Antiprotozoal activity of ferroquine.

Ferroquine (FQ, SSR97193) is a synthetic compound currently in development for the treatment of malaria. The use of a single compound to treat several parasitoses would be very convenient for multi-infected patients and also for financial considerations. In this work, the activity of FQ was investigated on three other Protista parasites: Kinetoplastidae (Leishmania and Trypanosoma) and the cosmopolite parasite Trichomonas vaginalis. FQ exhibited a significant in vitro activity on Trypanosoma brucei brucei and Trypanosoma brucei gambiense, the agents of African trypanosomiasis in a range from 0.2 to 3.1 µM. In vivo, intraperitoneally administered FQ demonstrated a weak but significant trypanocidal activity at 100 µmol/kg, which is however higher than the maximum tolerated dose. The drop of the parasitemia of the treated mice was significantly related to the amount of injected FQ. Furthermore, this organometallic compound was responsible for a delay in the appearance of bloodstream parasites at 50 µmol/kg. However, it was not able to cure infected mice. Although no synergy was identified in vitro between FQ and pentamidine, these results justify further investigations by evaluating analogues in this chemical series.

In vitro antileishmanial and antitrypanosomal activities of five medicinal plants from Burkina Faso.

After ethnobotanical surveys in central and western regions of Burkina Faso, five plants namely Lantana ukambensis (Verbenaceae), Xeoderris sthulmannii (Fabaceae), Parinari curatellifollia (Chrysobalanaceae), Ozoroa insignis (Anacardiaceae), and Ficus platyphylla (Moraceae) were selected for their traditional use in the treatment of parasitic diseases and cancer. Our previous studies have focused on the phytochemical, genotoxicity, antioxidant, and antiproliferative activities of these plants. In this study, the methanol extract of each plant was tested to reveal probable antileishmanial and antitrypanosomal activities. Colorimetric and spectrophotometric methods were used for the detection of antileishmanial and antitrypanosomal activities. Leishmania donovani (LV9 WT) and Trypanosoma brucei brucei GVR 35 were used to test the antileishmanial and antitrypanosomal activities, respectively. All extracts of tested plants showed a significant antitrypanosomal activity with minimum lethal concentrations between 1.5 and 25 µg/ml, the L. ukambensis extract being the most active. In the antileishmanial test, only the extract from L. ukambensis showed significant activity with an inhibitory concentration (IC(50)) of 6.9 µg/ml. The results of this study contribute to the promotion of traditional medicine products and are preliminary for the isolation of new natural molecules for the treatment of leishmaniasis and trypanosomiasis.

Antileishmanial activity of a formulation of 2-n-propylquinoline by oral route in mice model.

2-n-propylquinoline is presently a drug-candidate for the treatment of visceral leishmaniosis in pre-clinical development. As this compound is in an oily state, it needs to be formulated and the objectives of this study are: to prepare a formulation; to demonstrate that the new salted formulation did not alter the activity of the active ingredient; and finally, that this activity was quite good compared to the reference oral drug, miltefosine. Therefore, a 2-n-propylquinoline formulation, as camphorsulfonic salt, was prepared and characterised. On the Leishmania donovani / Balb/c mice model, a treatment by oral route at 60 mmoles/kg/day for ten consecutive days with this formulation was compared to 2-n-propylquinoline alone and to miltefosine, the oral reference drug. The salt formulation did not alter the activity of the 2-n-propylquinoline. The formulation reduced the parasite burden of 76% compared to 89% for miltefosine (not significant). The characteristics of this formulation results in a suitable drugability of 2-n-propylquinoline for further studies.

Membrane sterol depletion impairs miltefosine action in wild-type and miltefosine-resistant Leishmania donovani promastigotes.

OBJECTIVES: This study focuses on the importance of sterols in the action of miltefosine (hexadecylphosphocholine, HePC) against Leishmania donovani. METHODS: Plasma membranes of L. donovani promastigotes were depleted of sterol using methyl-beta-cyclodextrin (MCD) and cholesterol oxidase (CH-OX). Sterols were quantified and HePC susceptibility was assessed using the MTT test. A biomimetic model of the outer leaflet of a Leishmania plasma membrane was used to decipher the HePC-lipid interactions. RESULTS: CH-OX, which is known to act more specifically on condensed membranes, therefore at the level of lipid rafts, gave a better extraction yield in HePC-resistant parasites, confirming the more rigid structure of their membranes than those of wild-type parasites. Sterol depletion was responsible for a 40% decrease in HePC susceptibility in both wild-type and HePC-resistant parasites. Sterol repletion of the sterol-depleted parasites restored HePC susceptibility. The biomimetic model of the outer leaflet of a Leishmania plasma membrane confirmed that condensed microdomains were able to incorporate higher quantities of HePC than fluid ones and this result was amplified when the sterol concentration was increased. CONCLUSIONS: Sterol and lipid rafts probably play a significant role as an HePC reservoir providing a constant supply to the previously described transporter. In addition, (1)H NMR experiments suggested that HePC stimulated lipid trafficking in parasites.

