Walter Luyten

KU Leuven | ku leuven · Department of Biology

Abstract Background In Chinese Pharmacopeia, Picrasma quassioides (PQ) stems and leaves are recorded as Kumu with antimicrobial, anti-cancer, anti-parasitic effects, etc. However, thick stems are predominantly utilized as medicine in many Asian countries, with leaves rarely used. By now, the phytochemistry and bioactivity of PQ leaves are not well...

We assessed the antimicrobial activity of extracts prepared with four solvents (hexane, acetone, ethanol, water) from 45 medicinal plants used in Bangladesh. Food pathogenic bacteria (Gram‐positive: Bacillus cereus , Listeria innocua , Streptococcus faecalis , and Gram‐negative: Escherichia coli , Pseudomonas aeruginosa , Salmonella enterica , and...

This study was conducted to isolate and identify the bioactive compounds from the ethanolic extract of Syzygium cumini leaf against Vibrio species through a bioassay-guided fractionation. The ethanol extract was exposed to silica gel chromatography followed by reversed phase HPLC to isolate the most effective fraction against V. parahaemolyticus. U...

Tectona grandis Linn, commonly known as teak, is traditionally used to treat a range of diseases, including the common cold, headaches, bronchitis, scabies, diabetes, inflammation, and others. The present study was conducted with the purpose of isolating and identifying the active compounds in T. grandis leaf against a panel of Vibrio spp., which m...

The effect of betel (Piper betle) and amla (Phyllanthus emblica) leaf extracts as feed supplement was studied on the growth and immune functions of the shrimp Penaeus monodon when exposed to a virulent strain of Vibrio parahaemolyticus. Six experimental groups (PB-1, PB-2, PB-3 and PE-1, PE-2, PE-3) of shrimp were fed extract at varying concentrati...

This study was conducted to determine the effect of oral administration of Zingiber officinale and Aegle marmelos extracts on the growth performance and immunomodulatory activities of the shrimp Penaeus monodon against white spot syndrome virus (WSSV). A methanol extract of the Z. officinale rhizome and A. marmelos leaf was sprayed into a pellet fe...

Chimonanthus grammatus is used as Hakka traditional herb to treat cold, flu, etc. So far, the phytochemistry and antimicrobial compounds have not been well investigated. In this study, the orbitrap-ion trap MS was used to characterize its metabolites, combined with a computer-assisted structure elucidation method, and the antimicrobial activities w...

Disease outbreaks in shrimp have increased as the global shrimp aquaculture industry has become more intensive. The white spot syndrome virus (WSSV) is a highly virulent and lethal infection that causes the most harm to global penaeid shrimp production, with a massive mortality rate of 80 to 100% within 3 to 10 days of the onset of clinical symptom...

The presence of sugar in the gut causes induction of SGLT1, the sodium/glucose cotransporter in intestinal epithelial cells (enterocytes), and this is accompanied by stimulation of sugar absorption. Sugar sensing was suggested to involve a G-protein coupled receptor and cAMP - protein kinase A signalling, but the sugar receptor has remained unknown...

Parasitic helminths continue to pose problems in human and veterinary medicine, as well as in agriculture. Semen pharbitidis, the seeds of Pharbitis nil (Linn.) Choisy (Convolvulaceae), is a well-known traditional Chinese medicinal botanical preparation widely used for treating intestinal parasites in China owing to its desirable efficacy. However,...

Helminths, with an estimated 1.5 billion annual global infections, are one of the major health challenges worldwide. The current strategy of the World Health Organization to prevent helminth infection includes increasing hygienic awareness, providing better sanitation and preventative anthelmintic drug therapy in vulnerable populations. Nowadays, a...

Several biogerontology databases exist that focus on genetic or gene expression data linked to health as well as survival, subsequent to compound treatments or genetic manipulations in animal models. However, none of these has yet collected experimental results of compound-related health changes. Since quality of life is often regarded as more valu...

We examined the effects of the extracts from two traditional Chinese medicine plants, Cuscuta chinensis and Eucommia ulmoides, on the healthspan of the model organism Caenorhabditis elegans. C. chinensis increased the short-term memory and the mechanosensory response of aged C. elegans. Furthermore, both extracts improved the resistance towards oxi...

Background Traditional herbs played a crucial role in the health care of the Hakka people. However, studies to identify these traditional herbs are few. Here we document and assess the potential of these plants for treating microbial infections. Many herbs used by the Hakka people could potentially be a novel medicinal resource. Methods Local herb...

This study evaluated the effect of the extract and fractions of Bauhinia holophylla on Candida albicans planktonic growth, biofilm formation, mature biofilm, and hyphae growth. Three C. albicans strains (SC5314, ATCC 18804, and ATCC 10231) were tested. The crude extract and the fractions were obtained by exhaustive percolation and liquid–liquid par...

