Tormentic acid, a triterpenoid saponin, isolated from Rosa rugosa, inhibited LPS-induced iNOS, COX-2, and TNF-α expression through inactivation of the nuclear factor-κb pathway in RAW 264.7 macrophages.
We previously reported that extract of Rosa rugosa root and its active triterpenoids constituents exhibit anti-nociceptive and anti-inflammatory effects in animal models. However, little is known about the effects and the molecular mechanism of the 19α-hydroxyursane-type triterpenoids. Among the tested 19α-hydroxyursane-type triterpenoids (kaji-ichigoside F(1), rosamultin, euscaphic acid, tormentic acid (TA)), TA was found to most potently inhibit the production of nitric oxide (NO) in RAW 264.7 cells. We investigated the anti-inflammatory effects and its underlying molecular mechanisms of TA in lipopolysaccaride (LPS)-stimulated RAW 264.7 cells. TA dose-dependently reduced the productions of NO, prostaglandin E(2) (PGE(2)), and tumor necrosis factor-α (TNF-α) induced by LPS. In addition, TA significantly suppressed the LPS-induced expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α at the mRNA and protein levels. Moreover, treatment with TA decreased LPS-induced DNA binding of nuclear factor-kappa B (NF-κB) and nuclear translocation of p65 and p50 subunits of NF-κB. Consistent with these findings, TA also suppressed the LPS-stimulated degradation and phosphorylation of inhibitor of kappa B-α (IκB-α). Taken together, these results suggest that the anti-inflammatory activity of TA is associated with the down-regulation of iNOS, COX-2, and TNF-α through the negative regulation of the NF-κB pathway in RAW 264.7 cells.
Department of Pharmaceutical Biochemistry, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea.
Hyo-Jin
HJ
An
In-Tae
IT
Kim
Hee-Juhn
HJ
Park
Hyung-Min
HM
Kim
Jung-Hye
JH
Choi
Kyung-Tae
KT
Lee
D000818:Animals; D015153:Blotting, Western; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D024202:Electrophoretic Mobility Shift Assay; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D051379:Mice; D015394:Molecular Structure; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D018517:Plant Roots / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027824:Rosaceae / Q000737:chemistry*; D012503:Saponins / Q000302:isolation & purification / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D008070:Lipopolysaccharides; D016328:NF-kappa B; D012503:Saponins; D014315:Triterpenes; D014409:Tumor Necrosis Factor-alpha; C007695:euscaphic acid; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D051546:Cyclooxygenase 2