Chemical characterization, antibacterial and antifungal activity of honey pots and pollen pots obtained from the stingless bee Tetragonisca angustula (Latreille, 1811)

Abstract

This study aimed to determine the chemical composition of the ethanolic extracts of honey pots (EEHPTa) and pollen pots (EEPPTa) from the stingless bee Tetragonisca angustula, as well as to evaluate their antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Candida tropicalis. The chemical composition was determined using HPLC-Q-TOF-MS/MS and HPLC-DAD, while antimicrobial assays were performed using the broth microdilution method. Eleven compounds were identified in EEHPTa and nine in EEPPTa, including cirsimaritin, 3ʹ-prenylnaringenin, xanthohumol, lespedezaflavanone B, and 19α-hydroxyursolic acid. The extracts enhanced the action of norfloxacin against S. aureus (MIC reduced from 256 to 128 μg/mL). With gentamicin, EEHPTa reduced the MIC from 17.95 to 11.31 μg/mL, while EEPPTa reduced it to 12.69 μg/mL. Only EEHPTa was effective with ampicillin, reducing the MIC from 71.83 to 31.7 μg/mL. Against P. aeruginosa, EEHPTa decreased the MIC of gentamicin from 8 to 4 μg/mL, whereas EEPPTa exhibited an antagonistic effect. For E. coli, only EEPPTa reduced the MIC from 64 to 57.01 μg/mL. EEHPTa exhibited lower IC₅₀ values against yeast (C. albicans: 65.47 μg/mL; C. tropicalis: 29.79 μg/mL) compared to EEPPTa (C. albicans: 820.7 μg/mL; C. tropicalis: 809.9 μg/mL). Both extracts enhanced the effect of fluconazole against C. albicans but showed no effect on the C. tropicalis strain. These findings highlight the therapeutic potential of the secondary metabolites in these extracts, reinforcing their importance in the development of new antimicrobial and antifungal strategies.