Bioaccessibility of oil-soluble vitamins (A, D, E) in plant-based emulsions: impact of oil droplet size.

We systematically investigated the impact of oil droplet diameter (≈0.15, 1.6, and 11 µm) on the bioaccessibility of three oil-soluble vitamins (vitamin A palmitate, vitamin D, and vitamin E acetate) encapsulated within soybean oil-in-water emulsions stabilized by quillaja saponin. Lipid digestion kinetics decreased with increasing droplet size due to the reduction in oil-water interfacial area. Vitamin bioaccessibility decreased with increasing droplet size from 0.15 to 11 µm: 87 to 39% for vitamin A; 76 to 44% for vitamin D; 77 to 21% for vitamin E. Vitamin bioaccessibility also decreased as their hydrophobicity and molecular weight increased, probably because their tendency to remain inside the oil droplets and/or be poorly solubilized by the mixed micelles increased. Hydrolysis of the esterified vitamins also occurred under gastrointestinal conditions: vitamin A palmitate (∼90%) and vitamin E acetate (∼3%). Consequently, the composition and structure of emulsion-based delivery systems should be carefully designed when creating vitamin-fortified functional food products.

Enhanced retinoid response by a combination of the vitamin A ester retinyl propionate with niacinamide and a flavonoid containing Ceratonia siliqua extract in retinoid responsive in vitro models.

OBJECTIVES: Retinoids have been used for decades as efficacious topical agents to treat photoaged skin. The purpose of our present research is to evaluate whether the activity of the vitamin A ester retinyl propionate (RP) can be enhanced by niacinamide (Nam) and a flavonoid containing Ceratonia siliqua (CS) fruit extract in retinoid responsive in vitro models. METHODS: Retinyl propionate was tested alone and in combination with Nam and CS in an RARα reporter cell line for promoter activation and compared to trans-retinoic acid (tRA) activation. These treatments were also tested in keratinocytes for gene expression profiling by qPCR using a panel of 40 retinoid responsive genes. RESULTS: tRA or RP elicited RARα reporter activation in a dose-dependent manner. The combination of 0.5 µM or 2 µM RP with 10 mM Nam had a 56% and 95% signal increase compared to RP, respectively. The addition of 1% CS to 0.5 µM or 2 µM RP with 10 mM Nam elicited a further increase of 114% and 156%, respectively, over RP and Nam combinations. All retinoids elicited an increase in expression of 40 retinoid sensitive genes over control levels. Of the 40 genes, 27 were enhanced by either 0.1 µM RP or 0.5 µM RP with 10 mM Nam and 1% CS. Nam or CS had very modest activity in both models. CONCLUSION: The combination of RP with Nam and CS showed a higher retinoid response than RP in two separate retinoid responsive in vitro models. We hypothesize Nam and CS enhances RP activity by modulating metabolism to tRA via increasing NAD+ pools and inhibiting reduction of retinal (RAL) back to retinol, respectively. The findings provide evidence that this combination may have enhanced efficacy for treating the appearance of photoaged skin.

OBJECTIFS: Les rétinoïdes sont utilisés depuis des décennies comme agents topiques efficaces pour traiter la peau photo-âgée. Le but de notre recherche actuelle est d'évaluer si l'activité du propionate rétinyl ester de vitamine A (RP) peut être augmentée par le niacinamide (Nam) et un flavonoïde contenant un extrait de fruit de Ceratonia Siliqua (CS) dans les modèles in vitro sensibles aux rétinoïdes. MÉTHODES: RP a été testé seul et en combinaison avec Nam et CS dans une ligne de cellule rapporteur de RARα pour l'activation du promoteur et par rapport à l'activation de l'acide transrétinoïque(tRA). Ces traitements ont également été testés dans les kératinocytes pour le profilage d'expression génique par qPCR à l'aide d'un panel de 40 gènes rétinoïdes sensibles. RÉSULTATS: tRA ou RP ont provoqué l'activation du promoteur RARα d'une manière dépendante de la dose. La combinaison de 0,5 µM ou 2 µM de RP avec 10 mM de Nam a permis une augmentation respectivement de 56% et 95% du signal par rapport à RP. L'ajout de 1 % de CS à 0,5 µM ou 2 µM de RP avec 10 mM de Nam a permis une nouvelle augmentation de 114 % et 156 %, respectivement, qu'avec la combinaison RP et Nam. Tous les rétinoïdes ont provoqué une augmentation de l'expression de 40 gènes sensibles aux rétinoïdes sur les niveaux de contrôle. Sur les 40 gènes, 27 ont été améliorés soit par 0,1 µM de RP ou 0.5 µM de RP avec 10 mM de Nam et 1% de CS. Nam ou CS avaient une activité très modeste dans les deux modèles. CONCLUSION: La combinaison de RP avec Nam et CS a montré une réponse rétinoïde plus élevée que RP dans deux modèles in vitro séparés sensibles aux rétinoïdes. Nous émettons l'hypothèse que Nam et CS améliorent l'activité RP en modulant le métabolisme de tRA par l'augmentation des groupement NAD+ et en inhibant la réduction du rétinal (RAL) en rétinol, respectivement. Les résultats fournissent la preuve que cette combinaison peut améliorer l'efficacité du traitement de l'aspect de la peau photo-âgée.

Design of polymer-free Vitamin-A acetate/cyclodextrin nanofibrous webs: antioxidant and fast-dissolving properties.

The encapsulation of food/dietary supplements into electrospun cyclodextrin (CD) inclusion complex nanofibers paves the way for developing novel carrying and delivery substances along with orally fast-dissolving properties. In this study, CD inclusion complex nanofibers of Vitamin-A acetate were fabricated from polymer-free aqueous systems by using the electrospinning technique. The hydroxypropylated (HP) CD derivatives of HPßCD and HPγCD were used for both encapsulation of Vitamin-A acetate and the electrospinning of free-standing nanofibrous webs. The ultimate Vitamin-A acetate/CD nanofibrous webs (NWs) were obtained with a loading capacity of 5% (w/w). The amorphous distribution of Vitamin-A acetate in the nanofibrous webs by inclusion complexation and the unique properties of nanofibers (e.g. high surface area and porosity) ensured the fast disintegration and fast dissolution/release of Vitamin-A acetate/CD-NW in a saliva simulation and aqueous medium. The enhanced solubility of Vitamin-A acetate in the case of Vitamin-A acetate/CD-NW also ensured an improved antioxidant property for the Vitamin-A acetate compound. Moreover, Vitamin-A acetate thermally degraded at higher temperature in Vitamin-A acetate/CD-NWs, suggesting the enhanced thermal stability of this active compound. Here, HPßCD formed inclusion complexes in a more favorable way when compared to HPγCD. Therefore, there were some uncomplexed Vitamin-A acetate crystals detected in Vitamin-A acetate/HPγCD-NW, while Vitamin-A acetate molecules loaded in Vitamin-A acetate/HPßCD-NW were completely in complexed and amorphous states. Depending on this, better solubilizing effect, higher release amount and enhanced antioxidant properties have been provided for the Vitamin-A acetate compound in the case of Vitamin-A acetate/HPßCD-NW.