4 research outputs found
In vitro, ex vivo and clinical approaches to evaluate the potential effect of Gentiana lutea extract on skin
International audienceAbstract Background Dark circles affect subjects of all ages and in all skin types. They can be treated by various methods, particular by topical solutions. This investigation was directed towards exploring the effect of gentiopicroside (GP) on the skin around the eyes. For this, an extract of Gentiana lutea (GIE) containing GP (65% by dry matter) was evaluated on oxidant and angiogenesis parameters using in vitro and exâvivo studies. A clinical experimentation was also realized. Methods The effect of GIE at different concentrations on antioxidant gene was evaluated in vitro by RTâqPCR after treatment of NHDF. The effect of 2.93âÎŒgâmL â1 GIE on the release of VEGFâA and VEGFâC by NHDF was also studied. The effect of 87.9âÎŒgâmL â1 GIE was also evaluated on pseudotube formation in a coculture system of normal dermal microvascular endothelial cells (HMVECâd)âNHDF stimulated or not with VEGF as proâangiogenic factor. Prior to these assays, preliminary cytotoxicity assays were performed using a standard WSTâ8 reduction assay. The expressions of carboxymethylâlysine and glyoxalaseâ1 were quantified on skin explants topically treated with 147âÎŒgâmL â1 GIE in basal and UVAâirradiated conditions. A clinical study was conducted in 22 subjects using topical twice daily for 14âdays on eye area (splitâface application: cream containing 147âÎŒgâmL â1 GIE versus placebo). 3D image acquisition and skin colour measurement were performed at D0 and D14. Results Treatment of GIE upregulated the gene expression of NFE2L2 and downregulated the expression of CXCL8. GIE targeted AGEs pathways and reduced the formation of pseudotubes. A total of 147âÎŒgâmL â1 GIE gel cream significantly reduced significantly the average roughness and relief of the upper eyelid skin as well as the redness of dark circles after 14âdays of application. Conclusion By acting on the pathway of AGEs, VEGFâA and VEFGâC, GIE seems to allow a rejuvenation of the skin resulting, among others, in a decrease in redness. It now would be interesting to evaluate the efficacy of GIE on skin around eyes microbiota, antibacterial gentiopicroside property being wellâestablished.RĂ©sumĂ© Contexte Le contour des yeux est une zone sensible. Les cernes affectent les sujets de tout Ăąge et de tout type de peau. DiffĂ©rentes solutions peuvent ĂȘtre proposĂ©es, dont les solutions topiques. Cette Ă©tude visait a explorer l'effet dâun extrait de Gentiana lutea (GIE) riche en gentiopicroside (65% de matiĂšre sĂšche) sur des paramĂštres d'oxydation et d'angiogenĂšse au moyen dâĂ©tudes in vitro et exâvivo. Une expĂ©rimentation clinique a Ă©galement Ă©tĂ© rĂ©alisĂ©e. MĂ©thodes L'effet du GIE a diffĂ©rentes concentrations sur des gĂšnes antioxydants a Ă©tĂ© Ă©valuĂ© in vitro par RTâqPCR aprĂšs traitement de fibroblastes (NHDF). L'effet de 2.93 ÎŒg mLâ1 GIE sur la libĂ©ration de VEGFâA et VEGFâC a Ă©galement Ă©tĂ© Ă©tudiĂ©. Il en est de mĂȘme pour l'effet de 87.9 ÎŒg g mLâ1 GIE sur la formation de pseudotubes qui a Ă©tĂ© Ă©valuĂ© dans un systĂšme de coâculture de cellules endothĂ©liales (HMVECâd)â NHDF stimulĂ©es ou non avec du VEGF comme facteur proâangiogĂ©nique. Les expressions de la carboxymethylâlysine et de la glyoxalaseâ1 ont Ă©tĂ© quantifiĂ©es sur des explants cutanĂ©s traites par voie topique avec 147 ÎŒg g mLâ1 GIE dans des conditions basales et irradiĂ©es par UVA. Une Ă©tude clinique a Ă©tĂ© menĂ©e sur vingtâdeux sujets en utilisant un traitement topique deux fois par jour pendant 14 jours sur le contour des yeux (crĂšme contenant 147 ÎŒg g mLâ1 GIE contre placebo). L'acquisition d'images 3D et la mesure de la couleur de la peau ont Ă©tĂ© rĂ©alisĂ©es a J0 et J14. RĂ©sultats Le traitement par GIE a augmentĂ© l'expression gĂ©nĂ©tique de NFE2L2 et diminue l'expression de CXCL8. GIE a cible les voies des AGEs et a rĂ©duit la formation de pseudotubes. 147 ÎŒg g mLâ1 GIE gel crĂšme a significativement rĂ©duit la rugositĂ© moyenne et le relief de la peau de la paupiĂšre supĂ©rieure ainsi que la rougeur des cernes aprĂšs 14 jours d'application. Conclusion En agissant sur la voie des AGEs, du VEGFâA et du VEFGâC, GIE semble permettre un rajeunissement de la peau se traduisant, entre autres, par une diminution des rougeurs. Il serait maintenant intĂ©ressant d'Ă©valuer l'efficacitĂ© du GIE sur le microbiote de la peau du contour des yeux, la propriĂ©tĂ© antibactĂ©rienne du gentiopicroside Ă©tant bien Ă©tablie
Unlocking the potential of bio-inspired bioinks: A collective breakthrough in mammalian tissue bioprinting
International audienceThe composition of soft tissues in mammals can be simplified as approximately 60â65 % water, 16 % protein, 16 % fat, 1 % carbohydrate, and trillions of cells. This report brings together unpublished results from a collaborative efforts of 10 research groups over the past five years, all dedicated to producing mammalian tissues through extrusion-based bioprinting. What unified these studies was a common approach, with a shared bioink composition consisting of gelatin, alginate, and fibrinogen, and a post-printing consolidation strategy involving transglutaminase crosslinking, calcium chelation, and thrombin-mediated fibrin production. The range of Youngâs moduli achievable was 0.17â105 kPa, perfectly align with of tissue properties.By consolidating the findings of these studies, it was conclusively demonstrated that bioprinting and culturing all 19 cells tested from 14 different organs was indeed achievable. These remarkable outcomes were attributed not only to the bio-inspired nature of the common bioink but also to its unique rheological properties, such as significant shear-thinning and a sufficiently high static yield stress.The majority of these cells exhibited behaviours consistent with their natural in vivo environments. Clearly identifiable microstructures and organizations showcased intricate morphogenesis mechanisms resulting in the formation of micro-tubules, micro-vessels, and micro-acini. It is now evident that microextrusion bioprinting, especially when using bio-inspired bioink formulations, represents a promising avenue for generating a wide range of mammalian soft tissues