Lignans from the rhizomes of Coptis japonica differentially act as anti-inflammatory principles

Coptis japonico Makino (Ranunculaceae) is known to possess several biologic al activities such as anti-inflammatory effects. In this study, five lignan s, isolariciresinol (1), lariciresinol glycoside (2), pinoresinol (3), pino resinol glycoside (4) and syringaresinol glycoside (5), isolated from the r hizomes of C. japonico were tested to evaluate their in vitro anti-inflamma tory effects. Pinoresinol and isolariciresinol showed higher inhibitory eff ects on TNF-alpha production, whereas syringaresinol glycoside strongly sup pressed lymphocyte proliferation. The results indicate that the lignans may differentially modulate inflammatory cell responses, suggesting that these compounds may participate in anti-inflammatory processes by C. japonico.