ABSTRACT
Aim To investigate the effect of the active ingredients of toad venom (bufalin and cinobufagin) combined with sorafenib on the growth of hepatocellular carcinoma HepG2 cells,and to explore the possible mechanism.Methods The rates of inhibition after treated with drugs 12,24,48 h were detected by MTT assay.The changes of cell morphology were detected by Hoechst 33342 fluorescent staining.The changes of cell cycle were detected by flow cytometry.The expressions of proteins such as Akt,p-Akt (Ser473),IκB,NF-κB,p-NF-κB p65,Bcl-2,Bax,cyclin A,PCNA were detected by Western blot.Results Bufalin,cinobufagin and sorafenib could inhibit the proliferation of HepG2 cells,presenting a dose-and time-dependent manner.Meanwhile,it could significantly increase the inhibitory rate of cells compared with those of single treatment,and they performed a synergistic activity in sorafenib combined with cinobufagin or bufalin by Jin Formula after 24 h treatment (P ＜ 0.01).The results of fluorescence staining showed the observation of the morphological features of nuclear condensation.Sorafenib induced the cell cycle G0/G1 phase arrest (P ＜0.01),and bufalin,cinobufagin and the combination treatment generated the cell cycle S phase arrest (P ＜0.01).The results of Western blot showed that the expressions of Akt,NF-κB were not obviously changed between control and all other treatment.The expression levels of p-Akt (Ser473),p-NF-κB p65,Bcl-2,PC-NA and cyclin A in combination treatment significantly decreased,and the expression levels of IκB and Bax significantly increased compared to those in single treatment (P ＜ 0.01).Conclusion The active ingredients of toad venom (bufalin and cinobufagin) combined with sorafenib performs a synergetic effect on the anti-cancer of HepG2 cells by down-regulating Akt/ NF-κB signaling pathway.