Herbal medicine among vulnerable populations in Cameroon: a systematic review and meta-analysis with clinical, mechanistic, and global health perspectives.

ETHNOPHARMACOLOGICAL RELEVANCE: Herbal medicine (HM) is widely used in Cameroon, yet its prevalence, clinical evidence, and the pharmacological mechanisms supporting its use among vulnerable populations have not been comprehensively synthesised. AIM OF THE STUDY: To systematically review and meta-analyse HM use among women, adolescents, and children in Cameroon, summarise the available clinical and mechanistic evidence for commonly reported medicinal plants, and identify challenges relevant to policy and global health. MATERIALS AND METHODS: Following PRISMA guidelines, multiple databases were systematically searched. Random-effects meta-analysis was performed to estimate the pooled HM proportion. Also, a PubMed search for clinical evidence (randomised controlled trials, RCTs) and bioactive compounds/mechanistic insights was conducted to support the folkloric use of the identified plants. RESULTS: Sixteen studies involving ∼15,000 individuals were included. The pooled proportion of HM use was 46.9% (95% CI 30.7 - 63.4%), with subgroup estimates of 52.1% (95% CI 33.6 - 70.4%) in women and 26.4% (95% CI 0.0 - 85.0%) in children. A total of 93 plant species belonging to 79 genera and 44 families were identified. Anaemia, digestive problems, labour, and cancer were the main reasons for HM. Cordia platythyrsa and Entandrophragma candollei were classified as vulnerable/endangered by the IUCN. RCT evidence was available for only 19 plant species, including 6-shogaol (Zingiber officinale) and annonacin (Annona muricata) for cancer, quercetin-3-rhamnoside (Alchornea cordifolia) for anaemia, and oleic acid (Phoenix dactylifera) for labour. Mechanistic studies indicated that these bioactive compounds act through multiple pathways (e.g., shogaol - upregulated STAT3 pathway, reactive oxygen species generation, and cell cycle arrest in cancer cells). CONCLUSIONS: Nearly one in two individuals in these vulnerable populations reported HM use, despite limited high-quality clinical evidence supporting most medicinal plants. Strengthening epidemiological surveillance, clinical research, conservation of threatened medicinal species, and integration of traditional medicine into health systems could improve the safe and evidence-based use of HM in Cameroon and similar settings.