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Background: Obstructive sleep apnoea (OSA) is an independent risk factor for cardiovascular diseases. We aimed to investigate the role of nuclear factor‐kappa B (NF‐κB) in the changes of cardiac structures in OSA rabbits treated by mandibular advancement device (MAD). Methods: Eighteen male New Zealand white rabbits aged 6 months were randomly divided into three groups: control group, group OSA and group MAD. Hyaluronate gel was injected into the soft palate of the rabbits in group OSA and group MAD to induce OSA. The cone beam computer tomography (CBCT) of the upper airway and polysomnography (PSG) was performed to ensure successful modelling. CBCT and PSG were applied again to detect the effects of MAD treatment. All animals were induced to sleep in a supine position for 4–6 h a day for 8 weeks. Then the levels of NF‐κB, Interleukin 6 (IL‐6), Interleukin 10 (IL‐10) and the proportion of myocardial fibrosis (MF) were detected. Results: The higher activation of NF‐κB, IL‐6 and IL‐10 were found in the OSA group than in the control group, leading to the increase of collagen fibres compared with the control group. Furthermore, the apnoea‐hypopnea index (AHI) was positively correlated with the above factors. There were no significant differences between group MAD and the control group. Conclusion: The NF‐κB pathway was activated in the myocardium of OSA rabbits, which accelerated the development of MF. Early application of MAD could reduce the activation of NF‐κB in the myocardium and prevent the development of MF. [ABSTRACT FROM AUTHOR]

BACKGROUND: Compared with free astaxanthin (Asta), docosahexaenoic acid astaxanthin monoester (Asta‐C22:6) has higher stability and bioavailability. However, Asta‐E is still unable to be used in the water system. Hence it is necessary to build a water‐soluble delivery system. In this study, Asta‐C22:6 microemulsion and microcapsule using whey protein isolate (WPI) and hydroxypropyl‐β‐cyclodextrin (HPβ‐CD) as composite wall material were prepared. They were added to three dairy products (milk powder, yogurt and flavored dairy product). A dairy product rich in Asta‐C22:6 with high bioavailability was designed by measuring quality characteristics, sensory evaluation and in vivo experiments. RESULTS: Compared with spray drying, the freeze‐drying microcapsule had a higher encapsulation efficiency (72.5%), water content (4%) and better solubility, and Asta‐C22:6 microcapsule (1 g L−1) yogurt had the best quality. The bioavailability of Asta‐C22:6 microcapsule yogurt was further evaluated. After a single oral dose in mice, the bioavailability of Asta‐C22:6 microcapsule in yogurt was significantly increased (Cmax = 0.31 μg mL−1, AUC0–T = 3.20 h μg mL−1). CONCLUSION: We successfully prepared Asta‐C22:6 microcapsule yogurt, which improved the stability and bioavailability of Asta. The present research is meaningful for delivering unstable bioactive small molecules based on WPI and HPβ‐CD. It provides an experimental basis for the application of Asta‐C22:6 and the development of functional dairy products. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND Astaxanthin ester derived from Haematococcus pluvialis is often used as a functional and nutritional ingredient in foods. However, its utilization is currently limited as a result of its chemical instability and low bioavailability. Food matrix microcapsules are becoming increasingly popular because of their safety and high encapsulation efficiency. In the present study, the effect of protein matrixes on the properties of microcapsules was evaluated. RESULTS: We investigated the effects of storage on astaxanthin ester microcapsules and the corresponding rehydration solution at 40 °C under a nitrogen atmosphere, as well as in darkness. The results showed that the stability of products prepared based on whey protein (WP) and corn‐gluten was superior to that of products prepared based on lactoferrin, soy protein and sodium caseinate. The bioavailability of astaxanthin ester microcapsules encapsulated with different proteins and examined by means of astaxanthin concentrations in the serum and liver after oral administration was compared. All five protein wall materials could significantly improve the bioavailability of astaxanthin ester. The microcapsules prepared based on WP had the highest bioavailability, with a value of 10.69 ± 0.75 μg·h mL−1, which was 3.15 times higher compared to that of the control group. CONCLUSION: The results of the present study showed that protein encapsulation, especially WP encapsulation, could effectively improve the stability, water solubility and bioavailability of astaxanthin esters. Thus, WP can be used as the main wall material in delivery systems. