Integrative Metabolomics and Proteomics Approach to Identify Anticancer Compounds in Muscadine Grape

Muscadine grapes (Vitis rotundifolia), commonly found in southeastern United States, are known to be potential source of antioxidant and other polyphenol compounds, which are capable of inhibiting cancer cell growth. The objectives of this study are: 1) to determine anticancer activity, 2) identify the active compounds from muscadine berry extracts, and 3) identify proteins involved in biosynthesis of polyphenols. Both methanol and aqueous extracts of muscadine berry pulp and seed were tested against three different cancer cell lines. Cell viability test was performed using various concentrations of the crude extracts. Cytotoxicity of these extracts was found effective against breast, lung and prostate cancer cell lines. High rate of apoptosis was found in: i) lung cancer cell lines treated with methanol extract of seed and water extract of pulp, ii) breast cancer cell lines treated with methanol extract of seed and pulp, and iii) prostate cancer cell lines treated with both solvent and aqueous extracts of seed. Identities of active compounds were determined by IR, NMR and MS analysis. Proteomics of berry pericarp was carried out using both labeled and label free methods. Findings indicated 650 proteins through iTRAQ label, while over 1600 proteins identified label free using Thermo LTQ. In addition, biological pathways involving synthesis of anticancer compounds are described in detail.