Regulation of Ferroptosis in Intestinal Epithelial Cells by Formononetin via the RXRA/PPARG Pathway

Recent studies have revealed that formononetin, a naturally occurring isoflavone found in kudzu root and licorice, has the potential to inhibit ferroptosis in intestinal epithelial cells. Inflammatory bowel disease (IBD) often involves oxidative stress-related pathways, making the modulation of ferroptosis a promising therapeutic avenue. We employed a combination of several techniques to explore how formononetin regulates the retinoid X receptor alpha/peroxisome proliferator activated receptor gamma (RXRA/PPARG) pathway to inhibit ferroptosis in Fetal Human Colonic Epithelial Cells (FHC) induced by RSL3. These techniques included propidium iodide staining, the levels of reactive oxygen species (ROS), Fe²⁺, malondialdehyde (MDA), and ferroptosis-inhibitory proteins glutathione peroxidase 4 (GPX4) and FTH analysis, Western blot analysis, and gene silencing. Our results demonstrate that formononetin significantly mitigated RSL3-induced ferroptosis as evidenced by reduced cellular levels of ROS, Fe²⁺, and MDA, alongside an increased expression of GPX4 and FTH. Silencing the RXRA gene reverses the protective effects of formononetin, highlighting that formononetin inhibits ferroptosis in FHC by upregulating the levels of RXRA. These findings provide new molecular targets for potential therapeutic intervention in IBD, suggesting that upregulating RXRA and PPARG expression via formononetin could be a viable strategy to mitigate ferroptosis-associated cellular damage. This could potentially lead to novel treatments for patients suffering from IBD.