José Luis

Aix-Marseille University | AMU · Institut de neurophysiopathologie (INP; CNRS UMR 7051)

The efficacy of available treatments for melanoma is limited by side effects and the rapidly emerging resistance to treatment. In this context, the decavanadate compounds represent promising tools to design efficient therapeutic agents. In our study, we synthesized a dimagnesium disodium decavanadate icosahydrate compound (Mg2Na2V10O28·20H2O) and i...

Glioblastoma multiforme (GBM) is a highly aggressive and fatal primary brain tumor. The resistance of GBM to conventional treatments is attributed to factors such as the blood–brain barrier, tumor heterogeneity, and treatment-resistant stem cells. Current therapeutic efforts show limited survival benefits, emphasizing the urgent need for novel trea...

Microtubule targeting agents (MTA) are anti-cancer molecules that bind tubulin and interfere with the microtubule functions, eventually leading to cell death. In the present study, we used an in vitro microtubule polymerization assay to screen several venom families for the presence of anti-microtubule activity. We isolated myotoxin-3, a peptide of...

Integrin targeted therapies by natural bioactive compounds have attracted attention in the field of oncology and cancer treatment. This study evaluates the potential of phenolic extract from the medicinal herb Ecballium elaterium L. seed oil (PEO) to inhibit the adhesion and migration of the highly invasive human fibrosarcoma cell line HT1080. At s...

PIVL is a Kunitz-type serine protease inhibitor that was previously characterized from Tunisian snake venom, Macrovipera lebetina transmediterranea. It reduced glioblastoma cells’ development and significantly blocked angiogenesis in in-vitro and ex-vivo models. PIVL exerted these effects by interfering with αvβ3 integrin. In order to produce a bio...

Glioblastoma is the most aggressive and invasive form of central nervous system tumors due to the complexity of the intracellular mechanisms and molecular alterations involved in its progression. Unfortunately, current therapies are unable to stop its neoplastic development. In this context, we previously identified and characterized AaTs-1, a tetr...

Resistance to chemotherapy is the main problem in the treatment of cancer. In many cases, this resistance is due to the over-expression of the P-glycoprotein (pg-p) that pumped out therapeutic drugs. Luteolin, a natural flavonoïd, is abundant in our daily diet and has many pharmacological properties. A large body of evidence shows that luteolin is...

The venoms of Tunisian wildlife snakes are complex mixtures containing proteins/peptides and non-protein molecules. Proteins and peptides are the most abundant compounds responsible for the biological effects of venoms. Snake venoms proteins have enzymatic or non-enzymatic activities, which are grouped into different families including C-type lecti...

"VENOMS and TOXINS" Publishes articles (research articles, review articles, etc.) in the field of toxins from animal venoms, plants, bacteria, viruses, fungi and other toxic natural and synthetic compounds.

In the soft treatment of cancer tumours, consequent downregulation of the malignant tissue angiogenesis constitutes an efficient way to stifle tumour development and metastasis spreading. As angiogenesis requires integrin–promoting endothelial cell adhesion, migration, and vessel tube formation, integrins represent potential targets of new therapeu...

Prostate cancer is the most highly diagnosed cancer in men worldwide. It is characterized by high proliferation, great invasion and metastatic potential. Sodium channel subtypes have been identified as highly expressed in different prostate cancer cell lines. In this study, we have screened the negatively charged fractions of Androctonus australis...

Among the flavonoïds, luteolin is a flavone that has been identified in many plants. It is known for its apoptotic potential with damage to DNA and cell cycle blockage. Many studies have shown that luteolin has anti-oxidant, anti-inflammatory, and anti-cancer activities. However, it is known that heat treatment (boiling, cooking, and treating with...

Despite post-operative radio-chemotherapy, glioblastoma systematically locally recurs. Tumors contacting the periventricular zone (PVZ) show earlier and more distant relapses than tumors not contacting the PVZ. Since glioblastoma stem-like cells (GSCs) have been proposed to play a major role in glioblastoma recurrence, we decided to test whether GS...

Through the recent development of knowledge in biotechnology and bioinformatics, snake venoms are widely used to develop new drugs to treat diseases such as hypertension and cancer. We have previously reported that Lebetin 2 isolated from Macrovipera lebetina transmediterranea venom displays a potent anti-platelet activity and exerts a cardioprotec...

Sea anemones are a remarkable source of active principles due to a decentralized venom system. New blood vessel growth or angiogenesis is a very promising target against cancer, but the few available antiangiogenic compounds have limited efficacy. In this study, a protein fraction, purified from tentacles of Anemonia viridis, was able to limit endo...

Sea anemones are a remarkable source of active principles due to a decentralized venom system. Blood vessel formation or angiogenesis is a very promising target against cancer, but the few available anti-angiogenic compounds have a limited efficacy. In this study, a protein fraction was purified from tentacles of Anemonia viridis able to limit endo...

