Speaker
Description
Philipina Acheampong¹, Michael Konney Laryea¹, and Lawrence Sheringham Borquaye¹,²
¹Department of Chemistry, Kwame Nkrumah University of Science and Technology (KNUST), Ghana
²Central Laboratory, Kwame Nkrumah University of Science and Technology (KNUST), Ghana
Email: philipinacheampong32@gmail.com
Antimicrobial resistance (AMR) remains a critical global health challenge, largely driven by multidrug-resistant ESKAPE pathogens (E. faecium, S. aureus, K. pneumoniae, A. baumannii, P. aeruginosa, and Enterobacter spp.). In Ghana, AMR-related infections accounted for an estimated 4.95 million deaths in 2019. With decreasing efficacy of current antibiotics, antivirulence strategies such as quorum sensing (QS) and efflux pump inhibition offer promising alternatives that reduce pathogenicity without exerting strong selective pressure. Salacia debilis, a medicinal shrub from the Celastraceae family, is traditionally used to treat malaria. SD-03 (Benzyl 2-methoxybenzoate), SD-04 (1,10-dihydroxy-6H-benzo[c]chromen-6-one), and SD-05 (2,4-dimethoxy-8-methyldibenzo[b,d]furan-1-carboxylic acid) previously isolated from S. debilis, have shown moderate antimalarial and antimicrobial activity. However, there is no information on their QS and efflux pump inhibitory activities. This study, thus investigates the QS and efflux pump inhibitory activities of S. debilis extracts and compounds, using molecular docking and molecular dynamics simulations to identify potential protein targets. Crude and ethyl acetate extracts inhibited the growth of S. aureus and P. aeruginosa with minimum inhibitory concentrations ranging from 6.25 to 25.00 mg/ml. Molecular docking revealed strong interactions between SD-03, SD-04, and SD-05 with key QS proteins (LasR, RhlR, PqsR) and the NorA efflux pump protein. LasR binding affinities were -9.8, -10.4, and -6.6 kcal/mol, respectively. These preliminary results suggest that S. debilis compounds may have antivirulence potential by targeting QS and efflux mechanisms. Further in vitro and in silico studies are needed to confirm these effects and explore their mechanisms of action.
Keywords: Salacia debilis; antimicrobial resistance; ESKAPE pathogens; antivirulence; quorum sensing; efflux pump; molecular docking.