Anti-infective potential of caffeic acid and epicatechin 3-gallate isolated from methanol extract of Euphorbia hirta (L.) against Pseudomonas aeruginosa

Abstract

Euphorbia hirta (L.) plant is traditionally used in Malaysia for the treatment of gastrointestinal, bronchial and respiratory ailments caused by nosocomial infectious agents. Bioactivity-guided fractionation of the methanol extract of the aerial parts of E. hirta and analysis using high-performance liquid chromatography have led to the isolation of two antibacterial compounds. These compounds were identified as caffeic acid (CA) and (–)-epicatechin 3-gallate (ECG) based on spectroscopic analyses and comparison with previously published data. Using broth microdilution method, both ECG and CA had demonstrated significant minimum inhibitory concentration of 15.6  and 31.3 μg/mL respectively, against Pseudomonas aeruginosa. Time-kill assessment of ECG and CA displayed bactericidal effect on P. aeruginosa cells.

Keywords::

• Euphorbia hirta (L.); Pseudomonas aeruginosa
• antibacterial activity
• epicatechin 3-gallate
• caffeic acid

Funding

This project was funded by the E-Science Fund [305/PFARMASI/613223], the Ministry of Science, Technology and Innovation (MOSTI) and the Short-Term Research Grant [304/PFARMASI/6312024], Universiti Sains Malaysia. The first author acknowledges MyBrain15 (Ministry of Education, Malaysia) for providing scholarship.