Nosocomial dermatitis caused by Dermanyssus gallinae.

The mite Dermanyssus gallinae may cause pruritic dermatitis in humans. We describe a case of nosocomial infestation with D. gallinae from an abandoned pigeon nest suspended on the front wall of the Hôpital Henri Mondor near a window. Close surveillance and regular destruction of pigeon nests could prevent these incidents of infection in humans.

In vitro and in vivo antileishmanial efficacy of a new nitrilquinoline against Leishmania donovani.

The in vitro activity of a new analogue of 2-alkenylquinoline (2-nitrilquinoline or NQ) against Leishmania donovani was compared to oral reference drug miltefosine (HePC). IC(50) of NQ was found at 38.6 microM against promastigotes and 2.4 microM against intramacrophage amastigotes. In vivo evaluation in the L. donovani Balb/c mice model indicated that oral treatments at 12.5 and 25 mg/kg for 10 consecutive days significantly reduced the parasite burden in the liver by 68.9 and 68.5%, respectively. This activity was similar to those of HePC at 7.5 mg/kg for 10 days which reduced the parasite burden in liver by 72.5%. The present study shows the positive contribution of a nitril substitute being added into the alkenyl chain branched at the 2-position of the quinoline ring to the antileishmanial activity. In addition, any apparent toxicological disorder was observed during the experiments.

Postnatal electrical and morphological abnormalities in lumbar motoneurons from transgenic mouse models of amyotrophic lateral sclerosis.

Antidromically identified lumbar motoneurons intracellularly recorded in the entire brainstem/spinal cord preparation isolated from SOD1(G85R) postnatal mice (P3-P10) were labelled with neurobiotin and fully reconstructed in 3D from serial sections in order to analyse their morphology. This staining procedure revealed differences between WT and SOD1(G85R) dendritic trees for most metric and topologic parameters analyzed. A highly complex morphology of SOD1(G85R) motoneurons dendrites (increased number of branching points and terminations) was found and the dendritic trees were longer compared to the WT motoneurons. These morphological changes observed in P8-P9 motoneurons mice occurred concomitantly with a decrease in the input resistance and gain. During electrophysiological recordings, four patterns of discharge were observed in response to ramp stimulations, that were equally distributed in WT and SOD1(G85R) motoneurons. In slice preparation, whole cell patch-clamp recordings made from developing motoneurons in SOD1(G85R) and double transgenic SOD1(G93A)/Hb9-eGFP mice showed that Riluzole, a blocker of persistent inward sodium conductance, altered the repetitive firing in a similar way for the 2 strains. These results show that the SOD1 mutations linked to familial ALS alter the development of the electrical and morphological properties of lumbar motoneurons.

Striatal Neurons Expressing D1 and D2 Receptors are Morphologically Distinct and Differently Affected by Dopamine Denervation in Mice.

The loss of nigrostriatal dopamine neurons in Parkinson's disease induces a reduction in the number of dendritic spines on medium spiny neurons (MSNs) of the striatum expressing D1 or D2 dopamine receptor. Consequences on MSNs expressing both receptors (D1/D2 MSNs) are currently unknown. We looked for changes induced by dopamine denervation in the density, regional distribution and morphological features of D1/D2 MSNs, by comparing 6-OHDA-lesioned double BAC transgenic mice (Drd1a-tdTomato/Drd2-EGFP) to sham-lesioned animals. D1/D2 MSNs are uniformly distributed throughout the dorsal striatum (1.9% of MSNs). In contrast, they are heterogeneously distributed and more numerous in the ventral striatum (14.6% in the shell and 7.3% in the core). Compared to D1 and D2 MSNs, D1/D2 MSNs are endowed with a smaller cell body and a less profusely arborized dendritic tree with less dendritic spines. The dendritic spine density of D1/D2 MSNs, but also of D1 and D2 MSNs, is significantly reduced in 6-OHDA-lesioned mice. In contrast to D1 and D2 MSNs, the extent of dendritic arborization of D1/D2 MSNs appears unaltered in 6-OHDA-lesioned mice. Our data indicate that D1/D2 MSNs in the mouse striatum form a distinct neuronal population that is affected differently by dopamine deafferentation that characterizes Parkinson's disease.

