Anti-Toxoplasma Activity of Estragole and Thymol in Murine Models of Congenital and Noncongenital Toxoplasmosis.

Toxoplasmosis is caused by Toxoplasma gondii , an obligatory intracellular protozoan. Normally benign, T. gondii infections can cause devastating disease in immunosuppressed patients and through congenital infection of newborn babies. Few prophylactic and therapeutic drugs are available to treat these infections. The goal of the present study was to assess the anti-Toxoplasma effects in a congenital and noncongenital model of toxoplasmosis (using ME49 strain), besides assessing immunological changes, in vitro cytotoxicity, and in vivo acute toxicity of commercial estragole and thymol. The congenital experimental model was used with intermediate stages of maternal infection. The serum levels of immunoglobulin (Ig)M, IgG, interleukin (IL)-10, IL-12, and interferon-gamma (IFN-γ) were quantified from infected and treated C57Bl/6 mice. Estragole and thymol respectively exhibited low to moderate in vivo toxicity and cytotoxicity. Animals treated with estragole showed high IFN-γ and strong type 1 helper T cell response. Both compounds were active against T. gondii ME49 strain. Furthermore, orally administered estragole in infected pregnant mice improved the weight of offspring compared with untreated controls. Subcutaneous administration of both compounds also increased the weight of mouse offspring born to infected mothers, compared with untreated controls. Estragole and thymol display important anti-Toxoplasma activity. Further studies are needed to elucidate the mechanism of action of these compounds.

Epidemiological and serological profiles of ocular toxoplasmosis in the municipality of Natal, northeastern Brazil.

BACKGROUND: Toxoplasma gondii is the main culprit in most cases of infectious uveitis, in both acute and recurrent cases of congenital toxoplasmosis and acquired infections. METHODS: The ocular toxoplasmosis was evaluated in patients at the the reference unit in ophthalmology, in Rio Grande do Norte State, determining the risk factors, and the epidemic, serological and clinical profiles. The production of IgM and IgG antibodies to T. gondii was evaluated by microparticle enzyme immunoassay (MEIA). The same patients diagnosed with fundoscopic alterations have been subjected to the fundus photography procedure. RESULTS: Of the 116 patients with positive serology, 66 patients had bilateral ocular damage and 38 patients showed a higher frequency of lesions of type I. The epidemiological investigation showed that direct contact with cats, the consumption of raw or undercooked meat and direct contact with soil are factors not related to ocular toxoplasmosis development. The characterization of the sample was significant for patients aged 31-40 years. CONCLUSIONS: Ocular toxoplasmosis is widely distributed in Natal and other cities in Rio Grande do Norte state, with special relevance for bilateral lesions in 56.9% of the patients assessed, the most frequent being type I with intraocular disposition in the macula.

Comparative study on the antioxidant and anti-Toxoplasma activities of vanillin and its resorcinarene derivative.

A resorcinarene derivative of vanillin, resvan, was synthesized and characterized by spectroscopic techniques. We measured the cytotoxicity (in vivo and in vitro), antioxidant and anti-Toxoplasma activities of vanillin and the resorcinarene compound. Here we show that vanillin has a dose-dependent behavior with IC50 of 645 µg/mL through an in vitro cytotoxicity assay. However, we could not observe any cytotoxic response at higher concentrations of resvan (IC50 > 2,000 µg/mL). The in vivo acute toxicity assays of vanillin and resvan exhibited a significant safety margin indicated by a lack of systemic and behavioral toxicity up to 300 mg/kg during the first 30 min, 24 h or 14 days after administration. The obtained derivative showed greater antioxidative activity (84.9%) when comparing to vanillin (19.4%) at 1,000 µg/mL. In addition, vanillin presents anti-Toxoplasma activity, while resvan does not show that feature. Our findings suggest that this particular derivative has an efficient antioxidant activity and a negligible cytotoxic effect, making it a potential target for further biological investigations.