Joëlle Quetin-Leclercq

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• Emeritus professor at Catholic University of Louvain

Trypanosomiasis is a parasitic disease for which new treatments are needed due to the frequent occurrence of adverse side effects of current available drugs. Natural compounds found in traditionally used plants offer opportunities to discover innovative compounds that could prove pivotal to antitrypanosomal drug development. 3-O-p-(Z/E)-coumaroylto...

Parasitic diseases such as trypanosomiasis and leishmaniasis pose significant health challenges in Africa. The Senegalese Pharmacopoeia, known for its many medicinal plants with anti‐infectious properties, can be a source of antiparasitic natural products. This study aimed to evaluate the in vitro antiparasitic activities of 33 methanolic extracts...

In Gram-negative bacteria, the outer membrane (OM) is asymmetric, with lipopolysaccharides (LPS) in the outer leaflet and glycerophospholipids (GPLs) in the inner leaflet. The asymmetry is maintained by the Mla system (MlaA-MlaBCDEF), which contributes to lipid homeostasis by removing mislocalized GPLs from the outer leaflet of the OM. Here, we asc...

Farmers continue to use medicinal plants, alone or in combination with veterinary medicines, to treat animal diseases, especially in developing countries. The study aimed to determine the effect of climatic zone and anthropic disturbance level on the diversity of the natural stand and structures of Morinda lucida Benth, Spondias mombin L., Terminal...

Sawfly species of the genus Monophadnus are specialised on Ranunculaceae plants from which the larvae can sequester furostanol saponins into the haemolymph, mainly (25R)-26-[(α-L-rhamnopyranosyl)oxy]-22α-methoxyfurost-5-en-3β-yl-O-β-D-glucopyranosyl-(1→3)-O-[6-acetyl-β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranoside (compound 1). In this work, TLC, G...

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 metabo...

Introduction Human African trypanosomiasis, commonly known as sleeping sickness, is a vector-borne parasitic disease prevalent in sub-Saharan Africa and transmitted by the tsetse fly. Suramin, a medication with a long history of clinical use, has demonstrated varied modes of action against Trypanosoma brucei. This study employs a comprehensive work...

L’administration et le ciblage contrôlés de médicaments représentent un défi passionnant pour améliorer l’efficacité thérapeutique et/ou prophylactique des molécules biologiquement actives tout en réduisant leurs effets secondaires. Ainsi, différents systèmes tels que les supports macromoléculaires solubles, les liposomes et les particules polyméri...

Introduction : Les populations béninoises consomment au quotidien des huiles végétales de différent profil d’acides gras (AG) insaturés comme saturés, leur conférant des vitesses d’oxydabilité différentes. Les produits d’oxydation primaire (radicaux peroxydes) et secondaire (aldéhydes) sont nuisibles à la santé humaine et justifient la nécessité d’...

Morinda lucida Benth (Rubiaceae) is a medicinal plant traditionally used to treat malaria and digestive parasitosis. In vitro pharmacological studies have shown that extracts of the plant were very active against nematodes. The aim of our work was to identify the compounds responsible for the anthelmintic activity of M. lucida. To achieve this, the...

Introduction Alkanna tinctoria 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. However,...

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 Leishmania mexicana mexic...

Psidium guajava L. is known to possess immune-modulatory properties in humans and other mammals. Although the positive effects of P. guajava-based diets on the immunological status have been shown for some fish species, the underlying molecular mechanisms of its protective effects remain to be investigated. The aims of this study were to evaluate t...

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)). The low temperature method involved addition of sus...

Casearia coriacea 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 (1), corybulosin...

Volatiles metabolites from the liverwort Plagiochila porelloides 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,...

Terminalia leiocarpa 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...

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...

Simple Summary In the present study, we explored the anthelmintic activity, cytotoxicity, and chemical composition of the main plants used by small ruminant breeders in Benin to treat digestive parasitosis. The results obtained are relevant in the sense that they will allow a rational use of the plants studied in the control of digestive parasites...

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...

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 power...

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 3.9% ECG) and an EGCG-rich GTE (GTE2, catechin content: 60.6% EGCG, 17.7% EGC, 11.8% ECG, and 9.8% EC) in a DHA-rich...

Salvadora oleoides is used in Pakistani traditional medicine to treat inflammatory conditions, piles, boils, and ulcers. To evaluate the anti-inflammatory potential of S. oleoides (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 e...

The aim of this study is first to identify the major phenolic compound of a crude ethanol extract of Psidium guajava leaves collected in Vietnam and to develop validated methods for quantification of phenolic and triterpenic components by HPLC-PDA-HRMS. The major phenolic compound was determined as quercetin-3-O-sulfate which is isolated and quanti...

