Flavonoids isolated from Caribbean propolis show cytotoxic activity in human cancer cell lines.

Flavonoids are a heterogeneous group of polyphenolic compounds found ubiquitously in a wide variety of plants. Their chemical structure is based on 2-phenyl chromen, also known as flavan [1]. Flavonoids display a wide range of pharmacological properties, including antiinflammatory, antioxidative, antiviral, antibacterial and antiproliferative activities [1, 2]. Previous studies carried out by our group described the cytotoxic activity of mucronulatol, a flavonoid found originally in Indigofera sp. [3]. Here we describe for the first time diverse flavonoids, isolated from Caribbean propolis, which show high cytotoxic activitiy in various cancer cell lines.