[Antileishmanial activity of five 2- or 3- quinolines by enyne group]. / Activité anti leishmanienne de cinq quinoléines substitutées en position 2- ou 3- par un groupement, enyne.

INTRODUCTION: Leishmaniasis is an emergent orphan disease because of its co-infection with HIV AIDS. We report herein the in vitro biological evalution of five news quinolines, 2- or 3- substituted by an enyne group against Leishmania donovani (MHOM/ET/L82/LV9). PATIENTS AND METHODS: The quinolines has been synthesized by using a cross-coupling reaction between a chloroenyne and an organometallic coumpound in a presence of iron a "green" catalyst. Biological evalution is realized by a colorimetric method with the use of 3-(4,5-dimethylthiazol-2,5-diphényl)-tétrazolium bromide. RESULTS: Determination of the inhibitory concentrations as well as the minimal inhibitory concentrations has shown that the substitution by an enyne group made it possible to have a more important antileishmanial activity. In addition, we have seen that the -2 or the -3 position of the enyne group had no influence in the antileishmanial activity. CONCLUSION: Thus, we have shown the real interest of these quinolines which could be favourably compared with pentamidine, which is currently the reference product, and to consider the use of these quinolines in the treament of the leishmaniasis.

Antileishmanial and trypanocidal activities of new miltefosine liposomal formulations.

Liposomes composed of hexadecylphosphocholine/egg phosphatidylcholine/stearylamine (HePC/EPC/SA) 10:10:0.1, 10:10:0.5 and 10:10:1 (molar ratio) (1-3) were prepared and lyophilized. The liposomes were physicochemically characterized (size and zeta-potential) and they were found stable at 4 degrees C over a period of 4 weeks. In vitro, liposomes 1 and 2 were about twice more active than HePC against Leishmania donovani WT whereas liposomes 3 were about three times more active than HePC on HePC-resistant promastigotes. Although liposomes 1-3 were inactive on the in vitro intramacrophage amastigote model, the ability of the liposomes to accumulate within the liver where parasites are located justifies a further in vivo evaluation. We observed that liposome 1 was twice more active than HePC against Trypanosoma brucei brucei bloodstream forms maintained in vitro. In vivo results showed that liposomal HePC seemed to be less toxic than the free drug despite the absence of significant antitrypanosomal activity.

N-acetyl-beta-D-hexosaminidase from Trichomonas vaginalis: substrate specificity and activity of inhibitors.

Among chitinolytic activities previously described in Trichomonas vaginalis, N-acetyl-beta-D-hexosaminidase (NAHase) was the enzyme system expressing the highest level of specific activity. We report here some biochemical characteristics of NAHase purified from T. vaginalis. We found at first that the use of 4-methylumbellifferyl-substrate was responsible for a substrate affinity for the enzyme, about 1000-fold higher than those when using p-nitrophenyl-substrates (PNP). Whereas the optimum pH was 7.0 using PNP-substrate, it was at 4.5 using 4-methylumbelliferyl-substrate. Four different substrates were compared for their action on T. vaginalis NAHase and we have found that N-acetyl-beta-D-glucosaminide substrate was the most specific. DTT had no effect on enzyme activity suggesting that thiol group are not involved at the catalytic site. The use of previously described inhibitors showed a positive correlation between trichomonacidal activity and NAHase inhibition.

Screening of New Caledonian and Vanuatu medicinal plants for antiprotozoal activity.

Sixty-seven extracts of 30 medicinal plants traditionally used in New Caledonia or Vanuatu by healers to treat inflammation, fever and in cicatrizing remedies were evaluated in vitro for their antiprotozoal activity against Leishmania donovani, Leishmania amazonensis and Trypanosoma cruzi. Among the selected plants, Pagiantha cerifera was the most active against both Leishmania species; four extracts were active against promastigotes of Leishmania donovani at EC(50) values inferior to 5 microg/ml. Garcinia pedicillata extract had an EC(50) value of 12.5 microg/ml against intracellular amastigotes of Leishmania amazonensis. Alone Amborella trichopoda reduced by more of 80% the trypomastigotes of Trypanosoma cruzi in the blood.

[Antileishmanial activity of five 2- or 3- quinolines by enyne group]. / Activité anti leishmanienne de cinq quinoléines substituées en position 2- ou 3- par un groupement ényne.

