Ethnomedicinal Knowledge of plants used in Alternative Medicine to treat Acnes in Lubumbashi (Democratic Republic of Congo)

Traditional medicine is a primary healthcare option for many Congolese, particularly in Lubumbashi, yet remains under-documented and underutilized. This study aims to systematically document medicinal plant use in acne management among Lubumbashi residents. Data were gathered via direct interviews with households (n=368), herbalists (n=8), and traditional healers (n=14), totaling 390 informants (sex ratio M/F = 0.6; mean age = 43.6 ± 5 years; mean experience = 14 ± 7 years). Respondents identified 27 medicinal plant species, predominantly trees (48%), spanning 38 botanical families, with Fabaceae as the most represented (20%). Diabetes (8 species) emerged as the most frequently reported condition aside from acne. A total of 39 traditional anti-acne formulations were recorded, primarily using leaves (>44%) and prepared as poultices (>41%). For the first time, this study reports the ethnobotanical use of 20 plant species for acne treatment, including Afzelia quanzensis (CRF = 0.17), Byrsonima verbascifolia (CRF = 0.11), and Uapaca sansibarica (CRF = 0.11), which had the highest citation frequencies. Afzelia quanzensis (UVp = 0.18) and Uapaca nitida (UVp = 0.18) exhibited the highest usual values (UVp). The therapeutic applications documented here serve as a foundational database for future research. Further studies should validate traditional acne treatments through pharmacological analyses while promoting conservation of these valuable species in the Congolese flora.