Piperlongumine

Elevates cellular levels of reactive oxygen species selectively in cancer cell lines1. Irreversible glutathionylation leading to depletion of cellular glutathione is associated with its cellular toxicity2. Piperlongamine does not appear to have any effect on normal cells. Displays anti-tumor effects in a mouse xenograft tumor model as well as in spontaneously formed malignant breast tumors in mice1. Elevation of ROS levels may be due to inhibition of ubiquitin-proteasome system at a pre-proteasomal step.3