TY - JOUR
T1 - Wogonin but not Nor-wogonin inhibits lipopolysaccharide and lipoteichoic acid-induced iNOS gene expression and NO production in macrophages
AU - Huang, Guan Cheng
AU - Chow, Jyh-Ming
AU - Shen, Shing-Chuan
AU - Yang, Liang-Yo
AU - Lin, Cheng-Wei
AU - Chen, Yen-Chou
PY - 2007/8
Y1 - 2007/8
N2 - Wogonin (Wog; 5,7-dihydroxy-8-methoxy flavone) has been shown to effectively inhibit lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) gene expression and nitric oxide production in our previous study. In the present study, we found that Nor-wogonin (N-Wog; 5,7,8-trihydroxyl flavone), a structural analogue of Wog with an OH substitution at C8, performed different effect on LPS- or lipoteichoic acid (LTA)-induced iNOS gene expression and nitric oxide (NO) production in macrophages. Wog, but not N-Wog, significantly inhibits LPS- or LTA-induced NO production through suppressing iNOS gene expression at both protein and mRNA without affecting NO donor sodium nitroprusside-induced NO production, NOS enzyme activity, and cells viability. Activation of JNKs (not ERKs) via phosphorylation induction, and an increase in c-Jun (not c-Fos) protein expression were involved in LPS- and LTA-treated RAW264.7 cells, and those events were blocked by Wog, but not N-Wog, addition. Furthermore, 5,7-diOH flavone, but not 5-OH flavone, 7-OH flavone, 5-OH-7-OCH3 flavone, significantly inhibits LPS-induced iNOS protein expression and NO production, and 7,8-diOCH3 flavone performs more effective inhibitory activity on LPS-induced NO production and iNOS protein expression than 7-OCH3-8-OH flavone. These data suggest that OHs at both C5 and C7 are essential for NO inhibition of flavonoids, and OCH3 at C8 may contribute to this activity, and suppression of JNKs-c-Jun activation is involved.
AB - Wogonin (Wog; 5,7-dihydroxy-8-methoxy flavone) has been shown to effectively inhibit lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) gene expression and nitric oxide production in our previous study. In the present study, we found that Nor-wogonin (N-Wog; 5,7,8-trihydroxyl flavone), a structural analogue of Wog with an OH substitution at C8, performed different effect on LPS- or lipoteichoic acid (LTA)-induced iNOS gene expression and nitric oxide (NO) production in macrophages. Wog, but not N-Wog, significantly inhibits LPS- or LTA-induced NO production through suppressing iNOS gene expression at both protein and mRNA without affecting NO donor sodium nitroprusside-induced NO production, NOS enzyme activity, and cells viability. Activation of JNKs (not ERKs) via phosphorylation induction, and an increase in c-Jun (not c-Fos) protein expression were involved in LPS- and LTA-treated RAW264.7 cells, and those events were blocked by Wog, but not N-Wog, addition. Furthermore, 5,7-diOH flavone, but not 5-OH flavone, 7-OH flavone, 5-OH-7-OCH3 flavone, significantly inhibits LPS-induced iNOS protein expression and NO production, and 7,8-diOCH3 flavone performs more effective inhibitory activity on LPS-induced NO production and iNOS protein expression than 7-OCH3-8-OH flavone. These data suggest that OHs at both C5 and C7 are essential for NO inhibition of flavonoids, and OCH3 at C8 may contribute to this activity, and suppression of JNKs-c-Jun activation is involved.
KW - iNOS
KW - JNKs
KW - LPS
KW - LTA
KW - NO
KW - Nor-wogonin
KW - Wogonin
UR - http://www.scopus.com/inward/record.url?scp=34249991792&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34249991792&partnerID=8YFLogxK
U2 - 10.1016/j.intimp.2007.04.001
DO - 10.1016/j.intimp.2007.04.001
M3 - Article
C2 - 17570322
AN - SCOPUS:34249991792
VL - 7
SP - 1054
EP - 1063
JO - International Immunopharmacology
JF - International Immunopharmacology
SN - 1567-5769
IS - 8
ER -