Tetradenia riparia Hochsteter codd. (Lamiaceae) in its native African continent, is considered one of the most popular aromatic medicinal plants. In folk medicine it may be used as an infusion to treat respiratory problems, cough, headache, stomach pain, diarrhea, fever, malaria, and dengue; and in the form of compresses it is applied for the relie...

Background Locomotor assays in zebrafish have emerged as a screening test in early drug discovery for antiseizure compounds. However, parameters differ considerably between published studies, which may explain some discrepant results with (candidate) antiseizure medications. New method We optimized a locomotor-based seizure assay in zebrafish with...

[This corrects the article DOI: 10.3389/fphar.2021.761751.].

Calamintha species are frequently used in traditional medicine in Algeria as a stimulant, a tonic, an antiseptic, but also to treat digestive disorders and intestinal infections that cause diarrhea as well as pneumonia. Bioassay- guided fractionation led to the isolation of highly effective antistaphylococcal molecules from the aerial parts of Cala...

Background Plants are an abundant natural source of potential chemical compounds; they have been widely used in various industries, such as pharmaceuticals, cosmetics and food. This work aims to study two Saharan medicinal plants by evaluating the activity of plant extract against bacterial and fungal plant pathogens as well as against the model ne...

The stem of Picrasma quassioides (PQ) was recorded as a prominent traditional Chinese medicine, Kumu, which was effective for microbial infection, inflammation, fever, and dysentery, etc. At present, Kumu is widely used in China to develop different medicines, even as injection (Kumu zhusheye), for combating infections. However, the chemical basis...

Disease epidemics in shrimp aquaculture increase apace with the development of aquaculture systems throughout the world. The disease caused by Vibrio spp. (vibriosis) is considered the most devastating, which has made it the most feared bacterial disease in the shrimp sector. In aquaculture, several strategies have already been applied to control V...

Properties of chemically synthesized Zn1-xGdxO (x = 0.01, 0.03 and 0.05) nanorods were explored through microstructural, morphological, toxicity and magnetic characterizations. Hexagonal wurtzite structure of all the samples without any impurity phases was confirmed by X-ray diffraction characterization. The micrographs of transmission electron mic...

Antimicrobial resistance and cancer are two important problems affecting human health. Actively developing novel antibiotics and anticancer medicines is a priority. Natural pentacyclic triterpenoids have attracted wide attention due to their significant biological activities. In this study, a series of 1,2,3-triazolo fused triterpenoids (betulin, o...

Recently, nine Caenorhabditis elegans genes, grouped into two pathways/clusters, were found to be implicated in healthspan in C. elegans and their homologues in humans, based on literature curation, WormBase data mining and bioinformatics analyses. Here, we further validated these genes experimentally in C. elegans . We downregulated the nine genes...

Polygodial is a “hot” peppery-tasting sesquiterpenoid that was first described for its anti-feedant activity against African armyworms. Using the haploid deletion mutant library of Saccharomyces cerevisiae, a genome-wide mutant screen was performed to shed more light on polygodial’s antifungal mechanism of action. We identified 66 deletion strains...

A biologically guided isolation of secondary metabolites from Cousinia alata Schrenk wild plant growing in Akmola region, Kazakhstan, led to the isolation of the bioactive diterpene grindelic acid (1). Six flavonoids were also isolated and identified as retusine (2), pachipodol (3), jaranol (4), penduletin (5), casticin (6), and 5, 7, 3′-trihydroxy...

Several biogerontology databases exist that focus on genetic or gene expression data linked to health as well as survival, subsequent to compound treatments or genetic manipulations in animal models. However, none of these has yet collected experimental results of compound-related health changes. Since quality of life is often regarded as more valu...

To uncover potential anti-aging capacities of Traditional Chinese Medicine (TCM), the nematode Caenorhabditis elegans was used to investigate the effects of Eucommia ulmoides and Cuscuta chinensis extracts, selected by screening seven TCM extracts, on different healthspan parameters. Nematodes exposed to E. ulmoides and C. chinensis extracts, start...

Caco-2 cells are increasingly used to study the absorption of drugs and nutrients, including D-glucose, an important nutrient that mainly gets absorbed from the intestine by the sodium/glucose cotransporter 1 (SGLT1). However, disadvantages of Caco-2 cells for such studies have been reported, e.g., D-glucose cannot elicit translocation of the intra...

Ethnopharmacological relevance Tetradenia riparia (commonly known as ginger bush) is frequently used in traditional African medicine to treat foodborne infections including diarrhoea, gastroenteritis, and stomach ache. Aim of the study: The present study aims to identify in Tetradenia riparia the compounds active against foodborne pathogens. Mater...

