Effects of the UVB radiations on the liberation of pro-inflammatory mediators involved in skin aging : anti-aging activity of a Butea monosperma (Lam.) Taub. flowers extract

Le photo-vieillissement cutané est en partie dû aux effets néfastes des rayonnements UV qui induisent un stress oxydant. Celui-ci joue un rôle promoteur dans l’installation d’un statut micro-inflammatoire lié à la production de médiateurs tels que des cytokines pro-inflammatoires, des métalloprotéinases de la matrice extracellulaire (MMPs) et des prostaglandines E2. Mes travaux ont été effectués sur le kératinocyte, cellule majeure de l’épiderme et acteur du processus de vieillissement cutané. Dans une première partie, nous décrivons différentes expériences menées pour évaluer l’association de plusieurs molécules anti-oxydantes connues afin d’en potentialiser l’activité. Cette étude a mis en évidence que dans certains cas, un effet pro-oxydant pouvait être observé. Dans une seconde partie, grâce à un système de multiplexing, nous avons pu identifier 39 cytokines et 4 MMPs sécrétées par les kératinocytes suites à une irradiation par des UVB. Nous avons également pu mettre en évidence une différence entre donneurs jeunes et âgés, avec une augmentation des cytokines pro-inflammatoires et une diminution des cytokines anti-inflammatoires pour ces derniers. Dans une dernière partie, l’activité d’un extrait de fleurs de Butea monosperma a été étudiée. L’extrait présente une activité anti-oxydante en piégeant les EORs intracellulaires, anti-inflammatoire en diminuant la sécrétion de cytokines pro-inflammatoires (IL-1; IL-6 et IL-8) et protectrice du derme en inhibant la production de MMP-1 ; 2 ; 9 et 10. Cette étude multifactorielle a permis d’expliquer les utilisations traditionnelles de cette plante comme anti-inflammatoire. En conclusion, afin de comprendre et de limiter les effets des radiations UVB sur le vieillissement cutané, il est nécessaire d’avoir une approche multifactorielle. Comme nous l’avons observé, le stress oxydant n’est pas le seul responsable du statut micro-inflammatoire cutané mais en est le promoteur. Il faut donc agir en amont en limitant la production d’EORs et en aval en contrôlant la sécrétion de cytokines pro-inflammatoires et de MMPs.Early signs of skin aging are related amongst others by UV irradiation that induces an oxidative stress. This one is associated with a skin micro-inflammatory status which is the consequence of mediator productions as pro-inflammatory cytokines, matrix metalloproteinases (MMPs) and prostaglandin E2. Studies reported in this thesis were mainly conducted with human keratinocyte, one of the cells involved in the skin aging process. In a first part, we describe various experiments led to evaluate the association of several antioxydant molecules in the aim to increase their activities. This study has shown that in certain cases, a pro-oxidizing effect could be observed. In a second part, through a multiplexing system, we have identified 39 cytokines and 4 extracellular MMPs that are secreted upon UVB irradiation. We have also found a difference between the cytokines secreted by keratinocytes from young and old donors; the latter has an increase of pro-inflammatory cytokines and a decrease in anti-inflammatory cytokines. Finally, in a last part, an extract of flowers of Butea monosperma has been studied. The extract present an anti-oxidant activity by scavenging intracellular ROS, an anti-inflammatory effect by reducing the secretion of pro-inflammatory cytokines (IL-1 , IL-6 and IL-8) and a protective effect of the dermis by inhibiting the production of extracellular MMP-1, 2, 9 and 10. These results explain the strong protective anti-inflammatory activity of this plant which is widely used. In conclusion, in order to understand and limit the impact UVB radiations on skin aging, it is necessary to have a multifactorial approach. As we have observed, oxidative stress is not solely responsible for the micro-inflammatory status associated with photo-aging, but is the proponent. We must act upstream by limiting production of ROS and downstream by controlling the secretion of pro-inflammatory cytokines and MMPs

Effets des rayonnements UVB sur la libération de médiateurs pro-inflammatoires impliqués dans le vieillissement cutané (activité anti-âge d'un extrait de fleurs de Butea monosperma (Lam.) Taubert)

