Essential oils from Syzygium aromaticum and Zingiber officinale, administered alone or in combination with benznidazole, reduce the parasite load in mice orally inoculated with Trypanosoma cruzi II.

BACKGROUND: Trypanosoma cruzi is the etiological agent of Chagas disease (CD) or American trypanosomiasis, an important public health problem in Latin America. Benznidazole (BZ), a drug available for its treatment, has limited efficacy and significant side effects. Essential oils (EOs) have demonstrated trypanocidal activity and may constitute a therapeutic alternative. Our aim was to evaluate the efficacy of the EOs of clove (CEO - Syzygium aromaticum) and ginger (GEO - Zingiber officinale), administered alone and in combination with BZ, in Swiss mice infected with T. cruzi. METHODS: The animals were inoculated with 10,000 blood trypomastigotes of the Y strain of T. cruzi II by gavage and divided into four groups (n = 12 to 15): 1) untreated control (NT); 2) treated with BZ; 3) treated with CEO or GEO; and 4) treated with BZ + CEO or GEO. The treatments consisted of oral administration of 100 mg/kg/day, from the 5th day after parasite inoculation, for 20 consecutive days. All groups were submitted to fresh blood examination (FBE), blood culture (BC), conventional PCR (cPCR) and real-time PCR (qPCR), before and after immunosuppression with cyclophosphamide. RESULTS: Clove and ginger EOs, administered alone and in combination with BZ, promoted suppression of parasitemia (p < 0.0001), except for the animals treated with CEO alone, which presented a parasitemia curve similar to NT animals. However, there was a decrease in the BC positivity rate (p < 0.05) and parasite load (< 0.0001) in this group. Treatment with GEO alone, on the other hand, besides promoting a decrease in the BC positivity rate (p < 0.05) and parasite load (p < 0.01), this EO also resulted in a decrease in mortality rate (p < 0.05) of treated mice. CONCLUSIONS: Decreased parasite load, as detected by qPCR, was observed in all treatment groups (BZ, CEO, GEO and BZ + EOs), demonstrating benefits even in the absence of parasitological cure, thus opening perspectives for further studies.

Phase 1 Study of the Effects of the Tuberculosis Treatment Pretomanid, Alone and in Combination With Moxifloxacin, on the QTc Interval in Healthy Volunteers.

Tuberculosis (TB) continues to be a serious threat to public health throughout the world. Newer treatments are needed that could offer simplified regimens with activity against both drug-sensitive and drug-resistant bacilli, while optimizing safety. Pretomanid (PA-824), a nitroimidazooxazine compound, is a new drug for the treatment of pulmonary TB that was recently approved in the United States and Europe in the context of a regimen combined with bedaquiline and linezolid. This phase 1 double-blind, randomized, placebo-controlled crossover study specifically examined the effect of single-dose administration of pretomanid 400 or 1000 mg and pretomanid 400 mg plus moxifloxacin 400 mg on the QTc interval in 74 healthy subjects. Subjects were fasting at the time of drug administration. Pretomanid concentrations following single 400- or 1000-mg doses were not associated with any QT interval prolongation of clinical concern. Moxifloxacin did not alter the pharmacokinetics of pretomanid, and the effect of pretomanid 400 mg plus moxifloxacin 400 mg on the individually corrected QT interval was consistent with the effect of moxifloxacin alone. Both drugs were generally well tolerated. Although supratherapeutic exposure of pretomanid relative to the now-recommended dosing with food was not achieved, these findings contribute to the favorable assessment of cardiac safety for pretomanid.

Bedaquiline, moxifloxacin, pretomanid, and pyrazinamide during the first 8 weeks of treatment of patients with drug-susceptible or drug-resistant pulmonary tuberculosis: a multicentre, open-label, partially randomised, phase 2b trial.

