Anti-Helicobacter pylori effect of costunolide isolated from the stem bark ofMagnolia sieboldii.

Helicobacter pylori (H. pylori) infection is now established as the major pathogenic factor in chronic gastritis and peptic ulcer disease. In addition, there is accumulating evidence thatH. pylori plays an important role in the process of gastric carcinogenesis. On the other hand, oriental traditional medicines have been used for stomach disease for thousands of years. In the present study, methanol extract from the stem bark ofMagnolia sieboldii (M. sieboldii) and its components were investigated on their inhibitory effects against urease activity and growth ofH. pylori in vitro. The methanol extract ofM. sieboldii significantly inhibited the growth ofH. pylori ATCC 43504 at 5 mg/ml. From the further fractionation, the chloroform fraction inhibited the bacterial growth dose-dependently. Among four fractions separated from the chloroform fraction by silica gel column chromatography, MS-C-2 was the most potent. Costunolide was isolated from the MS-C-2 subfraction by preparative TLC and recrystallization using n-hexane. Anti-H. pylori effect of costunolide was investigated using one commercial strain (H. pylori ATCC 43504) and three clinical strains (H. pylori 4, 43, 82548). Costunolide exhibited potent anti-H. pylori activity, and the MIC was around 100-200 mug/ml. However, costunolide had no inhibitory effect ofH. pylori urease activity at the concentration used for the growth inhibition assay. From these results, we conclude that costunolide inhibits the growth ofH. pylori by the independent manner ofH. pylori urease inhibition.