In Vitro Antiinflammatory Activity of Kalopanaxsaponin A Isolated from Kalopanax pictus in Murine Macrophage RAW 264.7 Cells

In the present study, effects of various hederagenin monodesmosides isolated from the stem bark of Kalopanax pictus NAKAI, such as hederagenin, δ-hederin, kalopanaxsaponin A, kalopanaxsaponin I, and sapindoside C, have been evaluated on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2) and tumor necrosis factor-α (TNF-α) release by the macrophage cell line RAW 264.7. Among the tested monodesmosides, kalopanxsaponin A was the most potent inhibitor of NO production, and it also significantly decreased PGE2 and TNF-α release. Consistent with these observations, the expression level of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 enzyme was inhibited by kalopanxsaponin A in a concentration-dependent manner. Thus, this study suggests that kalopanaxsaponin A-mediated inhibition of iNOS, COX-2 expression, and TNF-α release may be one of the mechanisms responsible for the anti-inflammatory effects of the stem bark of Kalopanax pictus NAKAI.