Infectious diseases with bacterial origin are one of the leading causes of death worldwide, with about 17 million deaths each year [1]. Beside these bacterial infections, several parasitic infections deserve special attention due to a lack of effective treatments. Among these infections, human African trypanosomiasis, or sleeping sickness, and leis...

This study aimed to investigate the current use of drugs, chemicals, herbs, and herbal extract products in grow-out farms of snakehead (Channa striata) and Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. The survey was conducted with a total of 60 Pangasius catfish grow-out farms in An Giang and Dong Thap provinces, an...

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 to...

Convolvulus arvensis 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...

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 diff...

This study was conducted to evaluate the effects of herbal extracts on the quality of striped catfish (Pangasianodon hypophthalmus) fillets throughout the storage period. Quality changes during ice storage of striped catfish fillets were studied after dip treatments in aqueous solutions of ethanolic extract of Phyllanthus amarus (0.02% and 0.04%, w...

Staphylococcus aureus 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 S. aureus (MRSA). We here investigated the potenti...

Introduction : Traditional medicine has become an important component in the care system of African populations. Many products derived from it are increasingly used in the therapeutic arsenal. This work is an inventory of the production of these drugs in two countries of West Africa, Burkina Faso and Benin. Methods : A cross-sectional descriptive s...

Avec l’avènement de la médecine vétérinaire moderne, les pratiques traditionnelles vétérinaires sont reléguées au second plan dans la gestion zoosanitaire des animaux d’élevage. Toutefois, la médecine vétérinaire moderne n’a pas pu faire face à tous les problèmes sanitaires des exploitations d’élevage, surtout dans les milieux ruraux où l’accès aux...

The bioactivity and phytochemical composition of a partially purified extract of açai (PPEA), concentrated in phenolic compounds (PC) and without the presence of macronutrients, were investigated. The major PC quantified by UHPLC‐DAD‐LTQ‐Orbitrap MS‐MS/MS in the PPEA are anthocyanins. In vitro, PPEA showed a cytostatic effect on the K‐562 lymphoid...

Research for innovative drugs is crucial to contribute to parasitic infections control and eradication. Inspired by natural antiprotozoal triterpenes, a library of 12 hemisynthetic 3‐O‐arylalkyl esters was derived from ursolic and oleanolic acids through one‐step synthesis. Compounds were tested on Trypanosoma, Leishmania and the WI38 cell line alo...

Sheep and goats are two of the main animal species raised in Benin and one of the main sources of income for people living in rural areas. Faced with the inaccessibility of synthetic veterinary products and their low purchasing power, the majority of breeders use ethnoveterinary practices to treat small ruminants diseases. The specific objectives o...

During the last decade, the advent of multi-drug resistant pathogens responsible for skin infections tends to make conventional treatments obsolete. Even though many studies have reported the antimicrobial properties of essential oils (EOs), the inconsistent use of various susceptibility testing methods has made information on antimicrobial potenti...

Essential oils have known a renewed interest, particularly for their antimicrobial properties. In the field of skin delivery of essential oils, fluid oil-in-water (O/W) emulsions have been studied for several years in order to improve their stability. When dealing with infections of the upper skin layers, these vehicles, in spite of their low visco...

Ethnopharmacological relevance Ajuga iva (L.) Schreb. (Labiatae) (AI) is used in folk medicine for a variety of ailments, including diabetes mellitus and hypertension. The aim of the study: In this work, we aimed to investigate the antihypertensive and vasorelaxant effects of Ajuga iva aqueous extract in stroke prone spontaneously hypertensive rats...

Abstract Ethnopharmacological relevance Clerodendrum cyrtophyllum Turcz has been used in traditional medicine for the treatment of various diseases. In spite of its therapeutic applications, research on its toxicity and teratogenicity is still limited. Aim of the study The study aimed to investigate the developmental toxicity of the ethanol extrac...

This study aims at determining the in vitro antitrypanosomal, antileishmanial, antioxidant, and anti-inflammatory-like activities of Terminalia mollis root crude extracts. The antitrypanosomal and antileishmanial activities on Trypanosoma brucei brucei (strain 427) and promastigotes of Leishmania mexicana mexicana (MHOM/BZ/84/BEL46) were evaluated...

This study aimed to identify major phytochemical constituents, as well as compare the immunomodulatory effects of Psidium guajava L. and Phyllanthus amarus Schun and Thonn crude ethanol extracts and their fractions on striped catfish (Pangasianodon hypophthalmus) head kidney leukocytes (HKLs). Moreover, pure constituents were also investigated for...

