Anthelmintic activity of plants against gastrointestinal nematodes of goats: a review

Abstract

The gastrointestinal nematodes (GIN) stand out as an important cause of disease in small ruminant, especially on goat farm. Widespread resistance to synthetic anthelminthics has stimulated the research for alternative strategies of parasite control, including the use of medicinal plants. The present work summarizes the in vitro and in vivo studies of plants with activity against GIN of goats, focusing on the description of chemical constituents related to this effect. This review retrieved 56 scientific articles from 2008 to 2018 describing more than 100 different plant species. The most frequently investigated family was Fabaceae (30.7%). Most in vitro studies on the activity of plant extracts and fractions were carried out with of free-living stages nematodes. In vivo studies were conducted mainly with the use of plants in animal feed and generally showed lower effectiveness compared to in vitro assays. The main plant secondary metabolites associated with anthelmintic effect are condensed tannins, saponin and flavonoids. However, the studies with compounds isolated from plants and elucidation of their mechanisms of action are scarce. Herbal medicines are thought to be promising sources for the development of effective anthelmintic agents.

Effects of Medicinal Plants and Organic Selenium against Ovine Haemonchosis

“…Our previous studies found that the effect of medicinal plants on GIN-infected sheep depended on the variety and synergy of polyphenols in medicinal plants and on the combination of bioactive compounds that together had an effect contributing to pharmacological efficacy [ 7 , 8 , 9 , 10 ]. Most studies conducted mainly with the use of medicinal plants in ruminants, however, have generally found lower effectiveness of plant materials against parasites in vivo compared to in vitro [ 11 , 12 ]. The presence of a GIN infection also disturbs the mineral metabolism of ruminants, and mineral deficiencies in nutrition are associated with increased GIN burdens in animals.…”

Actividad antihelmíntica in vivo de terpenos y aceites esenciales en pequeños rumiantes

“…Compuestos fenólicos: De los cuales se han identificado 8,000 estructuras (42) y que representan el grupo de MSP más estudiados en lo que se refiere a las propiedades bioactivas en contra de los NGI en pequeños rumiantes. Dentro de este grupo, los taninos condensados han recibido una atención especial debido a su actividad AH y su presencia en varias especies de plantas presentes en sistemas de vegetación nativa a nivel mundial (43,44,45).…”

Small Ruminant Production Based on Rangelands to Optimize Animal Nutrition and Health: Building an Interdisciplinary Approach to Evaluate Nutraceutical Plants

“…Undoubtedly the more-studied PSC in terms of ruminant nutrition and AH activity are the CT [ 13 , 27 , 28 , 29 , 30 ]. Nonetheless, it is known that other PSC such as flavonoids, saponins, terpenes, alkaloids, hydrolysable tannins, among others, could influence the physiology of both ruminants and nematodes [ 34 , 190 , 191 , 192 , 193 , 194 , 195 , 196 ]. Hence, considering the plethora of plant species and PSC present in the LDF, we have a wide avenue of future research.…”

“…The majority of studies related to the assessment of nutraceutical properties of plants have been performed using in vitro tests [ 34 , 35 ], which could be related to their lower cost, rapid turnover and the possibility of obtaining and testing the activity of specific PSC through the use of solvents [ 148 , 152 ]. On the contrary, during in vivo trials, intake of different levels and concentrations of both nutrients and PSC is unavoidable when experimental plants are consumed (the higher the number of plants, the harder the possibility of interpreting the results).…”

“…Considering that conventionally, the gastrointestinal nematodes (GIN) infections are considered as one of the most significant constraints for small ruminants feeding on natural scenarios [ 22 , 23 , 24 ], efforts have been directed to assess, under in vitro and in vivo approaches, the anthelmintic (AH) effect of some PSC against the different life stages of GIN. The bulk of the research has been directed at identifying the AH activity of the condensed tannins (CT) [ 25 , 26 , 27 , 28 , 29 , 30 , 31 ], while some PSC, like saponins, flavonoids, terpenoids, alkaloids and sesquiterpene lactones, have also been studied more recently [ 32 , 33 , 34 ]. In the meantime, the growing evidence on the relationships between herbivores, plants, PSC and GIN served as the springboard for the introduction to the novel “ nutraceutical ” concept in the veterinary sciences.…”