Identification And Characterization Of Natural Anti-breast Cancer Compound:Costunolide

Breast cancer is the most common cancer among women,23%(1.3 million)of the total of new cases and the second leading cause of cancer death in women exceeded only by lung cancer.Natural medicines have been proven to be a central source of narrative agents with a pharmaceutical potential.Costunolide is sesquiterpene lactones consisting of diverse plant chemicals that exhibit anti cancer action through cytotoxic effects on various cancer cells.The objectives of present study were to explore the effects of natural compounds on the proliferation of MCF-7 cells and to determine the role of ROS in natural compounds-induced apoptosis in breast cancer cells with a therapeutic potential.Results showed that costunolide screened,possess potent anticancer properties against breast cancer MCF-7 cells,Costunolide was observed as strong anti-proliferative agent with IC50 = 50?M.The anti-proliferative effect of costunolide on MCF cells was confirmed by live/dead assay using fluorescent probes calcein AV/PI.The results demonstrated that treatment of cells with costunolide decreased the viability of MCF-7 cells in a dose-dependent manner.To determine the costunolide-induced apoptosis,flow cytometric analysis was carried out.The results showed that costunolide induced apoptosis in a dose-dependent manner in breast cancer MCF-7cells.ROS are well known mediators of intracellular signaling of cascades.The excessive generation of ROS can induce oxidative stress,loss of cell functioning,and apoptosis.In the present study,we assumed that costunolide might arouse ROS level,which could be involved in induction of apoptosis.Therefore,the intracellular ROS level was measured using the ROS-detecting fluorescence dye 2,7-dichlorofluorescein diacetate(DCF-DA).Interestingly these effects were significantly abrogated when the cells were pretreated with N-acetyl-cysteine(NAC),a specific ROS inhibitor.Costunolide induces apoptosis through extrinsic pathway in MCF-7 breast cancer cells,In order to examine whether costunolide suppresses cell growth inducing apoptotic cell death,we analyzed DNA contents and apoptosis-related proteins expression level by flow cytometry and western blot,respectively in MCF-7 breast cancer cells we investigated whether costunolide activates extrinsic apoptotic pathway.We examined the expression levels of death receptor signaling-related proteins,caspase-3,and PARP.The results showed that procaspase-3 was cleaved to yield 17 and 20kDa fragments and activation of PARP in treated cells with 25 and 50?M of costunolide.Costunolide induce apoptosis through intrinsic mitochondria pathway in MCF-7 breast cancer Cells.We examined the expression levels of mitochondrial apoptotic pathway related proteins such as anti-apoptotic protein,B-cell lymphoma protein-2(Bcl2),and pro-apoptotic protein Bax.Costunolide involved in the down regulation of Bcl-2 and up regulation of Bax.These results suggest that costunolide may have beneficial effects for the reduction of breast cancer growth,and new therapeutic strategy for the treatment of human cancers.