BACKGROUND: New anti-tuberculosis regimens that are shorter, simpler, and less toxic than those that are currently available are needed as part of the global effort to address the tuberculosis epidemic. We aimed to investigate the bactericidal activity and safety profile of combinations of bedaquiline, pretomanid, moxifloxacin, and pyrazinamide in the first 8 weeks of treatment of pulmonary tuberculosis. METHODS: In this multicentre, open-label, partially randomised, phase 2b trial, we prospectively recruited patients with drug-susceptible or rifampicin-resistant pulmonary tuberculosis from seven sites in South Africa, two in Tanzania, and one in Uganda. Patients aged 18 years or older with sputum smear grade 1+ or higher were eligible for enrolment, and a molecular assay (GeneXpert or MTBDRplus) was used to confirm the diagnosis of tuberculosis and to distinguish between drug-susceptible and rifampicin-resistant tuberculosis. Patients who were HIV positive with a baseline CD4 cell count of less than 100 cells per uL were excluded. Patients with drug-susceptible tuberculosis were randomly assigned (1:1:1) using numbered treatment packs with sequential allocation by the pharmacist to receive 56 days of treatment with standard tuberculosis therapy (oral isoniazid, rifampicin, pyrazinamide, and ethambutol; HRZE), or pretomanid (oral 200 mg daily) and pyrazinamide (oral 1500 mg daily) with either oral bedaquiline 400 mg daily on days 1-14 then 200 mg three times per week (BloadPaZ) or oral bedaquiline 200 mg daily (B200PaZ). Patients with rifampicin-resistant tuberculosis received 56 days of the B200PaZ regimen plus moxifloxacin 400 mg daily (BPaMZ). All treatment groups were open label, and randomisation was not stratified. Patients, trial investigators and staff, pharmacists or dispensers, laboratory staff (with the exception of the mycobacteriology laboratory staff), sponsor staff, and applicable contract research organisations were not masked. The primary efficacy outcome was daily percentage change in time to sputum culture positivity (TTP) in liquid medium over days 0-56 in the drug-susceptible tuberculosis population, based on non-linear mixed-effects regression modelling of log10 (TTP) over time. The efficacy analysis population contained patients who received at least one dose of medication and who had efficacy data available and had no major protocol violations. The safety population contained patients who received at least one dose of medication. This study is registered with ClinicalTrials.gov, NCT02193776, and all patients have completed follow-up. FINDINGS: Between Oct 24, 2014, and Dec 15, 2015, we enrolled 180 patients with drug-susceptible tuberculosis (59 were randomly assigned to BloadPaZ, 60 to B200PaZ, and 61 to HRZE) and 60 patients with rifampicin-resistant tuberculosis. 57 patients in the BloadPaZ group, 56 in the B200PaZ group, and 59 in the HRZE group were included in the primary analysis. B200PaZ produced the highest daily percentage change in TTP (5·17% [95% Bayesian credibility interval 4·61-5·77]), followed by BloadPaZ (4·87% [4·31-5·47]) and HRZE group (4·04% [3·67-4·42]). The bactericidal activity in B200PaZ and BloadPaZ groups versus that in the HRZE group was significantly different. Higher proportions of patients in the BloadPaZ (six [10%] of 59) and B200PaZ (five [8%] of 60) groups discontinued the study drug than in the HRZE group (two [3%] of 61) because of adverse events. Liver enzyme elevations were the most common grade 3 or 4 adverse events and resulted in the withdrawal of ten patients (five [8%] in the BloadPaZ group, three [5%] in the B200PaZ group, and two [3%] in the HRZE group). Serious treatment-related adverse events affected two (3%) patients in the BloadPaZ group and one (2%) patient in the HRZE group. Seven (4%) patients with drug-susceptible tuberculosis died and four (7%) patients with rifampicin-resistant tuberculosis died. None of the deaths were considered to be related to treatment. INTERPRETATION: B200PaZ is a promising regimen to treat patients with drug-susceptible tuberculosis. The bactericidal activity of both these regimens suggests that they have the potential to shorten treatment, and the simplified dosing schedule of B200PaZ could improve treatment adherence in the field. However, these findings must be investigated further in a phase 3 trial assessing treatment outcomes. FUNDING: TB Alliance, UK Department for International Development, Bill & Melinda Gates Foundation, US Agency for International Development, Directorate General for International Cooperation of the Netherlands, Irish Aid, Australia Department of Foreign Affairs and Trade, and the Federal Ministry for Education and Research of Germany.

Thermal Sensitive Liposomes Improve Delivery of Boronated Agents for Boron Neutron Capture Therapy.

PURPOSE: Boron neutron capture therapy (BNCT) has the potential to become a viable cancer treatment modality, but its clinical translation requires sufficient tumor boron delivery while minimizing nonspecific accumulation. METHODS: Thermal sensitive liposomes (TSLs) were designed to have a stable drug payload at physiological temperatures but engineered to have high permeability under mild hyperthermia. RESULTS: We found that TSLs improved the tumor-specific delivery of boronophenylalanine (BPA) and boronated 2-nitroimidazole derivative B-381 in D54 glioma cells. Uniquely, the 2-nitroimidazole moiety extended the tumor retention of boron content compared to BPA. CONCLUSION: This is the first study to show the delivery of boronated compounds using TSLs for BNCT, and these results will provide the basis of future clinical trials using TSLs for BNCT.

Administration of Hypoxia-Activated Prodrug Evofosfamide after Conventional Adjuvant Therapy Enhances Therapeutic Outcome and Targets Cancer-Initiating Cells in Preclinical Models of Colorectal Cancer.

