The aim of this work is to investigate the protective efficacy of emodin, an active, naturallyoccurring
anthraquinone derivative of several traditional Chinese herbs, against Brucella
abortus infection in macrophages. Brucella were incubated with different concentrations of
emodin and showed that bacterial survival rates were markedly reduced in a dose-dependent
manner at increasing incubation time points. Through bacterial infection assay, the highest
non-cytotoxic concentration of emodin demonstrated attenuated invasion of Brucella into
macrophages, however it did not inhibit the growth of these pathogens within the host cells.
On the other hand, emodin effectively decreased the number of bacteria that adhered to host
cells, which indicated its potential as an anti-adhesin agent. Furthermore, using
immunoblotting and FACS assay for detecting MAPK signaling proteins and F-actin
polymerization, respectively, the results showed that the emodin-incubated cells displayed
modest reduction in the phosphorylation levels of ERK1/2 and inhibition of F-actin
polymerization as compared to control cells. These findings indicate the potential use of
emodin as a naturally-occurring alternative method for the prevention of animal brucellosis
although this requires confirmation of safe clinical doses.
Brucella abortus, emodin, antibacterial, invasion