Indigenous Knowledge of Traditional Practitioners and Ethnobotanical Description of Underutilized Medicinal Plants Used in Treating Some Viral Infections in Southwestern Nigeria

Aims: The research aims to document underutilized medicinal plants used in treating viral infections in Southwestern Nigeria and to explore the traditional knowledge associated with their use. Study Design: A descriptive cross-sectional study was conducted across six southwestern states of Nigeria. From each state, three rural communities were selected from two Local Government Areas based on the prevalence of herbal healing practices, prominence of practitioners, and their indigenous knowledge of underutilized medicinal plants for treating infectious viral diseases. A total of 48 informants were randomly selected from the study locations. Place and Duration of Study: Osun, Oyo, Ondo, Ekiti, Ogun, and Lagos states, Nigeria; between October, 2024 and March, 2025. Methodology: Ethnobotanical details regarding medicinal plants were gathered from informants in the six states through structured interviews, observations, group discussions, and field excursions. The identification of rarely utilized medicinal plants was carried out by analyzing their life forms, growth habits, and environments, with support from the traditional healers involved. The Fidelity Level (FL), Informant Consensus Factor (ICF) were determined following established procedures. The pattern of distribution of medicinal plants was examined through a participatory approach Results: Over 50% of the respondents knew about the viral diseases and underused medicinal plants for their treatment. A total of 54 medicinal plant species from 32 different families were recorded and detailed. Most of the plant species were herbaceous, perennial, and regarded as either abundant or rare. The fidelity level (FL) values for each underutilized medicinal plant found ranged between 25 and 100%. The Informant Consensus Factor (ICF) value for viral diseases exceeded one (1). Conclusion: The indigenous herbal knowledge has highlighted the underutilized medicinal plants for viral disease treatment which can promote sustainable livelihoods in indigenous communities.