Ethnomedicinal knowledge of the Tharu community in Nepal: A systematic review and bibliometric analysis

Abstract

Background: Ethnomedicinal knowledge is an important component of Indigenous healthcare and biocultural heritage. However, evidence on the Tharu community of Nepal remains fragmented across locations, species, ailments, and research periods, despite the community’s extensive ethnoecological knowledge and centuries-long presence in Nepal. This review systematically synthesizes the diversity, distribution, therapeutic uses, and research gaps in Tharu ethnomedicinal knowledge.

Methods: A PRISMA 2020-guided systematic search of Google Scholar, PubMed, Scopus, and ScienceDirect identified 34 eligible studies from 1,580 records. Evidence was synthesized across spatial, temporal, taxonomic, therapeutic-use, and bibliometric dimensions, with botanical nomenclature and ailment categories standardized for comparison.

Results: The review documented 557 Tharu-based medicinal plant species belonging to 376 genera and 120 families across 14 districts, representing approximately 31.6% of Nepal’s reported medicinal flora. Research increased markedly after 2020 but remained geographically concentrated. Herbs were the dominant growth form, and leaves are the most frequently reported plant part. Across 4,407 use-citations, digestive disorders were most frequently reported, followed by skin, general/unspecified, and respiratory conditions; diarrhea/dysentery, fever, and wounds were the leading individual ailments. Azadirachta indica and Achyranthes aspera were the most consistently documented species, each reported in 24 of 34 studies. Despite this rich knowledge base, research remains largely descriptive, with limited attention to intergenerational knowledge transmission, conservation, and pharmacological validation.

Conclusions: This review moves beyond a conventional species inventory by integrating taxonomic, therapeutic, spatial, temporal, and bibliometric evidence. It reveals both the richness and vulnerability of Tharu ethnomedicinal knowledge and identifies priorities for geographically broader research, knowledge transmission, sustainable harvesting, and rigorous pharmacological investigation.

Keywords: Ethnomedicinal plants; Tharu community, Traditional knowledge, Healthcare practices, Nepal.