2 research outputs found
Characterization and Potentiating Effects of the Ethanolic Extracts of the Red Seaweed <i>Gracillaria</i> sp. on the Activity of Carbenicillin against <i>Vibrios</i>
β-lactam-resistant Vibrio strains
are a
significant clinical problem, and β-lactamase inhibitors are
generally coadministered with β-lactam drugs to control drug-resistant
bacteria. Seaweed is a rich source of natural bioactive compounds;
however, their potential as β-lactamase inhibitors against bacterial
pathogens remains unknown. Herein, we evaluated the potential β-lactamase
inhibitory effect of the ethanolic extracts of the red seaweed Gracilaria sp. (GE) against four Vibrio strains. The minimum inhibitory concentration, half-maximal inhibitory
concentration, checkerboard assay results, and time-kill study results
indicate that GE has limited antibacterial activity but can potentiate
the activity of the β-lactam antibiotic carbenicillin against Vibrio parahemolyticus and V. cholerae. We overexpressed and purified recombinant metallo-β-lactamase,
VarG, from V. cholerae for in vitro studies and observed that adding GE reduced the
carbenicillin and nitrocefin degradation by VarG by 20% and 60%, respectively.
Angiotensin I-converting enzyme inhibition studies demonstrated that
GE did not inhibit VarG via metal chelation. Toxicity assays indicated
that GE exhibited mild toxicity against human cells. Through gas chromatography
and mass spectrometry, we showed that GE comprises alkaloids, phenolic
compounds, terpenoids, terpenes, and halogenated aromatic compounds.
This study revealed that extracts of the red seaweed Gracillaria sp. can potentially inhibit β-lactamase activity