The plants belonging to Acanthopanax species (Araliaceae) are traditionally used in Korea as anti-rheumatoid arthritis, anti-inflammatory and anti-diabetic drugs and are recognized to have ginseng-like activities.1,2) 3,4-Secolupanetype triterpenoid family members, such as chiisanoside, chiisanogenin, 22-hydroxychiisanogenin, 24-hydroxychiisanogenin, etc. have been previously isolated from Acanthopanax species.1,3) Chiisanoside, the main terpenoid component of this plant, has been reported to have anti-hepatotoxic, anti-diabetic and antiviral effects, the latter of which was found to be associated with the inhibition of mitogen-induced lymphocyte proliferation. [4][5][6] We previously described the anti-inflammatory effects of chiisanoside and chiisanogenin in the rats induced by carrageenan-and Freund's complete adjuvant. 7) In addition, we demonstrated that chiisanoside can be converted to its aglycon, chiisanogenin by human intestinal bacteria and that chiisanogenin showed more potent cytotoxicity and anti-rotaviral activities. 1)During the inflammatory processes, large amounts of proinflammatory mediators, nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) are generated by the inducible isoforms of NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively. 8) In mammalian cells, NO is synthesized by three different isoforms of nitric oxide synthase (NOS), namely, neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Although nNOS and eNOS are constitutively expressed, iNOS is expressed in response to interferon-g, lipopolysccharide (LPS) and to a variety of proinflammatory cytokines.9,10) Cyclooxygenase (COX) is the enzyme that converts arachidonic acid to PGs. Like NOS, COX existed in two isoforms, i.e., COX-1 and COX-2.11) COX-1 is expressed constitutively in most tissues and appears to be responsible for maintaining normal physiological functions. In contrast, COX-2 is detectable in only certain types of tissues and is induced transiently by growth factors, proinflammatory cytokines, tumor promoters and bacterial toxins.12,13) Moreover, elevated levels of COX have been detected in different tumor types and this may account for the excessive production of inflammatory PGs. 14)Nuclear transcription factor kappa-B (NF-kB) is one of the most ubiquitous transcription factors and regulates gene involved in cellular proliferation, inflammatory responses and cell adhesion. The activation of NF-kB has been reported to induce the transcriptions of many pro-inflammatory mediators, e.g., iNOS, COX-2, TNF-a and interleukin (IL)-1b, -6 and -8. 15,16) Our previous investigations of chiisanoside and chiisanogenin demonstrated their anti-inflammatory syndromes in the rat induced by carrageenan and Freund's complete adjuvant reagents. 7) Thus, as a prelude to reveal the underlying mechanisms for the anti-inflammatory effects of chiisanoside and chiisanogenin, we evaluated and compared the effects of various triterpenoid derivatives (Fig. 1) In the present study, the effects of several triterpenes isolate...

No abstract