Evaluation of urease inhibition activity of zerumbone in vitro

A key virulence factor for urinary tract pathogens is the enzyme urease, which catalyzes the hydrolysis of urea into ammonium ions and carbonic acid. Urease activity plays an important role in the pathogenesis of urinary tract infection. In this study, the inhibitory effect of zerumbone against six urease-producing bacteria (Klebsiella oxytoca, K. pneumoniae, Morganella morganii, Proteus mirabilis, P. vulgaris, and Staphylococcus saprophyticus) and their urease activities were evaluated. The results of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests showed that zerumbone had antibacterial effect against these six urease-producing bacteria. The MIC and MBC of zerumbone ranged from 0.5 to 2 mM and 1 to 4 mM, respectively. In the urease inhibitory assay, zerumbone showed better urease inhibition (56.28 ± 2.45−37.83 ± 3.47%) than the standard urease inhibitor, acetohydroxamic acid (40.46 ± 1.94 – 22.99 ± 3.53%). However, zerumbone did not affect the levels of the urease subunit. These results clearly indicated that zerumbone has antibacterial potential against urease-producing bacteria and possesses excellent bacterial urease inhibition properties.