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Joëlle Quetin-leclercq - One of the best experts on this subject based on the ideXlab platform.

  • Chemical composition, in vitro antioxidant and Antiparasitic Properties of the essential oils of three plants used in traditional medicine in Benin.
    Journal of Medicinal Plants Research, 2019
    Co-Authors: Didier Kpadonou, Joanne Bero, Salom E Kpoviessi, Pierre Agbani, Fernand Gbaguidi, B En Edicta Kpadonou-kpoviessi, Brice Sinsin, Michel Fr Ed Erich, Joëlle Quetin-leclercq
    Abstract:

    Sclerocarya birrea (Sb), Psidium guajava (Pg) and Eucalyptus camaldulensis (Ec) are widely used in traditional medicine for the treatment of many diseases, some of which were related to oxidative stress and parasitic diseases. Their essential oils (EO) were analyzed by GC/MS and FID and tested in vitro for their antioxidant activities (DPPH), their anti-trypanosomal and anti-plasmodial activities against Trypanosoma brucei brucei (Tbb) (strain 427) and Plasmodium falciparum (Pf) (strain 3D7), respectively. Cytotoxicity was evaluated in vitro against CHO and WI38 cells (MTT) to evaluate the selectivity. They were shown to possess low antioxidant but a strong anti-trypanosomal and a good antiplasmodial activity with a good selectivity, except Ec oil whose anti-plasmodial activity was less interesting. Sb oil was the most active against Tbb(IC50 = 0.46 ± 0.28 µg/ml) and Pf (5.21 ± 1.12 µg/ml). All tested oils had low or no cytotoxicity against CHO and WI38 cells. GC/MS and GC/FID analysis revealed that composition of Sb (49 compounds) was characterised by the presence as main constituents of 7-epi-α-selinene, α-muurolene and valencene; Pg (60 compounds) by β-bisabolene, ar-curcumene and β-bisabolol; Ec (43 compounds) by γ-terpinene and p-cymene. The activity of these oils seems to be the result of a synergistic action of all their constituents, including minor ones. This study shows that essential oils of Sb and Pg can be good sources of anti-trypanosomal and anti-plasmodial agents. Key words: Essential oil, S. birrea, P. guajava, E. camaldulensis, antimalarial, antitrypanosomal, antioxidant.

  • Secochiliolide ester derivatives: Preparation and evaluation of their antitrypanosomal and antimalarial efficacy.
    Chemical biology & drug design, 2018
    Co-Authors: Romina J. Ronchi, Joëlle Quetin-leclercq, Joanne Bero, Jorge A. Palermo, Claire Beaufay, Juan B. Robirosa, Marcia Mazzuca, Marianela Sánchez
    Abstract:

    In the present study, a series of new esters of secochiliolide acid (SA), a diterpene isolated from Nardophyllum bryoides, were synthesized in good yield. All compounds were evaluated for their in vitro Antiparasitic Properties (on Plasmodium falciparum and Trypanosoma brucei brucei) and cytotoxicity (on WI38, normal mammalian cells). They displayed moderate antitrypanosomal activity with IC50 values between 2.55 and 18.14 μm, with selectivity indices >10, and low antiplasmodial effects with IC50  > 29 μm. The only exception was the n-hexyl ester of SA, which showed a strong and selective antiplasmodial activity (IC50  = 1.99 μm and selectivity index = 117.0). The in vivo antimalarial efficacy of this compound was then assessed according to the 4-day suppressive test of Peters in mice. An intraperitoneal treatment at 50 mg kg-1  day-1 induced a slight parasitaemia reduction by 56% which was statistically significant on day 4 post-infection and an increase in the survival time.

