To investigate the efficacy of scutellarin (SCU) on human colorectal cancer HCT116 cells and its underlying mechanism.Colorectal cancer HCT116 cells were treated with SCU at various concentrations,followed by measurement of cell proliferation with MTT assay,clonogenic assay,wound healing assay,Hoechst 33342/PI double staining,flow cytometry analysis of apoptosis,qRT-PCR and Western blotting.The results showed that SCU reduced the proliferation of HCT116 cells with altered morphological profile.SCU markedly deterred the colony formation and migration of HCT116 cells (P<0.01).Moreover,SCU triggered the apoptosis of HCT116 cells,with condensed nuclear staining and increased apoptosis rate,relative to the control (P<0.05 or P<0.01).Mechanistically,SCU significantly up-regulated the mRNA levels of caspase-9 and caspase-3 (P<0.01),promoted the mRNA and protein expression of Bax (P<0.01),and attenuated the mRNA and protein expression of Bcl-2 (P<0.01).In addition,the mRNA and protein expressions of MST1 and LATS1,and the protein level of p-YAP(Ser127) were elevated by SCU (P<0.05 or P<0.01),which lessened the mRNA and protein expressions of YAP1,TAZ and downstream target c-Myc in HCT116 cells (P<0.05 or P<0.01).Taken together,SCU may suppress the proliferation,migration and colony formation and induce cell apoptosis of colorectal cancer cells,by regulation of Hippo signaling pathway activity.