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Astaxanthin (Asta) is widely used in the nutraceutical and food industry because of its strong antioxidant properties. However, natural Asta mainly exists in the esterified form with various fatty acid chains, making it difficult to understand the particular molecular structure of astaxanthin esters (Asta‐Es) that have better antioxidant capacity. In this study, Asta‐Es with different molecular structures was systematically prepared, and identified by using thin‐layer chromatography (TLC), ultraviolet‐visible (UV‐visible), high‐performance liquid chromatography‐tandem mass spectrometry (HPLC‐MS/MS), and proton nuclear magnetic resonance (1H‐NMR). In addition, their antioxidant properties were evaluated by 2,2′‐diphenylpicrylhydrazyl (DPPH) and ABTS scavenging activity. RESULTS: Fourteen Asta‐Es with different molecular structures were systematically synthesized. This study used a simple and efficient method for the separation and purification of astaxanthin monoester (Asta‐ME) and astaxanthin diester (Asta‐DE) with high purity (86%–94%) by silica gel column chromatography. 13‐cis‐Asta‐E and 9‐cis‐Asta‐E were firstly identified from Asta‐E. The DPPH clearance rates and ABTS scavenging rates of Asta‐C4:0, Asta‐C8:0, Asta‐C12:0, and Asta‐C18:0 were relatively close, but the DPPH and ABTS scavenging rates of Asta‐C18:0, Asta‐C18:1, Asta‐C18:2, and Asta‐C22:6 increased gradually. Among all Asta‐Es, Asta‐C22:6/C22:6 showed the highest antioxidant capacity, with the DPPH and ABTS scavenging rates of 77.22 ± 3.29% and 51.84 ± 1.65%, respectively. CONCLUSION: In this study, it was concluded that chemically synthesized Asta‐Es contained cis‐astaxanthin ester and polyunsaturated fatty acid chain increased the antioxidant activity of Asta, showing less effect of the length of fatty acid chain. These results provide useful information for the production and use of highly efficient Asta‐E as functional food and pharmaceutical ingredients. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Astaxanthin ester (Asta‐E) is used as functional nutraceuticals in many food products. Unfortunately, Asta‐E utilization is currently limited owing to its chemical instability and low bioavailability. The purpose of this study is to investigate the promotion effect of oil matrixes on the stability, antioxidant activity, bioaccessibility and bioavailability of Asta‐E. RESULTS: The results showed that the stability of Asta‐E in six oil matrixes was improved. Based on the 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity experiment, the antioxidant activity of Asta‐E was positively correlated with the degree of unsaturation of the oil matrixes, but not with the side chain length. The in vitro gastrointestinal tract (GIT) simulation model and in vivo experiment using mice were also employed to investigate the digestion and absorption characteristics of Asta‐E in various oil matrixes. The results demonstrated that the bioaccessibility and bioavailability of Asta‐E increased with the increase of fatty acid chain length of oil matrixes (triglyceride oleate > triglyceride caprylate > triglyceride butyrate), as well as with the decrease of unsaturation degree (olive oil > corn oil > fish oil). CONCLUSION: Monounsaturated fatty acids (MUFA) and long‐chain triglyceride (LCT) in an oil matrix were the factors that could efficiently improve the bioavailability of Asta‐E. Moreover, the size of the mixed micelles of Asta‐E during digestion was the main factor influencing the bioaccessibility of Asta‐E. This study provides references for the design of suitable oil matrixes for Asta‐E. