Abstract
We attempted to isolate lipolytic substances from the stem and rhizome of Sinomenium actum Rehder et Wilson by using high-performance liquid chromatography (HPLC). S-I and S-II were isolated from the fractions showing lipolytic activity. S-I and S-II were identified as caffeine and 1,7-dimethylxanthine, respectively, by direct comparison with authentic samples. Caffeine (S-I) dose-dependently stimulated lipolytic activity in isolated fat cells of rats, at concentrations of 500 to 1000 µM. 1,7-Dimethylxanthine (S-II) also stimulated lipolytic activity at concentrations of 500 to 1000 µM. Furthermore, we found that caffeine and 1,7-dimethylxanthine enhanced catecholamine-induced lipolysis at lower concentrations of 0.1 to 1 µM.
