Determination of the Phenolic Profile, and Evaluation of Biological Activities of Hydroethanolic Extract from Aerial Parts of Origanum compactum from Morocco

Abstract

Origanum compactum belonging to the family Lamiaceae is widely used in food and pharmaceutical fields due to its biologically active substances. We aimed to investigate the total phenol and flavonoid contents and the phenolic composition, and to evaluate the antioxidant and antibacterial properties of hydroethanolic extract from of Origanum compactum. Total phenol and flavonoid contents were evaluated using gallic acid and quercetin as standards, respectively, and the phenolic profile was characterized using high-performance liquid chromatography coupled to a photodiode array and electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). The antioxidant activity was determined by two methods: ferric reducing power (FRAP) assay and the phosphomolybdate method. The antibacterial effect was evaluated against four bacteria (Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes) using the broth microdilution method. The findings show that the total phenolic and flavonoid contents were 107.789 ± 5.39 mg GAE/g dm and 14,977 ± 0.79 mg QE/g dm, respectively. A total of sixteen phenolic compounds belonging to phenolic acids and flavonoids were detected. Furthermore, the extract showed strong antioxidant activity, and displayed a bacteriostatic effect against Escherichia coli and Salmonella typhimuriumn, and a bactericidal effect against Staphylococcus aureus and Listeria monocytogenes. Therefore, this study reveals that Origanum compactum extracts display potential as antibacterial and natural antioxidant agents for fighting against pathogenic bacteria and preventing oxidative stress.