Annona glabra Flavonoids Act As Antimicrobials by Binding to Pseudomonas aeruginosa Cell Walls

Abstract

Pseudomonas aeruginosa is an important pathogen in opportunistic infections in humans. The increased incidence of antimicrobial-resistant P. aeruginosa isolates has highlighted the need for novel and more potent therapies against this microorganism. Annona glabra is known for presenting different compounds with diverse biological activities, such as anti-tumor and immunomodulatory activities. Although other species of the family display antimicrobial actions, this has not yet been reported for A. glabra. Here, we investigated the antimicrobial activity of the ethyl acetate fraction (EAF) obtained from the leaf hydroalcoholic extract of A. glabra. EAF was bactericidal against different strains of P. aeruginosa. EAF also presented with a time- and concentration-dependent effect on P. aeruginosa viability. Testing of different EAF sub-fractions showed that the sub-fraction 32-33 (SF32-33) was the most effective against P. aeruginosa. Analysis of the chemical constituents of SF32-33 demonstrated a high content of flavonoids. Incubation of this active sub-fraction with P. aeruginosa ATCC 27983 triggered an endothermic reaction, which was accompanied by an increased electric charge, suggesting a high binding of SF32-33 compounds to bacterial cell walls. Collectively, our results suggest that A. glabra-derived compounds, especially flavonoids, may be useful for treating infections caused by P. aeruginosa.

Phytochemical Profiling of Lavandula coronopifolia Poir. Aerial Parts Extract and Its Larvicidal, Antibacterial, and Antibiofilm Activity Against Pseudomonas aeruginosa

“…The extract inhibited the biofilm formation of P. aeruginosa in a dose-dependent manner and ranged from 17 to 38% ( Figure 5 ). These considerable antibiofilm properties are similar to that of polyphenol-rich extract from the bark of Salix tetrasperma and the leaves of Annona glabra and Gynura procumbens [ 54 , 55 , 56 ]. A recent study by Koely et al described the antibiofilm activities of Enydra fluctuans against P. aeruginosa .…”

Potencial antibacteriano (in vitro) do extrato metanólico da Annona muricata L.

“…Embora as bactérias Gram-negativas serem mais resistentes, foi observado halos de inibição contra a cepa de P. aeruginosa, descrito anteriormente (Tabela 1). Esse resultado se assemelha com os resultados encontrado no trabalho de Galvão, et al (2016), o qual realizou testes como a Annona glabra onde foi comprovada a atividade antibacteriana frente a cepa de P. aeruginosa. Essa ação antibacteriana foi relacionada aos flavonoides.…”

Evaluation of the interaction between polymyxin B and Pseudomonas aeruginosa biofilm and planktonic cells: reactive oxygen species induction and zeta potential

“…The time-kill curve assays for planktonic cells were performed as described previously [41] with modifications. Bacterial inoculum prepared to achieve a final concentration of 5.0 × 10 5 CFU/mL were treated with polymyxin B were prepared cation-adjusted Mueller-Hinton broth and added to the wells.…”