Inhibition of LPS-induced iNOS, COX-2 and cytokines expression by poncirin through the NF-kappaB inactivation in RAW 264.7 macrophage cells.
We previously reported that poncirin, a flavanone glycoside isolated from the EtOAc extract of the dried immature fruits of Poncirus trifoliata, is an anti-inflammatory compound that inhibits PGE(2) and IL-6 production. The present work was undertaken to investigate the molecular actions of poncirin in RAW 264.7 macrophage cell line. Poncirin reduced lipopolysaccharide (LPS)-induced protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and the mRNA expressions of iNOS, COX-2, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in a concentration-dependent manner, as determined by Western blotting and RT-PCR, respectively. Furthermore, poncirin inhibited the LPS-induced DNA binding activity of nuclear factor-kappaB (NF-kappaB). Moreover, this effect was accompanied by a parallel reduction in IkappaB-alpha degradation and phosphorylation that in by nuclear translocations of p50 and p65 NF-kappaB subunits. Taken together, our data indicate that anti-inflammatory properties of poncirin might be the result from the inhibition iNOS, COX-2, TNF-alpha and IL-6 expression via the down-regulation of NF-kappaB binding activity.
Kim
Jong-Bin
JB
Department of Pharmaceutical Biochemistry, College of Pharmacy, Kyung-Hee University, Dongdaemun-ku, Hoegi- Dong, Seoul 130-701, South Korea.
Han
Ah-Reum
AR
Park
Eun-Young
EY
Kim
Ji-Yeon
JY
Cho
Woong
W
Lee
Jun
J
Seo
Eun-Kyoung
EK
Lee
Kyung-Tae
KT
D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D016207:Cytokines / Q000096:biosynthesis*; D015232:Dinoprostone / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology*; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D052002:NF-kappa B p50 Subunit / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D009573:Nitrites / Q000378:metabolism; D032104:Poncirus / Q000737:chemistry; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051996:Transcription Factor RelA / Q000096:biosynthesis; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D016207:Cytokines; D005419:Flavonoids; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D009573:Nitrites; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D012313:RNA; C119641:poncirin; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D015232:Dinoprostone