Guava Psidium guajava L (Pg) and bhumi amla Phyllanthus amarus Schum. et Thonn (Pa) are well-known plants in traditional medicine. However, the capacity of these plants for improving the immune system of aquatic species has received less attention so far. This study aimed to investigate the effects of single supply or mixture of Pg and Pa extracts...

Background: Small ruminant health problems still represent a major constraint in Benin. Thus, to treat goats and sheep diseases, breeders use medicinal plants. However, little scientific work has been done on the traditional knowledge of these plants.The specific objectives of the current study were (i) to document the traditional knowledge regardi...

This study aimed to screen the in vitro antioxidant and antimicrobial activities of ethanolic extracts from 20 plants and three herbal commercial products empirically used for aquaculture improvement in Vietnam. The results of 2,2-diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging assays showed that Phyllanthus amarus extract was the strongest ant...

The inhibitory activity of the essential oils (EO) of mint and thyme on Candida albicans are well known, however, their valorization in a dosage form for the management of cutaneous candidiasis has been little explored. This study aimed to formulate innovative and cost-effective dermatological topicals based on mint and thyme essential oils for the...

This study was performed on all Eryngium species growing in Tunisia in order to evaluate their intra and interspecies variabilities and to investigate their biological activities. These species are used in traditional medicine, and literature about the phytochemical investigations of most of them is scarce. Antimicrobial and light‐enhanced activiti...

Cymbopogon giganteus Chiov. (Poaceae) is a medicinal plant used to treat various diseases in traditional medicine in several African countries. The present study aims to evaluate the oral and inhalation toxicity as well as the mutagenic effects of the essential oil of Cymbopogon giganteus leaves (EOCG) from a sample collected in Benin. Mutagenic po...

The success of the promotion policies of the Medicines Derived from Traditional Pharmacopoeia (MDTPs) requires a regulation that is adapted to realities and guarantees their quality, efficiency and safeness. This study aims to analyze the legal texts and the current guiding principles obtained from the heads of the departments in charge of traditio...

Résumé Objectif Dans le but d’améliorer la contribution des médicaments issus de la pharmacopée traditionnelle aux soins de santé, des pays africains comme le Burkina Faso ont adopté depuis plusieurs années des politiques et des réglementations organisant leur distribution. Ce travail a pour objectif d’analyser la situation de la vente en gros et...

Root extracts of a Cameroon medicinal plant, Dorstenia psilurus, were purified by screening for AMP-activated protein kinase (AMPK) activation in incubated mouse embryo fibroblasts (MEFs). Two isoprenylated flavones that activated AMPK were isolated. Compound 1 was identified as artelasticin by high resolution electrospray ionization mass spectrome...

Background/aims: During dermatological forms development, one of the simplest non-invasive techniques used to evaluate cutaneous tolerance of formulations is to monitor the color changes using a tristimulus chromameter. Most published tolerance studies involving chromametric measurements are performed on Caucasian subjects. However, in the context...

Many plants require animal pollinators for successful reproduction; these plants provide pollinator resources in pollen and nectar (rewards) and attract pollinators by specific cues (signals). In a seeming contradiction, some plants produce toxins such as alkaloids in their pollen and nectar, protecting their resources from ineffective pollinators....

The uncontrolled use of antimicrobials leads to an increase in the resistance of bacteria which becomes a public health problem. To overcome this problem, our study aims to establish a link between chemical composition and antimicrobial activity and then evaluate cytotoxicity, of seven essential oils. Antimicrobial activity of essential oils was as...

The chemical composition of essential oils extracted from aerial parts of Eryngium campestre collected in 37 localities from Western Algeria was characterized using GC-FID and GC/MS analyses. Altogether, 52 components, which accounted for 70.1 to 86.8% of the total composition oils were identified. The main compounds were Germacrene D (0.4–53.4%),...

A feeding trial was performed to compare the effects of five ethanol herbal extracts (bhumi amla, Phyllanthus amarus Schum and Thonn [Pa]; guava, Psidium guajava L. [Pg]; sensitive plant, Mimosa pudica L. [Mp]; neem, Azadirachta indica A. Juss [Ai] and asthma plant, Euphorbia hirta L. [Eh]) on the immune response and disease resistance against Edwa...

Many medicinal plants have been shown to possess biological effects, including immuno-modulatory activities on human and other mammals. However, studies about the potential mechanisms of plant extracts on the humoral and tissular immunities in fish have received less attention. This study aimed to screen the immunestimulating properties of 20 ethan...

