Abstract
Pseudomonas aeruginosa
is an opportunistic bacterium causing several health problems and having many virulence factors like biofilm formation on different surfaces. There is a significant need to develop new antimicrobials due to the spreading resistance to the commonly used antibiotics, partly attributed to biofilm formation. Consequently, this study aimed to investigate the anti-biofilm and anti-quorum sensing activities of
Dioon spinulosum,
Dyer Ex Eichler extract (DSE), against
Pseudomonas aeruginosa
clinical isolates. DSE exhibited a reduction in the biofilm formation by
P. aeruginosa
isolates both in vitro and in vivo rat models. It also resulted in a decrease in cell surface hydrophobicity and exopolysaccharide quantity of
P. aeruginosa
isolates. Both bright field and scanning electron microscopes provided evidence for the inhibiting ability of DSE on biofilm formation. Moreover, it reduced violacein production by
Chromobacterium violaceum
(ATCC 12,472). It decreased the relative expression of 4 quorum sensing genes (
las
I,
las
R,
rhl
I,
rhl
R) and the biofilm gene (
ndv
B) using qRT-PCR. Furthermore, DSE presented a cytotoxic activity with IC
50
of 4.36 ± 0.52 µg/ml against human skin fibroblast cell lines. For the first time, this study reports that DSE is a promising resource of anti-biofilm and anti-quorum sensing agents.