Chemical Composition of Bee Pollen and Leishmanicidal Activity of Rhusflavone

Bee pollen monofloral from Attalea funifera Mart., Arecaceae, known as piaçava, was analyzed with ultra-performance liquid chromatography coupled with diode array detector and quadrupole time-of-flight mass spectrometry for the profiling and structural characterization of the replicated compounds. The principal compound was isolated and tested against Leishmania amazonensis . Fifty-eight compounds were identified, including one sugar, ten flavonoids, two putrescine derivatives, sixteen hydroxycinnamic acid amide derivatives, two coumarate derivatives, and twenty-seven lipids. The isolated compound identified as the biflavonoid rhusflavone showed high leishmanicidal activity against both promastigote (IC 50 = 5 μM) and amastigote (76.7% mortality at 2 μM) forms of L. amazonensis , acting via a mechanism involving reactive oxygen species production, mitochondrial dysfunction, and membrane disruption in parasites. The compound showed low toxicity to mammalian cells and human erythrocytes, with selectivity index for erythrocytes >100 and for macrophages (CC 50 macrophages /IC 50 amastigotes ) > 10. These results indicate that rhusflavone is a promising candidate for the development of drugs against L. amazonensis.