Research Article Free Radical Scavenging Activity: Antiproliferative and Proteomics Analyses of the Differential Expression of Apoptotic Proteins in MCF-7 Cells Treated with Acetone Leaf Extract of Diospyros lycioides (Ebenaceae) M. C. Pilane, V. P. Bagla, M. P. Mokgotho, V. Mbazima, T. M. Matsebatlela, I. Ncube, and L. Mampuru Department of Biochemistry, Microbiology and Biotechnology, Faculty of Science and Agriculture, University of Limpopo, Turfoop Campus, Private Bag X1106, Sovenga, Limpopo 0727, South Africa Correspondence should be addressed to M. P. Mokgotho; matlou.mokgotho@ul.ac.za Received 9 June 2015; Accepted 5 August 2015 Academic Editor: Giuseppe Esposito Copyright © 2015 M. C. Pilane et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Breast cancer is the most common cancer in South Africa. Te acetone leaf extract of Diospyros lycioides was evaluated qualitatively and quantitatively for its antioxidant potential using DPPH assay and nitric oxide radical scavenging efect, while the viability of MCF-7 cells was evaluated using the MTT. MCF-7 treated cells were stained with Hoechst 335258 dye and annexin-V-FITC to be evaluated for apoptotic efect of the extract, while mRNA expression levels of apoptotic genes were assessed by quantitative real-time PCR and deferential protein expression levels using 2D gel electrophoresis and mass spectrometry. Results revealed presence of antioxidant constituents in the extract. Extract was shown to be cytotoxic in a concentration- and time-dependent manner. Cytotoxicity was demonstrated to be due to apoptosis, with 70% of the extract-treated cells being annexin-V-positive/PI negative at 48 hours. Te extract was also shown to upregulate the expression of p53 gene with concomitant downregulation of the Bcl-2 antiapoptotic gene while diferentially expressed proteins were identifed as enolase, pyruvate kinase, and glyceraldehyde-3- phosphate. Te extract in this study was shown to induce apoptosis at an early stage which makes it an ideal source that can be explored for compounds that may be used in the treatment and management of cancer. 1. Introduction Breast cancer remains a considerable health burden. It afects more than 1.3 million women worldwide annually and is responsible for about 14% of cancer-related deaths [1]. Indeed, the incidences of breast cancer have increased over the past decades and a substantial rise is projected in the coming years [2]. Breast cancer is a heterogeneous and polygenic disease which is infuenced by epigenetic mechanisms that afect the transcriptomes, proteomes, and metabolomes. Te metabolism of cancer cells has been extensively inves- tigated using numerous approaches leading to the unveiling of diverse mechanisms that are involved in metabolic repro- gramming of cancer cells. Cells undergoing apoptosis show distinct characteristic features which include cell shrinkage and rounding, due to the breakdown of the proteinaceous cytoskeleton by caspases, cytoplasmic condensation, chro- matin aggregation, and partitioning of the nucleus and cytoplasm into membrane-bound organelles known as apop- totic bodies [3]. Apoptosis can be induced by a variety of physiological conditions as well as damage or therapy- associated agents. Two major pathways of apoptosis have been identifed, namely, the death receptor (extrinsic) and the mitochondrial (intrinsic) pathways. Te intrinsic pathway can be triggered by a number of stimuli such as heat shock, UV radiation, and DNA damage. In this pathway, members of the Bcl-2 family of proteins afect the mitochondrial function and regulate the release of apoptosis-activating factors. Antiapoptotic members of Bcl-2 family such as Bcl-2 and Bcl-xL act to preserve mitochondrial Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2015, Article ID 534808, 13 pages http://dx.doi.org/10.1155/2015/534808