Physicochemical properties, antioxidant activities and in vitro sustained release behaviour of co-encapsulated liposomes as vehicle for vitamin E and ß-carotene.

BACKGROUND: In this study the potential of liposomes as a vitamin E (VE) and ß-carotene (ßC) delivery system was examined. The co-encapsulated liposomes of ßC and VE (L-VE-ßC) were prepared and characterized. Their antioxidant properties were evaluated by free radical scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), hydroxyl radical and lipid peroxidation assay. The in vitro sustained release behaviour was then investigated and discussed. RESULTS: VE and ßC were co-encapsulated in liposomes with high encapsulation efficiency, up to 92.49% and 86.16% for ßC and VE, respectively. The antioxidant activities of L-VE-ßC samples were significantly higher than that of single loaded liposome. Among different ratios of VE/ßC, L-VE-ßC at 5:3 exhibited the highest radical scavenging rates, with 66.80%, 56.58% and 34.39% for DPPH, ABTS and OH radical, respectively. L-VE-ßC samples also had a good ability to inhibit lipid peroxidation, especially the sample with ratios of VE/ßC at 5:3 and 3:1. In simulated gastrointestinal release, L-VE-ßC exhibited an excellent sustained release behaviour in SGF with the accumulated rate at about 20%, while the release rate in SIF increased to over 80%, where they should be absorbed. The release kinetics analysis indicated that ßC was released in the Higuchi model in stomach, and the Korsmeyr-Peppas model in intestine. CONCLUSION: Compared to single loaded liposomes, the combined-loaded liposomes exhibited higher antioxidant activity and bioavailability, suggesting the potential applications in functional foods. © 2022 Society of Chemical Industry.

Photoinduced-reset and multilevel storage transistor memories based on antimony-doped tin oxide nanoparticles floating gate.

Recently, antimony-doped tin oxide nanoparticles (ATO NPs) have been widely used in the fields of electronics, photonics, photovoltaics, sensing, and other fields because of their good conductivity, easy synthesis, excellent chemical stability, high mechanical strength, good dispersion and low cost. Herein, for the first time, a novel nonvolatile transistor memory device is fabricated using ATO NPs as charge trapping sites to enhance the memory performance. The resulting organic nano-floating gate memory (NFGM) device exhibits outstanding memory properties, including tremendous memory window (∼85 V), superhigh memory on/off ratio (∼109), long data retention (over 10 years) and eminent multilevel storage behavior, which are among the optimal performances in NFGM devices based on organic field effect transistors. Additionally, the device displays photoinduced-reset characteristic with low energy consumption erasing operation. This study provides novel avenues for the manufacture of simple and low-cost data storage devices with outstanding memory performance, multilevel storage behavior and suitability as platforms for integrated circuits.

Effect of ß-sitosterol self-microemulsion and ß-sitosterol ester with linoleic acid on lipid-lowering in hyperlipidemic mice.

BACKGROUND: The hypolipidemic effect of phytosterols has been wildely recognized, but its application is limited due to its insolubility in water and low solubility in oil. In this study, ß-sitosterol ester with linoleic acids and ß-sitosterol self-microemulsions were prepared and their hypolipidemic effects on hyperlipidemia mice were studied. METHODS: Firstly, the mice were randomly divided into normal group and model group,they were fed with basic diet and high-fat diet for 70 days respectively. After high-fat model mice was successfully established, the model group was further divided into eight groups: HFD (high-fat diet feeding), SELA-TSO(8 ml/kg, SELA:700 mg/kg), TSO (8 ml/kg), SSSM (8 ml/kg,SS:700 mg/kg), NLSM (8 ml/kg), SSHT-TSO (8 ml/kg, SS: 700 mg/kg) and SS-TSO (8 ml/kg, SS: 700 mg/kg) groups, and treated with ß-sitosterol ester with linoleic acid, ß-sitosterol self-microemulsion, commercial ß-sitosterol health tablets and ß-sitosterol powder for 35 days, respectively, and blank control groups were established. At the end of the treatment period, the blood lipid level, tissues, cholesterol and lipids in feces of mice in each group were investigated. Statistical and analytical data with SPSS 17.0 Software,statistical significance was set at p* < 0.05 and p** < 0.01 levels . RESULTS: The order of lowering blood lipid effect is listed as: SSSM> SELA-TSO > SSHT-TSO > SS-TSO, which shows that ß-sitosterolself-microemulsion have the highest treatment effect among the experimental groups. CONCLUSIONS: In this study, a new formulation of ß-sitosterol was developed, and its hypolipidemic effect was investigated. The results showed that ß-sitosterol self-microemulsion has a good blood lipid lowering effect.

