Letter	Planta Med 2005; 71: 1167-1170 DOI: 10.1055/s-2005-873147
© Georg Thieme Verlag KG Stuttgart · New York
Anti-Inflammatory Activity of 20(S)-Protopanaxadiol: Enhanced Heme Oxygenase 1 Expression in RAW 264.7 Cells
Sung Hee Lee1, Geom Seog Seo2, Geonil Ko1, Jae Baek Kim3, Dong Hwan Sohn1
1 College of Pharmacy, Medicinal Resources Research Institute, Wonkwang University, Iksan, Jeonbuk, Republic of Korea 2 Department of Internal Medicine, Wonkwang University Medical School, Iksan, Jeonbuk, Republic of Korea 3 Wonkwang Pharmaceutical Co. Ltd., Iksan, Jeonbuk, Republic of Korea

Abstract

20(S)-Protopanaxadiol (PPD) is one of the metabolites of ginsenosides from Panax ginseng. In this study, we demonstrate that PPD inhibits the increase in lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expression through inactivation of nuclear factor-κB by preventing degradation of inhibitory factor-κBα. PPD also induces heme oxygenase 1 (HO-1) expression in RAW 264.7 cells, at the mRNA and protein levels, in the presence and absence of LPS. This effect is associated with suppression of LPS-induced nitric oxide (NO) production and iNOS expression. The HO-1 inducer hemin is associated with the suppression of LPS-induced NO production in a dose-dependent manner, and the HO-1 inhibitor tin protoporphyrin attenuates the inhibitory activity of PPD on LPS-induced NO production. These results provide evidence for the role of HO-1 in the inhibition of LPS-induced NO production by PPD.