Pyrrole-Derivative of Chalcone, (E)-3-Phenyl-1-(2-Pyrrolyl)-2-Propenone, Inhibits Inflammatory Responses via Inhibition of Src, Syk, and TAK1 Kinase Activities

Abstract

(E)-3-Phenyl-1-(2-pyrrolyl)-2-propenone (PPP) is a pyrrole derivative of chalcone, in which the B-ring of chalcone linked to β-carbon is replaced by pyrrole group. While pyrrole has been studied for possible Src inhibition activity, chalcone, especially the substituents on the B-ring, has shown pharmaceutical, anti-inflammatory, and anti-oxidant properties via inhibition of NF-κB activity. Our study is aimed to investigate whether this novel synthetic compound retains or enhances the pharmaceutically beneficial activities from the both structures. For this purpose, inflammatory responses of lipopolysaccharide (LPS)-treated RAW264.7 cells were analyzed. Nitric oxide (NO) production, inducible NO synthase (iNOS) and tumor necrosis factor-α (TNF-α) mRNA expression, and the intracellular inflammatory signaling cascade were measured. Interestingly, PPP strongly inhibited NO release in a dose-dependent manner. To further investigate this anti-inflammatory activity, we identified molecular pathways by immunoblot analyses of nuclear fractions and whole cell lysates prepared from LPS-stimulated RAW264.7 cells with or without PPP pretreatment. The nuclear levels of p50, c-Jun, and c-Fos were significantly inhibited when cells were exposed to PPP. Moreover, according to the luciferase reporter gene assay after cotransfection with either TRIF or MyD88 in HEK293 cells, NF-κB-mediated luciferase activity dose-dependently diminished. Additionally, it was confirmed that PPP dampens the upstream signaling cascade of NF-κB and AP-1 activation. Thus, PPP inhibited Syk, Src, and TAK1 activities induced by LPS or induced by overexpression of these genes. Therefore, our results suggest that PPP displays anti-inflammatory activity via inhibition of Syk, Src, and TAK1 activity, which may be developed as a novel anti-inflammatory drug.

The skin protective effects of compound K, a metabolite of ginsenoside Rb1 from Panax ginseng

“…For the luciferase (Luc) reporter gene assay, HEK293T cells were transfected with 0.8 μg/mL of plasmids containing β-galactosidase and collagen (Col)1a1-Luc in the presence or absence of Flag-Smad3 using the polyethyleneimine (PEI) method in 24-well plates for 24 h. The cells were treated with CK for an additional 24 h. HEK293T cells were transfected with 0.8 μg/mL plasmid containing β-galactosidase, activator protein (AP)-1-Luc or cyclic adenosine monophosphate response element binding protein (CREB)-Luc for 24 h. Cells were treated with compound K for 24 h before termination. Luciferase assay was performed using the Luciferase Assay System (Promega, Madison, WI, USA), as previously reported [28] , [29] .…”

TANK‐binding kinase 1 and Janus kinase 2 play important roles in the regulation of mitogen‐activated protein kinase phosphatase‐1 expression after toll‐like receptor 4 activation

“…For overexpression of signaling proteins, HEK293 cells were transfected with the empty vector or the indicated plasmids (TBK1, JAK2, p38, Src, and Syk; 0.3 μg/ml), MKP1‐Promoter‐Luc (0.3 μg/ml), and β‐galactosidase (0.1 μg/ml) using polyethylenimine in a 24‐well plate, as reported previously (Yu et al, ). After 36 hr, the transfected cells were lysed, and luciferase assays were performed using the luciferase assay system (Promega, Madison, MA), as reported previously (Yang et al, ). In case of drug treatment, all drugs were treated for 12 hr before termination of transfection conditions.…”

Pyrrole and Fused Pyrrole Compounds with Bioactivity against Inflammatory Mediators

“…New drugs that selectively inhibit COX-2 exhibit a better gastric tolerance profile [ 5 , 9 , 11 , 14 , 15 , 16 , 17 , 18 ]. Among well-known NSAIDs, pyrrole ring derivatives [ 19 ] are of remarkable interest [ 20 , 21 , 22 , 23 ]. Examples are benzo[ b ]pyrrole derivatives such as indomethacin (Indacin ® ), acemetacin (Emflex ® ), and etodolac (Etodine ® ) and pyrrole derivatives like tolmetin (Rumatol ® ) and ketorolac (Ketolac ® ) [ 14 , 24 , 25 ].…”