TY - JOUR
T1 - Suppression of inducible nitric oxide synthase by (-)-isoeleutherin from the bulbs of Eleutherine americana through the regulation of NF-κB activity
AU - Song, Su Hyun
AU - Min, Hye Young
AU - Han, Ah Reum
AU - Nam, Joo Won
AU - Seo, Eun Kyoung
AU - Seoung Woo Park, Woo Park
AU - Sang Hyung Lee, Hyung Lee
AU - Sang Kook Lee, Kook Lee
N1 - Funding Information:
This work was supported by grant no. R15-2006-020 from the National Core Research Center (NCRC) program of the Ministry of Education, Science & Technology (MEST) and the Korea Science and Engineering Foundation (KOSEF) through the Center for Cell Signaling & Drug Discovery Research at Ewha Womans University.
PY - 2009/3
Y1 - 2009/3
N2 - Eleutherine americana Merr. et Heyne (Iridaceae) has been used as a folk medicine for the treatment of coronary disorders and wound-healing. In our previous phytochemical study, several pyranonaphthoquinoids, including (-)-isoeleutherin, were isolated from the bulbs of E. americana. Because inhibitors of inducible nitric oxide synthase (iNOS) might be useful as anti-inflammatory agents, we investigated the potential of pyranonaphthoquinoids to inhibit iNOS activity. We found that (-)-isoeleutherin inhibits lipopolysaccharide (LPS)-stimulated induction of nitric oxide (NO) in a dose-dependent manner (IC50 = 7.4 μM). Using western blots and reverse transcription-polymerase chain reaction, we showed that (-)-isoeleutherin suppresses the expression of iNOS protein and mRNA. In addition, (-)-isoeleutherin inhibited the expression of various cytokines such as interleukin-1β and interferon-β. Activation of the transcriptional activity of NF-κB by LPS was also inhibited by treatment with (-)-isoeleutherin, suggesting that (-)-isoeleutherin-mediated suppression of iNOS expression is associated with the regulation of transcription factor NF-κB. These findings suggest that (-)-isoeleutherin might be a novel anti-inflammatory agent, and that it may work by inhibiting NFkB activation in macrophages.
AB - Eleutherine americana Merr. et Heyne (Iridaceae) has been used as a folk medicine for the treatment of coronary disorders and wound-healing. In our previous phytochemical study, several pyranonaphthoquinoids, including (-)-isoeleutherin, were isolated from the bulbs of E. americana. Because inhibitors of inducible nitric oxide synthase (iNOS) might be useful as anti-inflammatory agents, we investigated the potential of pyranonaphthoquinoids to inhibit iNOS activity. We found that (-)-isoeleutherin inhibits lipopolysaccharide (LPS)-stimulated induction of nitric oxide (NO) in a dose-dependent manner (IC50 = 7.4 μM). Using western blots and reverse transcription-polymerase chain reaction, we showed that (-)-isoeleutherin suppresses the expression of iNOS protein and mRNA. In addition, (-)-isoeleutherin inhibited the expression of various cytokines such as interleukin-1β and interferon-β. Activation of the transcriptional activity of NF-κB by LPS was also inhibited by treatment with (-)-isoeleutherin, suggesting that (-)-isoeleutherin-mediated suppression of iNOS expression is associated with the regulation of transcription factor NF-κB. These findings suggest that (-)-isoeleutherin might be a novel anti-inflammatory agent, and that it may work by inhibiting NFkB activation in macrophages.
KW - (-)-Isoeleutherin
KW - Anti-inflammatory
KW - Eleutherine americana
KW - Inducible nitric oxide synthase (iNOS)
KW - Nitric oxide (NO)
KW - Nuclear factor kappa beta (NF-κB)
UR - http://www.scopus.com/inward/record.url?scp=60249085139&partnerID=8YFLogxK
U2 - 10.1016/j.intimp.2008.12.003
DO - 10.1016/j.intimp.2008.12.003
M3 - Article
C2 - 19135178
AN - SCOPUS:60249085139
SN - 1567-5769
VL - 9
SP - 298
EP - 302
JO - International Immunopharmacology
JF - International Immunopharmacology
IS - 3
ER -