Fig. 1. Effect of PGE concentration on the activity of 264.7 cells. 264.7 Cells were treated with different PGE concentrations for 24 h, and the cell viability was determined via the CCK-8 method. The absorbance at 450 nm was measured using a microplate reader. The value represents the average of the three experiments. Data were analyzed by paired t-test. There was a significant difference between the treatment group and the control group: *p < 0.05, **p < 0.001. The error line represents the SD.