Ethnopharmacological Study, Phytochemical Quality and Antibacterial Activity of the Essential Oils of Chenopodium ambrosioides, Eucalyptus camaldulensis and Origanum majorana from Taounate Region (Morocco)

Abstract

This study aims to collect the traditional uses of three medicinal plants, Chenopodium ambrosioïdes, Eucalyptus camaldulensis and Origanum majorana, in Taounate region of Morocco and to evaluate the phytochemistry and antimicrobial activity of their essential oils. The ethnobotanical survey showed that Eucalyptus camaldulensis is used to treat respiratory ailments (27%), followed by osteo-articular troubles (24%), neurological diseases (22%), genitourinary and also digestive tract ailments (11% for each), while only 2% use it against dermatological problems. Origanum majorana was recommended for cardiovascular diseases (31%), neurological diseases (25%), digestive tract diseases (25%) and genitourinary infections (14%), as well as metabolic troubles (5%). While Chenopodium ambrosioides is mainly consumed to treat neurological diseases (37%), digestive diseases (35%) and skin conditions (20%). After hydrodistillation, the essential oils were analyzed by gas chromatography and mass-spectrometry (GC/MS). The main component of Chenopodium ambrosioides essential oil is α-terpinene (80.74%). For Eucalyptus camaldulensis essential oil, 1,8-cineole (34.16%) and (-)-spathulenol (21.21%) are the main compounds. As for Origanum majorana essential oil, terpinene-4-ol (39.80%), α-phellandrene (15.15%) and carene (12.06%) represent the major components. The antibacterial activity of these essential oils indicates a stronger inhibitory effect on Gram-positive strains than Gram-negative strains; with minimum inhibitory concentrations varying between 5-40 μL/mL.