Nanoparticles of Zn1-xLaxO (x = 0, 0.01, 0.03 and 0.05) were successfully synthesized by a cost-effective chemical method. The influences of La on the microstructural, optical, antimicrobial and magnetic properties of these ZnO nanoparticles were investigated. XRD studies revealed the presence of hexagonal wurtzite phase of ZnO without any impurity...

Over the last decades a decrease in mortality has paved the way for late onset pathologies such as cardiovascular, metabolic or neurodegenerative diseases. This evidence has led many researchers to shift their focus from researching ways to extend lifespan to finding ways to increase the number of years spent in good health; “healthspan” is indeed...

The newly emerged SARS-CoV-2 strains from the coronavirus (CoV) family is causing one of the most disruptive pandemics of the past century. Developing antiviral drugs is a challenge for the scientific community and pharmaceutical industry. Given the health emergency, repurposing of existing antiviral, antiinflammatory or antimalarial drugs is an at...

Holarrhena pubescens is an important medicinal plant of the Apocynaceae family that is widely distributed over the Indian subcontinent. The plant is extensively used in Ayurveda and other traditional medicinal systems without obvious adverse effects. Beside notable progress in the biological and phytochemical evaluation of this plant over the past...

Evaluation des polyphénols et des capacités antioxydantes des fruits de Musa acuminata Colla subsp. burmannicoïdes De Langhe, un bananier sauvage asiatique acclimaté dans la région de Yangambi, RD Congo Musa acuminata subsp. burmannicoïdes est un bananier sauvage importé de la Birmanie il y a un demi-siècle et bien acclimaté dans la Réserve de Bios...

Holigarna caustica (Dennst.) Oken is used by the tribes of Northeast India for the treatment of intestinal problems. Therefore, the present study was undertaken to investigate the active principles of this plant responsible for its anthelmintic activity, using bioassay-guided fractionation. An ethanol extract of H. caustica fruit was fractionated o...

The molecular basis of aging and of aging-associated diseases is being unraveled at an increasing pace. An extended healthspan, and not merely an extension of lifespan, has become the aim of medical practice. Here, we define health based on the absence of diseases and dysfunctions. Based on an extensive review of the literature, in particular for h...

SARS‐CoV‐2 causes the potentially fatal COVID-19 disease. Already during the outbreak of SARS‐CoV‐1, the use of vitamin C was suggested. Many patients with severe COVID-19 have elevated levels of the mediators interleukin-6 and endothelin-1. These mediators may explain the age-dependence of COVID-19 pneumonia, the preponderance of male and obese or...

Chikungunya and yellow fever virus cause vector-borne viral diseases in humans. There is currently no specific antiviral drug for either of these diseases. Banana plants are used in traditional medicine for treating viral diseases such as measles and chickenpox. Therefore, we tested selected banana cultivars for their antiviral but also cytotoxic p...

SARS-CoV-2 causes the potentially fatal COVID-19 disease. Already during the outbreak of SARS-CoV-1, the use of vitamin C was suggested. Many severe COVID-19 patients have elevated levels of the mediators interleukin-6 and endothelin-1. These mediators may explain the age-dependence of COVID-19 pneumonia, the preponderance of male and obese or hype...

Background. Infections by microbes (viruses, bacteria, and fungi) and parasites can cause serious diseases in both humans and animals. Heavy use of antimicrobials has created selective pressure and caused resistance to currently available antibiotics, hence the need for finding new and better antibiotics. Natural products, especially from plants, a...

Ten banana (Musa spp.) cultivars were studied for their antimicrobial properties. Three plant parts (corm, pseudostem and leaves) were collected separately and extracted with different solvents, viz., hexane, acetone, ethanol and water. The 50% inhibitory concentration (IC 50) was evaluated using a broth microdilution assay. Eight human bacterial a...

Ten banana (Musa spp.) cultivars were studied for their antimicrobial properties. Three plant parts (corm, pseudostem and leaves) were collected separately and extracted with different solvents, viz., hexane, acetone, ethanol and water. The 50% inhibitory concentration (IC 50) was evaluated using a broth microdilution assay. Eight human bacterial a...

Antimicrobial activity of banana cultivars

Intestinal parasitic nematodes infect approximately two billion people worldwide. In the absence of vaccines for human intestinal nematodes, control of infections currently relies mainly on chemotherapy, but resistance is an increasing problem. Thus, there is an urgent need for the discovery and development of new anthelmintic drugs, especially one...

