Possible synergic action of propolis components against human laryngeal epidermoid carcinoma cells (HEp-2): resistance and cell death mechanisms

Author(s)

Lívia Matsumoto da Silva

• Document type: Master's Dissertation
• Press: Botucatu. 2016-09-22.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2016-07-27
• Advisor: José Mauricio Sforcin

Abstract

Propolis and its phenolic compounds are known for their antioxidant and anticancer properties. Propolis mechanisms of action have been the subject of research recently. This study aimed to elucidate the effects of propolis and three phenolic compounds (caffeic acid – Caf; dihydrocinnamic acid – Cin; p-coumaric acid – Cou) in the same proportion they are found in our propolis sample, alone or in combination, towards human larynx epidermoid carcinoma (HEp-2) cell. Cell viability, apoptosis/necrosis and cell cycle arrest, generation of reactive oxygen species (ROS) and the ability of propolis to induce doxorubicin (DOX) efflux using a P-glycoprotein (P-gp) inhibitor (verapamil) were assayed. Propolis exerted a cytotoxic effect in HEp-2 cells and exhibited an IC50 value of 80 µg/mL, whereas the isolated compounds (alone or in combination) had no effect on cell viability after 72 h. Hence, higher concentrations of these compounds were tested and Caf (IC50: 1.332 µM) induced necrosis in HEp-2 cells, while propolis induced apoptosis, both, probably due to ROS generation. Propolis induced cell cycle arrest at G2/M phase and, Caf at S phase. Propolis or its components, except Caf, can act as a P-gp inhibitor by modulating P-gp activity and inhibiting the efflux of DOX. Altogether, data suggested that propolis exerted cytotoxic effects against HEp-2 cells and some mechanisms are discussed. Its potential as an antitumor drug should be investigated in further assays. (AU)

• FAPESP's process: 14/13245-4 - A possible synergistic action of propolis components on human laryngeal epidermoid carcinoma (HEp-2) cells: mechanisms of resistance and cell death
• Grantee: Lívia Matsumoto da Silva
• Support Opportunities: Scholarships in Brazil - Master