Component Analysis of Wasabi Leaves and an Evaluation of their Anti-inflammatory Activity

Abstract

The methanol extracts of wasabi leaves (Wasabia japonica Matsumura) from Shizuoka, Japan have been found to inhibit the production of nitric oxide (NO) in an in vitro assay using murine macrophage J774.1 cells stimulated with lipopolysaccharide. Fourteen known compounds, including five phenylpropanoid glycosides (1 – 4 and 9), three phenylpropanoids (5 – 7), a phenolic glycoside (8), two flavonoid glycosides (10 and 11), two terpenoids (12 and 13) and a carotenoid (14), were isolated from wasabi leaves collected from Shizuoka and their structures elucidated using spectroscopic methods. This study therefore represents the first reported isolation of compounds 8, 9, 12, 13 and 14 from wasabi leaves. 5-Hydroxy ferulic acid methyl ester (5) and all-trans-lutein (14) were found to inhibit NO production in J774.1 cells with IC₅₀ values of 22 and 25 µM, respectively. The results therefore suggested that these compounds are the active components of wasabi leaves.