Antileishmanial and trypanocidal activity of brazilian Cerrado plants

The side effects and the emerging resistance to the available drugs against leishmaniasis and trypanosomiasis led to the urgent need for new therapeutic agents against these diseases. Thirty one extracts of thirteen medicinal plants from the Brazilian Cerrado were therefore evaluated in vitro for their antiprotozoal activity against promastigotes of Leishmania donovani, and amastigotes of Trypanosoma cruzi. Among the selected plants, Casearia sylvestris var. lingua was the most active against both L. donovani and T. cruzi. Fifteen extracts were active against promastigotes of L. donovani with concentrations inhibiting 50% of parasite growth (IC50) between 0.1-10 µg/ml, particularly those of Annona crassiflora (Annonaceae), Himatanthus obovatus (Apocynaceae), Guarea kunthiana (Meliaceae), Cupania vernalis (Sapindaceae), and Serjania lethalis (Sapindaceae). With regard to amastigotes of T. cruzi, extracts of A. crassiflora, Duguetia furfuracea (Annonaceae), and C. sylvestris var. lingua were active with IC50 values between 0.3-10 µg/ml. Bioassay fractionations of the more active extracts are under progress to identify the active antiparasite compounds

Etudes métabolique, analytique et biologique des quinoléines antileishmaniennes, en vue de la détermination de leur biodisponibilité

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Synthesis and biological evaluation of a series of tangeretin-derived chalcones.

International audienceA series of chalcones polyoxygenated on the ring A (with pentamethoxy or 2'-hydroxy-3',4',5',6'-tetramethoxy substitution patterns) was synthesized from tangeretin, a natural Citrus flavonoid. These chalcones were evaluated for their antiproliferative, activation of apoptosis, inhibition of tubulin assembly and antileishmanial activities. Comparison with the reference analogous 3',4',5'-trimethoxylated chalcones showed that such peroxygenated substitution patterns on the ring A were less beneficial to these activities

Safety, tolerability, pharmacokinetics, and pharmacodynamics of GLPG1690, a novel autotaxin inhibitor, to treat idiopathic pulmonary fibrosis (FLORA): a phase 2a randomised placebo-controlled trial

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) causes irreversible loss of lung function. People with IPF have increased concentrations of autotaxin in lung tissue and lysophosphatidic acid (LPA) in bronchoalveolar lavage fluid and exhaled condensate. GLPG1690 (Galapagos, Mechelen, Belgium) is a novel, potent, selective autotaxin inhibitor with good oral exposure. We explored the effects of GLPG1690 in patients with IPF. METHODS: This was a randomised, double-blind, placebo-controlled phase 2a study done in 17 centres in Italy, Ukraine and the UK. Eligible patients were aged 40 years or older, non-smokers, not taking pirfenidone or nintedanib, and had a centrally confirmed diagnosis of IPF. We used a computer-generated randomisation schedule to assign patients 1:3 to receive placebo or 600 mg oral GLPG1690 once daily for 12 weeks. The primary outcomes were safety (adverse events), tolerability, pharmacokinetics, and pharmacodynamics. Spirometry was assessed as a secondary outcome. This trial is registered with ClinicalTrials.gov, number NCT02738801. FINDINGS: Between March 24, 2016, and May 2, 2017, 72 patients were screened., of whom 49 were ineligible and 23 were enrolled in eight centres (six in Ukraine and two in the UK). Six patients were assigned to receive placebo and 17 to receive GLPG1690. 20 patients completed the study after one in each group discontinued because of adverse events and one in the GLPG1690 group withdrew consent. Four (67%) patients in the placebo group and 11 (65%) in the GLPG1690 group had treatment-emergent adverse events, most of which were mild to moderate. The most frequent events in the GLPG1690 group were infections and infestations (ten events) and respiratory, thoracic, and mediastinal disorders (eight events) with no apparent differences from the placebo group. Two (12%) patients in the GLPG1690 group had events that were judged to be related to treatment. Serious adverse events were seen in two patients in the placebo group (one had a urinary tract infection, acute kidney injury, and lower respiratory tract infection and the other had atrioventricular block, second degree) and one in the GLPG1690 group (cholangiocarcinoma that resulted in discontinuation of treatment). No patients died. The pharmacokinetic and pharmacodynamic profiles of GLPG1690 were similar to those previously shown in healthy controls. LPA C18:2 concentrations in plasma were consistently decreased. Mean change from baseline in forced vital capacity at week 12 was 25 mL (95% CI -75 to 124) for GLPG1690 and -70 mL (-208 to 68 mL) for placebo. INTERPRETATION: Our findings support further development of GLPG1690 as a novel treatment for IPF. FUNDING: Galapagos.status: publishe

High content analysis of primary macrophages hosting proliferating Leishmania amastigotes: application to anti-leishmanial drug discovery.

