10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 2 2015 (April - June) Breast cancer is one of most common cancers that are associated with females. Reactive oxygen species (ROS) are formed during metabolic processes.ROS has dual role depending on their concentration in cells if concentration is low, ROS act as "redox messengers" in intracellular signalling but when ROS concentration is elevated it induce depletion of intracellular antioxidant such as glutathione (GSH).Consequence of ROS generation lead to superoxide anion production and ATP depletion.ROS generation cause mitochondrial membrane potential dissipation. Thus a natural product that induces ROS generation could be used as potential molecule for breast combating cancer. In present investigation we found that Piperlonguimine (PLG) a natural product inhibited breast cancer cell line MCF-7 by ROS generation. We investigated that ROS generation by PLG causes severe ATP depletion, dissipation of mitochondrial membrane potential and super oxide anion generation. Overall results demonstrated that antiproliferative effect of PLG was facilitated by ROS generation. KULKARNI PRASAD SHASHIKANT, KSK RAO PATNAIKAND RAMAKRISHNA SISTLA Piperlonguimine (PLG), Reactive oxygen species, ATP depletion, Glutathione depletion, Mitochondrial membrane potential 293-302