Composition and antioxidant activity of propolis from three species of Scaptotrigona stingless bees
Alexandra Christine Helena Frankland Sawaya, Juliana Cristina Pereira Calado, Letícia Cavalcanti dos Santos, Maria Cristina Marcucci, Ivan Paulo Akatsu, Ademilson Espencer Egea Soares, Patrícia Verardi Abdelnur, Ildenize Barbosa da Silva Cunha, Marcos Nogueira Eberlin
Propolis is a resinous substance collected by bees from various plant sources; therefore, its composition depends on the season, the species of bee, vegetation and the area of collection. This study compared samples of propolis collected monthly from three species of Scaptotrigona bees from two distinct regions in Brazil. Ethanol extracts of the propolis samples were prepared and evaluated for their antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl free radical scavenging method (DPPH). The composition of the extracts was evaluated by Electrospray Ionization - Mass Spectrometry (ESI-MS) fingerprinting and the results were compared by Principal Component Analysis (PCA). Differences in the composition of samples from different species were observed as well as monthly variations within each species. Antioxidant activity also varied monthly for each species, with the highest activity (lowest ED50 results) observed in the spring. Seasonality and geographic origin affected the composition and antioxidant activity of Scaptotrigona bee propolis.