In vitro anthelmintic effects of Artemisia afra and Mentha longifolia against parasitic gastro-intestinal nematodes of livestock

Gastrointestinal nematodes are the most widespread and economically important class of the helminths. The major threat posed by nematode infections is the productivity loss due to their ability to disrupt nutrient utilization of the livestock resulting in hunger and malnutrition. Acetone and aqueous extracts were prepared from Mentha longifolia and Artemisia afra and tested on egg hatch, larval development and larval mortality assays at three concentrations 2.5, 5.0 and 7.5 mg/mL. Certain percentages of egg hatch and larval mortality were inhibited by both plants; however, larval development was totally inhibited at all concentrations as compared to the negative control. Generally the acetone extracts from the two plants were most effective against parasitic gastrointestinal nematodes of livestock. This report therefore validates the folkloric use of these species in the management of internal parasites by the Basotho of the eastern Free State Province of South Africa

The establishment of in vitro culture and drug screening systems for a newly isolated strain of Trypanosoma equiperdum

Dourine is caused by Trypanosoma equiperdum via coitus with an infected horse. Although dourine is distributed in Equidae worldwide and is listed as an internationally important animal disease by the World Organization for Animal Health (OIE), no effective treatment strategies have been established. In addition, there are no reports on drug discovery, because no drug screening system exists for this parasite. A new T. equiperdum strain was recently isolated from the genital organ of a stallion that showed typical symptoms of dourine. In the present study, we adapted T. equiperdum IVM-t1 from soft agarose media to HMI-9 liquid media to develop a drug screening assay for T. equiperdum. An intracellular ATP-based luciferase assay using CellTiter-Glo reagent and an intracellular dehydrogenase activity-based colorimetric assay using WTS-8 tetrazolium salt (CCK-8 reagent) were used in order to examine the trypanocidal effects of each compound. In addition, the IC50 values of 4 reference trypanocidal compounds (pentamidine, diminazene, suramin and melarsomine) were evaluated and compared using established assays. The IC50 values of these reference compounds corresponded well to previous studies involving other strains of T. equiperdum. The luciferase assay would be suitable for the mass screening of chemical libraries against T. equiperdum because it allows for the simple and rapid-evaluation of the trypanocidal activities of test compounds, while a simple, inexpensive colorimetric assay will be applicable in developing countries for the evaluation of the drug sensitivity of epidemic trypanosome strains. Keywords: Colorimetric assay, Drug screening system, Liquid culture, Luciferase assay, Trypanosoma equiperdu

Metal nanoparticles restrict the growth of protozoan parasites

TheTrypanosomaandToxoplasma spp, are etiological agents of diseases capable of causing significantmorbidity, mortality and economic burden, predominantly in developing countries. Currently, there areno effective vaccines for the diseases caused by these parasites; therefore, therapy relies heavily onantiprotozoal drugs. However, the treatment options for these parasitic diseases are limited, thusunderscoring the need for new anti-protozoal agents. Here, we investigated the anti-parasite action ofnanoparticles. We found that the nanoparticles have strong and selectivein vitroactivity againstT. b. bruceibut moderatein vitroactivity againstT. congolenseandT. evansi. An estimation of thein vitroanti-Trypanosomaefficacy showed that the nanoparticles had�200-fold selective activityagainst the parasite versus mammalian cells. Moreover, the nanoparticle alloys moderately suppressedthein vitrogrowth ofT. gondiiby�60%. In ourin vivostudy, the nanoparticles appeared to exhibit atrypanostatic effect, but did not totally suppress the rat parasite burden, thereby failing to appreciablyextend the survival time of infected animals compared with the untreated control. In conclusion, this isthe first study to demonstrate the selectivein vitroanti-Trypanosomaaction of nanoparticles and thussupports the potential of nanoparticles as alternative anti-parasitic agents