Anti-staphylococcal activity and antibiotic-modulating effect of Olax subscorpioidea, Piper guineense, Scorodophloeus zenkeri, Fagara leprieurii, and Monodora myristica against resistant phenotypes

Abstract

Background: The development of new drugs from plants seems to be an interesting alternative approach to overcoming microbial resistance. This study aims to investigate the anti-staphylococcal and antibiotic-potentiating activity of  methanolic extracts of five Cameroonian dietary plants namely Piper guineense, Fagara leprieurii, Olax subscorpioïdea, Monodora myristica and Scorodophloeus zenkeri against a panel of multidrug resistance (MDR) Staphylococcus aureus clinical isolates.

Methods: All antibacterial assays were done by broth microdilution method.

Results: Our results revealed that the studied extracts displayed antibacterial activities with minimal inhibitory concentration (MIC) values ranging from 256 to 2048 µg/mL.  Seeds extract of F. leprieurii (FLS) showed the most extensive antibacterial activity, with an inhibitory spectrum of 96% of the tested bacterial strains. The lowest MIC value of 256 µg/mL was obtained with extracts of Piper guineense seed (PGS) and Scorodophloeus zenkeri seeds (SZS) against S. aureus MRSA4 and SA68, respectively. Antibiotic-modulating effects against more than 70% of the S. aureus strains tested were obtained when Scorodophloeus zenkeri bark (SZB) and FLS (mostly at MIC/2) were combined with chloramphenicol, tetracycline and ceftriaxone.

Conclusions: The present study demonstrated that PGS, FLS, and SZS had anti-staphylococcal effects, and that, some studied extracts and mostly FLS, and SZB could be used as antibiotic resistance modulators to fight against resistant strains of staphylococcus aureus.