Publications by authors named "Helene Greige-Gerges"

Recently essential oils (EOs) encapsulation is experiencing growing applications in agricultural and agri-food sector. Encapsulation is reported as safe environmental technology leading to a reduction of conventional insecticides use. This study concerns the assessment of fumigant toxicity and persistence of EO encapsulated in two cyclodextrins β-CD and HP-β-CD against larvae of the date moth, The retention capacity, encapsulation efficacy, loading capacity and release behavior of the two inclusion complexes were investigated.

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On murine N2a cells, 7-ketocholesterol induced an oxiapotophagic mode of cell death characterized by oxidative stress (reactive oxygen species overproduction on whole cells and at the mitochondrial level; lipid peroxidation), apoptosis induction (caspase-9, -3 and -7 cleavage, PARP degradation) and autophagy (increased ratio LC3-II / LC3-I). Oxidative stress was strongly attenuated by diphenyleneiodonium chloride which inhibits NAD(P)H oxidase. Mitochondrial and peroxisomal morphological and functional changes were also observed.

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Cyclodextrins (CDs) are known for their ability to extract lipid components from synthetic and biological membranes and therefore to induce an increase of membrane permeability. However, the effect of cholesterol (CHOL) content in the membrane on the CD permeabilizing effect was not considered yet. Given that an increase in CHOL content reduces the membrane permeability, the aim of this work was to reveal how CHOL would modulate the CDs effect on the membrane.

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It is known that the activities of Na/K- and Ca-ATPases in the plasma membrane with an excess of cholesterol are compromised. Our main goal was to find out whether quercetin, resveratrol, or caffeic acid, in the nano- and low micromolar concentration ranges, can improve the ATPase activity in human erythrocyte membranes with excess cholesterol. These molecules belong to different chemical classes of polyphenols and are widely present in plant foods.

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Background: Synthetic insecticides are the most useful tools for preventing losses caused by insect pest's infestation during storage. However, the use of pesticides should be limited because of the development of insect resistance and their adverse effects on human health and environment. In the last decades, natural insecticidal products, principally essential oils (EOs) and their active components, exhibited potential alternatives for pest control.

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Abstract: Nerolidol is a natural sesquiterpene alcohol with promising but limited application in food and pharmaceutical fields due to several factors including low photostability and low aqueous solubility. Recently, several carriers loading nerolidol were prepared and tested in fresh orange juice. Lipid vesicles loading nerolidol did not exhibit satisfactory organoleptic properties in this beverage.

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Dermatophyte infections represent a significant public health concern, with an alarming negative impact caused by unsuccessful therapeutic regimens. Natural products have been highlighted as a promising alternative, due to their long-standing traditional use and increasing scientific recognition. In this study, honokiol and magnolol, the main bioactives from spp.

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Dermatophyte infections represent an important public health concern, affecting up to 25% of the world's population. and are the predominant dermatophytes in cutaneous infections, with a prevalence accounting for 70% of dermatophytoses. Although terbinafine represents the preferred treatment, its clinical use is hampered by side effects, drug-drug interactions, and the emergence of resistant clinical isolates.

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The essential oil component α-pinene has multiple biological activities. However, its application is limited owing to its volatility, low aqueous solubility, and chemical instability. For the aim of improving its physicochemical properties, α-pinene was encapsulated in conventional liposomes (CLs) and drug-in-cyclodextrin-in-liposomes (DCLs).

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Skin hyperpigmentation is caused by an excessive production of melanin. Cysteamine, an aminothiol compound physiologically synthetized in human body cells, is known as depigmenting agent. The aim of this study was to evaluate the depigmenting activity and skin penetration of liposome formulations encapsulating cysteamine hydrochloride.

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Since the membrane-related processes represent an integral part of the biological activities of drugs, their effect on the membrane dynamics is actually considered. In this study, we investigated the effect of pentacyclic triterpenes (TTPs), oleanolic acid (OA) and erythrodiol (ER), on the fluidity and permeability of liposomes membranes differing by their cholesterol content. All liposomes were prepared by reverse phase evaporation technique (REV).

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Quercetin (3,3',4',5,7-pentahydroxyl-flavone) is a natural flavonoid with many valuable biological effects, but its solubility in water is low, posing major limitations in applications. Quercetin encapsulation in liposomes increases its bioavailability; the drug effect on liposome elastic properties is required for formulation development. Here, we quantify the effect of quercetin molecules on the rigidity of lipoid E80 liposomes using atomic force microscopy (AFM) and molecular dynamics (MD) simulations.

