Abstract:Objective To explore the molecular mechanism of berberine inhibiting proliferation of HCT116 cells in mice. Methods Sixty mice were randomly divided into blank group, model group, control group, drug group (the drug groups with low, medium and high berberine). The micro syringe was used to absorb the HCT116 cell suspension 100 ul and was subcutaneously injected into the right forelimb of all mice except for blank group. The mice in the blank group were subcutaneously injected with 100 ul PBS, and the treatment drugs were given seven days later. The drug groups with low, medium and high berberine were intraperitoneally injected with concentration of 1, 2 and 4 mg/ml berberine saline solution respectively, and the dosage volume standard is 10 ml/kg. The mice in the control group were injected with 20 mg/kg fluorouracil intraperitoneally. In the blank group and model group,10 ml/kg of saline solution was injected intraperitoneally once a day. Results Berberine inhibited HCT116 cells in vitro, and the IC50 of berberine was 0.24±0.02 μmol/L. Comparison of body weight of mice in the berberineadministered group (low, medium, and high doses), positive drug group, model group, and control group on days 1, 7, 14 and 21 after injection, at different time points within the six groups, there was a difference in body weight between the mice (P < 0.05). The tumor long diameter, short diameter and volume of the low, medium and high dose berberine group were lower than those of the model group, and showed a dose-dependent change (P < 0.05). Compared with the model group, the survival rates of the low, medium and high dose berberine treatment group and the positive drug group were statistically higher (P < 0.05,) and the berberine treatment group was dose-dependently altered. The tumor weight of low, medium and high dose berberine groups was lower than that of model group, and the berberine treatment group was dose-dependent (P < 0.05). The tumor inhibition rates of the low, middle and high dose berberine group were higher. The high dose berberine group was higher than the low and medium dose berberine group (P < 0.05), and the positive control group was higher than the low and medium dose berberine group (P < 0.05). The expression of Caspase-9 and Caspase-3 mRNA in berberine group was higher than that in model group (P < 0.05). The expression levels of Cytochrome C, Caspase-9 and Caspase-3 protein in berberine group, especially in middle and high dose group, were higher than those in model group (all P < 0.05). Conclusions Berberine releases Cytochrome C by destroying mitochondria, and then activates the expression of apoptosis related protein Caspase-9 and Caspase-3, and induces apoptosis of tumor tissue, and then plays anti-tumor activity.