Storage Stability and In Vitro Bioaccessibility of Liposomal Betacyanins from Red Pitaya (Hylocereus polyrhizus)

In order to address the poor stability of the betacyanins from red pitaya (Hylocereus polyrhizus, HP), which are considered as good sources of natural colorant, liposomal-encapsulation technique was applied in this study. Thin-layer dispersion method was employed to prepare HP betacyacnin liposomes (HPBL). The formulation parameters for HPBL were optimized, and the characteristics, stability, and release profile of HPBL in in vitro gastrointestinal systems were evaluated.Results showed that an HP betacyanin encapsulation efficiency of 93.43 ± 0.11% was obtained after formulation optimization. The HPBL exhibited a narrow size distribution of particle within a nanometer range and a strong electronegative ζ-potential. By liposomal encapsulation, storage stability of HP betacyanin was significantly enhanced in different storage temperatures. When the environmental pH ranged from 4.3–7.0, around 80% of HP betacyanins were preserved on Day 21 with the liposomal protection. The loss of 2,2′-Diphenyl-picrylhydrazyl (DPPH) scavenging activity and color deterioration of HPBL were developed in accordance with the degradation of HP betacyanins during storage. In in vitro gastrointestinal digestion study, with the protection of liposome, the retention rates of HP betacyanins in vitro were enhanced by 14% and 40% for gastric and intestinal digestion, respectively.This study suggested that liposomal encapsulation was an effective approach to stabilize HP betacyanins during storage and gastrointestinal digestion, but further investigations were needed to better optimize the liposomal formulation and understand the complex liposomal system.     

Water in oil (w/o) and double (w/o/w) emulsions prepared with spans: microstructure,stability, and rheology

The objective was to analyze the microstructure, stability, and rheology of model emulsions prepared with distilled water, refined sunflower oil, and different Spans (20, 40, 60, and 80) as emulsifiers. The effects of the water content and Span 60 concentration were studied. The lowest water contents led to w/o emulsions, whereas higher percentages gave w/o/w emulsions. Microscopy analysis showed that w/o/w emulsions of higher water contents had a lower number of internal water droplets. W/o emulsions were destabilized by coalescence and sedimentation, whereas creaming was observed in unstable w/o/w emulsions. In the last ones, the creaming stability decreased with increasing water content and enhanced with higher Span 60 concentration; the same effect was observed in their viscoelasticity: They were from unstable liquids to stable gels. Solid Spans (40 and 60) produced more consistent w/o/w emulsions at low water contents and more stable systems at high water percentages in comparison with liquid Spans (20 and 80).     

Solution of telechelic ionomers in water/AOT/oil (w/o) microemulsions: a static and dynamic light scattering study

Static and quasielastic light-scattering measurements of endsulfonated polyisoprene in a water in oil (w/o) microemulsions were used to characterize the structure and diffusion properties of this complex system. The hydrophilic end groups of the polymer stick to the surfactant covered oil/water interface, thus bridging the water droplets. This structure formation decreases the mobility of the aqueous nanodroplets and polymer molecules. At interdroplet distances larger than the end-to-end distance of the ionomer chain a decrease of the osmotic modulus is observed. It can be explained by a depletion force of free ionomer chains acting on the nanodroplets. With increasing polymer concentration structure formation of the microemulsion is observed at nanodroplet concentrations where the ionomer chains just fit the average separation of two nanodroplets.     

Standardized Pomegranate (Pomella®) and Red Maple (Maplifa®) Extracts and Their Phenolics Protect Type I Collagen by the Inhibition of Matrix Metalloproteinases,Collagenase, and Collagen Cross-Linking

Phenolics enriched pomegranate fruit (Pomella^®) and red maple leaf (Maplifa^®) extracts and their major phenolic constituents have demonstrated beneficial skin effects through the protection of human skin keratinocytes from oxidative-stress-induced damage. However, their mechanisms of protection of cutaneous collagen are still unclear. Herein, the collagen protective effects of Pomella^® and Maplifa^®, and their major bioactive phytochemicals, namely, punicalagin (PA) and ginnalin A (GA), respectively, were evaluated using enzymatic assays including collagenase, anti-glycation and cell-based models as well as computational methods. The importance of the modulatory effects was validated at the protein level for type I collagen and matrix metalloproteinases (MMPs) using human-skin-derived keratinocytes. The synergistic collagenase inhibitory effects upon combinations of Pomella^® + Maplifa^® and PA + GA at a combination ratio of 1:2 and 1:1, respectively, were evaluated using their combination index (CI; a well-established assessment of synergism). Pomella^® (50–400 µg/mL), Maplifa^® (100–800 µg/mL), PA (50–400 µM), and GA (50–400 µM) dose-dependently inhibited collagenase activity by 26.3–86.3%, 25.7–94.0%, 26.2–94.0%, and 12.0–98.0%, respectively. The CI of the anti-collagenase activity of Pomella^® and Maplifa^® ranged from 0.53–0.90, while that of PA and GA (12.5/12.5 and 25/25 µM) ranged from 0.66 and 0.69, respectively, suggesting a synergistic inhibitory effect. Interestingly, in the cell-based assays by Western blotting, Pomella^® and Maplifa^® reduced the protein expression levels of collagen degradation enzymes (MMPs), while simultaneously increasing that of type I collagen in epidermoid carcinoma A431 cells. This is the first report to show that these extracts exert synergistic collagen protective effects. Taken together, these findings provide molecular insights into the usefulness of Pomella^® and Maplifa^® or their phenolics as bioactive ingredients for skin care products to slow down aging and enhance skin tone.