Antibacterial Activity and Mechanism of Action of 10-HDA Against Escherichia coli

10-HDA (10-hydroxy-2-decenoic acid), an unsaturated fatty acid, is the main active component of royal jelly. It has been demonstrated that 10-HDA possesses remarkable antibacterial activities. However, it is unclear in terms of the underlying antibacterial mechanism of 10-HDA. In our study, we showed that 10-HDA has obvious effects against Gram-negative bacteria and its antibacterial activity was not affected by pH and temperature. 10-HDA was shown to change membrane ionic conductivity and resulted in the leakage of K+, Ca2+, and Mg2+ from bacterial cells, suggesting that 10-HDA was able to compromise the integrity of the bacterial membranes. By detecting the 260 nm absorbing materials, it was showed that the membrane integrity was damaged and resulted in the leakage of large molecules. The results suggested that 10-HDA could damage the permeability and integrity of bacterial cell membrane, leading to the outflow of important large molecules from the cell and its eventual death.