Caenorhabditis elegans as a model to screen plant extracts and compounds as natural anthelmintics for veterinary use

Abstract

The most challenging obstacles to testing products for their anthelmintic activity are: (1) establishing a suitable nematode in vitro assay that can evaluate potential product use against a parasitic nematode of interest and (2) preparation of extracts that can be redissolved in solvents that are miscible in the test medium and are at concentrations well tolerated by the nematode system used for screening. The use of parasitic nematodes as a screening system is hindered by the difficulty of keeping them alive for long periods outside their host and by the need to keep infected animals as sources of eggs or adults when needed. This method uses the free-living soil nematode Caenorhabditis elegans as a system to screen products for their potential anthelmintic effect against small ruminant gastrointestinal nematodes, including Haemonchus contortus. This modified method uses only liquid axenic medium, instead of agar plates inoculated with Escherichia coli, and two selective sieves to obtain adult nematodes. During screening, the use of either balanced salt solution (M-9) or distilled water resulted in averages of 99.7 (± 0.73)% and 96.36 (± 2.37)% motile adults, respectively. Adult worms tolerated DMSO, ethanol, methanol, and Tween 80 at 1% and 2%, while Labrasol (a bioenhancer with low toxicity to mammals) and Tween 20 were toxic to C. elegans at 1% and were avoided as solvents. The high availability, ease of culture, and rapid proliferation of C. elegans make it a useful screening system to test plant extracts and other phytochemical compounds to investigate their potential anthelmintic activity against parasitic nematodes.

Effect of structurally related flavonoids from Zuccagnia punctata Cav. on Caenorhabditis elegans

“…The Order Rhabditida, to which C. elegans belongs, is closely associated with the Order Strongylida, which contains the important trichostrongyle parasites of ruminants, including Haemonchus contortus and Trichostrongylus spp. If tested drugs are effective in C. elegans cultures at low concentrations, it is reasonable to assume that they may have anthelmintic activity against related nematodes, including H. contortus (Thompson et al 1996;Katiki et al 2011).…”

“…A broad spectrum of biological activities, such as anthelmintic, antioxidant, antimicrobial and anti-inflammatory, is attributed to these polyphenols that might benefit human and/or animal health and aging (Nijveldt et al 2001;Ross and Kasum 2002;Katiki et al 2011;Daglia 2012;Ndjonkaa et al 2013;Menaa et al 2014). The activities of flavonoids are dependent on their chemical structures.…”

Tannin containing legumes as a model for nutraceuticals against digestive parasites in livestock

“…In addition, it is worth mentioning that the model represented by the free living nematode, Caenorhabditis elegans, is also increasingly being exploited to screen the AH properties of different plant resources (Katiki et al, 2012(Katiki et al, , 2013.…”

An ethnopharmacological survey and in vitro confirmation of the ethnopharmacological use of medicinal plants as anthelmintic remedies in the Ashanti region, in the central part of Ghana

“…Due to genetic and morphological similarities Caenorhabditis elegans shares with other nematodes, it is a useful model for parasitic nematodes showing the advantage of easy and low cost laboratory maintenance (Bürglin et al, 1998;Katiki et al, 2011).…”