Toxoplasma gondii: Effects of Artemisia annua L. on susceptibility to infection in experimental models in vitro and in vivo

Abstract

Considering that the treatment for toxoplasmosis is based on drugs that show limited efficacy due to their substantial side effects, the purpose of the present study was to evaluate the effects of Artemisia annua on in vitro and in vivo Toxoplasma gondii infection. A. annua infusion was prepared from dried herb and tested in human foreskin fibroblasts (HFF) or mice that were infected with the parasite and compared with sulfadiazine treatment. For in vitro experiments, treatment was done on parasite before HFF infection or on cells previously infected with T. gondii and the inhibitory concentration (IC(50)) values for each treatment condition were determined. Viability of HFF cells in the presence of different concentrations of A. annua infusion and sulfadiazine was above 72%, even when the highest concentrations from both treatments were tested. Also, the treatment of T. gondii tachyzoites with A. annua infusion before infection in HFF cells showed a dose-response inhibitory curve that reached up to 75% of inhibition, similarly to the results observed when parasites were treated with sulfadiazine. In vivo experiments with a cystogenic T. gondii strain demonstrated an effective control of infection using A. annua infusion. In conclusion, our results indicate that A. annua infusion is useful to control T. gondii infection, due to its low toxicity and its inhibitory action directly against the parasite, resulting in a well tolerated therapeutic tool.

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

“…In a recent study, the cytotoxicity of A. annua infusions was assessed by determining cellular viability using the (2-methoxy-4-nitro-5-sulphophenyl)-2H-tetrazolium-5-carboxanilide assay. In that study, the viability of cells in the presence of different concentrations of A. annua infusion was above 72% even when the highest concentrations were tested (Oliveira et al 2009). These data are consistent with the generally low cytotoxicity of A. annua infusions.…”

Lectins from Synadenium carinatum (ScLL) and Artocarpus heterophyllus (ArtinM) Are Able to Induce Beneficial Immunomodulatory Effects in a Murine Model for Treatment of Toxoplasma gondii Infection

“…Currently, toxoplasmosis is still treated with the synergistic combination of sulfadiazine and pyrimethamine or triple sulfonamides, which cause bone marrow damage, in addition to the potential life-threatening allergic reactions. For these reasons, alternative drugs as treatment options, including azithromycin, clarithromycin, dapsone, and artemisinin, have been studied for toxoplasmosis treatment, but an extensive number of side effects still persists (Araujo et al, 1992a,b; Bosch-Driessen et al, 2002; D'Angelo et al, 2009; de Oliveira et al, 2009; Yan et al, 2013; Rostkowska et al, 2016). Thus, it is necessary to investigate alternative approaches to find efficient and well-tolerated therapeutic agents against T. gondii infection.…”

Human toxoplasmosis–Searching for novel chemotherapeutics

“…In vitro studies showed similar activity of this plant toward T. gondii. The infusion of A. annua tea decreased the penetration of human foreskin fibroblasts by tachyzoites up to 75% and reduced intracellular replication of the parasite up to 55%, in a dose-dependent manner [73]. Recent experiments performed in vivo with a semi-synthetic tiazole derivative of artemisinin CPH-4 146 demonstrated their modest efficacy in acute as well as chronic toxoplasmosis in laboratory mice [74].…”