Inhibition of LPS-induced NO and PGE2 production by asiatic acid via NF-kappa B inactivation in RAW 264.7 macrophages: possible involvement of the IKK and MAPK pathways.
In the present study, we investigated the effect of asiatic acid (the aglycon of asiaticoside) and asiaticoside isolated from the leaves of Centella asiatica (Umbelliferae) on LPS-induced NO and PGE(2) production in RAW 264.7 macrophage cells. Asiatic acid more potently inhibited LPS-induced NO and PGE(2) production than asiaticoside. Consistent with these observations, the protein and mRNA expression levels of inducible iNOS and COX-2 enzymes were inhibited by asiatic acid in a concentration-dependent manner. In addition, asiatic acid dose-dependently reduced the production of IL-6, IL-1 beta and TNF-alpha in LPS-stimulated RAW 264.7 macrophage cells. Furthermore, asiatic acid inhibited the NF-kappaB activation induced by LPS, and this was associated with the abrogation of I kappa B-alpha degradation and with subsequent decreases in nuclear p65 and p50 protein levels. Moreover, the phosphorylations of IKK, p38, ERK1/2, and JNK in LPS-stimulated RAW 264.7 cells were suppressed by asiatic acid in a dose-dependent manner. These results suggest that the anti-inflammatory properties of asiatic acid might be the results from the inhibition of iNOS, COX-2, IL-6, IL-1 beta, and TNF-alpha expressions through the down-regulation of NF-kappaB activation via suppression of IKK and MAP kinase (p38, ERK1/2, and JNK) phosphorylation in RAW 264.7 cells.
Yun
Kyung-Jin
KJ
Department of Pharmaceutical Biochemistry, College of Pharmacy, Kyung-Hee University, Dongdaemun-ku, Hoegi-Dong, Seoul 130-701, South Korea.
Kim
Ji-Yeon
JY
Kim
Jong-Bin
JB
Lee
Kyung-Won
KW
Jeong
Seo-Young
SY
Park
Hee-Juhn
HJ
Jung
Hyun-Ju
HJ
Cho
Young-Wuk
YW
Yun
Kijoo
K
Lee
Kyung-Tae
KT
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis; D015232:Dinoprostone / Q000096:biosynthesis*; D051550:I-kappa B Kinase / Q000502:physiology*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D009569:Nitric Oxide / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D053978:Pentacyclic Triterpenes; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D014315:Triterpenes / Q000494:pharmacology*
D016207:Cytokines; D008070:Lipopolysaccharides; D016328:NF-kappa B; D053978:Pentacyclic Triterpenes; D014315:Triterpenes; D009569:Nitric Oxide; C017032:asiatic acid; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D019908:Proto-Oncogene Proteins c-raf; D051550:I-kappa B Kinase; C496562:Ikbkb protein, mouse; D015232:Dinoprostone; C004446:asiaticoside