Ginsenoside Rp₁, a Ginsenoside Derivative, Blocks Promoter Activation of iNOS and COX-2 Genes by Suppression of an IKKβ-mediated NF-κB Pathway in HEK293 Cells

Abstract

Ginsenoside (G) Rp1 is a ginseng saponin derivative with anti-cancer and anti-inflammatory activities. In this study, we examined the mechanism by which G-Rp1 inhibits inflammatory responses of cells. We did this using a strategy in which DNA constructs containing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) promoters were transfected into HEK293 cells. G-Rp1 strongly inhibited the promoter activities of COX-2 and iNOS; it also inhibited lipopolysaccharide induced upregulation of COX-2 and iNOS mRNA levels in RAW264.7 cells. In HEK293 cells G-Rp1 did not suppress TANK binding kinase 1-, Toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-β (TRIF)-, TRIFrelated adaptor molecule (TRAM)-, or activation of interferon regulatory factor (IRF)-3 and nuclear factor (NF)-кB by the myeloid differentiation primary response gene (MyD88)-induced. However, G-Rp1 strongly suppressed NF-кB activation induced by IкB kinase (IKK)β in HEK293 cells. Consistent with these results, G-Rp1 substantially inhibited IKKβ-induced phosphorylation of IкBɑ and p65. These results suggest that G-Rp1 is a novel anti-inflammatory ginsenoside analog that can be used to treat IKKβ/NF-кB-mediated inflammatory diseases.

In vitro and in vivo anti-inflammatory activity of Phyllanthus acidus methanolic extract

“…To this end, we employed an NF-κB-driven reporter construct in LPS-stimulated RAW264.7 cells and in MyD88-transfected HEK293 cells. NF-κB-mediated luciferase reporter activity has been reported to be strongly induced in these systems Shen et al, 2011). Consistent with our previous data, we observed that Pa-ME significantly (po0.05) inhibited luciferase activity by up to 55.371.7% at 300 μg/ml; furthermore, this inhibition was dose-dependent ( Fig.…”

Methanol extract of Osbeckia stellata suppresses lipopolysaccharide- and HCl/ethanol-induced inflammatory responses by inhibiting Src/Syk and IRAK1

“…HEK293 cells (1 Â 10 6 cells/ml) were transfected with 1 mg of plasmids containing NF-kB-Luc, CREB-Luc, or AP-1-Luc, as well as b-galactosidase using the calcium phosphate method (Shen et al, 2011) in a 12-well plate according to the manufacturer's protocol. The cells were used for experiments 48 h after transfection.…”

PDK1 in NF-κB signaling is a target of Xanthium strumarium methanolic extract-mediated anti-inflammatory activities

“…To examine whether Xs-ME could suppress the activation and translocation of NF-κB, a major transcription factor controlling inflammatory gene expression, we employed an NF-κB-driven reporter construct in LPS-stimulated RAW264.7 cells and in MyD88-transfected HEK293 cells. NF-κB-mediated luciferase reporter activity has been reported to be strongly induced in these systems Shen et al, 2011). We observed that 300 μg/ml Xs-ME significantly (P o0.01) inhibited luciferase activity up to 74% in a dose-dependent manner (Fig.…”