International audienceBACKGROUND/OBJECTIVES:Human leishmaniases are parasitic diseases causing severe morbidity and mortality. No vaccine is available and numerous factors limit the use of current therapies. There is thus an urgent need for innovative initiatives to identify new chemotypes displaying selective activity against intracellular Leishmania amastigotes that develop and proliferate inside macrophages, thereby causing the pathology of leishmaniasis.METHODOLOGY/PRINCIPAL FINDINGS:We have developed a biologically sound High Content Analysis assay, based on the use of homogeneous populations of primary mouse macrophages hosting Leishmania amazonensis amastigotes. In contrast to classical promastigote-based screens, our assay more closely mimics the environment where intracellular amastigotes are growing within acidic parasitophorous vacuoles of their host cells. This multi-parametric assay provides quantitative data that accurately monitors the parasitic load of amastigotes-hosting macrophage cultures for the discovery of leishmanicidal compounds, but also their potential toxic effect on host macrophages. We validated our approach by using a small set of compounds of leishmanicidal drugs and recently published chemical entities. Based on their intramacrophagic leishmanicidal activity and their toxicity against host cells, compounds were classified as irrelevant or relevant for entering the next step in the drug discovery pipeline.CONCLUSIONS/SIGNIFICANCE:Our assay represents a new screening platform that overcomes several limitations in anti-leishmanial drug discovery. First, the ability to detect toxicity on primary macrophages allows for discovery of compounds able to cross the membranes of macrophage, vacuole and amastigote, thereby accelerating the hit to lead development process for compounds selectively targeting intracellular parasites. Second, our assay allows discovery of anti-leishmanials that interfere with biological functions of the macrophage required for parasite development and growth, such as organelle trafficking/acidification or production of microbicidal effectors. These data thus validate a novel phenotypic screening assay using virulent Leishmania amastigotes growing inside primary macrophage to identify new chemical entities with bona fide drug potential

Effect of various anti-leishmanial molecules on the viability of <i>L. amazonensis</i> promastigotes.

<p>Procyclic promastigotes (2×10⁴/well) were incubated with different concentrations of compounds (0.0125 to 25 µM). Parasites cultured in medium alone (C−, 0% growth inhibition) or in the presence of 1 µM Amphotericin B (C+, 100% growth inhibition) were used as negative and positive controls, respectively. After 64 h incubation with compounds, resazurin (2.5 µg/ml) was added to each well and parasites were incubated for an additional 8 h before measuring resofurin fluorescence (λex = 550 nm, bandwidth = 9 nm; λem = 590 nm, bandwidth = 20 nm). Each compound concentration was tested in quadruplicates and the average ± standard deviation is displayed. EC50 values were calculated using SigmaPlot (SPSS, SSI, San Jose,CA, USA) 4-parameter logistic nonlinear regression analysis (values in parenthesis in the upper right panel).</p

Pairwise comparison for replicates within P1 to P4.

<p>The results for each replicate (R1 to R4) were compared and the rate of identical outcomes was reported after plate pairwise comparison.</p

QC metrics by variables (Am, PV/HM and VI) expressed as robust Z′factor and (SSMD) values.

<p>To validate the robustness of controls in each plate, the QC metrics were performed for each variable using different controls depending on the biological readout <i>i.e.</i> leishmanicidal activity or toxicity on host cells: C− (64 and 24 wells for P1–P4 and P5–P9, respectively)/C+ (n = 20) for (Am) and (PV/HM) variables and C− (n = 24)/C† (n = 20) for (VI). Of note is the fact that the QC metrics for the VI variable was only available in the P5–P9 when the C† control was included (NA: not applicable).</p

Screening results.

<p>Merged images for nucleus, PV and amastigote fluorescence of one acquisition field representing different phenotypes are displayed. Scale bar corresponds to 50 µm for all images. Each compound has been categorized into High, Low, ∼Toxic and Cytotoxic based on its SSMD values and following the decision tree described in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002154#pntd.0002154.s003" target="_blank">Figure S3</a>. The Medium class has been introduced to define compounds that were classified as “High” and “Low” in independent replicate experiments. Percentages per category are indicated.</p