Investigation of antibacterial property and mode of action of medicinal plants against resistant pathogenic bacteria

Abstract

This project illustrates the antibacterial efficacy of crude aqueous infusions ofmedicinal plants against resistant pathogens including Methicillin-resistantStaphylococcus aureus (MRSA), Klebsiella pneumoniae, Acinetobacterbaumannii, Pseudomonas aeruginosa, and Escherichia coli. The plantinfusions of Rheum palmatum L., Arctium lappa L. and Paeonia suffructicosaAndr demonstrated the strongest anti-MRSA activity via multiple targets, withthe minimum inhibitory concentration (MIC) of 7.8 μg/mL. While strongantibacterial activity was exhibited by Sanguisorba officinalis L., Cyrtomiumfortunei J.Smith, Smilax china L. and Cornus officinalis Siebold & Zuccaqueous infusions against Gram negative resistant bacteria, with disruption ofthe bacteria membrane and interference with the intracellular structures bymultiple targets. A combination of plant infusions and antibiotics providedenhanced antibacterial activity of antibiotics, resulting in a significant decreasein antibiotic MIC, providing a potential path to restoring pathogen susceptibilityto antibiotics. Furthermore, both in vitro and in vivo toxicity tests have beenconducted on these plant infusions, indicating their safety profile. It can beconcluded from the results that multi-targeted action of aqueous crudemedicinal plant infusions contained synergistic phytochemicals effectivelyinhibits ESKAPE strains, which further suggested that medicinal plants couldpotentially be used to treat infectious diseases caused by resistant pathogensas a viable alternative to antibiotics, and could be an effective approach in thecontrol of antibiotic resistance in the near future.

Date of Award	Dec 2022
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Irene R. Grant (Supervisor) & Chen Situ (Supervisor)