The Effect Of Dihydromyricetin On NF-κB Activation And Its Signaling Pathways

Objective:Dihydromyricetin,from the traditional herb Ampelopsis grossedentata,is a potent nattural NF-κB inhibitor.Its main active ingredients are flavonoids,which have many bioactive properties such as scavenging free,radicals,antioxidant,anti-thrombus,anti-tumor,anti-inflammatory.In this study,we demonstrated the effect of dihydromyricetin on NF-κB activation in TNF-a-induced HeLa cells.Methods:MTT assay was used to detect the survival rate of HeLa cells.The activity of NF-κB was detected by luciferase reporter assay.The expression of NF-κB-related protein was detected by Western blot.The expression of cyclin D1/iNOS/VEGF mRNA was detected by RT-PCR.Immunofluorescence assay was used to detect p65 nuclear translocation.Western blot was used to detect the effect of dihydromyricetin on the expression of TNFR1 Pathway-related protein.The proliferation of HeLa cells was detected by MTT assay,colony formation assay and EdU assay.The apoptosis rate of HeLa cells was detected by flow cytometry.Result:MTT assay and luciferase reporter gene assay show that dihydromyricetin inhibits TNF-a-induced NF-κB activation and no significant cytotoxicity at 20-200 uM.Western blot showed that dihydromyricetin could inhibit the phosphorylation and degradation of IκBα and nuclear translocation of p65,and also inhibit the expression of NF-κB target gene.Immunofluorescence assay further indicated that dihydromyricetin inhibited nuclear translocation of p65.Western blot showed that dihydromyricetin could inhibit the phosphorylation of IKKa/β and the expression of TRAF2 and RIP1 in TNFR1 signaling pathway.RT-PCR showed that dihydromyricetin could inhibit the expression of cyclin D1/iNOS/VEGF mRNA.MTT assay,colony formation assay and EdU assay showed that dihydromyricetin could inhibit the proliferation of HeLa cells.Flow cytometry showed that dihydromyricetin promoted TNF-α-induced apoptosis of HeLa cells.Conclusion:Dihydromyricetin inhibits the NF-κB activation and the expression of NF-κB-related proteins.Dihydromyricetin inhibits the expression of protein and mRNA,such as apoptosis,proliferation,migration and angiogenesis.Dihydromyricetin can inhibit cell proliferation and promote TNF-α-induced apoptosis.