OBJECTlVE To investigate the correIation between baicaIin metaI(Ni2+,Co2+,Cu2+) compIexes(BmC)with their anti-tumor activity and the abiIity of BmC to bind to hepatoma ceII DNA. METHODS The cheIating Iigand method was used to synthesize BmC,and the composition and struc-ture of BmC were characterized. mTT,PI staining method and AnnexinⅤ-FITC doubIe staining method were used to anaIyze the effect of BmC on SmmC-7721 ceII proIiferation,cycIe and apoptosis,and to expIore their cytotoxic effect on SmmC-7721 ceIIs in combination with morphoIogy. With DNA extracted from hepatoma ceIIs as a target,cycIic voItammetry and AC impedance were used to study the interaction of BmC with DNA. The interaction mechanism between BmC and DNA was expIored. RESULTS Three new types of BmS were successfuIIy prepared. The moIecuIar formuIas of compIexes were Na2 Ni(C21 H16 O11 )2·10H2 O,Na2 Co(C21 H16 O11 )2·8H2 O,and Na2 Cu(C21 H16 O11 )2·8H2 O,respec-tiveIy. CeII proIiferation and morphoIogy detection reveaIed that BmC 6.25-100 mg·L-1 treatment for 24, 48 and 72 h couId inhibit SmmC-7721 ceII survivaI. BmC cytotoxicity was Iisted as foIIows:baicaIin-cop-per( BC-Cu)﹥ baicaIin-cobaIt( BC-Co)﹥ baicaIin-nickeI( BC-Ni)﹥ baicaIin( BC),in a concentration-dependent manner(P﹤0.01)and time-dependent manner(P﹤0.01). According to the resuIts of ceII cycIe and apoptosis detection,BmC retarded the growth of ceIIs from G0 / G1 phase into S phase or G2 / m phase whiIe inducing apoptosis of SmmC-7721 ceIIs. The resuIts of eIectrochemicaI anaIysis showed that BmC and hepatoma SmmC-7721 ceII DNA formed a non-eIectroactive supermoIecuIar compound through the mixed-mode of eIectrostatic interaction and insertion effect. The binding parameters were obtained:the binding number m = 2,the binding constant βBC = 2.77 ×106 L·moI-1 ,βBC-Ni = 5.46 ×106 L·moI-1 ,βBC-Co =7.74×106 L·moI-1 ,and βBC-Cu =1.21×107 L·moI-1 . The abiIity of BmC to bind to DNA was signifi-cantIy enhanced by BC compIexes with metaI ions,and their abiIity was Iisted as foIIows:BC-Cu﹥BC-Co﹥BC-Ni﹥BC. CONCLUSlON BmC shows cytotoxicity by bIocking the ceII cycIe,inhibiting ceII proIiferation and motivaing apoptosis. The abiIity of BmC to bind to DNA is consistent with its cytotoxicity. BmC,after binding to ceII DNA,wiII bIock DNA repIication,inhibit ceII proIiferation,Iead to ceII apoptosis,and exhibit anti-tumor activity.