Characterization and quality control of five essential oils according to the European Pharmacopeia and Antimicrobial activity

Essential oils, well-known for their many virtues, were already gaining attention for their potential health benefits before COVID-19, then, significantly rose during the pandemic. However, alarms regarding their safety use persist. Morocco, one of the leading countries producing essential oils and aromatic extracts, has a great tradition of distilling aromatic plants. Among the most popular essential oils on the market are Cinnamon, Eucalyptus Lavender, Lemon, and Tea tree. In the present study, we evaluated the potential antimicrobial activity of these five commercial essential oils against three well-known reference pathogens bacterial strains, using Disc-diffusion, Minimum inhibitory, and bactericidal concentrations tests. Subsequently, we investigated their chemical composition throughout the GC-MS. Furthermore, recognizing the potential risks associated with heavy metal contamination in essential oils, we examined the presence of (Cu, Pb, Zn, and Hg) in accordance with European Pharmacopoeia standards. Results indicated strong antimicrobial activity in all Essential oils except Lemon, with Cinnamon showing the highest efficacy. Major compounds identified were Cinnamaldehyde (82.26%), Eucalyptol (86.25%), Linalool, Linalyl isobutyrate (43.17% - 40.18%), Limonene (59.55%), and Terpinene-4-ol (40.28%). Heavy metal levels were low, meeting safety standards. In conclusion, this study highlights the safety and quality of five Moroccan essential oils, offering promising therapeutic applications.