccharide-Induced RAW264.7 Cell

Abstract EN

The rhizome of Smilax glabra has 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 of S.

glabra, which possess potential anti-inflammatory activities.

As a result, nine known compounds were isolated from the rhizome of S.

glabra with 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, 2 and 3 were isolated for the first time from S.

glabra.

In addition, the potential anti-inflammatory activities of the isolated compounds were evaluated in vitro in lipopolysaccharide- (LPS-) induced RAW264.7 cells.

Results indicated that 4 and 7 showed significant inhibitory effects on NO production of RAW264.7 cells, and 1, 2, 3, and 5 showed moderate suppression effects on induced NO production.

1, 7, and 5 exhibited high inhibitory effects on TNF-α production, with the IC50 values less than 2.3, 4.4, and 16.6 μM, respectively.

These findings strongly suggest that compounds 1, 2, 3, 4, 5, 7, and 9 were the potential anti-inflammatory active compositions of S.

glabra.