Publications by authors named "Joelle Quetin-Leclercq"

Background: Artemisia spp. have been used for millennia in traditional medicine to treat a variety of ailments, including malaria. Extracts of Artemisia afra and A.

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  • The study investigates the antitrypanosomal effects of Crossopteryx febrifuga, a plant used in traditional African medicine to treat trypanosomiasis, and identifies active compounds in its extracts.
  • The researchers prepared four extracts using different solvents and found that the dichloromethane extract was the most effective against Trypanosoma brucei brucei.
  • Through metabolic profiling, 33 compounds were identified in the most active fractions, with maslinic, corosolic, and oleanolic acids linked to the observed antitrypanosomal activity, supporting the plant's traditional medicinal use.
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  • Sawfly species specialized in feeding on Ranunculaceae plants can sequester specific furostanol saponins into their haemolymph, which may help them in defense against predators.
  • Research involving various chemical analyses and bioassays indicated that while one species predominantly fed on a non-nutritional stimulant from its host, both species showed differences in response to different plant fractions, with β-sitosterol identified as a nutritional stimulant.
  • The study found that the larvae of both sawfly species do not produce ecdysteroids endogenously but accumulate them from their diet, using them effectively as a deterrent against ant predators, especially in the initial days following simulated attacks.
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Trypanosoma brucei (Tb) is the causative agent of human African trypanosomiasis (HAT), also known as sleeping sickness, which can be fatal if left untreated. An understanding of the parasite's cellular metabolism is vital for the discovery of new antitrypanosomal drugs and for disease eradication. Metabolomics can be used to analyze numerous metabolic pathways described as essential to Tb.

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  • Human African trypanosomiasis, or sleeping sickness, is caused by the parasite Trypanosoma brucei and transmitted by the tsetse fly, with the study focusing on the effects of the drug suramin on this parasite.
  • The research aims to analyze how suramin alters the metabolism of T. brucei using advanced techniques like liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy, supported by extensive statistical analysis.
  • Results indicate significant metabolic changes in T. brucei after suramin treatment, especially in amino acid and sugar metabolism, with clear distinctions observed between treated and untreated samples through various statistical methods.
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Malaria is a parasitic disease that remains a global concern and the subject of many studies. Metabolomics has emerged as an approach to better comprehend complex pathogens and discover possible drug targets, thus giving new insights that can aid in the development of antimalarial therapies. However, there is no standardized method to extract metabolites from in vitro Plasmodium falciparum intraerythrocytic parasites, the stage that causes malaria.

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Zinc is one of the most studied trace elements, commonly used as supplement in diabetes treatment. By its involvement in the synthesis, secretion of insulin, promotion of insulin sensitivity and its multiple enzymatic functions it is known to contribute to reduce hyperglycemia. Researchers have shown that zinc administered under the form of zinc oxide nanoparticles (ZnONPs) is more effective than under its ionic form.

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Introduction: Tausch. is a medicinal plant well-known to produce important therapeutic compounds, such as alkannin/shikonin and their derivatives (A/Sd). It associates with arbuscular mycorrhizal fungi (AMF), which are known, amongst others beneficial effects, to modulate the plant secondary metabolites (SMs) biosynthesis.

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  • Psidium guajava L. (guava) has immune-modulatory effects in humans and some fish, but the specific molecular mechanisms in fish are not fully understood.
  • This study tested two guava extract fractions (dichloromethane and ethyl acetate) on striped catfish both in lab experiments (in vitro) and live fish (in vivo) to assess their immune responses.
  • Results showed that the guava fractions can differently affect immune responses, particularly enhancing pathways related to inflammation and apoptosis, and suggest that these extracts could be beneficial for fish health by modulating immune and inflammatory pathways.
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Leishmaniasis is a neglected tropical disease that still infects thousands of people per year throughout the world. The occurrence of resistance against major treatments for this disease causes a healthcare burden in low-income countries. Eugenol is a phenylpropanoid that has shown in vitro antileishmanial activity against () promastigotes with an IC of 2.

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Zinc oxide nanoparticles (ZnONPs) have shown antidiabetic activity in multiple studies and can be produced by different plant-mediated ("green") methods. This study aimed to compare ZnONPs prepared via different "green" approaches (heating at high temperatures (400 °C) vs. low temperature (70 °C)).

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Vent., an endemic plant from the Mascarene Islands, was investigated following its antiplasmodial potentialities highlighted during a previous screening. Three clerodane diterpene compounds were isolated and identified as being responsible for the antiplasmodial activity of the leaves of the plant: caseamembrin T (), corybulosin I (), and isocaseamembrin E (), which exhibited half maximal inhibitory concentrations (IC) of 0.