Le photo-vieillissement cutané est en partie dû aux effets néfastes des rayonnements UV qui induisent un stress oxydant. Celui-ci joue un rôle promoteur dans l installation d un statut micro-inflammatoire lié à la production de médiateurs tels que des cytokines pro-inflammatoires, des métalloprotéinases de la matrice extracellulaire (MMPs) et des prostaglandines E2. Mes travaux ont été effectués sur le kératinocyte, cellule majeure de l épiderme et acteur du processus de vieillissement cutané. Dans une première partie, nous décrivons différentes expériences menées pour évaluer l association de plusieurs molécules anti-oxydantes connues afin d en potentialiser l activité. Cette étude a mis en évidence que dans certains cas, un effet pro-oxydant pouvait être observé. Dans une seconde partie, grâce à un système de multiplexing, nous avons pu identifier 39 cytokines et 4 MMPs sécrétées par les kératinocytes suites à une irradiation par des UVB. Nous avons également pu mettre en évidence une différence entre donneurs jeunes et âgés, avec une augmentation des cytokines pro-inflammatoires et une diminution des cytokines anti-inflammatoires pour ces derniers. Dans une dernière partie, l activité d un extrait de fleurs de Butea monosperma a été étudiée. L extrait présente une activité anti-oxydante en piégeant les EORs intracellulaires, anti-inflammatoire en diminuant la sécrétion de cytokines pro-inflammatoires (IL-1 ; IL-6 et IL-8) et protectrice du derme en inhibant la production de MMP-1 ; 2 ; 9 et 10. Cette étude multifactorielle a permis d expliquer les utilisations traditionnelles de cette plante comme anti-inflammatoire. En conclusion, afin de comprendre et de limiter les effets des radiations UVB sur le vieillissement cutané, il est nécessaire d avoir une approche multifactorielle. Comme nous l avons observé, le stress oxydant n est pas le seul responsable du statut micro-inflammatoire cutané mais en est le promoteur. Il faut donc agir en amont en limitant la production d EORs et en aval en contrôlant la sécrétion de cytokines pro-inflammatoires et de MMPs.Early signs of skin aging are related amongst others by UV irradiation that induces an oxidative stress. This one is associated with a skin micro-inflammatory status which is the consequence of mediator productions as pro-inflammatory cytokines, matrix metalloproteinases (MMPs) and prostaglandin E2. Studies reported in this thesis were mainly conducted with human keratinocyte, one of the cells involved in the skin aging process. In a first part, we describe various experiments led to evaluate the association of several antioxydant molecules in the aim to increase their activities. This study has shown that in certain cases, a pro-oxidizing effect could be observed. In a second part, through a multiplexing system, we have identified 39 cytokines and 4 extracellular MMPs that are secreted upon UVB irradiation. We have also found a difference between the cytokines secreted by keratinocytes from young and old donors; the latter has an increase of pro-inflammatory cytokines and a decrease in anti-inflammatory cytokines. Finally, in a last part, an extract of flowers of Butea monosperma has been studied. The extract present an anti-oxidant activity by scavenging intracellular ROS, an anti-inflammatory effect by reducing the secretion of pro-inflammatory cytokines (IL-1 , IL-6 and IL-8) and a protective effect of the dermis by inhibiting the production of extracellular MMP-1, 2, 9 and 10. These results explain the strong protective anti-inflammatory activity of this plant which is widely used. In conclusion, in order to understand and limit the impact UVB radiations on skin aging, it is necessary to have a multifactorial approach. As we have observed, oxidative stress is not solely responsible for the micro-inflammatory status associated with photo-aging, but is the proponent. We must act upstream by limiting production of ROS and downstream by controlling the secretion of pro-inflammatory cytokines and MMPs.ORLEANS-SCD-Bib. electronique (452349901) / SudocSudocFranceF

Pentacyclic triterpenes from Manilkara bidentata resin. Isolation, identification and biological properties

International audienceThree pentacyclic triterpenes were isolated for the first time from resinous plant Manilkara bidentata. Ultrasound-assisted extraction with ethanol was chosen after a comparison of various extraction methods. Analysis of the extract was performed by HPLC with evaporative light scattering detection and semi-preparative HPLC has enabled us to isolate two urs-12-enes (3 beta-O-acetyl-alpha-amyrin and 3 beta-O-trans cinnamyl-alpha-amyrin) and a lupane-type derivative (3 beta-O-trans cinnamyl lupeol). Structures were elucidated on the basis of HRESIMS, atmospheric pressure photoionization MS, and homo- and heteronuclear correlation NMR experiments. Antioxidant and anti-inflammatory activities were determined on Manilkara extract and isolated fractions. We have also investigated their action on collagen and fibronectin synthesis, two very important proteins of the extracellular matrix. Thus, Manilkara extract was able to decrease IL-1 beta and IL-8 pro-inflammatory cytokines. These activities exhibit the potential use of Manilkara extract as an anti-inflammatory and anti-aging ingredient for pharmaceutical and cosmetic industries

