Ultrastructural study of adult Haemonchus contortus exposed to polyphenol-rich materials under in vivo conditions in goats

Abstract

This study assessed the ultrastructural changes caused in adult Haemonchus contortus obtained from goats fed fodder based on polyphenol-rich plants Lysiloma latisiliquum or Onobrychis viciifolia or from goats drenched with quebracho extract, Schinopsis spp. The H. contortus were obtained from artificially infected goats used as models to investigate the anthelmintic effect of feeding or drenching with the polyphenol-rich materials. Nematode populations were exposed to polyphenol-rich plant materials by feeding host goats for 8 consecutive days (D28 to D35 post-infection) with (a) L. latisiliquum fodder at 800 g fresh basis/day, (b) O. viciifolia fodder offered ad libitum, and (c) drenched with a solution containing quebracho extract (90 g/day). Meanwhile, control H. contortus were obtained from goats fed polyphenol-free diets. The H. contortus specimens were recovered from the goats on D36 post-infection, and transmission electron microscopy (TEM) was used to identify ultrastructural changes. In vivo exposure to different polyphenol-rich plant materials caused vacuolization of the nematodes’ intestinal, muscular and hypodermal cells. These alterations represent the first evidence of cell damage caused in H. contortus when hosts were fed or drenched with polyphenol-rich materials. Ultrastructural changes affecting several types of cells could explain modifications in worm motility and nutrition, eventually affecting H. contortus reproductive success. This study contributes to our understanding of the mechanisms of action of polyphenol-rich plants against H. contortus when given as nutraceuticals to goats.

Natural Compounds from the Marine Brown Alga Caulocystis cephalornithos with Potent In Vitro-Activity against the Parasitic Nematode Haemonchus contortus

“…The major tissue damage and associated cytoplasmic and mitochondrial vacuolisation seen in the adult stage exposed to compound 4 and the rapid decline in the worms' motility and viability indicate a marked disruption of cellular physiology and functions, possibly resulting from a direct or indirect effect on mitochondria, an imbalance of fluid exchanges between the pseudo-coelomic space and muscle and/or an abnormal osmotic pressure within the worm. Surprisingly, these tissue and cellular alterations are similar to those seen in adults of H. contortus collected from goats fed tannin-rich plants [44]. The extracts of these plants, however, caused the formation of lesions on the cuticle, including mouth, of H. contortus in vivo and in vitro [45,46], presenting a distinctly different phenotype from that induced by compound 4.…”

A Systematic Review on Comparative Analysis, Toxicology, and Pharmacology of Medicinal Plants Against Haemonchus contortus

“…The alterations to the intestinal cells may be due to the ingestion of active compounds by the parasite, and the resulting direct contact between the bioactive compounds and the intestinal cells. The cytoplasmic vacuolization described can be interpreted as signs of disturbances in cellular functions, possibly due to imbalance of fluid exchanges between the intestinal and pseudocoelomic space and/or between the muscle and the pseudocoelomic space ( Martínez-Ortiz-de-Montellano et al, 2019 ).…”

Epidemiological, Morphological, and Morphometric Study on Haemonchus spp. Recovered From Goats in Egypt

“…Importantly, the role played by SEM in detecting and characterizing Haemonchus spp. was documented in several studies (21,(72)(73)(74)(75)(76). In this study, SEM was used to identify and differentiate some ultrastructures that aid in the taxonomic differentiation of several Haemonchus spp.…”