This paper describes the purification of two guanidine alkaloids: N1, N2-diisopentenyl guanidine (DIPG) 1 and N1,N2,N3- triisopentenyl guanidine (TIPG) 2 from Alchornea cordifolia root bark and reports their cytotoxic properties on cancer (HeLa, Mel-5, J774) and non cancer (WI 38) cells. TIPG showed the highest cytotoxicity with IC50 values from 0....

The chemical compositions of the essential oils of the fresh and dried leaves of Ipomea pes-caprae from Mauritius were studied for the first time by gas chromatography-mass spectrometry and 70 compounds were identified. The major components were found to be 8-cedren-13-ol (13.0%), (E)-nerolidol (7.0%), guaiol (6.2%), α-cadinol (6.2%) and limonene (...

Human African trypanosomiasis (HAT), known as sleeping sickness and caused by Trypanosoma brucei, is threatening low-income populations in sub-Saharan African countries with 61 million people at risk of infection. In order to discover new natural products against HAT, thirty-seven Vietnamese essential oils (EOs) were screened for their activity in...

New anti-infective agents are urgently needed to fight microbial resistance. Methicillin-resistant Staphylococcus aureus (MRSA) strains are particularly responsible for complicated pathologies that are difficult to treat due to their virulence and the formation of persistent biofilms forming a complex protecting shell. Parasitic infections caused b...

Introduction The increase in multidrug resistance and lack of efficacy in malaria therapy has propelled the urgent discovery of new antiplasmodial drugs, reviving the screening of secondary metabolites from traditional medicine. In plant metabolomics, NMR-based strategies are considered a golden method providing both a holistic view of the chemical...

To investigate the effect of the harvest daytime of the Cymbopogon citratus (cd) Stapf (Cc) and Cymbopogon schoenantus (L). Spreng (Cs) leaves on the yields, composition, antitrypanosomal activity and cytotoxicity of their essential oils (EOs), volatile compounds of Cc and Cs leaves collected at three different times (7 am, 1 pm, 7 pm) on the same...

Euphorbia hirta L. has been proved a medicinally important plant. This study aimed to investigate the antioxidant capacities of fractioned extracts and some isolated compounds from Euphorbia hirta L. on pancreatic β-cells MIN6 exposed to hydrogen peroxide-oxidative stress conditions. Four pure compounds were isolated from ethyl acetate and methanol...

The chemical composition of a hexanic extract of Eryngium campestre, obtained from its aerial parts, was investigated by GC-FID, GC/MS, HRMS, NMR and VCD analyses. The main compounds were germacrene D (23.6%), eudesma-4(15)-7-dien-1-β-ol (8.2%) and falcarindiol (9.4%), which are associated with a new uncommon and naturally found 17-membered ring la...

The aim of this study is to develop validated methods for the extraction and quantification of antimalarial triterpene esters from Keetia leucantha and from plasma samples. These compounds, showing in vitro and in vivo antiplasmodial activities, were optimally extracted from Keetia leucantha twigs using ultrasounds with dichloromethane and from pla...

Euphorbia hirta L., a kind of herbs belonging to family Euphorbiaceae, has been found a lot in the Mekong Delta. From the ethyl acetat and methanol fractions of this plant, four pure compounds were isolated and identified their chemical structure by spectroscopic techniques including quercitrin (1), luteolin (2), quercetin (3) and caffeic acid (4)....

Given the increasing emergence of antibiotic resistance, the discovery of novel therapeutic options for the treatment of infections is urgently needed. One strategy for overcoming bacterial resistance mechanisms is the use of drugs in combination, such as β‐lactams together with β‐lactamase inhibitors. Here, via a screen of direct and indirect anti...

Staphylococcus aureus infections are considered as seriously problematic for human health and necessitate the development of new medicines and innovative antimicrobial strategies. Plant secondary metabolites have already demonstrated their potential as antibacterials when used alone but also in combination with other antimicrobial agents to potenti...

Endoplasmic reticulum (ER) stress plays an important role in the pathogenesis of diabetes, contributing to pancreatic β‐cell loss and insulin resistance in type 2 diabetes mellitus (T2DM). In this study, the effect of ethanol extracts of Euphorbia hirta L. (Eup), Phyllanthus amarus L. (Phy), Mimosa pudica L. (Mim), Psidium guajava L. (Psi) and Azad...

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 displaye...

Strychnogucine B is a bisindole alkaloid previously isolated from Strychnos icaja that possesses promising in vitro antiplasmodial properties. This compound was synthesized in four steps from (−)-strychnine. As no acute toxicity was observed at the highest tested cumulative dose of 60 mg/kg, its in vivo antimalarial activity was determined intraper...