Potential Toxicity of Medicinal Plants Inventoried in Northeastern Morocco: An Ethnobotanical Approach

Herbal medicine and its therapeutic applications are widely practiced in northeastern Morocco, and people are knowledgeable about it. Nonetheless, there is a significant knowledge gap regarding their safety. In this study, we reveal the toxic and potential toxic species used as medicines by people in northeastern Morocco in order to compile and document indigenous knowledge of those herbs. Structured and semi-structured interviews were used to collect data, and simple random sampling was used as a sampling technique. Based on this information, species were collected, identified, and herbarium sheets were created. The collected data were analyzed using two quantitative indices: informant consensus factor (ICF) and fidelity level (Fl), as the degree of these indices give an insight into the level of toxicity of a given plant. The results revealed the knowledge of 55 species belonging to 36 families. The most represented families were Apiaceae, Asteraceae, Solanaceae, and Fabaceae. Furthermore, the majority of the species cited were herbs (67%), and the most common toxic parts were seeds, followed by leaves and roots. According to the informant consensus factor, death (0.81%) had the highest agreement, followed by the urological (0.76%) and skin (0.75%) categories. The most significant plants in terms of fidelity level were Solanum sodomaeum L. and Nerium oleander L. for death, Arisarum vulgare O. Targ. Tozz., Mentha spicata L., and Morus alba L. for the digestive category, Petroselinum crispum (Mill.) Fuss. and Citrus x aurantium L. for cardiovascular category, Urtica dioica L. for skin category, Datura stramonium L, and Ephedra altissima Desf. for neurological category, and finally Crocus sativus L. for general and unspecified category. This work highlights a valuable traditional knowledge of poisonous and potential poisonous plants in northeastern Morocco. Further phytochemical and toxicological research is needed to determine the safety of these prized herbs.