A participatory science approach to ethnobotanical survey in Mayotte: supporting the integration of plants into the French pharmacopeia

Traditional medicine is widely practiced in Mayotte, yet it remains poorly documented scientifically. This work focused on four Mahoran medicinal plants: Coleus madagascariensis (Pers.) A.Chev., Leptadenia madagascariensis Decne., Ouret lanata (L.) Kuntze and Paullinia pinnata L. These species were selected based on their frequent citation and documented medicinal uses in a previous ethnobotanical survey, as well as their relevance to the French Pharmacopoeia. The aim was to assess whether participatory ethnobotanical surveys conducted by high school students could confirm and complement previous ethnobotanical data while contributing to the valorization of the Mahoran pharmacopoeia. Between May 2025 and April 2026, 169 high school students specializing in life and earth sciences from three schools in Mayotte were trained to conduct ethnobotanical interviews using standardized questionnaires. Participants were recruited by students from their family and social networks, yielding a purposive convenience sample; data were analyzed descriptively. Surveys documented traditional uses, plant parts used, preparation methods, dosages and treatment duration for the four species. A feedback phase, including restitution session and evaluation questionnaires, was also conducted with participating students. The surveys generated 364 use-reports across the four species, including 165 for C. madagascariensis (45.3%), 92 for O. lanata (25.3%), 55 for L. madagascariensis (15.1%) and 52 for P. pinnata (14.3%). Fifty distinct health conditions were reported, mainly digestive, respiratory and genital disorders. The surveys confirmed several previously documented uses and identified additional therapeutic indications, along with detailed preparation methods, dosages, treatment durations and administration frequencies. C. madagascariensis and O. lanata were frequently reported for both medicinal and food-related uses, and should be prioritized for their integration into the French Pharmacopeia. Feedback questionnaires indicated a self-reported increase in student’s awareness of medicinal plants, biodiversity, and traditional knowledge transmission despite some methodological difficulties linked to the short duration of the training. This study shows that participatory ethnobotanical surveys involving high school students can effectively complement existing knowledge on Mahoran medicinal plants and support their documentation for pharmacopoeial evaluation. This participatory approach also lays the groundwork for further pharmacological, toxicological and quality-control investigations needed for their future integration into the French Pharmacopoeia.