Antibacterial activity, phytochemical profiling and ADMET prediction of bioactive compounds in Origanum syriacum and Salix alba

Abstract

The ever-increasing global predicament of multidrug-resistant (MDR) infections necessitates the urgent discovery of novel antimicrobials, with medicinal plants representing a promising source of new therapeutic agents. This study investigated the antibacterial efficacy of Origanum syriacum and Salix alba organic and aqueous extracts against the investigated MDR pathogens using plant and bacterial samples sourced from Egypt, with findings expected to inform broader applications beyond this geographic origin. Antibacterial activity of the extracts was evaluated through agar-well diffusion, and MIC was assessed using broth microdilution assay, while the phytochemical composition of potent extracts (acetonic and ethanolic) was characterized using GC-MS analysis. Pharmacokinetic and toxicity profiles of the dominant bioactive compounds were in silico predicted employing ADMET modeling. The results demonstrated that organic extracts exhibited superior and broad-spectrum antibacterial activity compared to aqueous extracts. Notably, O. syriacum acetone extract showed potent effectiveness against MRSA. GC-MS analysis revealed that this efficacy strongly correlates with a high abundance of phenolic monoterpenes, primarily thymol (49.82% in acetone extract). In silico ADMET predictions further identified thymoquinone, eugenol, p-coumaric acid, and ferulic acid as lead compounds, demonstrating favorable drug-likeness, promising oral bioavailability, and manageable toxicological profiles. This integrated approach supports the ethnobotanical use of O. syriacum and S. alba extracts and identifies specific phytochemicals that merit further evaluation as potential therapeutic leads against recalcitrant MDR infections.