Voltage-gated potassium (Kv) channels are known to play a pivotal role in the progression of various cancer types and considered as new targets for designing anti-cancer therapy. However, the fact that many Kv channels are expressed in different cell lines makes it difficult to ascribe a functional role for a given Kv channel on a specific aspect o...

Cancer is the leading cause of death worldwide (Ferlay in Int J Cancer 127:2893–2917, 2010). Metastasis can be considered as a cascade of interrelated sequential steps.

Résumé Notre étude vise à montrer la présence illicite de certains ingrédients dans la composition de produits cosmétiques dépigmentants. Dans ce but, une nouvelle procédure faisant appel à la chromatographie liquide à haute performance couplée à la spectrométrie de masse a été mise au point, rendant possible la caractérisation, l’identification et...

Integrins are essential protagonists in the complex multistep process of cancer progression and are thus attractive targets for the development of anticancer agents. Cucurbitacin B, a triterpenoid purified from the leaves of Tunisian Ecballium elaterium exhibited an anticancer effect and displayed anti-integrin activity on human glioblastoma U87 ce...

In the present study, the effect of Ecbalium elaterium seed oil on adhesion, migration and proliferation of human brain cancer cell line (U87) was determined. Treatment of U87 cell line with the seed oil resulted in strong inhibition of their adhesion to fibrinogen (Fg), fibronectin (Fn). It also reduced their migration and proliferation in a dose-...

Introduction Actuellement, la réglementation des produits cosmétiques est en perpétuel remaniement. Moins encadré que l’industrie pharmaceutique, le domaine de la cosmétique tend aujourd’hui vers une réglementation plus stricte. Celle-ci est régie par un texte de loi unique applicable en l’état par tous, le règlement (CE) no 1223/2009 du parlement...

Lung and colorectal cancer are the principal causes of death in the world. Rutin, an active flavonoid compound, is known for possessing a wide range of biological activities. In this study, we examined the effect of rutin on the viability, superoxide anion production, adhesion and migration of human lung (A549) and colon (HT29 and Caco-2) cancer ce...

The NADPH oxidase proteins catalyse the formation of superoxide anion which act as signalling molecules in physiological and pathological processes. Nox1-dependent NADPH oxidase is expressed in heart, lung, colon, blood vessels and brain. Different strategies involving Nox1 inhibition based on diphenylene iodonium derivatives are currently tested f...

Laccase was used to enzymatically polymerize esculin. Oligoesculin fraction was obtained after ultrafiltration through a 5-kDa membrane. Several studies have been carried out to prove the effectiveness of natural substances such as immunomodulators to promote the anti-cancer activity in situ. The purpose of our report was to explore whether the ant...

Angiogenesis constitutes a fundamental step in tumor progression. Thus, targeting tumour angiogenesis has been identified to be promising in cancer treatment. In this work, CC5 and CC8, two highly homologous disintegrins isolated from the venom Cerastes cerastes viper from the south of Tunisia, were assessed for their anti-angiogenic effect by test...

Cancer metastasis is the major cause of cancer-related death. Chemoprevention is defined as the use of natural or synthetic substances to prevent cancer formation or cancer progress. In the present study, we investigate the antitumor activity of esculin and its oligomer fractions in U87 glioblastoma cells. We showed that esculin and its oligomers r...

Allium roseum L. (Alliaceae) endemic mediterranean specie was represented in the North Africa by 12 different taxa. In the present study, chemical composition, antiproliferative, antioxidant and antimicrobial activities of the essential oil extracted from A. roseum var. grandiflorum Briq. bulbs collected in the North of Tunisia were investigated. C...

Increased reactive oxygen species (ROS) production is associated with inflamed ileal lesions in Crohn's disease colonized by pathogenic adherent-invasive Escherichia coli LF82. We investigated whether such ileal bacteria can modulate ROS production by epithelial cells, thus impacting on inflammation and mucin expression. Ileal bacteria from patient...

In this work the physicochemical characteristics including fatty acids, tocopherols and sterols composition of Ecballium elaterium (L.) A. Rich seed oil was determined. Results showed that linoleic acid (48.64%) and punicic acid (22.38%) were the major polyunsaturated fatty acids. Among the phytosterols, β-sitosterol was the most abundant (396.25 m...

C-type lectins like proteins display various biological activities and are known to affect especially platelet aggregation. Few of them have been reported to have anti-tumor effects. In this study, we have identified and characterized a new C-type lectin like protein, named lebecin. Lebecin is a heterodimeric protein of 30 kDa. The N-terminal amino...

C-type lectins like proteins display various biological activities and are known to affect especially platelet aggregation. Few of them have been reported to have anti-tumor effects. In this study, we have identified and characterized a new C-type lectin like protein, named lebecin. Lebecin is a heterodimeric protein of 30 kDa. The N-terminal amino...

Snake venoms are rich sources of serine proteinase inhibitors that are members of the KunitzBPTI (bovine pancreatic trypsin inhibitor) family. Generally, these inhibitors are formed by 60 amino acids approximately. Their folding is characterised by a canonical loop that binds in a complementary manner to the active site of serine protease. Some var...