Protective Effect of Tea Saponins on Alcohol-Induced Gastric Mucosal Injury in Mice.

Excessive alcohol consumption harms the human body, particularly the digestive system, by causing damage to the gastric mucosa. Tea saponin is a natural active substance extracted from tea tree seeds that has gastroprotective potential against alcohol-induced mucosal damage. However, the protective mechanism of tea saponins is not fully understood. The current study aimed to explore the protective mechanism of tea saponins against alcohol-induced gastric mucosal injury in mice. Histopathological changes, immunohistochemistry, immunoblotting, and gastric mucosa-related cytokine levels were analyzed in three groups of male mice: model, control, and tea saponin-treated. Compared to the model group, the tea saponin group prominently ameliorated alcohol-induced gastric mucosal injury by improving cell necrosis, inflammatory cell infiltration, and edema. Downregulation of inflammation-related factors cluster of differentiation 68 (CD68), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) was also found in the tea saponin group. These results suggest that tea saponins have a protective effect against alcohol-induced gastric mucosal damage in mice. Therefore, tea saponin may serve as a food additive for gastric mucosal protection.

The potential application of vegetable oils in the D-xylose and L-cysteine Maillard reaction system for meaty aroma production.

Vegetable oils with different unsaturated degrees (corn > peanut > olive > palm > coconut) and corresponding enzymatic hydrolysis-thermal oxidation (ENTH) oils were added into D-xylose and L-cysteine Maillard reaction (MR) system, respectively, for potential meaty aroma production. Results indicated that coconut oil and palm oil had lower peroxide, p-anisidine, total antioxidant values, and malondialdehyde content after ENTH and MR. Corn, peanut, and olive oils after ENTH could significantly promote MR because they caused the lower pH, higher reactants depletion, and higher browning degree in the water phase separated from the oil-Maillard reaction system. Additionally, the volatiles were mainly formed from oil phase. Corn, peanut, and olive oils were beneficial to volatiles formation in the oil-MR system due to fatty acid oxidation, especially oleic acid and linoleic acid. Meanwhile, compared to raw oils, adding ENTH oils to the MR system could reduce the content of oxygen, nitrogen, and sulfur-containing heterocycles.

Multilevel storage and photoinduced-reset memory by an inorganic perovskite quantum-dot/polystyrene floating-gate organic transistor.

Inorganic halide perovskite quantum dots (IHP QDs) have been widely studied in optoelectronic devices because of their size-dependent tunable bandgaps, long electron-hole diffusion lengths and excellent absorption properties. Herein, a novel floating-gate organic field-effect transistor memory (FGOFETM) is demonstrated, comprising a floating-gate of IHP QDs embedded in a polystyrene matrix. Notably, the FGOFETM exhibits photoinduced-reset characteristic that allows data removal by photo irradiation. This feature makes low energy-consuming memory and innovative devices possible. The nonvolatile devices also show a large memory window (≈90 V), ultrahigh memory on/off ratio (over 107) and therefore excellent multilevel information storage, in which 4 recognizable non-volatile states and long retention time (up to 10 years) are obtained. This work not only offers an effective guideline of high-performance FGOFETMs, but also shows great potential to realize multilevel data storage under electrical programming and photoinduced-reset processes.

Low pH-shifting treatment would improve functional properties of black turtle bean (Phaseolus vulgaris L.) protein isolate with immunoreactivity reduction.

Low pH-shifting was firstly applied in the black turtle bean (Phaseolus vulgaris L.) protein isolate treatment by acidic (pH 1.0-3.0) buffer incubation for 8 h, then was adjusted to pH 7.2 and kept 3 h for protein stabilizing. Mild loss of secondary structure was confirmed in the protein isolate after low pH-shifting treatment by CD and FT-IR analyses. Intrinsic fluorescence, UV spectra, surface hydrophobicity, SH content and SDS-PAGE analyses indicated the protein conformation was unfolded with the exposure of much more buried hydrophobic residues, which would result in the enhancement of emulsifying properties, foaming properties and fat holding capacity, and lead to the reduction of solubility and water holding capacity. Furthermore, lower immunoreactivity was observed by the ELISA, and improved digestibility was found in in vitro digestion assay. Our results suggested the low pH-shifting treatments would broaden the application of bean protein isolate with better hydrophobic processing functions and safety.