Purpose: Cancer-initiating cells (C-IC) have been described in multiple cancer types, including colorectal cancer. C-ICs are defined by their capacity to self-renew, thereby driving tumor growth. C-ICs were initially thought to be static entities; however, recent studies have determined these cells to be dynamic and influenced by microenvironmental cues such as hypoxia. If hypoxia drives the formation of C-ICs, then therapeutic targeting of hypoxia could represent a novel means to target C-ICs.Experimental Design: Patient-derived colorectal cancer xenografts were treated with evofosfamide, a hypoxia-activated prodrug (HAP), in combination with 5-fluorouracil (5-FU) or chemoradiotherapy (5-FU and radiation; CRT). Treatment groups included both concurrent and sequential dosing regimens. Effects on the colorectal cancer-initiating cell (CC-IC) fraction were assessed by serial passage in vivo limiting dilution assays. FAZA-PET imaging was utilized as a noninvasive method to assess intratumoral hypoxia.Results: Hypoxia was sufficient to drive the formation of CC-ICs and colorectal cancer cells surviving conventional therapy were more hypoxic and C-IC-like. Using a novel approach to combination therapy, we show that sequential treatment with 5-FU or CRT followed by evofosfamide not only inhibits tumor growth of xenografts compared with 5-FU or CRT alone, but also significantly decreases the CC-IC fraction. Furthermore, noninvasive FAZA-PET hypoxia imaging was predictive of a tumor's response to evofosfamide.Conclusions: Our data demonstrate a novel means to target the CC-IC fraction by adding a HAP sequentially after conventional adjuvant therapy, as well as the use of FAZA-PET as a biomarker for hypoxia to identify tumors that will benefit most from this approach. Clin Cancer Res; 24(9); 2116-27. ©2018 AACR.

Drug repurposing strategy against Trypanosoma cruzi infection: In vitro and in vivo assessment of the activity of metronidazole in mono- and combined therapy.

Metronidazole (Mtz) is a commercial broad-spectrum nitroimidazolic derivative with relevant antimicrobial activity and relative safety profile. Therefore, it is fair to consider Mtz a candidate for drug repurposing for other neglected conditions such as Chagas disease (CD), a parasitic pathology caused by Trypanosoma cruzi. CD is treated only with benznidazole (Bz) and nifurtimox, both introduced in clinics decades ago despite important limitations, including low efficacy on the later disease stage (chronic form) and severe side effects. New cheap and fast alternative treatments for CD are needed, thus the repurposing of Mtz was assessed in vitro and in vivo in mono- and combined therapy. In vitro assays demonstrated EC50>200µM for Mtz, while for Bz the values ranged from 2.51µM (intracellular forms) to 11.5µM (bloodstream trypomastigotes). When both drugs were combined in fixed-ratio proportions, Mtz promoted Bz potency (lower EC50 values). In vivo toxicity assays for Mtz in mice showed no adverse effects neither histopathological alterations up to 2000mg/kg. Regarding experimental T. cruzi infection, Bz 100mg/kg suppressed parasitemia while Mtz (up to 1000mg/kg) in monotherapy did not, but prolonged animal survival at 250 and 500 regimen doses. The combination of both drugs (Bz 10+Mtz 250) prevented mortality (70%) besides protected against electric cardiac alterations triggered by the parasite infection. Although not able to reduce parasite load, the combination therapy prevented animal mortality; this was possibly due to a protection of the electric cardiac physiology that is normally altered in experimental infection of T. cruzi. It also suggested that the interaction with Mtz could have improved the pharmacokinetics of Bz. Our study emphasizes the importance of drug repurposing and combined therapy for CD to contribute to alternative therapies for this neglected and silent pathology.

Preclinical Benefit of Hypoxia-Activated Intra-arterial Therapy with Evofosfamide in Liver Cancer.