INTRODUCTION: Leishmaniasis is an emergent orphan disease because of its co-infection with HIV AIDS. We report herein the in vitro biological evalution of five news quinolines, 2- or 3-substituted by an enyne group against Leishmania donovani (MHOM/ET/L82/LV9). PATIENTS AND METHODS: The quinolines has been synthesized by using a cross-coupling reaction between a chloroenyne and an organometallic coumpound in a presence of iron a "green" catalyst. Biological evalution is realized by a colorimetric method with the use of 3-(4,5-diméthylthiazol-2,5-diphényl)-tetrazolium bromide. RESULTS: Determination of the inhibitory concentrations as well as the minimal inhibitory concentrations has shown that the substitution by an enyne group made it possible to have a more important antileishmanial activity. In addition, we have seen that the -2 or the -3 position of the e nyne group h ad no influence in the antileishmanial activity. CONCLUSION: Thus, we have shown the real interest of these quinolines which could be favourably compared with pentamidine, which is currently the reference p roduct, and to consider the use of these quinolines in the treament of the leishmaniasis.

[Pomalidomide for multiple myeloma]. / Le pomalidomide dans le myélome multiple.

Once characterized by a very poor outcome, multiple myeloma (MM) now has a significantly prolonged survival, with major improvements allowed by the use of "novel agents": proteasome inhibitors (first-in-class bortezomib) and immunomodulatory compounds (IMiDs; first-in-class thalidomide and lenalidomide). However, the vast majority - if not all - of patients with MM ultimately end up being refractory to all existing drugs, including these efficient novel agents. There is a clear unmet medical need in this situation, which warrants the development of the next generation of proteasome inhibitors and IMiDs, as well as new drug classes. This review focuses on pomalidomide, the next generation IMiD, recently approved by the US FDA and the EMA for patients with relapsed or refractory MM who have received at least two prior therapies, including lenalidomide and bortezomib, and have demonstrated disease progression on their last therapy.

New antifilarial agents. 1. Epoxy sulfonamides and ethynesulfonamides.

Two series of 2-substituted 1,2-epoxyethanesulfonamides 2 and ethynesulfonamides 5 were synthesized and evaluated for their antifilarial activity. The trans epoxides 2T were stereospecifically prepared by a Darzens reaction between aldehydes and halomethanesulfonamides. The cis isomers 2c were obtained from ethynesulfonamides 5 by semihydrogenation followed by KOCl epoxidation. 2-Substituted ethynesulfonamides 5 were synthesized from appropriate trans-ethenesulfonamides by a bromination/dehydrobromination sequence. These products, as well as several synthetic intermediates, were evaluated for antifilarial activity against Molinema dessetae either in vivo in its natural host, the rodent Proechimys oris, or in vitro by a new test using cultures of the infective larvae. Most of the epoxides 2T and acetylenic derivatives 5 bearing a 2-aryl substituent were active in vitro. Among these compounds, four epoxides 2T and one acetylenic derivative 5 showed marked macrofilaricidal activity in vivo without any microfilaricidal activity. The differences between the in vivo and in vitro results may be due, in part, to the low chemical stability of the epoxy sulfonamides 2T. Despite this limitation, the activities observed in this reliable animal model suggest further development and testing of both series 2T and 5 as macrofilaricides.

Experience with doxorubicin-bound polyisohexylcyanoacrylate nanoparticles on murine alveolar echinococcosis of the liver.

The parasiticidal properties of doxorubicin against the metacestode of Echinococcus multilocularis were investigated after binding of that drug to polyisohexylcyanoacrylate nanoparticles, a colloidal biodegradable drug carrier. A reduction of the hepatic parasite development and a reduced viability of the metacestode were observed in mice injected with 5 mg kg-1 body weight-1, but 7.5 mg kg-1 body weight-1 did not appear more efficient. Free doxorubicin or unbound nanoparticles had no antiparasitic activity.

In vitro quantitative assessment of Echinococcus multilocularis metacestode viability after in vivo and in vitro maintenance.

The aim of this study was to apply the enzymatic MTT (3,5 dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide--formazan colorimetry for quantifying the viability of Echinococcus multilocularis whole cysts, after maintenance in vivo or in vitro. The enzymatic activities of young cysts freshly removed from rodents were linearly correlated with the parasite cyst weight. A comparative evaluation of the MTT assay and the in vitro viability assessments showed that the number of animals used for drug-screening purposes would be reduced by 35.8%. In this way, the use of different parasite samples removed from the same host is required, because of their different ages and their subsequent different abilities to reduce MTT. Cysts removed from mice exhibited higher colorimetric values than those removed from jirds. Thus, small entire cysts obtained from mice were maintained in the CMRL 1066 culture medium. Their enzymatic activities were evaluated at different times. The results indicate that, in such conditions, the optimal period of time for testing the effect of drugs against the metacestodes is limited to the 10 days following their transfer from mouse to culture flasks. The MTT assay encourages further studies to improve the viability of the whole cysts in vitro, using other standardizable culture conditions.

