Medicinal and Agrochemical Plants Used by Tanzanian Tribes: A PRISMA-Based Systematic Review of Ethnobotanical Knowledge, Phytochemistry, and Functional Applications

Medicinal plants remain central to healthcare and crop protection across Tanzania, yet the evidence supporting their use is scattered across tribes, regions, and disciplines. This review systematically synthesizes the ethnobotanical, phytochemical, pharmacological, and agrochemical literature on medicinal and pesticidal plants used by major Tanzanian tribes. Following the PRISMA framework, 94 peer-reviewed studies published between 2010 and 2025 were analyzed, yielding 100 plant species across 87 genera and46 families. Four quantitative indices,Use Value (UV), Relative Frequency of Citation (RFC), Informant Consensus Factor (ICF), and Family Importance Value (FIV),were used to rank species and families by cultural importance. Fabaceae, Asteraceae, and Lamiaceaewere the most prominent families, and leaves were the most frequently used plant part (52%), suggesting comparatively sustainable harvesting. High ICF values (0.85–0.92) for malaria, gastrointestinal, and dermatological conditions indicated strong agreement among knowledge holders, while insecticidal and repellent applications dominated agrochemical use, underscoring the promise of botanical pesticides. Many culturally important species, however, remain insufficiently validated by phytochemical and pharmacological research. These findings position Tanzania's plant resources as valuable assets for sustainable healthcare, biodiversity conservation, and green agriculture, and identify clear priorities for future validation.