Phytochemical Screening and Antibacterial Activity of the Aerial Parts of Origanum majorana L. (Lamiaceae)

This study explores the phytochemical composition and antibacterial activity of the methanolic extract obtained from the aerial parts of Origanum majorana L. (Lamiaceae), a plant commonly used in traditional medicine. Phytochemical screening highlighted the presence of several secondary metabolites, including polyphenols, flavonoids, tannins, coumarins, anthocyanins, and cardiotonic glycosides, while alkaloids, saponins, and anthraquinones were not detected. The antibacterial activity was evaluated using the agar diffusion method at decreasing extract concentrations. The extract showed a concentration-dependent inhibitory effect. A strong activity was observed against Staphylococcus aureus ATCC 25923 (inhibition zone > 28 mm) and methicillin-sensitive S. aureus (28.70 mm). Pseudomonas aeruginosa CIP showed high susceptibility at higher concentrations, whereas P. aeruginosa ATCC 27853 was resistant. Moderate inhibition was recorded for Escherichia coli MCR-1 (18.83–6 mm), E. coli ATCC 25922 (12.74–6 mm), and Bacillus cereus (16.53–4.75 mm). The results suggest that Origanum majorana exhibits notable antibacterial activity, particularly against Gram-positive bacteria, which could be related to its richness in bioactive compounds.