Phospholipases type A2 (PLA2s) are the most abundant proteins found in Viperidae snake venom. They are quite fascinating from both a biological and structural point of view. Despite similarity in their structures and common catalytic properties, they exhibit a wide spectrum of pharmacological activities. Besides being hydrolases, secreted phospholi...

A novel Kunitz-type serine proteinase inhibitor, termed PIVL, was purified to homogeneity from the venom of the Tunisian snake Macrovipera lebetina transmediterranea. It is a monomeric polypeptide chain cross-linked by three disulfide linkages with an isotope-averaged molecular mass of 7691.7 Da. The 67-residue full-length PIVL sequence was deduced...

Lebecetin is an anticoagulant C-type lectin-like protein that was previously isolated from Macrovipera lebetina venom and described to consist of two subunits (alpha and beta). It was reported to potently prevent platelet aggregation by binding to glycoprotein Ib and to exhibit a broad spectrum of inhibitory activities on various integrin-mediated...

Previous studies have reported that cross-talk between integrins may be an important regulator of integrin-ligand binding and subsequent signalling events that control a variety of cell functions in many tissues. We previously demonstrated that αvβ5/β6 integrin represses α2β1-dependent cell migration. The αv subunits undergo an endoproteolytic clea...

AaCtx is the first chlorotoxin-like peptide isolated from Androctonus australis scorpion venom. Its amino acid sequence shares 70% similarity with chlorotoxin from Leiurus quinquestriatus scorpion venom, from which it differs by twelve amino acids. Due to its very low concentration in venom (0.05%), AaCtx was chemically synthesized. Both native and...

Selectins belong to the family of adhesion molecules that recognize sugars as ligands through their Carbohydrate Recognition Domain (CRD). There are three types of selectin: the L-selectin (CD62L), which is constitutively expressed by most leukocyte populations, the P-selectin (CD62P) is found on activated platelets and endothelial cells, and the E...

Background information. Previous studies have reported that cross-talk between integrins may be an important regulator of integrin-ligand binding and subsequent signalling events that control a variety of cell functions in many tissues. We previously demonstrated that alpha v beta 5/beta 6 integrin represses alpha 2 beta 1-dependent cell migration....

MVL-PLA2 does not significantly affect HMEC-1 viability. (A) HMEC-1 cells, seeded in 96-well plates, were treated with various concentrations of MVL-PLA2 for 72 h. After incubation 3 hours with 0.5 mg/ml 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), the stain was eluted with 100 μl DMSO and absorbance was measured at 550 nm....

Microtubule dynamics in MVL-PLA2-treated HMEC-1 cells. HMEC-1 cells expressing GFP-tubulin were treated with 100 nM MVL-PLA2 for 1 h and observed using the ×100 objective lens of an inverted fluorescence microscope (Leica). Thirty-one images per cell were acquired at 4-second intervals using a digital camera driven by Metamorph software as previous...

MVL-PLA2 alter the size and the cell distribution of FA HMEC-1 cells were treated or not with 100 nM MVL-PLA2, permeabilized and co-stained for paxillin with anti-paxillin antibody (green) and for actin with TRITC-conjugated phalloidin (red). Scale bars: 10 µm. (9.97 MB TIF)

HMEC-1 cells expressing GFP-tubulin were treated without MVL-PLA2 for 1 h and observed using the ×100 objective lens of an inverted fluorescence microscope (Leica). Thirty-one images per cell were acquired at 4-second intervals using a digital camera driven by Metamorph software as previously described (Pourroy et al. (2006) Cancer Res 66: 3256). (...

Integrins are essential protagonists of the complex multi-step process of angiogenesis that has now become a major target for the development of anticancer therapies. We recently reported and characterized that MVL-PLA2, a novel phospholipase A2 from Macrovipera lebetina venom, exhibited anti-integrin activity. In this study, we show that MVL-PLA2...

Integrins are essential in the complex multistep process of angiogenesis and are thus attractive targets for the development of antiangiogenic therapies. Integrins are antagonized by disintegrins and C-type lectin-like proteins, two protein families from snake venom. Here, we report that CC-PLA2-1 and CC-PLA2-2, two novel secreted phospholipases A(...

Disintegrins are natural toxins found in snake venom having anti angiogenic activity. The KTS disintegrins group appears to be the most interesting as specific blocking agent of tumor growth. We report the chemical synthesis of three KTS disintegrins (Lebes-tatin, Obtustatin and Viperistatin) carried out with different substitution. The activity of...

Leberagin-C, a new member of the disintegrin-like/cysteine-rich (D/C) family, was purified to homogeneity from the venom of Tunisian snake Macrovipera lebetina transmediterranea. It is a monomeric protein with a molecular mass of 25,787 Da. Its complete sequence of 205 amino acid residues was established by cDNA cloning. The leberagin-C shows many...