Phytochemical and ethnobotanical investigation of 29 aromatic and medicinal plants from Dakhla-Oued Ed-Dahab region and their traditional uses

Phytochemical and ethnobotanical investigations were conducted in the Dakhla-Oued Ed-Dahab region of southwestern Morocco. The aim of the present study was to compile data on aromatic and medicinal plants traditionally used by the local population, mainly in phytotherapy to treat various diseases. Twenty-nine spontaneous species belonging to 20 families were collected and inventoried. Amaranthaceae represented 18% of the documented species, followed by Fabaceae with 14%. The most commonly used plant part was the leaves (53.85%) and the main preparation method was decoction (63.16%). In the studied region, plants were predominantly used to treat gastrointestinal disorders (25.71%), skin infections (20%), and diabetes (11.43%). Most of the plants exhibited strong antioxidant activity, particularly Limonium tuberculatum (Boiss.) Kuntze (IC50 = 14.43 μg/mL), followed by Rhus tripartita Moffet (IC50 = 15.35 μg/mL), Acacia raddiana Savi (fruit) (IC50 = 19.66 μg/mL), A. raddiana Savi (leaf) (IC50 = 18.03 μg/mL), Tamarix amplexicaulis Ehrenb. (IC50 = 20.89 μg/mL), Frankenia corymbosa Desf. (IC50 = 21.37 μg/mL), and Ziziphus lotus subsp. saharae (Batt. and Trab.) Maire (IC50 = 25.84 μg/mL). The total phenolic content varied from 3 to 476 μg of gallic acid equivalents (GAE) per gram of dry matter. R. tripartita Moffet extract had the highest total phenolic content (476 μg GAE/mg), succeeded by A. raddiana Savi (leaf) extract (317 μg GAE/mg). The total flavonoid content varied from 1.88 to 253.97 μg quercetin equivalents (QE)/mg of dry matter, with the maximum recorded for R. tripartita Moffet at 317 μg QE/mg. This study emphasizes the abundance of secondary metabolites, especially phenolic compounds, in the flora of the Dakhla-Oued Ed-Dahab region, highlighting the potential for future pharmaceutical applications.