A preliminary study of the preventive and blocking effect of green tea grown in Mengding Mountain area on the esophageal cancer in rats

Three groups (positive control or nitrosamine alone group, test group and control group) were included in this experiment. After the beginning of the experiment, the rats of the test group were given 2% green tea (common grade) solution by free drinking daily for 24 weeks. After 2 weeks of the beginning of the experiment, the rats of the nitrosamine alone group and test group were injected with MANA, 5 mg/kg weekly for 20 weeks. The animals were sacrificed at 4 intervals. The incidence rates of esophageal cancer in the rats of the two groups sacrified at every interval were significantly different. The result suggested that green tea should have a preventive and blocking effect on the occurrence of esophageal cancer in rats.