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND In this paper, the changes in free astaxanthin (F‐AST) and astaxanthin esters (AST‐Es) in Litopenaeus vannamei during iced storage and frozen storage were investigated. The liquid chromatography–atmospheric pressure chemical ionization tandem mass spectrometry method was used to quantify the molecular species of AST‐Es in shrimp during storage. RESULTS: Based on the analysis of autoxidation products, apo‐12‐astaxanthinal and apo‐13‐astaxanthinone docosahexaenoic acid (DHA) ester were identified as the major oxidation products of F‐AST and AST‐Es in L. vannamei during storage. The total astaxanthin (T‐AST) content decreased by 34.51% after 7 days in iced storage. In contrast, the content of T‐AST decreased by 43.76% after 12 weeks in frozen storage. The content of F‐AST decreased by 29.99% while 13‐cis‐astaxanthin increased after 3 days in iced storage, which indicated that degradation of AST was accompanied by isomerization. Total volatile basic nitrogen and T‐AST content showed a significant negative correlation while in frozen storage, where the concentration of T‐AST might be one indicator to evaluate shrimp freshness. CONCLUSION: The correlation coefficients between phenol oxidase, lipoxygenase, apo‐12‐astaxanthinal, and apo‐13‐astaxanthinone DHA ester were all greater than 0.97 (P < 0.01). This correlation indicates that phenol oxidase and lipoxygenase were the main internal factors to improve oxygenation of astaxanthin in L. vannamei. These results provide a theoretical basis for further study of oxidation and the degradation mechanism in astaxanthin, as well as a new idea for the development and utilization of astaxanthin compounds in Pacific white shrimp. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: We synthesized astaxanthin succinate diester (ASD), a novel astaxanthin (AST) derivate, with succinic anhydride and free AST. ASD was purified and characterized using silica gel column chromatography and spectrometry, respectively. RESULTS: The ASD final synthesis rate was 82.63%. A stability test revealed a high AST and ASD retention rate at pH 5.0–7.0. ASD showed better stability than did AST under acidic conditions. Both sample ions showed lower retention rates under Fe2+ and Fe3+ states. The ASD metabolic curve showed serum and liver area under the curve from 0 h to time t (AUC0–t) values of 45.05 ± 4.58 and 120.38 ± 23.66 µg h−1 mL−1, respectively. The long‐term accumulation was significantly higher in the ASD group than in the AST group, which showed higher accumulation in the heart, muscle and spleen than in other tissues in vivo. CONCLUSION: The thermal stability and bioavailability of ASD were higher than that of the non‐esterified free AST and common free AST, respectively. Additionally, AST accumulation in different tissues of the ASD group was multifold higher than that of free AST. These results prove that ASD may serve as a better source of AST for human nutrition than does free AST. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Skin flaps are frequently performed for diabetic patients in spite of countless detrimental effects of diabetes on flap survival, most of which may result from a defective response of the tissues to low oxygen tension. In this study, the authors explored the feasibility of applying human adipose-derived stem cells (ASCs) to increase the viability of random-patterned skin flaps in streptozotocin-induced diabetic mice. ASCs were isolated from the fresh human lipoaspirates and expanded ex vivo for three passages. After the elevation of caudally based random-patterned skin flaps (3 cm long and 1 cm wide), ASCs suspensions were then injected into the flap (group A). Media containing no ASCs were similarly injected as a control (group B), although nothing was injected into the flap base of mice in control group C. Flap assessments were carried out at post-operative day 7 for evaluation of flap viability. The flap survival rate of group A was significantly higher than those of groups B and C, whereas no difference was observed between groups B and C. Histological examination also demonstrated a statistically significant increase in capillary density in group A over both groups B and C. Furthermore, it was found that ASCs not only augmented the expression of vascular endothelial growth factor and hypoxia-inducible factor-1α (HIF-1α) in flap tissues from dermis of diabetes mice, but also promoted their expression in dermal fibroblasts from diabetic mice. Thus, ASCs could enhance the survival of random-patterned skin flaps in streptozotocin-induced diabetic mice via elevated expression of HIF-1α. [ABSTRACT FROM AUTHOR]