PURPOSE: To evaluate safety and characterize anticancer efficacy of hepatic hypoxia-activated intra-arterial therapy (HAIAT) with evofosfamide in a rabbit model. EXPERIMENTAL DESIGN: VX2-tumor-bearing rabbits were assigned to 4 intra-arterial therapy (IAT) groups (n = 7/group): (i) saline (control); (ii) evofosfamide (Evo); (iii) doxorubicin-lipiodol emulsion followed by embolization with 100-300 µm beads (conventional, cTACE); or (iv) cTACE and evofosfamide (cTACE + Evo). Blood samples were collected pre-IAT and 1, 2, 7, and 14 days post-IAT. A semiquantitative scoring system assessed hepatocellular damage. Tumor volumes were segmented on multidetector CT (baseline, 7/14 days post-IAT). Pathologic tumor necrosis was quantified using manual segmentation on whole-slide images. Hypoxic fraction (HF) and compartment (HC) were determined by pimonidazole staining. Tumor DNA damage, apoptosis, cell proliferation, endogenous hypoxia, and metabolism were quantified (γ-H2AX, Annexin V, caspase-3, Ki-67, HIF1α, VEGF, GAPDH, MCT4, and LDH). RESULTS: cTACE + Evo showed a similar profile of liver enzymes elevation and pathologic scores compared with cTACE. Neither hematologic nor renal toxicity were observed. Animals treated with cTACE + Evo demonstrated smaller tumor volumes, lower tumor growth rates, and higher necrotic fractions compared with cTACE. cTACE + Evo resulted in a marked reduction in the HF and HC. Correlation was observed between decreases in HF or HC and tumor necrosis. cTACE + Evo promoted antitumor effects as evidenced by increased expression of γ-H2AX, apoptotic biomarkers, and decreased cell proliferation. Increased HIF1α/VEGF expression and tumor glycolysis supported HAIAT. CONCLUSIONS: HAIAT achieved a promising step towards the locoregional targeting of tumor hypoxia. The favorable toxicity profile and enhanced anticancer effects of evofosfamide in combination with cTACE pave the way towards clinical trials in patients with liver cancer. Clin Cancer Res; 23(2); 536-48. ©2016 AACR.

Preclinical comprehensive physicochemical and pharmacokinetic profiling of novel nitroimidazole derivative IIIM-019 - A potential oral treatment for tuberculosis.

New compounds against tuberculosis are urgently needed to combat the crisis of drug resistance in tuberculosis (TB). We have identified a nitrodihydroimidazooxazole analog, IIIM-019 as a new anti-tubercular agent with a MIC of 0.23 µM against H37Rv. Physicochemical properties, in-vitro pharmacokinetics and in-vivo multiple-doses pharmacokinetics were studied for the compound. In silico physicochemical parameters and Lipinski's violations were determined for drug like properties. Lipophilicity was determined experimentally as Octanol-PBS partition coefficient (log P). Passive and active permeability of the compound was determined by PAMPA and Caco-2 cell permeability analysis, respectively. Plasma protein binding was determined by Rapid equilibrium dialysis. Metabolism by liver microsomes revealed the t1/2 and intrinsic clearance of the compound. Hepatotoxicity of IIIM-019 was determined alone and in combination to first line anti-tubercular drugs. The compound was also estimated for nuclear DNA damage. Single doses of IIIM-019 (2.5, 10, 25 and 100 mg/kg) were administered orally to Balb/c mice and the blood samples were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). IIIM-019 exhibited very good lipophilicity (log P) of 2.47 which makes it optimal for oral administration. The compound showed low solubility and permeability and high plasma protein binding. However, it was highly stable in rat liver microsomes with t1/2 > 2 h and very low intrinsic clearance. It was found to be non-hepatotoxic and did not induce any significant DNA damage at high concentrations even up to 100 µM. IIIM-019 showed satisfactory in-vivo pharmacokinetic properties. By increasing the dose from 2.5 mg/kg to 10 mg/kg, AUC0-t increased from 14935 ng h/ml to 81,478 ng h/ml. However the exposure of IIIM-019 in plasma suggested that the levels reached saturation at higher concentrations. The compound showed a good oral bioavailability of 58.7%. The results insinuate that IIIM-019 should undergo further development as a potential treatment for tuberculosis.

The in vivo trypanocidal effect of the diterpene 5-epi-icetexone obtained from Salvia gilliesii.

The search for new compounds with trypanocidal activity is crucial for the treatment of Chagas' disease. Previous in vitro studies have shown that the diterpene 5-epi-icetexone (ICTX) is active against Trypanosoma cruzi. The aim of this work was to evaluate the effect of ICTX on the parasites in infected mice, in an experimental model that mimics the acute phase of the disease. Swiss albino mice were infected with T. cruzi and treated daily with 10mg/kg/day ICTX (i.p.). Infected mice and mice injected with either saline or the vehicle DMSO were used as controls. Animals' survival and parasitemia were monitored once a week and histological studies were made at necropsy by the 5th week after infection. It was observed that the administration of ICTX increased the survival of mice infected, and induced a significant decrease in the parasitemia, as compared to controls. A similar protective effect was observed when animals were treated orally with benznidazole (BZN, used as a control of antiparasitic effect). By the 5th week post-infection, the presence of amastigote nests was observed within the fibers of the cardiac and skeletal muscle in controls, but not in animals treated with either ICTX or BZN. In addition, inflammatory infiltrates were observed in the tissues of controls, but not in animals treated with the drugs. We conclude that ICTX has an antiparasitic effect against T. cruzi, thus constituting an interesting option for the treatment of Chagas' disease, alone or combined with other drugs.

Impact of the Use of Benznidazole Followed by Antioxidant Supplementation in the Prevalence of Ventricular Arrhythmias in Patients With Chronic Chagas Disease: Pilot Study.

