Managing sexually transmitted infections in Benin: An ethnopharmacology study among traditional medicine practitioners and in vitro activity evaluation of prioritized medicinal plants against Chlamydia trachomatis

Abstract Background Sexually transmitted infections (STIs) represent a significant health problem in low- and middle-income countries, where access to care is limited and antimicrobial resistance worsens therapeutic outcomes. Medicinal plants and traditional healing practices stand as accessible and culturally acceptable alternatives for STI management, but they remain poorly documented and lack scientific validation. To address this knowledge gap, the present study had two complementary objectives: to document the knowledge, attitudes and practices of traditional medicine practitioners (TMPs) regarding the management of STIs in Benin, and to evaluate in vitro the antichlamydial activity of the most frequently cited medicinal plants. Methods A cross-sectional interview survey was conducted among 48 TMPs originating from 10 departments of Benin, utilizing questionnaires completed with individual discussions with each participant from June to July 2024. Four most frequently cited medicinal plant species were subjected to plant material collection, aqueous and ethanolic extraction and cytotoxicity evaluation in HeLa-229 cells. The antichlamydial activity of the plant extracts was studied by determining Chlamydia trachomatis inclusion counts, genomic replication, infectious progeny production and elementary body (EB) infectivity. For data analysis, one-way ANOVA with Dunnett's post-hoc test was used. Results According to the interview data, the practitioners diagnose STIs through patient-reported symptoms and transmission route as well as their own clinical examination. While the participating TMPs expressed mixed views on collaboration with modern medicine, 71% of them stated guiding patients to formal healthcare in cases of treatment failure or severe symptoms. Regarding treatment practices, complementing medicinal plants with animal or mineral-derived preparations or spiritual rituals were reported by approximately half of the participants. A total of 63 plant species were cited for treating STIs by the survey participants. Ethanolic extracts of all experimentally evaluated plant material exhibited a dose-dependent inhibition of C. trachomatis growth, most notably Jatropha curcas (100–250 µg/ml, P = 0.001–0.002, η² = 0.799), alongside significant effects for Mangifera indica , Ocimum gratissimum and Phyllanthus amarus ( P = 0.005–0.045). Genomic replication was similarly reduced (η² = 0.775), as was infectious progeny production ( P = 0.001–0.031, η² = 0.851–0.942). M. indica extracts additionally suppressed EB infectivity (η² = 0.962), while aqueous extracts showed generally weaker but still significant effects (growth inhibition P = 0.001–0.009, infectious progeny inhibition 0.006–0.043). Conclusions Local traditional medicine resources may contribute to STI management in low-resource settings but require support to guide their evidence-based use. Our findings support the possible efficacy of ethnopharmacologically prioritized plants against C. trachomatis and highlight the need for further in vivo antimicrobial studies against STI pathogens. Graphical abstract, created by Biorender with organization licence