Stigmasterol affects ovarian cancer cell apoptosis and tumor formation in ES2 and OV90 cells. (A,B) Western blot bands showed the expression of proapoptotic signaling molecules in both cell types following stigmasterol treatments (0, 5, 10, and 20 μg/mL). Alpha-tubulin (TUBA) was used as a control. (C,D) Spheroid formation of ovarian cancer cells was compared between vehicle-treated cells and stigmasterol-treated cells. (E,F) Annexin V and propidium iodide (PI) staining were performed to determine cell death in ES2 and OV90 cells. The quadrant of the dot blot represents the state of apoptosis in ES2 and OV90 cells. The comparative graph represents changes in late apoptosis due to stigmasterol treatment (0, 5, 10, and 20 μg/mL) compared to the vehicle-treated control (100%) in ES2 and OV90 cells. (G,H) Histogram presents cell cycle progression in stigmasterol-treated (0, 5, 10, and 20 μg/mL) ovarian cancer cells. Comparative graph represents the % of cells in the subG1, G0/G1, S, and G2/M phases in stigmasterol-treated (0, 5, 10, and 20 μg/mL) ovarian cancer cells.