Hypericum perforatum extract and hyperforin inhibit the growth of neurotropic parasite Toxoplasma gondii and infection-induced inflammatory responses of glial cells in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Hypericum perforatum L. has been widely used as a natural antidepressant. However, it is unknown whether it is effective in treating infection-induced neuropsychiatric disorders. AIM OF THE STUDY: In order to evaluate the effectiveness of H. perforatum against infection with neurotropic parasite Toxoplasma gondii, which has been linked to neuropsychiatric disorders, this study investigated the anti-Toxoplasma activity using in vitro models. MATERIALS AND METHODS: Dried alcoholic extracts were prepared from three Hypericum species: H. perforatum, H. erectum, and H. ascyron. H. perforatum extract was further separated by solvent-partitioning. Hyperforin and hypericin levels in the extracts and fractions were analyzed by high resolution LC-MS. Anti-Toxoplasma activities were tested in vitro, using cell lines (Vero and Raw264), murine primary mixed glia, and primary neuron-glia. Toxoplasma proliferation and stage conversion were analyzed by qPCR. Infection-induced damages to the host cells were analyzed by Sulforhodamine B cytotoxicity assay (Vero) and immunofluorescent microscopy (neurons). Infection-induced inflammatory responses in glial cells were analysed by qPCR and immunofluorescent microscopy. RESULTS: Hyperforin was identified only in H. perforatum among the three tested species, whereas hypericin was present in H. perforatum and H. erectum. H. perforatum extract and hyperforin-enriched fraction, as well as hyperforin, exhibited significant anti-Toxoplasma property as well as inhibitory activity against infection-induced inflammatory responses in glial cells. In addition, H. perforatum-derived hyperforin-enriched fraction restored neuro-supportive environment in mixed neuron-glia culture. CONCLUSIONS: H. perforatum and its major constituent hyperforin are promising anti-Toxoplasma agents that could potentially protect neurons and glial cells against infection-induced damages. Further study is warranted to establish in vivo efficacy.

Adjunctive bradyzoite-directed therapy for reducing complications of congenital toxoplasmosis.

Congenital toxoplasmosis is caused by in utero infection of the fetus with the intracellular parasite Toxoplasma gondii. Upon infection, the parasite forms life-long cysts in fetal brain and eyes which are resistant to the currently accepted therapy of pyrimethamine and sulfadiazine. These cysts commonly reactivate later in life causing chorioretinitis and visual impairment, and rarely cause neurological complications. I hypothesize that adjunctive, bradyzoite-directed therapies have the potential to alleviate a significant burden of disease by reducing cyst burden in neonatal brain and eyes. Atovaquone is perhaps the most promising drug for further evaluation given its low side-effect profile, established safety, and efficacy in animal models reducing cyst burden. Very limited observational data in humans suggests atovaquone may prevent Toxoplasma-associated chorioretinitis recurrence. Clinical trials are needed to evaluate it and other potential drugs as adjunctive treatment in congenital toxoplasmosis.

Patient and treatment pathways for toxoplasmosis in the United States: data analysis of the Vizient Health Systems Data from 2011 to 2017.

Toxoplasmosis causes substantial morbidity and mortality in the United States (US). Clinical manifestations to toxoplasmosis vary and there is limited information on incidence or treatment patterns in the US. Treatment pathways for pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) for toxoplasmosis hospitalizations were investigated using the Vizient Health Systems inpatient and outpatient data. Between January 1st, 2011 and December 31st, 2017, 10,273 hospital visits from 4,736 unique patients received a primary or secondary ICD-9/ICD-10 diagnosis for toxoplasmosis. The projected annual hospital visits with a diagnosis of toxoplasmosis was 68,821, corresponding to a total annual incidence of 9,832 comprising ocular toxoplasmosis of 2,169, toxoplasmic encephalitis of 1,399, unspecified toxoplasmosis of 4,368, congenital toxoplasmosis of 381, multisystemic toxoplasmosis of 69 and other toxoplasmosis of 1,446. Only 16.3% of the study population received treatment with pyrimethamine-based regimens or TMP-SMX. Pyrimethamine-based regimens were used significantly more often than TMP-SMX in toxoplasmic encephalitis (88.7% vs 79.6%, p = 0.01), other toxoplasmosis (85.0% vs 79.2%, p = 0.04), and unspecified toxoplasmosis (87.6% vs 77.9%, p = 0.03) in hospitals with 300 beds or more. A significantly higher percentage of visits with TMP-SMX as first-line treatment switched to pyrimethamine-based regimens compared to visits initiated on pyrimethamine-based treatments (26.7% vs 4.1%, p < .001). Ocular toxoplasmosis patients receiving pyrimethamine-based therapy were more likely to be discharged home compared to TMP-SMC at rates of 72.4% and 55.2%, respectively. Our analysis of commercial insurance records suggest toxoplasmosis is undertreated. Overall, pyrimethamine-based regimens are favored over TMP-SMX, have higher rates of discharge home, and have lower switch rates.

Cerebral toxoplasmosis in an allogeneic peripheral stem cell transplant recipient: case report and review of literature.

