Traditional medicinal knowledge and diversity of medicinal plants in Benin: a systematic review (2014–2023)

The richness of flora and traditional medical knowledge in the West African country Benin translate into the integral role of medicinal plants in local healthcare. This study explored the current status of traditional medicine research in Benin by evaluating data from ethnopharmacological and ethnobotanical surveys carried out between 2014 and 2023 and identifying knowledge gaps within the sustainable use of plant-based remedies. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol was used to guide the execution of the review. A total of 129 studies identified in scientific databases were analysed. The top 20 cited plant species were subjected to a comprehensive literature review to evaluate the experimental evidence to support the reported traditional uses. A total of 765 plant species belonging to 141 botanical families were cited in the included studies to treat various animal and human diseases, including infectious diseases, digestive disorders and metabolic diseases. Severe gaps in the documentation of plant collection practices, preparation stability, and preservation techniques were observed. Khaya senegalensis A.Juss. (41 citing studies), Parkia biglobosa (Jacq.) R.Br. ex G. Don (37 citing studies) and Ocimum gratissimum L. (33 citing studies) were the most frequently cited plants. Comparison of the scientific literature on the 20 most cited plant species revealed a lack of experimental evidence, even for the most frequent traditional uses. This study illustrated the wide spectrum of plant species applied in Beninese traditional medicine and the critical lack of experimental evidence for their traditional applications and the conservation of medicinal preparations. These findings underscore the need for sustainable harvesting practices, community-based conservation measures, and evidence-based use of plant resources to preserve biodiversity and support long-term availability. This calls for a national database, quality standards, and better integration of traditional medicine into modern healthcare.