Lemon Grass Essential Oil Does not Modulate Cancer Cells Multidrug Resistance by Citral-Its Dominant and Strongly...

Area of Science:

• Natural Products Chemistry
• Pharmacology
• Microbiology

Background:

• Lemongrass essential oil (Cymbopogon) is known for its antimicrobial properties, with citral identified as a dominant component.
• Citral is recognized for its biological activities, prompting investigation into its role within the essential oil.

Purpose of the Study:

• To compare the antimicrobial and anticancer activities of lemongrass essential oil and isolated citral.
• To investigate the synergistic or antagonistic effects of other compounds in lemongrass essential oil.
• To explore the potential of lemongrass essential oil in overcoming drug resistance.

Main Methods:

• Lemongrass essential oil extraction via vacuum distillation.
• Citral content analysis using gas chromatography/high-resolution mass spectrometry (GC-HRMS).
• Antimicrobial activity assessment using broth dilution method.
• Biofilm inhibition and disruption assays for Pseudomonas aeruginosa and Staphylococcus aureus.
• Drug-sensitization assays for methicillin-resistant Staphylococcus aureus (MRSA) and doxorubicin-resistant ovarian carcinoma cells.

Main Results:

• Lemongrass essential oil yielded 0.5% with 63% citral content.
• Both citral and lemongrass essential oil exhibited strong antimicrobial activity against tested bacteria and fungi.
• Citral demonstrated significantly higher antimicrobial and biofilm prevention activity compared to the essential oil.
• Lemongrass essential oil, but not citral alone, sensitized MRSA and ovarian carcinoma cells to antibiotics and chemotherapy drugs, potentially via P-glycoprotein efflux pump inhibition.

Conclusions:

• While citral is a potent antimicrobial agent, the complex mixture in lemongrass essential oil offers unique benefits, including overcoming multidrug resistance.
• The non-citral components in lemongrass essential oil may play a crucial role in its overall biological effects.
• Direct application of lemongrass essential oil may be more advantageous than using it solely as a source for citral isolation, particularly for combating resistant pathogens and cancer cells.