With the aim to discover interesting lead compounds that could be further developed into compounds active against pharmacoresistant epilepsies, we first collected 14 medicinal plants used in traditional Chinese medicine (TCM) against epilepsy. Of the six extracts that tested positive in a pentylenetetrazole (PTZ) behavioral zebrafish model, only th...

Essential oils (EOs) have been used therapeutically for centuries. In recent decades, randomized controlled (clinical) trials have supported efficacy in specific therapeutic indications for a few of them. Some EOs, their components or derivatives thereof have been approved as drugs. Nevertheless, they are still considered products that are mainly u...

Introduction and aims: Oncology treatments research aim at identify and develop new anti-cancer drugs with improved efficacy and no cross-resistance to complement the present chemotherapeutics, and chromones and coumarins derivatives have shown such activity [1,2]. In this study, we test a novel series of synthetic chromone and coumarin derivatives...

Background: Resistance to known anthelmintics has become a growing concern 1. Based on 2017-2019 ethnomedical and ethnoveterinary surveys carried out in Katanga Province, several species of shrub locally identified as Vitex species (Lamiaceae) are used to treat animal helminthiases. Aim of the study: In this study, 4 Vitex species (including differ...

The objective of this study is to evaluate the in vitro antibacterial effectiveness of select Indian medicinal plants against multidrug-resistant (MDR) and biofilm-forming Staphylococcus. Twenty Indian medicinal plants used traditionally were preselected for testing against 17 different clinical strains (originating from animal or hospital patients...

Ethnopharmacological relevance: Warburgia ugandensis Sprague subspecies ugandensis is a plant widely distributed in Eastern, Central and Southern Africa. In humans, it is used to treat respiratory infections, tooth aches, malaria, skin infections, venereal diseases, diarrhea, fevers and aches. Aim of the study: This study aims to identify the bi...

Dengue virus (DENV) is the most prevalent mosquito-borne viral pathogen and made the disease a major health concern worldwide. However, specific antiviral drugs against this arbovirose or vaccines are not yet available for treatment or prevention. Thus, here we aimed to study the antiviral activity of hydroethanolic extract, fraction ethyl acetate...

Insects constitute an alternate source of protein with the benefits of lower environmental impacts than conventional livestock. Ruspolia differens is among the favourite insects used to reduce food insecurity across Sub-Saharan Africa. Current indigenous knowledge rumours the utilisation of this insect as traditional medicine for specific ailments,...

The anti-microbial activity of crude extracts (hexane, acetone, ethanol, and aqueous) of 46 edible plants from Odisha, India, was studied using a broth microdilution assay against 8 common food-borne pathogens (Gram-positive: Bacillus cereus, Streptococcus faecalis, Listeria innocua, Micrococcus luteus, and Gram-negative: Escherichia coli, Pseudomo...

Different parts of Cnestis ferruginea are used in traditional African medicine for treating infectious diseases such as dysentery, bronchitis, eye troubles, conjunctivitis, sinusitis, gonorrhea, and syphilis. Despite its long traditional use in the treatment of infections, this plant is not well studied for its in vitro antimicrobial properties. Th...

G Protein-Coupled Receptors (GPCRs) transduce extracellular signals and activate intracellular pathways, usually through activating associated G proteins. Due to their involvement in many human diseases, they are recognized worldwide as valuable drug targets. Many experimental approaches help identify small molecules that target GPCRs, including in...

Each year, fruit growers have hundreds of tons of bark and pruning waste. Despite their potential for chemical recycling, residues from this waste are frequently used for applications with low added value. By converting the waste stream into a valuable source, this study emphasizes waste valorisation and engenders re-use strategies for the producti...

Despite increasing research efforts, there is a lack of consensus on defining aging or health. To understand the underlying processes, and to foster the development of targeted interventions towards increasing one's health, there is an urgent need to find a broadly acceptable and useful definition of health, based on a list of (molecular) features;...

Salvia officinalis is frequently used in traditional Algerian medicine to treat diverse microbial infections, including oral and vaginal candidiasis. The aerial parts of S. officinalis collected in Annaba, Algeria were extracted in parallel by maceration with four solvents viz. hexane, acetone, methanol and water. All the extracts were tested in vi...

Parasitic nematodes continue to cause significant economic losses in livestock globally. Given the limited number of anthelmintic drugs on the market and the currently increasing drug resistance, there is an urgent need for novel anthelmintics. Most motility assays of anthelmintic activity for parasitic nematodes are laborious and low throughput, a...

Ethnopharmacological relevance Semen Pharbitidis, the seeds of Pharbitis nil (Linn.) Choisy (Convolvulaceae) is a well-known traditional Chinese medicinal plant used for treating helminthiasis and epilepsy in China. Aim of the study This study aims to identify the anti-seizure components from Semen Pharbitidis. Methods A bioassay-guided isolation...