Antioxidant and Antibacterial Activities of Essential Oils from Three Moroccan Species (Lavandula mairei Humbert, Lavandula dentata L. and, Lavandula stoechas L.)

This study aimed to evaluate the antioxidant and the antibacterial activities of the essential oils from three Moroccan species of the genus Lavandula (Lavandula dentata L., Lavandula mairei Humbert and, Lavandula stoechas L.). The antibacterial activities were evaluated by the minimal inhibitory concentration (MIC) and the disc diffusion method, against Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Citrobacter koseri) and Gram-positive bacteria (Staphylococcus aureus). The antioxidant potential was evaluated using free radical Scavenging against 2,2-diphenyl-1-picrylhydrzyl (DPPH), ferric reducing activity power (FRAP), and total antioxidant capacity (TAC). The antibacterial activity of the essential oils showed higher activity against tested nosocomial bacteria especially against Klebsiella pneumoniae, Citrobacter koseri, and Staphylococcus aureus. The essential oil of Lavandula stoechas L. revealed the higher antioxidant activity as measured by DPPH (IC50 = 3,11 ± 0,13 mg/ml), FRAP (EC50 = 6,88 ± 0,8 mg/ml) and TAC (443,2 ± 38 mg AAE/g EO) assays. The essential oil of Moroccan Lavandula stoechas L. could have potential as antimicrobial compounds for the treatment of many infectious bacterial diseases, including multi-resistant bacterial strains of nosocomial origin.