Phytochemicals as inhibitors of pathogenesis to combat ostertagiosis, toxocariasis, trichostrongylosis and trichuriasis in cattle: A systematic review.

Abstract

Highly pathogenic gastrointestinal nematodes (GIN) pose a severe global threat to cattle health and productivity, causing significant economic losses. With their widespread prevalence (96%) and growing anthelmintic resistance, phytochemicals (PC) present a promising alternative. This review evaluates studies from 2001 onward on herbal remedies as an effective alternative to combat the pathogenesis of ostertagiosis, toxocariasis, trichostrongylosis, and trichuriasis in cattle. A systematic literature review of electronic databases has identified 87 unique plant species from 45 publications against GIN of cattle, with 60 plants in 25 studies specifically targeting four key GINs. Thymus vulgaris, Curcuma longa, Punica granatum and Propolis were frequently employed plants, while the research was primarily led by Egypt (20%) and Denmark (17.78%). These plants belonged to 31 families, with Fabaceae (11.86%) and Lamiaceae (13.56%) being prominent, whereas whole plants (36%) and leaves (20%) were frequently utilized parts. 70% of these plants were administered in the form of extracts, of which aqueous extracts (33.33%) were the most common type. All plant extracts demonstrated anthelmintic effects through ovicidal, larvicidal, and adulticidal mechanisms. Key PC identified were alkaloids, saponins, condensed tannins, and flavonoids, which targeted multiple pathways of parasites, disrupting cellular, neural and metabolic functions, also enhancing host health. 18 plant species achieved 100% efficacy against four targeted GIN. Comparative analysis revealed considerable variability in the potency between synthetic anthelmintics and medicinal plants. MP's efficacy also varied based on experimental setting and target parasite. Cichorium intybus and P. granatum exhibited a decline in efficacy from in vitro (100%, 86%) to in vivo (57%, 83%) settings. T. vulgaris was significantly more effective against Toxocara vitulorum (73%) than Trichostrongylus axei (27%), while C. longa performed better against T. vitulorum (50%) compared to Trichuris (36%). Overall, this review provides compelling evidence of plants potential as anthelmintics against GIN in cattle, thereby underscoring the necessity for further long-term studies.