Patients with chronic Chagas disease have a higher prevalence of premature ventricular contraction (PVC) because of immunoinflammatory response magnified by the increased oxidative stress. Thus, the sequential treatment with benznidazole (BZN) and antioxidants can reduce the prevalence of PVC. We wish to establish whether the etiological treatment of Chagas disease followed by supplementation with the antioxidant vitamins E and C decreases the prevalence of PVC in these patients. A sample of 41 patients with chronic Chagas disease at different stages of the heart disease was selected for the treatment against the causative agent using BZN (5 mg·kg·d, minimum dose 300 mg daily) for 2 months followed by supplementation with antioxidants such as vitamins E (800 UI/d) and C (500 mg/d) for 6 months. The prevalence of PVC was observed by conducting 24-hour Holter. To evaluate the oxidative status of the patients, serum markers of oxidative stress like glutathione peroxidase, superoxide dismutase, catalase, glutathione reductase, and glutathione S-transferase were measured, and also reduced glutathione, vitamin E, and markers of tissue damage like thiobarbituric acid reactive substances and protein carbonyl. A decrease in the prevalence of PVC in patients with advanced Chagas heart disease was observed (5391 vs. 1185, P = 0.0068). This reduction was followed by decrease of serum markers of oxidative stress. In patients with a lower degree of cardiac damage, the reduction on prevalence of PVC was not significant. The etiological treatment with BZN followed by supplementation with antioxidant vitamins E and C reduces episodes of PVC in patients with severe Chagas heart disease.

Nanomedicines against Chagas disease: an update on therapeutics, prophylaxis and diagnosis.

Chagas disease is a neglected parasitic infection caused by the protozoan Trypanosoma cruzi. After a mostly clinically silent acute phase, the disease becomes a lifelong chronic condition that can lead to chronic heart failure and thromboembolic phenomena followed by sudden death. Antichagasic treatment is only effective in the acute phase but fails to eradicate the intracellular form of parasites and causes severe toxicity in adults. Although conventional oral benznidazol is not a safe and efficient drug to cure chronic adult patients, current preclinical data is insufficient to envisage if conventional antichagasic treatment could be realistically improved by a nanomedical approach. This review will discuss how nanomedicines could help to improve the performance of therapeutics, vaccines and diagnosis of Chagas disease.

Nitroimidazo-oxazole compound DNDI-VL-2098: an orally effective preclinical drug candidate for the treatment of visceral leishmaniasis.

OBJECTIVES: The objective of this study was to identify a nitroimidazo-oxazole lead molecule for the treatment of visceral leishmaniasis (VL). METHODS: A library of 72 nitroimidazo-oxazoles was evaluated in vitro for their antileishmanial activity against luciferase-transfected DD8 amastigotes of Leishmania donovani. On the basis of their in vitro potency and pharmacokinetic properties, the promising compounds were tested in acute BALB/c mouse and chronic hamster models of VL via oral administration and efficacy was evaluated by microscopic counting of amastigotes after Giemsa staining. The best antileishmanial candidates (racemate DNDI-VL-2001) and its R enantiomer (DNDI-VL-2098) were evaluated in vitro against a range of Leishmania strains. These candidates were further studied in a hamster model using various dose regimens. Cytokine and inducible nitric oxide synthase estimations by real-time PCR and nitric oxide generation by Griess assay were also carried out for DNDI-VL-2098. RESULTS: In vitro screening of nitroimidazo-oxazole compounds identified the racemate DNDI-VL-2001 (6-nitroimidazo-oxazole derivative) and its enantiomers as candidates for further evaluation in in vivo models of VL. DNDI-VL-2098 (IC50 of 0.03 µM for the DD8 strain) showed excellent in vivo activity in both mouse and hamster models, with an ED90 value of 3.7 and <25 mg/kg, respectively, and was also found to be very effective against high-grade infection in the hamster model. Our studies revealed that, along with leishmanicidal activity, DNDI-VL-2098 was also capable of inducing host-protective immune cells to suppress Leishmania parasites in hamsters. CONCLUSIONS: These studies led to the identification of compound DNDI-VL-2098 as a preclinical candidate for further drug development as an oral treatment for VL.