Development of an injectable formulation of albendazole and in vivo evaluation of its efficacy against Echinococcus multilocularis metacestode.

The loading of poly (D, L-lactide) nanoparticles with ABZ has led us to evaluate the potential of this new colloidal drug delivery system against E. multilocularis, using a murine model of hepatic alveolar echinococcosis. ABZ-loaded nanoparticles had a monodisperse size distribution between 100 and 150 nm. The efficiency of drug loading to nanoparticles was over 97%. In vitro, at an ABZ concentration of 1.0 microgram ml-1, the formulation had no toxicity for peritoneal macrophages harvested from uninfected mice. In vivo, the ABZ-loaded nanoparticles exhibited no signs of toxicity at any of the doses tested. Intravenous injections of 6 mg kg-1 of bound ABZ to infected mice had an equivalent antiparasitic effect on the metacestode growth to that of a treatment with 1500 mg kg-1 of orally administered free ABZ. The parasite hepatic superficial size as well as the peritoneal metastatic burden was significantly reduced by these 2 courses of treatment, as compared to those of untreated mice. Our results should encourage further study in order to explain the absence of dose-dependent efficacy of ABZ-loaded nanoparticles demonstrated in the present study.

Serum and tissue nitrate levels in murine visceral leishmaniasis correlate with parasite load but not with host protection.

Nitrate levels were measured in serum and in organs from Lshs BALB/c and Lshr C3H/HeN mice during the acute phase (30 d) of infection by Leishmania donovani strain LV9. Serum nitrate levels increased rapidly in BALB/c mice from a baseline level (17 +/- 4 mumol/L) to a plateau (504 +/- 129 mumol/L) at 24 d and correlated with parasite loads in the liver (r = 0.817, P < 0.01) and in the spleen (r = 0.854, P < 0.001). Liver and spleen nitrate contents were enhanced 2.7-fold and 22.8-fold, respectively, with respect to uninfected controls (2692 +/- 249 vs. 992 +/- 231 nmol, P < 0.02 and 20 +/- 1 vs. 456 +/- 43 nmol, P < 0.02). In contrast, serum nitrate increased to a lesser extent in C3H/HeN mice, from 31 +/- 5 mumol/L to 86 +/- 5 mumol/L at 20 d. Liver nitrate content did not differ significantly between infected and control mice (1093 +/- 83 vs. 867 +/- 104 nmol), whereas the former had a higher spleen nitrate content (145 +/- 22 vs. 40 +/- 2 nmol, P < 0.02). Our findings indicate that production of NO by the susceptible BALB/c strain exceeded that of the resistant C3H/HeN strain during the acute stage of infection by L. donovani. Tissue NO overproduction in organs infected by L. donovani was related to the progression of parasitic disease and contributed to high nitrate serum levels. It would be very interesting to extend this investigation to human disease with the aim of evaluating serum nitrate as a marker of parasite load in the follow-up of patients suffering from visceral leishmaniasis.

Marked elevation of serum N-acetyl-beta-D-hexosaminidase activity in rheumatoid rheumatoid arthritis.

OBJECTIVE: To study N-acetyl-beta-D-hexosaminidase (NAHase) activity in the sera of rheumatoid arthritis (RA) patients and to determine its source. METHODS: NAHase activity in the serum and synovial fluid of RA patients was measured with p-nitrophenyl beta-N-acetylglucosaminide as substrate. The p-nitrophenol released was measured spectrophotometrically in an ELISA reader. Rabbit articular chondrocytes in primary culture were stimulated with interleukin-1 beta (IL-1 beta). RESULTS: Serum NAHase activity was higher in 35% of the RA patients than in healthy patients. The median activity was about twice that of the serum of healthy volunteers. RA patients with high serum NAHase activity also had more joint destruction (85%) than those with normal NAHase activity (57%, p < 0.05), but their inflammatory status was similar. The source of NAHase in RA was investigated by assaying it in RA synovial fluids (SF) and measuring its release from articular chondrocytes in primary culture. NAHase activity was detected in all 23 RA SF, at a median concentration that was 2 times that of the serum. NAHase activity in the medium of articular chondrocytes was stimulated by IL-1 beta (p < 0.005 compared to unstimulated cells), suggesting that cartilage is a source of serum and SF NAHase activity. CONCLUSION: The serum concentration of the matrix hydrolase, NAHase, is higher in destructive RA than in inflammatory RA.