Oxyresveratrol induces ER stress and growth inhibition associated with glutathione depletion in breast cancer cells.

Polyphenolic stilbene oxyresveratrol (OXYRES) is produced by various plant species. It exhibits a wide range of biological activities, including anti-inflammatory, anticancer, antibacterial, and anti-melanogenic activities. However, the molecular mechanisms underlying these effects are not well understood. In this study, we demonstrate that OXYRES inhibits the proliferation of MCF-7 human breast cancer cells in a dose-dependent manner. Additionally, OXYRES induces apoptosis, autophagy, and cell cycle arrest in MCF-7 cells. Our data suggest that these processes involve the unfolded protein response (UPR) associated with endoplasmic reticulum (ER) stress. Importantly, we found that a decrease in intracellular glutathione (GSH) levels may mediate these effects independently of reactive oxygen species (ROS) production.