Mechanism of Action of Isolated Caffeic Acid and Epicatechin 3-gallate from Euphorbia hirta against Pseudomonas aeruginosa

Background: The escalating dominance of resistant Pseudomonas aeruginosa strains as infectious pathogen had urged the researchers to look for alternative and complementary drugs. Objective: The objective of this study is to address the biological targets and probable mechanisms of action underlying the potent antibacterial effect of the isolated compounds from Euphorbia hirta (L.) against P aeruginosa. Materials and Methods: The action mechanisms of caffeic acid (CA) and epicatechin 3-gallate (ECG) on P aeruginosa cells were investigated by several bacterial physiological manifestations involving outer membrane permeabilization, intracellular potassium ion efflux, and nucleotide leakage. Results: The findings revealed that ECG and CA targeted both cell wall and cytoplasmic membrane of P aeruginosa. The cellular membrane destruction and ensuing membrane permeability perturbation of P aeruginosa had led to the ascending access of hydrophobic antibiotics, release of potassium ions, and leakages of nucleotides. Conclusion: The overall study concludes that ECG and CA isolated from E. hirta possess remarkable anti-infective potentials which can be exploited as drug template for the development of new antibacterial agent against resistant P aeruginosa pathogen.