In vitro antibacterial activity of medicinal plants against biofilm-forming methicillin-resistant Staphylococcus aureus: efficacy of Moringa stenopetala and Rosmarinus officinalis extracts

Abstract

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is slowly rising in Ethiopia for the past few decades. Therefore, novel classes of antibiotics are indispensable to combat the increased incidence of newly emerging multidrug-resistant bacteria like MRSA. Terrestrial flora is considered as a reservoir of novel bioactive secondary metabolites as they have provided us with the largest array of natural products. In this background, the present study is intended to evaluate the in-vitro antibacterial efficacy of five medicinal plants (Ocimum lamiifolium Hochst. ex Benth., Rosmarinus officinalis L, Catharanthus roseus Linn., Azadirachta indica A. Juss and Moringa stenopetala Bac) against a panel of seven biofilm-forming MRSA. The leaves of the plants were extracted in organic solvents of varying polarity and the resultant crude extracts of respective medicinal plants were inspected for their antimicrobial activity by well diffusion technique. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the plant extracts against MRSA were determined by the broth dilution method. Besides, an anti-biofilm assay of the most potent plant extract was also performed, after which its chemical constituents were delineated by combined Gas Chromatographic and Mass Spectroscopic profiling (GC-MS). The results revealed that, of the five plants, three species including M. stenopetala, R. officinalis, and O. lamifolium exhibited significant antibacterial activity. Organic solvents with high and medium polarity were excellent in extracting antimicrobials compared to nonpolar solvents. The broadest and highest rank of activity was observed in the crude ethanolic extract of M. stenopetala. Based on the MIC/MBC ratio, the crude ethanolic extract of M. stenopetala was determined to be bacteriostatic. Anti-biofilm assay showed that the extract of M. stenopetala fairly inhibited the growth of MRSA in the preformed biofilm matrix. The GC-MS analysis of M. stenopetala revealed the presence of twelve compounds with antimicrobial activity. The present study provides new insight into the development of novel drug leads to the management of MRSA.

In vitro Antibacterial and In silico Toxicity Properties of Phytocompounds from Ricinus communis Leaf Extract

“…The promising antibacterial activities observed by the methanol extract in could be due to the variation in the number of antibacterial constituents in the extract because of the polarity of methanol and solubility of the compounds in it in comparison to other solvents. 30 Similar findings were observed other studies. 31,32 The promising results demonstrated by the methanolic extract prompted us to evaluate its MIC and MBC using microdillition method.…”

Antibacterial Activity of Rosmarinus officinalis against Multidrug-Resistant Clinical Isolates and Meat-Borne Pathogens

“…AMP11) was done from the local markets of Arba Minch town, Gamo Gofa zone of Ethiopia. The plant specimen was botanically authenticated as previously indicated [ 15 ]. It was identified to the genus and species level with the aid of an eminent plant taxonomist (Dr. Remesh Moochikkal, Jazan University, Kingdom of Saudi Arabia).…”

“…In addition, the leaves of this plant find frequent application as a flavouring agent in local traditional meat dishes both cooked and raw. Results obtained from our previous study showed that the EtOH extract of R. officinalis has anti-methicillin resistant S. auerus activity [ 15 ]. To acquire more relevant data related to its antimicrobial activity, further comprehensive evaluations are imperative.…”

Anticancer potential of methanolic extracts from Pleurotus species on raji cells and antibacterial activity against Methicillin-Resistant Staphylococcus aureus

“…The MIC was determined as the lowest concentration of extract that completely inhibited the growth of the MRSA detected by the unaided eye (Valle et al 2015). MBC was defined as the concentration which exhibits zero growth of the colonies compared to the culture of the initial inoculum of the same strain (Manilal et al 2020;Prastiyanto et al 2020b). The Wells were subcultured using a 10 µL inoculating loop on to a BAP at (35 ± 2) o C for 16-20 h incubation.…”