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Volatiles metabolites from the liverwort harvested in Corsica were investigated by chromatographic and spectroscopic methods. In addition to already reported constituents, three new compounds were isolated by preparative chromatography and their structures were elucidated by mass spectrometry (MS) and NMR experiments. Hence, an atypic aliphatic compound, named 1,2-dihydro-4,5-dehydronerolidol and two isomers, (E) and (Z), possessing an unusual humbertiane skeleton (called -menth-1-en-3-[2-methylbut-1-enyl]-8-ol) are newly reported and fully characterized in this work.

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is a medicinal plant widely used in ethnoveterinary medicine to treat digestive parasitosis whose extracts were shown to be active against gastrointestinal nematodes of domestic ruminants. The objective of our study was to identify compounds responsible for this activity. Column fractionation was performed, and the activity of the fractions was assessed on and as well as their cytotoxicity on WI38 fibroblasts.

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is used in Pakistani traditional medicine to treat inflammatory conditions, piles, boils, and ulcers. To evaluate the anti-inflammatory potential of (a mixture of aerial branches, leaves, and stem bark), we prepared crude extracts in Soxhlet apparatus by successively using different solvents and found the methanolic extract (OLM) to significantly inhibit the LPS-induced expression of pro-inflammatory cytokines and enzymes in J774 macrophages, at 50 µg/mL concentration. We also analysed the chemical constituents of OLM by dereplication, performed by HPLC-MS/MS and molecular networking.

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Inflammation is a defensive response of the organism to traumatic, infectious, toxic, ischemic, and autoimmune injury. Inflammatory mediators are released to effectively eliminate the inflammatory trigger and restore homeostasis. However, failure of these processes can lead to chronic inflammatory conditions and diseases such as inflammatory bowel diseases, rheumatoid arthritis, inflammatory lung diseases, atherosclerosis, and neurodegenerative diseases.

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Diabetes is a metabolic pathology with chronic high blood glucose levels that occurs when the pancreas does not produce enough insulin or the body does not properly use the insulin it produces. Diabetes management is a puzzle and focuses on a healthy lifestyle, physical exercise, and medication. Thus far, the condition remains incurable; management just helps to control it.

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Medicinal plants continue to be used alone or in combination with veterinary drugs to treat animal ailments, especially in developing countries where livestock farmers often lack access to modern veterinary services and drugs. In addition, digestive parasitosis remain a major constraint for small ruminant livestock. The objective of this study was to screen the anthelmintic activity of the main plants used in the treatment of the digestive parasitosis of small ruminants in Benin.

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Malaria is a parasitic disease that remains a global health issue, responsible for a significant death and morbidity toll. Various factors have impacted the use and delayed the development of antimalarial therapies, such as the associated financial cost and parasitic resistance. In order to discover new drugs and validate parasitic targets, a powerful omics tool, metabolomics, emerged as a reliable approach.

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This study investigated the effect of the catechins profile on the antioxidant activity of green tea extracts (GTEs) by comparing the antioxidant activity of an EGC-rich GTE (GTE1, catechin content: 58% EGC, 30.1% EGCG, 7.9% EC, and 3.

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Background: Trypanosoma brucei is the causative agent of Human African Trypanosomiasis (also known as sleeping sickness), a disease causing serious neurological disorders and fatal if left untreated. Due to its lethal pathogenicity, a variety of treatments have been developed over the years, but which have some important limitations such as acute toxicity and parasite resistance. Metabolomics is an innovative tool used to better understand the parasite's cellular metabolism, and identify new potential targets, modes of action and resistance mechanisms.

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is used in Pakistani traditional medicine to treat inflammation-related disorders. Its anti-inflammatory potential was evaluated on hexane, dichloromethane, ethyl acetate, methanol, and aqueous extracts of whole plant on pro-inflammatory mediators in LPS-activated murine macrophage J774 cells at the non-cytotoxic concentration of 50 µg/mL. Ethyl acetate (ARE) and methanol (ARM) extracts significantly decreased mRNA levels of IL-6, TNF-α, MCP-1, COX-2, and iNOS.

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Pentacyclic triterpenes (PTs) are commonly found in medicinal plants with well-known antiparasitic effects. Previous research on C-3 and C-27 triterpenic esters showed effective and selective in vitro antiparasitic activities and in vivo effectiveness by parenteral routes. The aim of this study was to determine triterpenic esters' stability in different biological-like media and the main microsomal degradation products.

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is an opportunistic pathogen and the major causative agent of life-threatening hospital- and community-acquired infections. A combination of antibiotics could be an opportunity to address the widespread emergence of antibiotic-resistant strains, including Methicillin-Resistant (MRSA). We here investigated the potential synergy between ampicillin and plant-derived antibiotics (pentacyclic triterpenes, ursolic acid (UA) and oleanolic acid (OA)) towards MRSA (ATCC33591 and COL) and the mechanisms involved.

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