Indigenous knowledge of the use of medicinal plants in the North-West of Morocco and their biological activities

Introduction This study is the first ethnopharmacological survey that investigates the traditional uses of medicinal plants in the province of Ouezzane (North-West of Morocco) as well as the indigenous knowledge related to the use of this natural resource in healthcare by the local population in order to preserve and protect this invaluable inheritance. We aimed also to reveal the in vitro pharmacological activities of some reported medicinal plants in this study. Methods In the survey, 113 informants (local inhabitants and herbalists) were interviewed using the semistructured and unstructured methods and using a stratified sampling technique. Data collected were analyzed calculating three quantitative parameters: Use Value (UV), Fidelity Level (FL) and Informant Consensus Factor (ICF). Pharmacological properties of some reported medicinal plants were evaluated. The antioxidant activity was estimated by the DPPH radical scavenging assay and the antibacterial activity was evaluated using agar well diffusion assay and microtitration method. Results The results showed that 11% of the local population use traditional medicine, against 67% who use both traditional and modern medicine. The ethnomedicinal uses of 44 medicinal species representing 28 families were reported on. Lamiaceae were the most representative and include 32% of the identified species. The medicinal use revealed that leaves are the most used part of plants to prepare drugs, the decoction is the most widely used preparation method and remedies are often administered orally. The highest value of MUV was obtained for Origanum compactum Benth. (MUV = 0.62) and Myrtus communis L. (MUV = 0.52). In addition, In addition, the highest value of FL was recorded for Origanum compactum Benth. (100%), Myrtus communis L. (93.50%) and Arbutus unedo L. (93.50%). While, while the highest value of ICF was mentioned for respiratory system diseases (ICF = 0.69), dermocosmetology (ICF = 0.68), digestive system problems (ICF = 0.63) and nervous system disorders (ICF = 0.69). Plant extracts and essential oils showed important antibacterial properties against pathogenic strains and significant antioxidant capacities. Conclusions The ethnopharmacological data documented in this work revealed the use of medicinal plants in North-West of Morocco to fight against diseases. Therefore, efforts are needed for improving the level of the documentation, the conservation and standardisation of these species, and to preserve the transmission of traditional healing knowledge. Also, further studies testing other plant extracts in other pharmacological systems are needed to explore the scientific biological potential of these plants.