A comparison of the effects of two dinitroanilines againstCryptosporidium parvumin vitro and in vivo in neonatal mice and rats

Abstract

The effects of two dinitroanilines, oryzalin and trifluralin, were compared against Cryptosporidium parvum, in vitro using HCT-8 cells and in vivo using neonatal Swiss ARC mice and Wistar neonatal rats. In vitro, oryzalin and trifluralin exhibited IC(50) values (concentration necessary to cause a 50% inhibition) of 750 and 800 nM, respectively. A viability assay showed that neither compound produced a cytotoxic effect on the host cells at concentrations as high as 1 microM. The in vivo component of this study consisted of inoculation of neonatal mice and neonatal rats with 10(5) viable oocysts of C. parvum per animal and the subsequent treatment of this infection with trifluralin and oryzalin administered via gastric intubation. At doses of 100 mg kg(-1) body weight administered twice daily for 3 consecutive days, trifluralin had no statistically significant effect on the number of oocysts recovered from the gut of either rats or mice compared with controls, whereas at the same concentration, oryzalin caused 90 and 79% inhibition of oocysts recovered from mice and rats, respectively.

In Vitro Susceptibility of Cryptosporidium parvum to Plant Antiparasitic Compounds

“…Trifluralin (Sigma-Aldrich ® ) was used as a standard drug control. Trifluralin is a dinitroaniline, a promising class of anti-cryptosporidial compounds with tubulin-binding properties that were initially recognised for their herbicidal properties [ 20 , 30 ]. Trifluralin has been shown to be effective in inhibiting C. parvum growth in vitro (IC 50 = 650.4 mg/L) [ 30 ].…”

“…Compared to animal models, in vitro models are less expensive, less time-consuming, and more convenient for screening drugs for their efficacy against parasites [ 18 , 19 ]. Using in vitro cultures to assess the infectivity and proliferation of the parasite may also help reduce the use of experimental animal models [ 19 , 20 ]. Various cell lines have been successfully applied for in vitro studies on C. parvum, with human ileocaecal adenocarcinoma (HCT-8) cells having been proven to be a suitable cell line for developing the complete life cycle of C. parvum [ 21 , 22 , 23 , 24 ].…”

Traditional medicinal plants in the treatment of gastrointestinal parasites in humans: A systematic review and meta‐analysis of clinical and experimental evidence

“…In vitro experiments provide insights into the cellular response to a plant or drug in a controlled, isolated environment. In vitro screening of plants is cost-effective, less time-consuming than in vivo studies, has a quick turnover of results and allows large-scale screening and does not require the use of animals (Armson et al, 1999). Promising results through a series of in vitro experiments provide a platform for further in vivo studies, which can further evaluate a plant or drug's safety, efficacy and delivery using animal models.…”