20 research outputs found

    Aryl hydantoin Ro 13-3978, a broad-spectrum antischistosomal

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    Objectives Praziquantel is the only drug available for the treatment of schistosomiasis and the state of the exhausted drug discovery pipeline is alarming. We restarted investigations on the abandoned antischistosomal Ro 13-3978, an aryl hydantoin discovered in the early 1980s by Hoffmann La-Roche. Methods Newly transformed schistosomula and adult Schistosoma mansoni were studied in the presence of Ro 13-3978 in vitro. The metabolic stability of Ro 13-3978 was determined in vitro using human and mouse liver S9 fractions. Dose-response relationship, stage specificity, hepatic shift and scanning electron microscopy studies were carried out in S. mansoni-infected mice. In addition, efficacy experiments were conducted in rodents infected with Echinostoma caproni and Fasciola hepatica as well as in S. mansoni-infected immunocompromised nude (Foxn1nu) mice. Results Ro 13-3978 showed minor in vitro activity and no damage to the tegument was found. No cytotoxicity was detected for Ro 13-3978. Ro 13-3978 was metabolically stable. ED50 values of 138.9 and 14.6 mg/kg were calculated for the treatment of juvenile and adult S. mansoni infections, respectively, with a single oral dose of Ro 13-3978. SEM studies revealed severe damage to the worms 48 h post-treatment of infected mice. A single oral dose of Ro 13-3978 (100 mg/kg) administered to S. mansoni-infected (Foxn1nu) mice reduced the worm burden by 88%. Ro 13-3978 was not active against E. caproni and F. hepatica in vivo. Conclusions Ro 13-3978 has excellent antischistosomal properties in vivo. Structure-activity relationship studies with the aryl hydantoins have been launched in order to elucidate active pharmacophores, further investigate the mechanism of action and to identify a derivative with minimal antiandrogenic effect

    Aryl hydantoin Ro 13-3978, a broad-spectrum antischistosomal

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    Praziquantel is the only drug available for the treatment of schistosomiasis and the state of the exhausted drug discovery pipeline is alarming. We restarted investigations on the abandoned antischistosomal Ro 13-3978, an aryl hydantoin discovered in the early 1980s by Hoffmann La-Roche.; Newly transformed schistosomula and adult Schistosoma mansoni were studied in the presence of Ro 13-3978 in vitro. The metabolic stability of Ro 13-3978 was determined in vitro using human and mouse liver S9 fractions. Dose-response relationship, stage specificity, hepatic shift and scanning electron microscopy studies were carried out in S. mansoni-infected mice. In addition, efficacy experiments were conducted in rodents infected with Echinostoma caproni and Fasciola hepatica as well as in S. mansoni-infected immunocompromised nude (Foxn1(nu)) mice.; Ro 13-3978 showed minor in vitro activity and no damage to the tegument was found. No cytotoxicity was detected for Ro 13-3978. Ro 13-3978 was metabolically stable. ED50 values of 138.9 and 14.6 mg/kg were calculated for the treatment of juvenile and adult S. mansoni infections, respectively, with a single oral dose of Ro 13-3978. SEM studies revealed severe damage to the worms 48 h post-treatment of infected mice. A single oral dose of Ro 13-3978 (100 mg/kg) administered to S. mansoni-infected (Foxn1(nu)) mice reduced the worm burden by 88%. Ro 13-3978 was not active against E. caproni and F. hepatica in vivo.; Ro 13-3978 has excellent antischistosomal properties in vivo. Structure-activity relationship studies with the aryl hydantoins have been launched in order to elucidate active pharmacophores, further investigate the mechanism of action and to identify a derivative with minimal antiandrogenic effects

    Mononuclear phagocyte intercellular crosstalk facilitates transmission of cell-targeted nanoformulated antiretroviral drugs to human brain endothelial cells

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    Despite the successes of antiretroviral therapy (ART), HIV-associated neurocognitive disorders remain prevalent in infected people. This is due, in part, to incomplete ART penetration across the blood–brain barrier (BBB) and lymph nodes and to the establishment of viral sanctuaries within the central nervous system. In efforts to improve ART delivery, our laboratories developed a macrophage-carriage system for nanoformulated crystalline ART (nanoART) (atazanavir, ritonavir, indinavir, and efavirenz). We demonstrate that nanoART transfer from mononuclear phagocytes (MP) to human brain microvascular endothelial cells (HBMEC) can be realized through cell-to-cell contacts, which can facilitate drug passage across the BBB. Coculturing of donor MP containing nanoART with recipient HBMEC facilitates intercellular particle transfer. NanoART uptake was observed in up to 52% of HBMEC with limited cytotoxicity. Folate coating of nanoART increased MP to HBMEC particle transfer by up to 77%. To translate the cell assays into relevant animal models of disease, ritonavir and atazanavir nanoformulations were injected into HIV-1-infected NOD/scid-γcnull mice reconstituted with human peripheral blood lymphocytes. Atazanavir and ritonavir levels in brains of mice treated with folate-coated nanoART were three- to four-fold higher than in mice treated with noncoated particles. This was associated with decreased viral load in the spleen and brain, and diminished brain CD11b-associated glial activation. We postulate that monocyte-macrophage transfer of nanoART to brain endothelial cells could facilitate drug entry into the brain
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