An Investigation into the Antibacterial Properties of Citrus and Plant Essential Oils

Abstract

Langmuir Monolayers of dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG), and E.coli lipid extract were used to investigate the antibacterial properties of essential oils, in particular sweet orange oil. DPPC served as the control membrane while DPPG served as the gram positive bacteria model and E.coli lipid extract was the gram negative bacteria model. The Langmuir Monolayer technique is useful for forming model cell membranes and allows for the analysis of the interactions between phospholipids and their molecular organization in the presence of another molecule. The main chemical in sweet orange oil, limonene, was found to disrupt phospholipid‐phospholipid interactions in all models except for DPPG simply because PG headgroups hydrogen bond with each other and there is no space for the hydrophobic limonene molecule. The largest disruption was observed for the E.coli extract lipids due to the unsaturated tails in these lipids resulting in less tight packing. Monolayers were seen in all three membrane systems to be destabilized as evidenced by the decrease in collapse pressure of the monolayer film but the E.coli lipid extract monolayer was the most affected in terms of fluidity as seen by the compression modulus. The antibacterial effects of orange oil on these systems is currently being compared to that of peppermint oil.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.