Antioxidant activities of three stingless bee propolis and green propolis types

Propolis is a bee product that results from the mixture of beeswax and resinous compounds. It can scavenge free radicals; therefore, it displays antioxidant activity. Here, we have investigated the antioxidant potential of propolis produced by three Brazilian stingless bee species: Melipona quadrifasciata anthidiodes (Mandacaia) and Tetragona clavipes (Bora), which inhabit the southeastern region of Brazil (state of Sao Paulo), and Scaptotrigona spp. (Tubi), which inhabits the northeastern region of Brazil (state of Maranhao). The antioxidant activities of propolis produced by different bee species were compared to the well-known antioxidant activity of green propolis, produced by the honey bee Apis mellifera. The ethanolic extract of propolis produced by Mandacaia displayed the strongest antioxidant activity. The activity was even stronger than the antioxidant activity of green propolis. The ethyl acetate and aqueous fraction of propolis produced by Mandacaia presented the highest antioxidant activity. This result agreed with the higher total polyphenol content verified in this propolis. high performance liquid chromatography analysis revealed that the groups of compounds present in propolis produced by Mandacaia, Tubi, and Bora were not the same as those previously identified as the main constituents of green propolis. In fact, propolis produced by Mandacaia contained many other polyphenols in the fingerprint, and hence its composition requires further elucidation.