RESUMEN
Aim To explore the mechanism by which total coumarins in Pileostegia tomentella (TCPT) inhibits the proliferation of small cell lung cancer (SCLC) H1688 cells via inducing ferroptosis. Methods The gradient concentrations of TCPT were used to treat H1688 cells. CCK-8 assay was applied for detection of proliferative inhibition of H1688 cells. Transmission electron microscopy was used to approach the morphological changes of H1688 cells under the treatment of TCPT. Additionally, dichlorofluorescein (DCFH-DA) probe was used to detect the intracellular reactive oxygen species (ROS) level. BODIPY 581/ 589 Cll probe was applied to examine the intracellular lipid peroxide formation. Western blotting was employed to detect the expression levels of glutathione peroxidase 4 (GPX4), kelch-like ECH-associated protein (KEAP1), nuclear factor E2 related factor 2 (NRF2), ferritin heavy chain 1 (FTH1) proteins in HI688 cells. Results The proliferation of small cell lung cancer cell H1688 was dramatically inhibited after TCPT intervention (P < 0. 05, P < 0. 01). The morphological characteristics of ferroptosis induced by TCPT were observed by transmission electron microscope. TCPT could also effectively elevate intracellular level of ROS and lipid peroxide. In HI688 cells the expression of ferroptosis markers GPX4, NRF2, and FTH1 was down-regulated, while the expression of KEAP1 was up-regulated, and there were statistically significant differences among the markers mentioned a-bove (P<0. 01). Conclusions Total coumarins in TCPT can significantly inhibit the proliferation of H1688 cells, possibly through increasing ROS and intracellular lipid peroxide levels and eventually inducing ferroptosis.