Supercritical fluid extracts of Moringa oleifera and their unsaturated fatty acid components inhibit biofilm formation by Staphylococcus aureus

Biofilm formation by Staphylococcus aureus plays a critical role in the persistence of chronic infections because of the ability of the bacterium in biofilms to tolerate antibiotics and host defenses. S. aureus produces hemolysin, which has been implicated in the pathogenesis of sepsis and pneumonia. Hence, the inhibitions of biofilm formation and/or toxin production by S. aureus are viewed as alternative means of addressing infections. In the present study, the antibiofilm activities of Moringa oleifera extracts were examined. Of the various solvent extraction methods examined, the supercritical carbon dioxide extracts of the leaves and seeds of M. oleifera were found to efficiently inhibit biofilm formation by S. aureus. Analyses of the extracts by GC-MS revealed the presences of palmitoleic acid, oleic acid, linoleic acid, linolenic acid, cis-11-eicosenoic acid, and cis-11,14-eicosadienoic acid at concentrations of 0.01% significantly inhibited S. aureus biofilm formation. In addition, supercritical fluid extract of the leaves of M. oleifera and its major component cis-11-eicosenoic acid significantly decreased the hemolysis of human red blood cells by S. aureus. These findings suggest supercritical carbon dioxide fluid extract of M. oleifera and its unsaturated fatty acids are potentially useful for controlling biofilm formation by and the virulence of S. aureus. (C) 2017 Elsevier Ltd. All rights reserved.