Ethanolic Extract of Propolis from Tetragonula laeviceps: Selective Cytotoxicity for MCF-7 Breast Cancer cells

Introduction: Many patients with breast cancer fail to respond to conventional chemotherapeutic agents; these agents are also associated with numerous adverse events and toxicities. These concerns have led to the ongoing search for natural ingredients with antitumor effects. As such, the aim of this study was to explore the anti-cancer properties of an ethanolic extract of propolis (EEP), a natural product derived from the stingless bee, from Tetragonula laeviceps. Methods: Bioactive components of EEP were identified by gas chromatography–mass spectrometry (GC–MS) and antioxidant capacity was tested by 2.2-diphenyl1-picrylhydrazyl (DPPH) analysis. Selective cytotoxic actions of EEP on both MCF-7 and Vero cells were then evaluated using the MTT assay. Polyphenols were identified as the major components of EEP from T. laeviceps. Results: our results indicated that EEP was selectively toxic for human MCF-7 breast cancer cells and had only limited impact on African Green Monkey kidney Vero cells. Conclusion: EEP from T. laeviceps has bioactive components that may selectively inhibit the proliferation of cancer cells. As such, EEP may be useful source material to be used for the development of novel anti-cancer agents.