Medicinal Plant Diversity and Traditional Knowledge Among Ethnic Groups in Burkina Faso Central-West Region
Introduction Medicinal plants constitute a cornerstone of traditional healthcare systems globally, particularly in developing countries where access to modern medical services remains limited [1]. In sub-Saharan Africa, approximately 80% of rural populations continue to rely on plant-based resources for disease prevention and treatment [2] [3]. Beyond their therapeutic value, these plants represent a significant component of cultural heritage, transmitted orally across generations [4]. In Burkina Faso, traditional medicine is largely grounded in the use of a diverse array of medicinal plant species [5]. However, anthropogenic pressures, deforestation, declining plant biodiversity, and the globalization of lifestyles are accelerating the erosion of this ancestral knowledge [6] [7]. In this context, the documentation and valorization of local ethnobotanical knowledge are critical for both the conservation of medicinal plant species and the intergenerational transmission of traditional practices [8]. The Central-West region of Burkina Faso, characterized by rich floristic diversity and a long-standing tradition of medicinal plant use, remains insufficiently studied from an ethnobotanical perspective [9]. Recording the species employed and the associated knowledge is essential not only for biodiversity conservation but also for supporting the integration of traditional pharmacopoeia into local healthcare strategies [1] [3]. This study aims to inventory the medicinal plant species used in the Central-West region of Burkina Faso and to analyze the diversity and therapeutic applications of these taxa. Materials and Methods Study Area and Surveyed Population The survey was conducted in 30 villages located within the Boulkiemdé and Sanguié provinces, in the Central-West region of Burkina Faso (Figure 1). These sites were selected based on criteria such as accessibility, ethnic diversity, and their recognized role in the transmission of traditional knowledge related to medicinal plant use. The participants included a wide range of individuals, primarily traditional healers, herbalists, folk medicine practitioners, and elderly persons acknowledged for their expertise in traditional pharmacopoeia. Data Collection Data were collected using three complementary methods: semi-structured interviews, direct observations, and botanical specimen collection. Semi-structured interviews were conducted with traditional healers, herbalists, and other local knowledge holders. An interview guide was used to gather information on the medicinal plant species used, plant parts utilized, preparation methods, treated ailments, and conservation practices. Direct observations were carried out at collection sites, in local markets, and within households to document actual practices related to the use and management of medicinal plants. Specimen collection was conducted with the assistance of informants. Plant samples were harvested, pressed, and transported to the laboratory for identification. The identification process was based on regional floras and standard reference works [10] [11]. Data Analysis Statistical Analysis All statistical and graphical analyses were performed using RStudio version 4.5.1, according to the requirements for processing, structuring, and visualizing the ethnobotanical survey data. Absolute and relative frequencies were calculated to describe the socio-demographic characteristics of the respondents. The Use Value (UV) of each plant species was computed following the formula proposed by [12]: Ui represents the number of use reports mentioned by informant i, and N is the total number of informants. This index serves to assess the relative importance of a plant species within traditional medicinal practices. In addition, the Relative Frequency of Citation (RFC) was calculated to measure the proportion of informants who cited each species, using the formula: FC is the number of citations for a given species, and N is the total number of participants. To explore the diversity of dosage types and administration times associated with the therapeutic uses of plants, heatmaps were generated based on binary or frequency-weighted occurrence matrices. Finally, the integrated structure of traditional therapeutic knowledge was visualized using a circular network diagram (chord diagram), linking plant species, ethnic groups, preparation methods, and types of treated ailments. This graphical representation illustrates the density of interconnections within the traditional medicinal system and highlights the central species in the network of ethnomedical knowledge. Results Socio-demographic Characteristics of Respondents Data analysis highlights two key aspects of the respondents’ profiles: age and educational level. Regarding age distribution, the majority of participants, representing 67%, were aged 50 years and above, while 33% were under 50 years. This demographic structure indicates a strong representation of elderly individuals within the sample. Concerning educational attainment, a large proportion of respondents (72.1%) had no formal schooling. Only 18.9% reached the primary education level, and 9% attained secondary education. This low level of education reflects a generally limited educational context among the majority of participants (Table 1). Use Value of the Studied Plant Species The most utilized species is Euphorbia hirta, which recorded the highest use value (UV = 0.737). This high score reflects both a significant frequency of use and a notable diversity of applications reported by informants. A group of species exhibited intermediate use values, with a UV of 0.368. These include Ximenia americana, Vitex cuneata, Spondias mombin, Detarium microcarpum, and Acacia macrostachya. These plants are also well established in the local pharmacopoeia, suggesting their recognized utility in traditional practices. Other species fall within a moderate use value category, with UVs ranging from 0.274 to 0.342. Among these are Guiera senegalensis, Combretum paniculatum, Diospyros mespiliformis, Terminalia avicennioides, and Nauclea latifolia. Finally, the least cited species are Gardenia erubescens, with a UV of 0.221, and Piliostigma thonningii, which has the lowest use value in the studied panel (UV = 0.132), indicating a lesser importance in the reported medicinal uses (Figure 2). Relative Frequency of Citation (RFC) of the Studied Species The graph presents the relative frequency of citation (RFC) of various medicinal plant species, an indicator measuring the importance and frequency of use of each plant within traditional medicine practices. Euphorbia hirta is the most cited species with an RFC of 0.15. This high value reflects its central importance in ethnobotanical knowledge and suggests widespread use in treating diverse ailments. Diospyros mespiliformis ranks second with an RFC of 0.10, also indicating significant recognition in local medicinal applications. A group of ten species shows intermediate RFC values, each around 0.07. These include Ximenia americana, Vitex cuneata, Spondias mombin, Detarium microcarpum, Acacia macrostachya, Terminalia avicennioides, Nauclea latifolia, Guiera senegalensis, … Read more