  • Structure-activity relationship of hybrids of Cinchona alkaloids and bile acids with in vitro antiplasmodial and antitrypanosomal activities.
    European journal of medicinal chemistry, 2015
    Co-Authors: Aurélie Leverrier, Joëlle Quetin-leclercq, Joanne Bero, Julián Cabrera, Michel Frederich, Jorge A. Palermo
    Abstract:

    In this work, a series of hybrid compounds were tested as Antiparasitic substances. These hybrids were prepared from bile acids and a series of Antiparasitic Cinchona alkaloids by the formation of a covalent C-C bond via a decarboxylative Barton-Zard reaction between the two entities. The bile acids showed only weak Antiparasitic Properties, but all the hybrids exhibited high in vitro activities (IC50: 0.48-5.39 μM) against Trypanosoma brucei. These hybrids were more active than their respective parent alkaloids (up to a 135 fold increase in activity), and displayed good selectivity indices. Aditionally, all these compounds inhibited the in vitro growth of a chloroquine-sensitive strain of Plasmodium falciparum (3D7: IC50: 36.1 nM to 8.72 μM), and the most active hybrids had IC50s comparable to that of artemisinin (IC50: 36 nM). Some structure-activity relationships among the group of 48 hybrids are discussed. The increase in Antiparasitic activity may be explained by an improvement in bioavailability, since the more lipophilic derivatives showed the lowest IC50s.

  • Screening for in vitro antifungal activities of some indole alkaloids.
    Planta medica, 1995
    Co-Authors: Joëlle Quetin-leclercq, Guy Balansard, A. Favel, P Regli, Luc Angenot
    Abstract:

    Several indole alkaloids were tested by the agar dilution technique on a panel of human pathogenic fungi, yeasts, and dermatophytes. Our results indicate that the most active compounds possess a beta-carboline skeleton and that the presence of a 3-4 double bond enhances the activity. Our results also show that antifungal activities are not linked to the cytotoxic, antimicrobial or Antiparasitic Properties.

  • Potential anticancer and Antiparasitic indole alkaloids
    Journal de pharmacie de Belgique, 1994
    Co-Authors: Joëlle Quetin-leclercq
    Abstract:

    Many drugs are derived from active molecules isolated from plants or micro-organisms. Nevertheless, a lot of species have not yet been studied; they constitute an important source of new structures that could possess interesting pharmacological activities and/or original modes of action, for example in the field of anticancer or Antiparasitic drugs (taxol, artemisinin, swainsonine, camptothecin,...). Among all the bioactive natural products, we studied more particularly indole alkaloids extracted from different tropical Strychnos species. Several new alkaloids have been isolated from cytotoxic crude extracts. Some of them possess interesting cytotoxic, antitumor or Antiparasitic Properties. We also realised molecular modelling studies in order to explain the activity of usambarensine.

Wim M. De Borggraeve - One of the best experts on this subject based on the ideXlab platform.

  • chemical structure and biological Properties of sulfated fucan from the sequential extraction of subantarctic lessonia sp phaeophyceae
    Carbohydrate Polymers, 2018
    Co-Authors: David Leal, M Moncadabasualto, Michel Lapier, Juan Diego Maya, Andres Mansilla, Betty Matsuhiro, Claudio Oleaazar, Wim M. De Borggraeve
    Abstract:

    Abstract This work is related to the structural characterization of the sulfated polysaccharide from Lessonia sp and the study of its antioxidant and Antiparasitic Properties. Sequential extraction afforded D-mannitol as the only low MW sugar alcohol. Extraction with 2% CaCl2 afforded in 3.0% yield, a sulfated fucan (SF). Its major fraction (48.5% yield), isolated by ion-exchange chromatography corresponds to a linear polymer of α- l -fucopyranosil residues linked 1→3, sulfated at the O–4 and partially at O–2 positions. By alkaline extraction, sodium alginate (10.3% yield) was obtained. The antioxidant capacity of SF by ESR showed high elimination index (IC50, mg/mL) of hydroxyl (0.27), alkoxy (10.05), and peroxyl (82.88) radicals in relation to commercial mannitol. SF showed activity against the epimastigote form of Trypanosoma cruzi parasite (250 μg/mL) and low cytotoxicity in murine cells (367 μg/mL). The elimination capacity of radicals in aqueous medium of SF would allow its potential biomedical application.