The Association of Ponderal Benznidazole with its Ultra-high Diluted Formula Reduces the Toxic Effects and Allows Increasing of Dose in Dose-dependent Protocol in Mice Infected with Trypanosoma cruzi

Although several diseases are treated by toxic drugs, their side effects may hamper adherence to the therapy. The aim of this study is to evaluate the effect of the association of ponderal benznidazole (BZ) with its ultra-high diluted (UHD) formula on clinical and parasitological parameters of mice infected by Trypanosoma cruzi (T. cruzi). 24 non-isogenic Swiss mice were divided into groups: CI – infected animals treated with 7% alcohol; BZp – infected animals treated with BZ (500 mg/ kg) from the beginning of infection; BZp+d – infected animals treated with ponderal BZ and with UHD BZ, which started to be administered four days after the beginning of treatment with ponderal BZ; CNI - group of non-treated and non-infected animals. The UHD medicine was prepared according to Phamacopoeia until 30x. The different treatment schedules were statistically compared through parasitological and clinical parameters. The group BZp+d displayed more favorable clinical evolution than the group BZp, with improvement of mass gain, feed conversion and water intake, presenting data approximated to CNI group. The significant increase of the body temperature of BZp+d group indicates an activation of the immune system which was not observed in the other groups. Moreover, the anti-parasitic effect of the ponderal drug was maintained in all parasitological parameters of this group. By reducing the side effects and maintaining the action of the ponderal drug, the combination of toxic drugs with their UHD formula could be considered a way of improving efficacy of the treatment...

A infecção por Trypanossoma cruzi é um problema de saúde pública e o único medicamento disponível no Brasil é o benznidazol (BZ), com efeitos limitados e tóxicos. Estudos anteriores com BZ na dose de 200 mg/kg indicaram que a administração de BZ diluído (30d) controla os efeitos tóxicos da droga em dose ponderal, sem alterar a sua ação terapêutica. Sob essa perspectiva e considerando a ação do BZ dose dependente, aumentar a quantidade de droga administrada significaria uma melhora na eficácia do tratamento. Portanto, este trabalho teve como objetivo avaliar o efeito do BZ ponderal (BZP), na dose de 500 mg/kg associado com BZ diluído (BZD) nos parâmetros clínicos de camundongos infectados por T. cruzi. Em estudo cego, controlado e randomizado, foram utilizados 23 camundongos suíços, machos, com 8 semanas divididos em grupos: CNI - Não infectados e não tratados; CI - Infectados e tratados com álcool 7 %; BZP - Infectados tratados com BZ (500 mg/kg de peso/ animal) a partir do início da infecção; BZP + BZD - Infectados e tratados com a associação de BZP e BZD. Os medicamentos foram administrados por gavagem (0,2 mL/ dia/ animal). O BZP foi administrado a partir da constatação da infecção. O BZ diluído foi preparado de acordo com a Farmacopeia Homeopática Brasileira e administrado 4 dias após o início do tratamento com BZP. Os parâmetros clínicos, avaliados diariamente, incluíram: peso, consumo de ração e água, temperatura e quantidade de excretas. A análise clínica apontou melhores resultados nos grupos BZP e BZP + BZD, mostrando melhor evolução de peso, consumo de ração, água e excretas quando comparado aos grupos não tratados (p< 0.05)...

The Association of Ponderal Benznidazole with its Ultra-high Diluted Formula Reduces the Toxic Effects and Allows Increasing of Dose in Dose-dependent Protocol in Mice Infected with Trypanosoma cruzi

Although several diseases are treated by toxic drugs, their side effects may hamper adherence to the therapy. The aim of this study is to evaluate the effect of the association of ponderal benznidazole (BZ) with its ultra-high diluted (UHD) formula on clinical and parasitological parameters of mice infected by Trypanosoma cruzi (T. cruzi). 24 non-isogenic Swiss mice were divided into groups: CI – infected animals treated with 7% alcohol; BZp – infected animals treated with BZ (500 mg/ kg) from the beginning of infection; BZp+d – infected animals treated with ponderal BZ and with UHD BZ, which started to be administered four days after the beginning of treatment with ponderal BZ; CNI - group of non-treated and non-infected animals. The UHD medicine was prepared according to Phamacopoeia until 30x. The different treatment schedules were statistically compared through parasitological and clinical parameters. The group BZp+d displayed more favorable clinical evolution than the group BZp, with improvement of mass gain, feed conversion and water intake, presenting data approximated to CNI group. The significant increase of the body temperature of BZp+d group indicates an activation of the immune system which was not observed in the other groups. Moreover, the anti-parasitic effect of the ponderal drug was maintained in all parasitological parameters of this group. By reducing the side effects and maintaining the action of the ponderal drug, the combination of toxic drugs with their UHD formula could be considered a way of improving efficacy of the treatment. (AU)

