Luteolin Promotes Apoptosis of Endometriotic Cells and Inhibits the Alternative Activation of Endometriosis-Associated Macrophages

Luteolin, a flavonoid present in several fruits, vegetables, nuts, and herbs reportedly exhibits anti-cancer and anti-inflammatory properties. However, the effect of luteolin on endometriosis, a painful condition characterized by the ectopic growth of endometrial tissue and pelvic inflammation, remains elusive. Herein, we observed that luteolin inhibited cell growth and induced apoptosis of 12Z human endometriotic cells by activating caspase-3, -8, and -9. Additionally, luteolin significantly inhibited the expression of key chemokines, C-C motif chemokine ligand 2 (CCL2) and CCL5, required for monocyte/macrophage influx at endometriotic sites. In macrophages stimulated by endometriotic cells, luteolin treatment suppressed the intracellular expression of M2 markers and endometriosis-promoting factors. Collectively, our data suggest that luteolin exerts anti-endometriotic effects by stimulating endometriotic cell apoptosis and hindering the alternative activation of macrophages.