Critical Appraisal of Indian Medicinal Plants as Anthelmintic Agents: Emphasis on In Vitro vs. In Vivo Models in Ruminant Helminthiasis

Gastrointestinal helminth infections in ruminants pose a serious threat to Indian livestock, with synthetic anthelmintics becoming increasingly ineffective due to resistance and cost barriers. This review systematically evaluates the anthelmintic potential of Indian medicinal plants as alternative therapies, emphasizing the distinction between in vitro and in vivo models. A total of 56 studies were included, predominantly in vitro, with only limited in vivo validation. The most frequently studied plant families include Apiaceae, Euphorbiaceae, and Fabaceae. While many plant extracts demonstrated promising effects against helminths in screening assays using free-living organisms (e.g., Caenorhabditis elegans, Pheretima spp.), these findings cannot be directly equated with clinical efficacy. Our analysis underscores the need for biologically relevant models and standardized evaluation protocols. We highlight critical gaps in methodological rigor, model relevance, and regional specificity in helminth susceptibility. This review advocates for future research prioritizing in vivo trials, phytochemical characterization, and pharmacodynamic profiling to transition from preliminary screening to validated therapeutic applications.