Cucurbitacin E Inhibits TNF-α-induced Inflammatory Cytokine Production In Human Synoviocyte MH7A Cells Via Modulation Of PI3K/Akt/nf- κB Pathway

Objective:Increasing studies indicate that Cucurbitacin E(CuE), a derivative isolated from Cucurbitaceae plants may exert anti-inflammatory effect. In this study we explore the effect of CuE on TNF-α-induced inflammatory cytokines production in human synoviocyte MH7 A cells, and further explore the detailed molecular mechanism involved in its anti-inflammatory effect.Methods:1. MH7 A cell lines were cultured in 1640 supplemented with 10% FBS in a humidified incubator with 5% CO2 at 37°C.2. The cytotoxicity of CuE to MH7 A cell lines(CCK-8 assay).3.The effects of CuE to TNF-α-induced inflammatory cytokines(IL-1β、IL-6、IL-8)production in MH7 A cell lines(RT-PCR).4.The effects of CuE to TNF-α-induced inflammatory cytokines(IL-1β、IL-6、IL-8)production in MH7 A cell lines(ELISA).5. The effects of CuE to TNF-α-induced activation of PI3K/Akt /NF-κB in MH7 A cell lines(Western-blot).6. The effect of CuE to TNF-α-induced nuclei translocation of NF-κB p65 in MH7 A cell lines(Confocal fluorescence microscopy).Results:CuE suppresses TNF-α-induced interleukin-1β(IL-1β), interleukin-6(IL-6), and interleukin-8(IL-8) mRNA and protein expression in MH7 A cells in a dose-dependent manner with no apparent cytotoxicity. CuE also suppresses TNF-α-inducedphosphorylation of NF-κB-p65, p-IKKα/β, p-IκBα as well as NF-κB-p65 nuclear translocation in a dose-and time-dependent manner. Furthermore, CuE suppresses the TNF-α-induced activation of PI3K/Akt similarly as the PI3 K inhibitor LY294002, which also decreases the activation of NF-κB as well as mRNA and protein expression of IL-1β,IL-6, and IL-8 in TNF-α-induced MH7 A cells.Conclusion:These findings demonstrate that Cucurbitacin E as a potential therapeutic agent for Rheumatoid arthritis can inhibits TNF-α-induced inflammatory cytokine production in human synoviocyte MH7 A cells via modulation of PI3K/Akt/NF- κB pathway.