Objective:To study the toxicity features of high glucose on the endothelial cell cycle and the influence of Dan Gua-Fang(丹瓜方),a Chinese herbal compound prescription,on the reproductive cycle of vascular endothelial cells cultivated under a high glucose condition;to reveal the partial mechanisms of Dan GuaFang in the prevention and treatment of endothelial injury caused by hyperglycemia in diabetes mellitus(DM);and offer a reference for dealing with the vascular complications of DM patients with long-term high blood glucose. Methods:Based on the previous 3-(4,5)-dimethylthiahiazo(z-y1)-3-5-diphenytetrazoliumromide(MTT) experiment, under different medium concentrations of glucose and Dangua liquor,the endothelial cells of vein-304(ECV-304) were divided into 6 groups as follows:standard culture group(Group A,5.56 mmol/L glucose);1/300 herb-standard group(Group B);high glucose culture group(Group C,16.67 mmol/L glucose);1/150 herb-high glucose group (Group D);1/300 herb-high glucose group(Group E);and 1/600 herb-high glucose group(Group F).The cell cycle was assayed using flow cytometry after cells were cultivated for 36,72 and 108 h,respectively.Results:(1) The percentage of cells in the G_0/G_1 phase was significantly increased in Group C compared with that in Group A (P<0.05),while the percentage of S-phase(S%) cells in Group C was significantly reduced compared with Group A (P<0.05);the latter difference was dynamically related to the length of growing time of the endothelial cells in a high glucose environment.(2) The S%cells in Group A was decreased by 30.25%(from 40.23%to 28.06%) from 36 h to 72 h,and 12.33%(from 28.06%to 24.60%) from 72 h to 108 h;while in Group C,the corresponding decreases were 23.05%and 21.87%,respectively.The difference of S%cells between the two groups reached statistical significance at 108 h(P<0.05).(3) The percentage difference of cells in the G_2/M phase between Group C and Group A was statistically significant at 72 h(P<0.01).(4) 1/300 Dan Gua-Fang completely reversed the harmful effect caused by 16.67 mmol/L high glucose on the cell cycle;moreover it did not disturb the cell cycle when the cell was cultivated in a glucose concentration of 5.56 mmol/L.Conclusions:High glucose produces an independent impact on the cell cycle.Persistent blocking of the cell cycle and its arrest at the G_0/G_1 phase are toxic effects of high glucose on the endothelial cell cycle.The corresponding variation of the arrest appears in the S phase.1/300 Dan Gua-Fang completely eliminates the blockage of high glucose on the endothelial cell cycle. Objective: To study the toxicity features of high glucose on the endothelial cell cycle and the influence of Dan Gua-Fang, a Chinese herbal compound prescription, on the reproductive cycle of vascular endothelial cells cultivated under a high glucose condition; to reveal the partial mechanisms of Dan GuaFang in the prevention and treatment of endothelial injury caused by hyperglycemia in diabetes mellitus (DM); and offer a reference for dealing with the vascular complications of DM patients with long-term high blood glucose. Methods: Based on the previous 3- (4,5) -dimethylthiahiazo (z-y1) -3-5-diphenytetrazoliumromide (MTT) experiment, under different medium concentrations of glucose and Dangua liquor, the endothelial cells of vein- 304 (ECV- 304) 1/300 herb-standard group (Group B); high glucose culture group (Group C, 16.67 mmol / L glucose); 1 / 150 herb-high glucose group (Group D); 1/300 herb-high glucose (Group E); and 1/600 herb-high glucose group (Group F). The cell cycle was assayed using flow cytometry after cells were cultivated for 36, 72 and 108 h, respectively. Results: (1) The percentage of cells in the G_0 / G_1 phase were significantly increased in Group C compared with that in Group A (P <0.05), while the percentage of S-phase (S%) cells in Group C was significantly reduced compared to Group A (P < (2) The S% cells in Group A was decreased by 30.25% (from 40.23% to 28.06%) from 36 while in Group C, the corresponding decreases were 23.05% and 21.87%, respectively. The difference of S% cells between the two groups (from 28.06% to 24.60%) from 72 h to 108 h; (3) The percentage difference of cells in the G_2 / M phase between Group C and Group A was statistically significant at 72 h (P <0.01). (4) 1/300Dan Gua-Fang-induced by 16.67 mmol / L high glucose on the cell cycle; moreover it did not disturb the cell cycle when the cell was cultivated in a glucose concentration of 5.56 mmol / L. Conclusions: an independent impact on the cell cycle. Persistent blocking of the cell cycle and its arrest at the G_0 / G_1 phase are toxic effects of high glucose on the endothelial cell cycle. the corresponding variation of the arrest in the phase 1.1 / 300 Dan Gua-Fang completely eliminates the blockage of high glucose on the endothelial cell cycle.