The saponin ginsenoside Rk1 is a major compound isolated from ginseng.Ginsenoside Rk1 has been reported to have anti-inflammatory and anti-tumor properties and to be involved in the regulation of metabolism.However,th...The saponin ginsenoside Rk1 is a major compound isolated from ginseng.Ginsenoside Rk1 has been reported to have anti-inflammatory and anti-tumor properties and to be involved in the regulation of metabolism.However,the effect and mechanism of anti-inflammatory action of ginsenoside Rk1 has not been fully clarified.We investigated whether ginsenoside Rk1 could suppress the inflammatory response in lipopolysaccharide-stimulated RAW264.7 macrophages and to explore its mechanism of the action.RAW264.7 cells were treated with LPS(1 μg×mL^(–1))in the absence or the presence of Ginsenoside Rk1(10,20,and 40 μmol×L^(–1)).Then the inflammatory factors were tested with Griess reagents,ELISA,and RT-PCR.The proteins were analyzed by Western blotting.Ginsenoside Rk1 inhibited lipopolysaccharide-induced expression of nitric oxide(NO),interleukin(IL)-6,IL-1β,tumor necrosis factor(TNF)-α,and monocyte chemotactic protein(MCP)-1.Ginsenoside Rk1 inhibited the lipopolysaccharide-stimulated phosphorylation of NF-κB and janus kinase(Jak)2 and signal transducer and activator of transcription(Stat)3 at Ser727 and Tyr705.These data suggested that ginsenoside Rk1 could inhibit expression of inflammatory mediators and suppress inflammation further by blocking activation of NF-κB and the Jak2/Stat3 pathway in LPS-stimulated RAW264.7 cells.展开更多
Annexin A2, a multifunctional tumor associated protein, promotes nuclear factor-kappa B （NF-κB） activation by interacting with NF-κB p50 subunit and facilitating its nuclear translocation. Here we demonstrated tha...Annexin A2, a multifunctional tumor associated protein, promotes nuclear factor-kappa B （NF-κB） activation by interacting with NF-κB p50 subunit and facilitating its nuclear translocation. Here we demonstrated that two ginsenosides Rg5 （G-Rg5） and Rkl （G-Rkl）, with similar structure, directly bound to Annexin A2 by molecular docking and cellular thermal shift assay. Both Rg5 and Rkl inhibited the interaction between Annexin A2 and NF-κB p50 subunit, their translocation to nuclear and NF-κB activation. Inhibition of NF-κB by these two gin- senosides decreased the expression of inhibitor of apoptosis proteins （lAPs）, leading to caspase activation and apoptosis. Over expression of K302A Annexin A2, a mutant version of Annexin A2, which fails to interact with G-Rg5 and G-Rkl, effectively reduced the NF-κB inhibitory effect and apoptosis induced by G-Rg5 and G-Rkl. In addition, the knockdown of Annexin A2 largely enhanced NF-κB activation and apoptosis induced by the two molecules, indicating that the effects of G-Rg5 and G-Rkl on NF-κB were mainly mediated by Annexin A2. Taken together, this study for the first time demon- strated that G-Rg5 and G-Rkl inhibit tumor cell growth by targeting Annexin A2 and NF-κB pathway, and G-Rg5 and G-Rkl might be promising natural compounds for targeted cancer therapy.展开更多
基金supported by the National Natural Science Foundation of China(Nos.81173369,81303253,81530097,and 81222051)the National Key Technology R&D Program “New Drug Innovation” of China(Nos.2012ZX09301002-002-002 and 2012ZX09304-005)+1 种基金the Natural Science Foundation of Beijing,China(No.132210)the Doctoral Scientific Fund Project of the Ministry of Education of China(No.20120001110105)
文摘The saponin ginsenoside Rk1 is a major compound isolated from ginseng.Ginsenoside Rk1 has been reported to have anti-inflammatory and anti-tumor properties and to be involved in the regulation of metabolism.However,the effect and mechanism of anti-inflammatory action of ginsenoside Rk1 has not been fully clarified.We investigated whether ginsenoside Rk1 could suppress the inflammatory response in lipopolysaccharide-stimulated RAW264.7 macrophages and to explore its mechanism of the action.RAW264.7 cells were treated with LPS(1 μg×mL^(–1))in the absence or the presence of Ginsenoside Rk1(10,20,and 40 μmol×L^(–1)).Then the inflammatory factors were tested with Griess reagents,ELISA,and RT-PCR.The proteins were analyzed by Western blotting.Ginsenoside Rk1 inhibited lipopolysaccharide-induced expression of nitric oxide(NO),interleukin(IL)-6,IL-1β,tumor necrosis factor(TNF)-α,and monocyte chemotactic protein(MCP)-1.Ginsenoside Rk1 inhibited the lipopolysaccharide-stimulated phosphorylation of NF-κB and janus kinase(Jak)2 and signal transducer and activator of transcription(Stat)3 at Ser727 and Tyr705.These data suggested that ginsenoside Rk1 could inhibit expression of inflammatory mediators and suppress inflammation further by blocking activation of NF-κB and the Jak2/Stat3 pathway in LPS-stimulated RAW264.7 cells.
文摘Annexin A2, a multifunctional tumor associated protein, promotes nuclear factor-kappa B （NF-κB） activation by interacting with NF-κB p50 subunit and facilitating its nuclear translocation. Here we demonstrated that two ginsenosides Rg5 （G-Rg5） and Rkl （G-Rkl）, with similar structure, directly bound to Annexin A2 by molecular docking and cellular thermal shift assay. Both Rg5 and Rkl inhibited the interaction between Annexin A2 and NF-κB p50 subunit, their translocation to nuclear and NF-κB activation. Inhibition of NF-κB by these two gin- senosides decreased the expression of inhibitor of apoptosis proteins （lAPs）, leading to caspase activation and apoptosis. Over expression of K302A Annexin A2, a mutant version of Annexin A2, which fails to interact with G-Rg5 and G-Rkl, effectively reduced the NF-κB inhibitory effect and apoptosis induced by G-Rg5 and G-Rkl. In addition, the knockdown of Annexin A2 largely enhanced NF-κB activation and apoptosis induced by the two molecules, indicating that the effects of G-Rg5 and G-Rkl on NF-κB were mainly mediated by Annexin A2. Taken together, this study for the first time demon- strated that G-Rg5 and G-Rkl inhibit tumor cell growth by targeting Annexin A2 and NF-κB pathway, and G-Rg5 and G-Rkl might be promising natural compounds for targeted cancer therapy.