A infecção por Trypanossoma cruzi é um problema de saúde pública e o único medicamento disponível no Brasil é o benznidazol (BZ), com efeitos limitados e tóxicos. Estudos anteriores com BZ na dose de 200 mg/kg indicaram que a administração de BZ diluído (30d) controla os efeitos tóxicos da droga em dose ponderal, sem alterar a sua ação terapêutica. Sob essa perspectiva e considerando a ação do BZ dose dependente, aumentar a quantidade de droga administrada significaria uma melhora na eficácia do tratamento. Portanto, este trabalho teve como objetivo avaliar o efeito do BZ ponderal (BZP), na dose de 500 mg/kg associado com BZ diluído (BZD) nos parâmetros clínicos de camundongos infectados por T. cruzi. Em estudo cego, controlado e randomizado, foram utilizados 23 camundongos suíços, machos, com 8 semanas divididos em grupos: CNI - Não infectados e não tratados; CI - Infectados e tratados com álcool 7 %; BZP - Infectados tratados com BZ (500 mg/kg de peso/ animal) a partir do início da infecção; BZP + BZD - Infectados e tratados com a associação de BZP e BZD. Os medicamentos foram administrados por gavagem (0,2 mL/ dia/ animal). O BZP foi administrado a partir da constatação da infecção. O BZ diluído foi preparado de acordo com a Farmacopeia Homeopática Brasileira e administrado 4 dias após o início do tratamento com BZP. Os parâmetros clínicos, avaliados diariamente, incluíram: peso, consumo de ração e água, temperatura e quantidade de excretas. A análise clínica apontou melhores resultados nos grupos BZP e BZP + BZD, mostrando melhor evolução de peso, consumo de ração, água e excretas quando comparado aos grupos não tratados (p< 0.05). A associação BZP + BZDobteve melhor evolução de peso, consumo de água e produção de excretas (p< 0.05) quando comparada com o grupo tratado BZP, revelando-se uma alternativa para diminuir os efeitos indesejados do medicamento convencional, permitindo o aumento da dose administrada e maior eficácia do tratamento. A associação destes medicamentos deve ser explorada em outras condições clínicas onde existem poucos medicamentos disponíveis e efeitos colaterais que comprometem a terapêutica

First report of a family outbreak of Chagas disease in French Guiana and posttreatment follow-up.

The outbreak of acute Chagas disease due to oral transmission of the parasite is a well-known phenomenon mainly occurring in the Amazon. Such an event is described here for the first time in French Guiana. Eight patients of the same family, presenting epidemiological and clinical histories compatible with recent Trypanosoma cruzi infection of Chagas disease due to the ingestion of palm Oenocarpus bacaba juice were, rather late after the putative date of infection, underwent four parasitological and two serological specific tests for confirmation of the diagnosis. Real-time PCR results were positive for all the patients; strains were isolated by hemoculture from four patients, PCR identification of TcI DTU was made for six patients, while parasites were not detected in any of the patients by direct microscopic examination. The results of two serologic tests were positive. All patients were treated with benznidazole, and two patients were additionally given nifurtimox. A 6-year follow-up was possible for six patients. Real-time PCR was negative for these patients after 1 year, while the antibody rates decreased slowly and serology results were negative only after several years (1-5 years). Our findings confirm the occurrence of an outbreak of Chagas infection in members of the same family, with the oral mode of infection being the most likely hypothesis to explain this group of cases. Our results show the successful treatment of patients infected by TcI and the usefulness of real-time PCR for the emergency diagnosis of recent Chagas disease cases and in posttreatment follow-up.

PA-824 , moxifloxacin and pyrazinamide combination therapy for tuberculosis.

INTRODUCTION: New treatment regimens are urgently required for tuberculosis (TB). The existing four-drug regimen for TB is > 20 years old, with multidrug resistant (MDR) and extensively drug-resistant (XDR) TB on the increase. AREAS COVERED: Recently, the first novel potential combination TB treatment regimen for both drug-sensitive and MDR TB incorporating a new nitroimidazole compound, PA-824 , was investigated in a Phase II proof-of-concept clinical trial. This article reviews the rationale for this novel study, discusses the development strategy for PA-824 and highlights the study findings and its implications for future development of this regimen. EXPERT OPINION: Expert opinion will be offered on the utility of this new multicomponent treatment regimen. We will highlight how this study informs the development pathway for future novel TB regimens and explore the PA-824, moxifloxacin (MOX) and pyrazinamide combination as a first step towards developing a single treatment regimen for both drug-sensitive and drug-resistant diseases.

Evaluation of the relationship between MR estimates of blood oxygen saturation and hypoxia: effect of an antiangiogenic treatment on a gliosarcoma model.