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Encapsulation in liposomes has been an efficient strategy to improve the stability of sensitive bioactive compounds such as essential oils (EOs). However, the stability of liposomal formulations remains a key parameter controlling the delivery of encapsulated ingredients. Cholesterol (Chol) modulates the membrane properties conferring stability to the lipid bilayer.

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The aminothiol cysteamine, derived from coenzyme A degradation in mammalian cells, presents several biological applications. However, the bitter taste and sickening odor, chemical instability, hygroscopicity, and poor pharmacokinetic profile of cysteamine limit its efficacy. The use of encapsulation systems is a good methodology to overcome these undesirable properties and improve the pharmacokinetic behavior of cysteamine.

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Membrane elastic properties play a major role in membrane remodeling events, such as vesicle fusion and fission. They are also crucial in drug delivery by liposomes. Different experimental techniques are available to measure elastic properties.

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The Mediterranean diet is associated with health benefits due to bioactive compounds such as polyphenols. The biological activities of three polyphenols (quercetin (QCT), resveratrol (RSV), apigenin (API)) were evaluated in mouse neuronal N2a cells in the presence of 7-ketocholesterol (7KC), a major cholesterol oxidation product increased in patients with age-related diseases, including neurodegenerative disorders. In N2a cells, 7KC (50 µM; 48 h) induces cytotoxic effects characterized by an induction of cell death.

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Despite the high aqueous solubility of cysteamine, its unpleasant organoleptic properties, hygroscopicity, instability in solutions, and poor pharmacokinetic profile are the main drawbacks that limit its use for medical and cosmetic purposes. In this study, cysteamine-loaded liposomes were prepared using the ethanol injection method. Liposomes were characterized for their size, homogeneity, surface charge, and morphology.

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The emergence of multidrug resistant pathogens is a great challenge to the medical field and a major global health threat requiring novel therapeutic strategies. Among plant products, essential oils have significant antimicrobial properties that make them promising agents in the fight against drug resistant human pathogens. The aim of the present review was to highlight the most important essential oil-based antimicrobial strategies as revealed by recent studies.

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In this work, a series of novel low melting mixtures (LMM) based on cyclodextrins (CD) and levulinic acid and inspired by the deep eutectic solvents (DES), were prepared. These supramolecular mixtures are the first reported CD-based mixtures that are liquid at room temperature. Density, viscosity and rheological measurements as well as differential scanning calorimetry and thermogravimetric analysis were performed to characterize these new LMM.

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The brain, which is a cholesterol-rich organ, can be subject to oxidative stress in a variety of pathophysiological conditions, age-related diseases and some rare pathologies. This can lead to the formation of 7-ketocholesterol (7KC), a toxic derivative of cholesterol mainly produced by auto-oxidation. So, preventing the neuronal toxicity of 7KC is an important issue to avoid brain damage.

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Liposomes are lipid vesicles made of one or multiple lipid bilayers surrounding an internal aqueous core. They are broadly employed as models to study membrane structure and properties. Among these properties, liposome membrane permeability is crucial and widely assessed by fluorescence techniques.

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A supramolecular solvent based on cyclodextrin (CD) is presented here for the first time. Indeed, a low melting mixture was obtained by mixing levulinic acid and a CD derivative, which retained its inclusion ability in the resulting solvent. This new system gives rise to a new family of solvents that could be called SUPRADES (supramolecular deep eutectic solvents).

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Drug-in-cyclodextrin-in-liposome (DCL) represents a very promising approach for preserving essential oil (EO) components, thereby extending their shelf life and activity. In this study, we examined the effect of chemical structure, octanol/water partition coefficient (log P), and Henry's law constant (H) on the encapsulation and the release of monoterpenes (eucalyptol, pulegone, terpineol, and thymol) and phenylpropenes (estragole and isoeugenol) from DCLs. Hydroxypropyl-β-cyclodextrin/EO component (HP-β-CD/EO component) inclusion complexes were prepared in aqueous solution and loaded into liposomes by the ethanol injection method.

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The use of proteins and defined amino acid sequences as therapeutic drugs have gained a certain interest in the past decade. However, protein encapsulation within protein nanoparticles was never endeavored. For this reason, human serum albumin (HSA) nanoparticles were prepared by nanoprecipitation method.

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Oleanolic acid (OA) is a triterpenoid, widely found in plants and possesses antitumor activity in many cancer lines. However, cancer cells develop multidrug resistance (mdr) hindering the effect of anticancer drugs. P-glycoprotein (P-gp) is a major cause of mdr.

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