Propolis Component Kills Cancer Cells

Constituents of Brazilian Red Propolis and Their Preferential Cytotoxic Activity Against Human Pancreatic PANC-1 Cancer Cell Line in Nutrient-Deprived Condition
Bioorganic & Medicinal Chemistry, Article in Press

Abstract: Human pancreatic cancer cells such as PANC-1 are known to exhibit marked tolerance to nutrition starvation that enables them to survive for prolonged period of time even under extremely nutrient-deprived conditions. Thus, elimination of this tolerance to nutrition starvation is regarded as a novel approach in anticancer drug development.

In this study, the MeOH soluble extract of Brazilian red propolis was found to kill 100% PANC-1 cells preferentially in the nutrient-deprived condition at the concentration of 10 μg/mL.

Further phytochemical investigation led to the isolation of 43 compounds including three new compounds, (6aS,11aS)-6a-ethoxymedicarpan (1), 2-(2′,4′-dihydroxyphenyl)-3-methyl-6-methoxybenzofuran (2), and 2,6-dihydroxy-2-[(4-hydroxyphenyl)methyl]-3-benzofuranone (3).

Among them, (6aR,11aR)-3,8-dihydroxy-9-methoxypterocarpan (21, DMPC) displayed the most potent 100% preferential cytotoxicity (PC100) at the concentration of 12.5 μM.

Further study on the mode of cell death induced by DMPC against PANC-1 cells indicated that killing process was not accompanied by DNA fragmentation, rather through a nonapoptotic pathway accompanied by necrotic-type morphological changes.