Assessment of nematocidal activity of novel N-alkyl analogues of nitrofurantoin on Caenorhabditis elegans nematode model

MSc (Integrated Pest Management), North-West University, Potchefstroom Campus

Caenorhabditis elegans is considered as a simple but important invertebrate model which provides a versatile platform of various experiments such as drug studies. The C. elegans is commonly used in anthelmintic drug studies because it shares common anatomical and physiological characteristics with majority of species in the phylum Nemathelminthes. Amongst nematodes infecting livestock, Haemonchus spp., Trichostrongylus spp. and Paramphistomum spp. commonly infect small stock and result in devastating effects, both clinically and economically. Several of pharmaceutical chemicals used to manage these gastrointestinal nematodes are beginning to lose their effectiveness due to resistance in these nematodes. Alternative drugs that can possibly be used in the successful management of small ruminants are nitrofurantoin derivatives. The aim of this study was to assess the effect of novel N-alkyl analogues of nitrofurantoin on the larval development and larval mortality on C. elegans nematode model.C. elegans eggs were conserved and maintained on agar plates with E. coli as a food source. After an incubation period of three days, worms with the same life stage were obtained by means of following the ISO standard for water quality that enables the determination of turbidity. Ten L1 stage larvae were placed in a 12 well plate as well as a food medium, M9-medium and 150 μl of the eight different nitrofurantoin derivatives (that were dissolved in a 10% DSM/PBS solution). The wells with the L1 stage larvae were then incubated for four days at 21 °C. After the incubation period, the test was terminated and the nematodes were transferred to a petri dish for observation.It is clear that compounds 104, 105, and 106, had the best nematocidal effect on the round worms, with compound 106 being the most effective at killing C. elegans. Compounds 104, 105, and 106, had the least amount of larval development, with compound 105 inhibiting larval development the best. Compound 104 had the least amount of L1 stage larvae and the highest number of dead larvae. This means that compound 104 caused C. elegans to reproduce less offspring than the other compounds. This study has shown that derivatives of N-alkyl analogues of nitrofurantoin are all unique have in vitro anthelminthic activity against C. elegans nematode model. These findings pave way for future studies that should confirm efficacy in selected nematodes that infect livestock such as Haemonchus contortus and then conduct in vivo efficacy and toxicity tests on experimental animals.

Masters