Antibacterial activities and bioactive compounds of the ethyl acetate extract of the sea cucumber Holothuria forskali from Tunisian coasts

Previous scientific studies have listed chemical compounds from sea cucumber species. The ability to produce bioactive metabolites derives from their response to various ecological stresses and avoidance of predation. In view of this, the present work aimed to evaluate the antibacterial activity and quantitatively assess the active components of different organs of the sea cucumber Holothuria foskali collected from the north-east of Tunisia. The antibacterial activity of ethyl acetate extracts was tested against Bacillus subtilis, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. It was revealed that Escherichia coli and Bacillus subtilis were inhibited by the sea cucumber extracts. To identify the composition of these extracts, Gas Chromatography-Mass Spectroscopy (GC-MS) and Liquid Chromatography-Mass Spectroscopy (LC-MS) methods were used. The GC-MS revealed the presence of 25 major components, the most concentrated ones were characterized as C26H27N5O6 Morphinan-4,5-epoxy-3,6-diol, 6 amino;C17H31F3O2 3-trifluoroacetoxypentadecane; C31H50O2 Stigmasta-5,22-dien-3-ol,acetate; C11H14O2 1-Phthalanol,1,3,3-trimethyl 1-phenyl; C30H48O2 Ergosta-5,22-dien-3-ol,acetate and C25H40O2 (9E)-8-Phenyl-9-octadecenoic acid methyl ester; while the LC-MS revealed the presence of eight molecules, identified as phenolic acid, phytosterol and fat-soluble vitamins. Some molecules are interesting and deserve to be explored for their potential uses as ingredients in functional foods or as raw materials for new drug forms.