We present a patient who underwent allogeneic peripheral stem cell transplantation (PSCT) for chronic myelocytic leukemia. Twenty months after the PSCT he experienced status epilepticus. Magnetic resonance imaging (MRI) revealed a focus in the ventral thalamus-hypothalamus region. Using stereotactic biopsy with histology and specific polymerase chain reaction investigation from brain tissue, cerebral toxoplasmosis was diagnosed and treated with antiparasitic therapy. Early recognition of such serious and potentially lethal disease enabled prompt specific treatment. This case report emphasizes the role of stereotactic biopsy in diagnosis of cerebral toxoplasmosis. Other methods such as MRI are non-invasive but not sufficiently specific and sensitive.

A clinical-parasitological monotherapy cure in the treatment of experimental infection by a highly virulent strain of Toxoplasma gondii.

Toxoplasmic encephalitis in patients with the acquired immunodeficiency syndrome (AIDS) is treated classically with pyrimethamine plus sulfadiazine. Unfortunately, up to 40% of these patients are unable to complete the course of therapy because of adverse reactions to sulfonamides. This study considers the possible usefulness of monotherapies in the treatment of acute toxoplasmosis, producing parasitological cures 2-3 months after the date of infection. With this therapy, the main adverse effects are suppressed. Groups of mice infected with the RH strain of Toxoplasma gondii were treated with pyrimethamine alone, sulfadiazine alone, and pyrimethamine plus sulfadiazine for 7 d. Treatment with pyrimethamine plus sulfadiazine produced clinical cures in 100% of the infected mice 1 month after infection. Treatment with pyrimethamine gave a 60% survival rate (clinical cure) at 1 month postinfection. Finally, treatment with sulfadiazine produced a 60% survival rate at 1 month postinfection. Although the antitoxoplasmic regimen with pyrimethamine plus sulfadiazine has proven to be effective in intensive treatment of toxoplasmic encephalitis, relapses occur in more than 80% of cases after cessation of antitoxoplasmic therapy, making secondary prophylaxis mandatory. In this study the efficacy of treatment was also evaluated in terms of parasitological cure. None of the three therapies showed parasitological cure after 1 month of treatment. When the intervals were extended to a 3-month observation, monotherapy with pyrimethamine and sulfadiazine alone produced a parasitological cure.

[Sulfadiazine nephrolithiasis and nephropathy]. / Sulfadiazin-Nephrolithiasis und-Nephropathie.

Sulfadiazine-nephropathy and -nephrolithiasis were well known complications of high dose sulfadiazine therapy 50 years ago. In the last few years high dose sulfadiazine therapy has been widely used for treatment of toxoplasmic encephalitis in AIDS patients. As a consequence sulfadiazine-nephropathy and -nephrolithiasis have become increasingly common. We describe 2 patients with the typical picture of these complications. Therapy is based on the fact that the solubility of sulfadiazine and its acetylated metabolite are markedly improved at higher urine-pH levels. Urine alkalinization is also effective for prophylaxis during sulfadiazine treatment. We present our guidelines for prophylaxis and treatment of these complications.

[Therapeutic alternatives for cases of cerebral toxoplasmosis in patients with AIDS: clarithromycin and atovaquone]. / Alternativas terapéuticas para casos de toxoplasmosis cerebral en pacientes con SIDA: claritromicina y atovacuona.

BACKGROUND: Cerebral toxoplasmosis is the most common opportunistic infection of the central nervous system in AIDS patients. Its rate varies between 3-40% according to the prevalence of toxoplasmosis in the different geographic areas. Conventional treatments used for this pathology are: sulphadiacin or clindamycin plus pyrimethamine, but all can occasionally produce severe side effects. Therefore, the search for new alternative therapies is recommended. METHODS: Two cases of encephalic toxoplasmosis in AIDS patients who developed severe toxicity to conventional treatment with pyrimethamine and sulphadiacin and later to clindamycin are described. RESULTS: The first patient had a complete clinical and neuroradiological curation using clarithromycin 2 g/day and pyrimethamine 50 mg/day for 6 weeks. At 22 months follow up with a maintenance dose of 1 g/day of clarithromycin, the patient still remains asymptomatic. The second patient was successfully treated with atovaquone (750 mg/6 h) for 8 weeks and at 12 months of follow up with a maintenance dose of 750 mg/8 h remains asymptomatic. CONCLUSIONS: The authors believe that clarithromycin and atovaquone may constitute valid alternatives for the treatment of cerebral toxoplasmosis. Nonetheless, their use may, at present, be recommended only as an alternative for the cases of therapeutic failure or severe intolerance when the usual schedules are used.

[Usefulness of folinic acid in cytopenia induced by antiparasitic drugs in AIDS patients]. / Utilité de l'acide folinique dans les cytopénies induites par les médicaments antiparasitaires au cours du SIDA.

The scientific basis for using folinic acid in combination with the antiparasitic drugs prescribed to AIDS patients has been reviewed. In vitro and experimental data are unclear. On the basis of folinic acid metabolism and pharmacology and of clinical experience, we suggest that folinic acid should not be systematically added to the curative treatment of pneumocystosis with cotrimoxazole. Folinic acid may be added to prophylactic regimens using high-dose cotrimoxazole (i.e. 800 mg sulfamethoxazole twice a day) and in malnourished patients. It should be administered as soon as cytopenia occurs in the course of treatment. Concerning toxoplasmosis, the addition of folinic acid is recommended in doses of 10 to 20 mg/day in acute therapy and 5 to 10 mg/day in maintenance therapy. Dosage must be adjusted to the results of blood counts.