PURPOSE: To assess the reproducibility of the magnetic resonance (MR) estimate of blood oxygen saturation (sO(2)) in the rat brain, to evaluate the relationship between low MR estimate of sO(2) values and tissue hypoxia in a hypoxic and necrotic glioscarcoma model (9L gliosarcoma cells), and to evaluate the capability of the MR estimate of sO(2) parameter to help identify modifications induced by an antiangiogenic treatment (sorafenib) in 9L gliosarcoma tumors. MATERIALS AND METHODS: Experiments were performed with permits from the French Ministry of Agriculture. Forty-eight male rats bearing a 9L gliosarcoma were randomized in untreated and treated (sorafenib) groups. MR blood volume fraction and MR estimate of sO(2) parameters were estimated 1 day before and 1, 3, 5, and 8 days after the start of the treatment. The in vivo MR estimate of sO(2) measurement was correlated with the ex vivo hypoxia assessment by using pimonidazole staining. Paired and unpaired t tests, as well as parametric Pearson tests, were used for the statistical analyses. RESULTS: In healthy tissues, MR estimate of sO(2) measurements were comparable to literature values and were reproducible (mean across all animals, 68.0% ± 6.5 [standard deviation]). In untreated tumors, MR estimate of sO(2) and immunohistochemical analysis yielded correlated fractional hypoxic-necrotic areas (R(2) = 0.81). In tumors treated with antiangiogenic therapy, tumor MR estimate of sO(2) was decreased with respect to the healthy tissue (P< .001). CONCLUSION: Results of this study suggest that the MR estimate of sO(2) is a reproducible estimate that could be used as an in vivo probe of hypoxia in brain tumors and as a sensitive reporter of the hypoxic effects of antiangiogenic therapies.

TH-302, a hypoxia-activated prodrug with broad in vivo preclinical combination therapy efficacy: optimization of dosing regimens and schedules.

PURPOSE: Subregional hypoxia is a common feature of tumors and is recognized as a limiting factor for the success of radiotherapy and chemotherapy. TH-302, a hypoxia-activated prodrug selectively targeting hypoxic regions of solid tumors, delivers a cytotoxic warhead to the tumor, while maintaining relatively low systemic toxicity. The antitumor activity, different dosing sequences, and dosing regimens of TH-302 in combination with commonly used conventional chemotherapeutics were investigated in human tumor xenograft models. METHODS: Seven chemotherapeutic drugs (docetaxel, cisplatin, pemetrexed, irinotecan, doxorubicin, gemcitabine, and temozolomide) were tested in combination with TH-302 in eleven human xenograft models, including non-small cell lung cancer (NSCLC), colon cancer, prostate cancer, fibrosarcoma, melanoma, and pancreatic cancer. RESULTS: The antitumor activity of docetaxel, cisplatin, pemetrexed, irinotecan, doxorubicin, gemcitabine, and temozolomide was increased when combined with TH-302 in nine out of eleven models tested. Administration of TH-302 2-8 h prior to the other chemotherapeutics yielded superior efficacy versus other sequences tested. Simultaneous administration of TH-302 and chemotherapeutics increased toxicity versus schedules with dosing separations. In a dosing optimization study, TH-302 administered daily at 50 mg/kg intraperitoneally for 5 days per week in the H460 NSCLC model showed the optimal response with minimal toxicity. CONCLUSIONS: TH-302 enhances the activity of a wide range of conventional anti-neoplastic agents in a broad panel of in vivo xenograft models. These data highlight in vivo effects of schedule and order of drug administration in regimen efficacy and toxicity and have relevance to the design of human regimens incorporating TH-302.

Pharmacokinetics of TH-302: a hypoxically activated prodrug of bromo-isophosphoramide mustard in mice, rats, dogs and monkeys.

PURPOSE: To characterize the pharmacokinetics of the prodrug, TH-302, and its active metabolite, bromo-IPM (Br-IPM), in nonclinical species. METHODS: TH-302 was administered in single oral, intraperitoneal and intravenous bolus doses to mice, rats, dogs and monkeys as well as in acute and chronic safety studies in rats and dogs as a 30-min intravenous infusion given once a week for 3 weeks. Assessments were made using liquid chromatography-tandem mass spectrometry. RESULTS: TH-302 was extensively distributed with high systemic clearance exceeding hepatic plasma flow in all species studied, resulting in half-lives ranging between 8 min (mice) and over 4 h (rats). In rats, TH-302 exhibited linear kinetics following intravenous administration and good oral bioavailability. In acute and chronic safety studies, there was no accumulation of TH-302 following once weekly dosing for 3 weeks in the rat and dog. Br-IPM plasma concentrations were a small fraction of the TH-302 plasma concentrations with significantly smaller percentages present in dogs than in rats. Allometric scaling predicted that the systemic clearance and steady-state volume of distribution in humans would be 38.8 l/h/m(2) and 34.3 l/m(2), respectively, resulting in a terminal elimination half-life of about 36 min. These values were similar to those observed in patients with solid tumors (27.1 l/h/m(2), 23.5 l/m(2) and 47 min). CONCLUSIONS: TH-302 exhibited good safety, efficacy and pharmacokinetic properties in nonclinical species, translating into favorable properties in humans.