The ethanolic extract of the fungus Trichoderma stromaticum decreases the Toxoplasma gondii replication in vitro and ameliorates the experimental toxoplasmosis in vivo.

Trichoderma are fungi that are well-known to inhibit the growth of a variety of plant pathogens. Currently, there is an increasing search for new drugs to treat toxoplasmosis. The aims of this study were to investigate the effect of ExtTs in the control of Toxoplasma gondii proliferation in vitro and the course of toxoplasmosis in a mouse model. Firstly, the cytotoxicity of the ExtTs was evaluated by cultivating macrophages with different concentrations of the extract and cell viability was assessed by the MTT assay. Next, the infectivity of the T. gondii treated with extract was analyzed by infecting J774 macrophages. To evaluate the effect of the ExtTs in vivo, C57BL/6 mice were infected orally with T. gondii, ME-49, treated daily with ExtTs, and clinical, biochemical and histological changes were monitored. It was demonstrated that the extract did not affect the host cellular viability and, the treatment of parasites with ExtTs altered their morphology and decreased their ability to proliferate inside macrophages. Additionally, the treatment of mice with ExtTs decreased the parasitism and inflammation in the small intestine and liver of infected mice in parallel with increased IL-10/TNF ratio systemically and prevented alterations to serum VLDL and triglyceride levels. Thus, ExtTs could be considered an alternative/complementary therapy to control toxoplasmosis.

Toxoplasma gondii Infection Decreases Intestinal 5-Lipoxygenase Expression, while Exogenous LTB4 Controls Parasite Growth.

5-Lipoxygenase (5-LO) is an enzyme required for the production of leukotrienes and lipoxins and interferes with parasitic infections. In vitro, Toxoplasma gondii inhibits leukotriene B4 (LTB4) production, and mice deficient in 5-LO are highly susceptible to infection. The aim of this study was to investigate the effects of the pharmacological inhibition of the 5-LO pathway and exogenous LTB4 supplementation during experimental toxoplasmosis. For this purpose, susceptible C57BL/6 mice were orally infected with T. gondii and treated with LTB4 or MK886 (a selective leukotriene inhibitor through inhibition of 5-LO-activating protein [FLAP]). The parasitism, histology, and immunological parameters were analyzed. The infection decreased 5-LO expression in the small intestine, and treatment with MK886 reinforced this reduction during infection; in addition, MK886-treated infected mice presented higher intestinal parasitism, which was associated with lower local interleukin-6 (IL-6), interferon gamma (IFN-γ), and tumor necrosis factor (TNF) production. In contrast, treatment with LTB4 controlled parasite replication in the small intestine, liver, and lung and decreased pulmonary pathology. Interestingly, treatment with LTB4 also preserved the number of Paneth cells and increased α-defensins expression and IgA levels in the small intestine of infected mice. Altogether, these data demonstrated that T. gondii infection is associated with a decrease in 5-LO expression, and on the other hand, treatment with the 5-LO pathway product LTB4 resulted in better control of parasite growth in the organs, adding to the knowledge about the pathogenesis of T. gondii infection.

Anti-parasitic activity of Annona muricata L. leaf ethanolic extract and its fractions against Toxoplasma gondii in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Sulfadiazine and pyrimethamine are the two drugs used as part of the standard therapy for toxoplasmosis, however; they may cause adverse side effects and fail to prevent relapse in many patients, rendering infected individuals at risk of reactivation upon becoming immunocompromised. Extracts from various parts of Annona muricata have been widely used medicinally for the management, control and/or treatment of several human diseases, acting against parasites that cause diseases in humans. AIM OF THE STUDY: This study was performed to investigate the action of the ethanolic extract of A. muricata (EtOHAm) and its fractions in the control of the apicomplexan parasite Toxoplasma gondii in vitro and in vivo, and the effect of EtOHAm on the inflammatory response and lipid profile alteration induced by in vivo T. gondii infection. MATERIALS AND METHODS: The cytotoxicity of EtOHAm and its fractions ethyl acetate (EtOAcAm), n-butanol (BuOHAm), aqueous (H2OAm), hexane (HexAm) and dichloromethane (CH2Cl2Am) was evaluated in NIH/3T3 fibroblasts using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The cells were infected with T. gondii, treated with the extracts, and parasite proliferation was analyzed. For the in vivo experiments, C57BL/6 mice were orally infected with T. gondii and, treated with different concentrations of extract fractions that were effective in vitro (EtOHAm, EtOAcAm, HexAm and CH2Cl2Am). Tissue parasitism, histological alterations, systemic cytokine and lipid profile were investigated. RESULTS: EtOHAm, EtOAcAm, BuOHAm, H2OAm presented low cytotoxicity until doses of 200 µg/mL, while HexAm and CH2Cl2Am presented toxicity from doses of 100µg/mL. EtOHAm, HexAm and CH2Cl2Am decreased the parasitism in vitro, presenting a therapeutic index of 2.62, 2.44, and 2.96, respectively. In vivo, EtOHAm, HexAm and CH2Cl2Am improved the survival rate of infected animals, however, only EtOHAm was able to decrease the parasitism in the small intestine and lung. Additionally, EtOHAm decreased the systemic interferon (IFN)-γ and tumor necrosis factor (TNF) systemically in infected mice, and was able to maintain the triglycerides and very-low-density lipoprotein (VLDL) lipid fractions at similar levels to uninfected animals. Although treatment with EtOHAm could not control the inflammation induced by oral infection in the tissues analyzed, it was able to preserve the number of goblet cells in the small intestine. CONCLUSIONS: Ethanolic A. muricata leaf extract could be considered as a good candidate for the development of a complementary/alternative therapy against toxoplasmosis, and also as an anti-inflammatory alternative for decreasing TNF and IFN-γ concentrations and lipid fractions in specific diseases.