Objective To analyze the composition of the aqueous extract of Polygonatum Cyrtonema Hua(PCHE)and evaluate its antitumor activity in vitro and in vivo.Our aim is to provide a theoretical basis for the further development and utilization of Polygonatum Cyrtonema Hua.Methods(1)PCHE was prepared by aqueous extraction,and the chemical composition of PCHE was analyzed by UPLC-Q-TOF/MS and phenol-sulfuric acid method.The inhibitory activity on tumor cells proliferation of PCHE was detected by CCK-8 assay.Cell cycle and apoptosis were detected by flow cytometry,and the expression of apoptosis-related proteins Bcl-2 and Bax was detected by Western Blot.The inhibitory activity of PCHE-containing serum on cell proliferation was detected.(2)A B16 tumor-bearing mice model was constructed and model mice were randomly divided into the model group(saline),the positive drug group(CTX:50 mg·kg-1),and PCHE low-,medium-,and high-dose groups(55.9,111.8,223.6 mg·kg-1),and treated by gavage for 7 days.Changes in body weight and tumor volume of mice were observed during the treatment period.The mice were executed after the treatment,and the histopathological changes of heart,liver,spleen,lung,kidney and tumor were observed by hematoxylin-eosin(HE)staining.The protein expression of Bcl-2 and Bax in tumor tissues was detected by immunohistochemistry(IHC).Results The polysaccharide content of PCHE reached(10.07±1.3)%,and the flavonoid content was(0.044±0.004)%,and thirty-nine components were detected by UPLC-Q-TOF/MS,which contained antitumor components such as flavonoids(baicalein,quercetin,luteolin and rutin),organic acids(ferulic acid)and polyphenols(gallic acid),etc.PCHE exhibited the inhibitory effects on Hela,A549,4T1,B16,MFC and HepG2 cells,among which the inhibitory effect on B16 cells was the most significant(P＜0.001),and PCHE induced cell cycle arrest at G0/G1 phase in B16 cells(P＜0.001).The results of double-staining flow cytometry and Western Blot showed that PCHE significantly promoted apoptosis of B16 cells,decreased the expression of Bcl-2,and promoted the expression of Bax(P＜0.01,P＜0.001).and PCHE constituents absorbed into blood also had an inhibitory effect on B16 cells(P＜0.001).In addition,the results of in vivo activity assay showed that different doses of PCHE could inhibit tumor growth,induce tumor cell necrosis,reduce Bcl-2 expression,and increase Bax expression compared with the model group.Conclusion The ingredients in PCHE are abundant.It contains a variety of antitumor active ingredients,which can inhibit tumor growth,induce tumor cell apoptosis,show strong anti-tumor effects and be worthy of in-depth study.