  • Chemical structure and biological Properties of sulfated fucan from the sequential extraction of subAntarctic Lessonia sp (Phaeophyceae)
    'Elsevier BV', 2018
    Co-Authors: Leal D, Mansilla A, Matsuhiro B, Moncada-basualto M, Lapier M, Jd Maya, Olea-azar C, Wim M. De Borggraeve
    Abstract:

    This work is related to the structural characterization of the sulfated polysaccharide from Lessonia sp and the study of its antioxidant and Antiparasitic Properties. Sequential extraction afforded D-mannitol as the only low MW sugar alcohol. Extraction with 2% CaCl2 afforded in 3.0% yield, a sulfated fucan (SF). Its major fraction (48.5% yield), isolated by ion-exchange chromatography corresponds to a linear polymer of α-l-fucopyranosil residues linked 1→3, sulfated at the O-4 and partially at O-2 positions. By alkaline extraction, sodium alginate (10.3% yield) was obtained. The antioxidant capacity of SF by ESR showed high elimination index (IC50, mg/mL) of hydroxyl (0.27), alkoxy (10.05), and peroxyl (82.88) radicals in relation to commercial mannitol. SF showed activity against the epimastigote form of Trypanosoma cruzi parasite (250 μg/mL) and low cytotoxicity in murine cells (367 μg/mL). The elimination capacity of radicals in aqueous medium of SF would allow its potential biomedical application.status: publishe

Pedro L S Pinto - One of the best experts on this subject based on the ideXlab platform.

  • promethazine exhibits Antiparasitic Properties in vitro and reduces worm burden egg production hepatomegaly and splenomegaly in a schistosomiasis animal model
    Antimicrobial Agents and Chemotherapy, 2019
    Co-Authors: Daniel B Roquini, Ramon M Cogo, Ana C Mengarda, Susana F Mazloum, Cristiane S Morais, Rogerio P Xavier, M C Salvadori, F S Teixeira, Luiz E Ferreira, Pedro L S Pinto
    Abstract:

    : The treatment and control of schistosomiasis, a neglected disease that affects more than 200 million people worldwide, rely on the use of a single drug, praziquantel. A vaccine has yet to be developed and since new drug design and development is a lengthy and costly process, drug repurposing is a promising strategy. In this study, the efficacy of promethazine, a first-generation antihistamine, was evaluated against Schistosoma mansoniex vivo and in a murine model of schistosomiasis. In vitro assays demonstrated that promethazine affected parasite motility, viability, and it induced severe tegumental damage in schistosomes. The LC50 of the drug was 5.84 μM. Similar to promethazine, schistosomes incubated with atropine, a classical anticholinergic drug, displayed reduced motor activity. In an animal model, promethazine treatment was introduced at an oral dose of 100 mg/kg for five successive days at different intervals from the time of infection, for the evaluation of the stage-specific susceptibility (pre-patent and patent infections). Various parasitological criteria indicated the in vivo antischistosomal effects of promethazine: there were significant reductions in worm burden, egg production, and hepato- and splenomegaly. The highest worm burden reduction was achieved with promethazine in patent infections (> 90%). Taken together, considering the importance of the repositioning of drugs in infectious diseases, especially those related to poverty, our data revealed the possibility of promethazine repositioning as an antischistosomal agent.

  • Promethazine exhibits Antiparasitic Properties in vitro and reduces worm burden, egg production, hepato-, and splenomegaly in a schistosomiasis animal model.
    Antimicrobial agents and chemotherapy, 2019
    Co-Authors: Daniel B Roquini, Ramon M Cogo, Ana C Mengarda, Susana F Mazloum, Cristiane S Morais, Luiz E Ferreira, R. Xavier, Maria Cecília Barbosa Da Silveira Salvadori, Fernanda De Sá Teixeira, Pedro L S Pinto
    Abstract:

    The treatment and control of schistosomiasis, a neglected disease that affects more than 200 million people worldwide, rely on the use of a single drug, praziquantel. A vaccine has yet to be developed and since new drug design and development is a lengthy and costly process, drug repurposing is a promising strategy. In this study, the efficacy of promethazine, a first-generation antihistamine, was evaluated against Schistosoma mansoni ex vivo and in a murine model of schistosomiasis. In vitro assays demonstrated that promethazine affected parasite motility, viability, and it induced severe tegumental damage in schistosomes. The LC50 of the drug was 5.84 μM. Similar to promethazine, schistosomes incubated with atropine, a classical anticholinergic drug, displayed reduced motor activity. In an animal model, promethazine treatment was introduced at an oral dose of 100 mg/kg for five successive days at different intervals from the time of infection, for the evaluation of the stage-specific susceptibility (pre-patent and patent infections). Various parasitological criteria indicated the in vivo antischistosomal effects of promethazine: there were significant reductions in worm burden, egg production, and hepato- and splenomegaly. The highest worm burden reduction was achieved with promethazine in patent infections (> 90%). Taken together, considering the importance of the repositioning of drugs in infectious diseases, especially those related to poverty, our data revealed the possibility of promethazine repositioning as an antischistosomal agent.

M Moncadabasualto - One of the best experts on this subject based on the ideXlab platform.

  • chemical structure and biological Properties of sulfated fucan from the sequential extraction of subantarctic lessonia sp phaeophyceae
    Carbohydrate Polymers, 2018
    Co-Authors: David Leal, M Moncadabasualto, Michel Lapier, Juan Diego Maya, Andres Mansilla, Betty Matsuhiro, Claudio Oleaazar, Wim M. De Borggraeve
    Abstract:

    Abstract This work is related to the structural characterization of the sulfated polysaccharide from Lessonia sp and the study of its antioxidant and Antiparasitic Properties. Sequential extraction afforded D-mannitol as the only low MW sugar alcohol. Extraction with 2% CaCl2 afforded in 3.0% yield, a sulfated fucan (SF). Its major fraction (48.5% yield), isolated by ion-exchange chromatography corresponds to a linear polymer of α- l -fucopyranosil residues linked 1→3, sulfated at the O–4 and partially at O–2 positions. By alkaline extraction, sodium alginate (10.3% yield) was obtained. The antioxidant capacity of SF by ESR showed high elimination index (IC50, mg/mL) of hydroxyl (0.27), alkoxy (10.05), and peroxyl (82.88) radicals in relation to commercial mannitol. SF showed activity against the epimastigote form of Trypanosoma cruzi parasite (250 μg/mL) and low cytotoxicity in murine cells (367 μg/mL). The elimination capacity of radicals in aqueous medium of SF would allow its potential biomedical application.

Juan F Masello - One of the best experts on this subject based on the ideXlab platform.

  • can the intake of Antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild psittaciformes
    Parasites & Vectors, 2018
    Co-Authors: Juan F Masello, Luciano Calderon, Luis Ortizcatedral, Igor Berkunsky, Jörn Theuerkauf, Javier Martinez, Petra Quillfeldt, Virginia Sanz, Michael Wink, Dianne H. Brunton
    Abstract:

    Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing Antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general Antiparasitic Properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general Antiparasitic Properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general Antiparasitic Properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates.

  • Can the intake of Antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?
    Parasites & Vectors, 2018
    Co-Authors: Juan F Masello, Luciano Calderon, Igor Berkunsky, Jörn Theuerkauf, Javier Martinez, Petra Quillfeldt, Virginia Sanz, Michael Wink, Luis Ortiz-catedral, Dianne Brunton
    Abstract:

    Background Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites ( Plasmodium ), intracellular haemosporidians ( Haemoproteus , Leucocytozoon ), unicellular flagellate protozoans ( Trypanosoma ) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing Antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general Antiparasitic Properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general Antiparasitic Properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general Antiparasitic Properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates.