Bibliometric analysis on the pharmacological/therapeutic effects of earthworms (Dilong)

Abstract

In Traditional Chinese Medicine (TCM), earthworm (Dilong) has been used for over two millennia in clinical practice. However, most existing studies focus on individual bioactive components or specific diseases, and the broader landscape of global research on their pharmacological effects has remained largely unexplored. This study conducted a bibliometric analysis of the pharmacological and therapeutic effects of earthworms (Dilong), aiming to identify current research hotspots, emerging trends, and collaborative networks (authors, institutions, countries) in this field. Data were retrieved from the Web of Science (WoS) Core Collection and analyzed using Bibliometrix and CiteSpace. A total of 313 publications were identified for the period 1989–2024. The results showed a steady increase in the number of publications on the pharmacological and therapeutic effects of earthworms. More than 60% of the publications originated from Asia, with China the leading contributor (34.2%), followed by the United States. The most productive author was Prof. Edwin Cooper (University of California, Los Angeles; n = 16 publications, 566 citations). Keyword analysis revealed three major research clusters: characterization of bioactive proteins (notably lumbrokinase and antimicrobial peptides), mechanistic investigation of anti-inflammatory and antitumor activities, and thrombolytic and cardiovascular applications. Current research hotspots center on the purification and functional characterization of earthworm-derived proteins, with high-impact studies increasingly incorporating advanced methodologies such as cryo-electron microscopy and nanoparticle-based delivery systems. Evidence for pharmacological effects derives predominantly from in vitro assays and animal models; robust clinical data remain limited. This bibliometric analysis provides a systematic overview of the evolving research landscape in earthworm-based pharmacology, mapping key contributors, thematic clusters, and emerging trends from 1989 to 2024. The findings suggest that earthworm-derived compounds may exert diverse therapeutic effects, including thrombolysis, antimicrobial, anti-inflammatory, and antitumor activities, though most evidence currently derives from preclinical studies. Future work should prioritize multicenter clinical trials, standardized quality control, comprehensive multi-omics characterization, exploration of nanodelivery systems, and One Health–oriented applications to accelerate translation from traditional use to evidence-based therapeutics. Not applicable.