Marine algae as attractive source to skin care

International audienceAs the largest organ in the human body, the skin has multiple functions of which one of the most important is the protection against various harmful stressors. The keratinised stratified epidermis and an underlying thick layer of collagen-rich dermal connective tissues are important components of the skin. The environmental stressors such as ultraviolet radiation (UVR) and pollution increase the levels of reactive oxygen species (ROS), contributing to clinical manifestations such as wrinkle formation and skin aging. Skin aging is related to the reduction of collagen production and decrease of several enzymatic activities including matrix metalloproteinases (MMPs), which degrade collagen structure in the dermis; and tissue inhibitor of metalloproteinases (TIMPs), which inhibit the action of MMPs. In addition to alterations of DNA, signal transduction pathways, immunology, UVR, and pollution activate cell surface receptors of keratinocytes and fibroblasts in the skin. This action leads to a breakdown of collagen in the extracellular matrix and a shutdown of new collagen synthesis. Therefore, an efficient antioxidants strategy is of major importance in dermis and epidermis layers. Marine resources have been recognised for their biologically active substances. Among these, marine algae are rich-sources of metabolites, which can be used to fight against oxidative stress and hence skin aging. These metabolites include, among others, mycosporine-like amino acids (MAAs), polysaccharides, sulphated polysaccharides, glucosyl glycerols, pigments, and polyphenols. This paper reviews the role of oxidative processes in skin damage and the action of the compounds from algae on the physiological processes to maintain skin health

Protective effect of a Butea monosperma (Lam.) Taub. flowers extract against skin inflammation: Antioxidant, anti-inflammatory and matrix metalloproteinases inhibitory activities

International audienceButea monosperma (Lam.) Taubert (Syn. Butea frondosa; family Fabaceae) is a common plant of the Indian continent (Das et al., 2011; Sharma and Deshwal, 2011). The brightly orange flowers of this plant are widely used in traditional medicine and more particularly for inflammatory disease.AIM OF THE STUDY:In vitro anti-inflammatory mechanism of a hydroethanolic extract of B. monosperma flowers (BME) and more specifically of an enriched fraction in butrin and isobutrin (BI) was studied using cell culture of Normal Human Keratinocyte, cells involved in the skin inflammatory.MATERIALS AND METHODS:Dried and crushed B. monosperma flowers were extracted with Ethanol/H2O (70/30 v/v). The butrin/isobutrin fraction was obtained by centrifugal Partition Chromatography (CPC). Experiments were conducted on UV-B treated normal human epidermis keratinocytes, cells involved in the skin inflammatory response. To evaluate extract anti-inflammatory activity, cytokines IL-1β, IL-6, IL-8, prostaglandin E2 and metalloproteinases MMP-1, -2, -9 and -10 were measured in the cells supernatant.RESULTS:Our data clearly showed that hydroalcoholic B. monosperma flower extract was able to decrease the secretion of IL-1β, IL-6 and IL-8 pro-inflammatory cytokines of -32, -33 and -18% respectively. Interestingly, Prostaglandin E2 production and the secretion of MMP-1, -2, -9 and -10 were also inhibited. Same results were observed in presence of enriched fraction in butrin and isobutrin and confirmed the participation of these molecules in the anti-inflammatory activity.CONCLUSION:These results explain the anti-inflammatory activity of B. monosperma and confirm the interest to use it in traditional Indian medicine. Moreover, its metalloproteinases inhibitory activities coupled with its anti-inflammatory action also give anti-aging property to this plant

Synthesis, Purification, and Activity of Salidroside

International audienc

Bio-Guided Targeting for Preservative and Anti-Ageing Cosmetic Ingredient Development

To develop a new antioxidant, antibacterial and natural cosmetic ingredient without cytotoxicity to skin cells, bioactive molecules contained in Kalanchoe pinnata leaf methanolic extract were targeted using semi-preparative HPLC fractionation linked to biological activity tests. Chromatographic effluent was collected at the column outlet into a 96 deep-well microplate, filling successively all the wells. After freeze-drying, the microplate was ready to use for different biological tests such as antimicrobial activity on microorganisms, skin cell viability and antioxidant activity on human keratinocyte cells. The injection of only 2.64 mg of crude extract into the HPLC system reveals a good correlation between the chromatographic peaks and the different biological activities. One fraction is mainly of interest since good antibacterial and antioxidant activities without cytotoxicity are observed. The analysis of this fraction using mass spectrometry allows the identification of glycoside derivatives of quercetin, isorhamnetin and kaempferol. Thus, a correlation between biological activity and the presence of these flavonoids is obtained. This screening method allows a rapid fractionation associated with a biological activity evaluation and a first molecular identification, saving time by limiting sample treatments and solvent consumption