Objective:To investigate whether asiaticoside(ASI)regulates the malignant biological behavior of hepatocellular carcinoma Huh7 cells via the cyclic adenosine monophosphate/protein kinase A/cAMP-response element binding protein(cAMP/PKA/CREB)signaling pathway.Methods:After determining the suitable ASI concentration and treatment duration using MTT assay,Huh7 cells were divided into the following groups:control,ASI-L(20 μmol/L),ASI-M(40 μmol/L),ASI-H(80 μmol/L),and ASI-H+Forskolin(80 μmol/L ASI+100 μmol/L cAMP activator Forskolin)groups.After 48 h of treatment,cell proliferation was assessed using MTT and colony formation assays;cell migration and invasion were analyzed using Transwell assays;apoptosis was detected using an Annexin V-FITC apoptosis detection kit.The secretion level of cAMP and the protein expression levels of phosphorylated PKA(p-PKA)and phosphorylated CREB(p-CREB)were evaluated using ELISA and Western blotting,respectively.A subcutaneous xenograft model was established by injecting Huh7 cells into the right abdomen of nude mice.ASI was administered by gavage at doses of 5,15,and 45 mg/kg for 4 weeks.Tumors were then harvested and weighed.Results:Treatment with 40 μmol/L ASI for 48 hours(close to the IC??)was determined to be the appropriate concentration and duration.Compared with the control group,the ASI-L,ASI-M,and ASI-H groups showed significantly reduced Huh 7 cell proliferation,colony formation,migration,invasion,cAMP levels,and expression of p-PKA/PKA and p-CREB/CREB(all P<0.05),while apoptosis rates were significantly increased(P<0.05).Compared with the ASI-H group,the ASI-H+Forskolin group exhibited significantly increased proliferation,colony formation,migration,invasion,cAMP level,and expression of p-PKA/PKA and p-CREB/CREB(all P<0.05),but apoptosis was significantly reduced(all P<0.05).In the nude mouse xenograft model,ASI at 5,15,and 45 mg/kg markedly decreased tumor weight in nude mice(all P<0.05).Conclusion:ASI inhibits the malignant biological behaviors and promotes apoptosis of Huh7 cells,as well as suppresses tumor growth in nude mice,by downregulating the expression of proteins in the cAMP/PKA/CREB signaling pathway.