In vivo anthelmintic effects of polyphenol-rich extracts from the salt-tolerant species Cladium mariscus (L.) Pohl, 1809 and Limoniastrum monopetalum (L.) Boiss., 1848 against gastrointestinal parasitic nematodes in lambs

Abstract Background Parasitic gastrointestinal infections caused by strongyle nematodes in grazing small ruminants endure as main cause of reduced animal productivity, health and welfare, compromising farm economy. For several decades, synthetic anthelmintics have been the cornerstone to control such parasites and limit their consequences but increasing issues regarding parasite resistances and concerns of chemical residues in the food chain, led to the exploration of novel approaches within the concept of integrated management solutions. Among them, bioactive plants and their associated secondary metabolites, have been increasingly explored. Recently, promising in vitro results were obtained with acetone aqueous extracts of polyphenol-rich salt-tolerant plants, namely Cladium mariscus (L.) Pohl, 1809 and Limoniastrum monopetalum (L.) Boiss., 1848. The current study aims to obtain the first proof of concept of these two plant extracts’ in vivo anthelmintic value, relying on prior in vitro data . Methods To assess the effects of drenching the plant extracts in Haemonchus contortus and Trichostrongylus colubriformis mixed infections, twenty lambs were divided into three experimental groups: a control group (C), a C. mariscus treated group (CM) and a L. monopetalum treated group (LM). Lambs were infected (DPI 0), drenched with extracts (DPI 30) and the experiment ended on DPI 48. Blood and fecal samples were collected regularly to assess parasitological and pathophysiological measurements. Results Overall, results do not indicate significant in vivo parasitological effects for the two plant extracts, in the studied conditions. However, significant differences in PCV values were observed between the treated and control groups, hypothesizing potential effects on the overall animal health status, to be explored in future work. Conclusions This work outcomes are discussed based on the available in vivo anthelmintic works using plant extracts, and methodological challenges are appraised.