Combined effects of pH and thermal treatments on IgE-binding capacity and conformational structures of lectin from black kidney bean (Phaseolus vulgaris L.).

Combined effects of pH and thermal treatments on black kidney bean lectin (BKBL) were investigated by response surface methodology (RSM). Low-pH (1.0, 2.0, 3.0) incubation decreased hemagglutination activity (HA) and IgE-binding capacity, but the activities would be restored when the lectin was treated by pH shifting to 7.2. Conformational structure analyses indicated that low-pH induced protein unfolding and pH-shifting treatment resulted in a limited structural rearrangement. Mild heating, such as 60 °C for 3 min, slightly increased the HA and IgE-binding activities of pH shifted BKBL, but no obvious effects in the pH 1.0 incubated BKBL. High-temperature and long-time treatment might induce the protein aggregation, further decreased HA and IgE-binding capacities. RSM results showed both IgE-binding capacity and HA were the lowest under the combination of pH 1.0 incubation with 80 °C heating for 15 min or pH shifting from 1.0 to 7.2 with 100 °C heating for 10 min.

Physicochemical properties of polysaccharides separated from Camellia oleifera Abel seed cake and its hypoglycemic activity on streptozotocin-induced diabetic mice.

Two homogeneous polysaccharide fractions named SCP-1 (7.16 × 106 Da) and SCP-2 (2.00 × 104 Da) were purified by DEAE-52 cellulose and Sephadex G-200 column chromatography successively from Camellia oleifera Abel seed cake. They were characterized by Fourier transformed infrared (FT-IR), high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) spectroscopy and differential scanning calorimetry (DSC). The monosaccharide compositions of SCP-1 were d­mannose, d­glucose and l­xylose with a molar ratio of 1.77:0.93:1 and that of the SCP-2 were d­mannose, l­rhamnose, d­glucose and l­xylose with a molar ratio of 5.27:1.21:0.16:1. Animal experiments suggested that the plasma glucose levels in hyperglycemia mice were reduced by 11.34%, 30.70%, 46.83% after administration of high, medium and low doses of SCP-1, and reduced by 16.67%, 23.93% and 33.00% after administration of high, medium and low doses of SCP-2, respectively. SCP-1 and SCP-2 also increased the activities of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD), as well as decreased the content of malondialdehyde (MDA) in the hyperglycemia mice. These results suggested that SCP-1 and SCP-2 possessed strong hypoglycemic activities in streptozotocin-induced model mice. In addition, the hypoglycemic activity of SCP-1 was stronger than that of SCP-2.

Purification of Tea Saponins and Evaluation of its Effect on Alcohol Dehydrogenase Activity.

Tea saponins, extracted from a Camellia oleifera cake, were found to have a potent effect on de-alcoholic activity. To obtain highly pure tea saponins, which can better maintain the activity of alcohol dehydrogenase (ADH), this paper presents an extraction method for tea saponins using deionized water as the extraction agent and a two-stage precipitation method, including ethanol precipitation and CaO precipitation. The optimum conditions for ethanol precipitation were 95% alcohol, a duration of 1.5h and a solid/liquid ratio of 1:4; while the optimum conditions for CaO precipitation were a duration of 2h and an NH4HCO3/CaO ratio of 2:1. Under the optimum conditions, the content of saponins was 87.58%. The results showed that the greater the amount of tea saponins and the higher its purity, the more significant its activating effect on ADH. When the purity of tea saponins was above 75%, it activated ADH. It indicated that the de-alcoholic mechanism of tea saponins is associated with the activity of ADH. Furthermore, the study characterized the structure of tea saponins by UV absorption and Fourier Transform Infrared (FTIR) spectrometry and LC-MS.

Application of L-Amino acid in determination of Huperzine A by high performance liquid chromatography.

A selective HPLC method for determination of Huperzine A in Huperzia serrata Extract has been developed and validated. Huperzine A was dissolved in 0.01 mol/L HCl, chromatographed on an Agilent Zorbax SB-C18 (150 mm x 4.6 mm i.d., 5 microm) column, with a mobile phase consisting of methanol-1mM L-Lysine water solution (50:50, v/v), and detected at 310 nm. The UV peak areas were used for quantitation of Huperzine A content. The correlation coefficient (R(2)) of the calibration was 0.9999 over the range of 1-25 microg/ml and intra- and interday precision over this range were not more than 2%. The method was successfully applied to characterize and determine the Huperzine A in Huperzia serrata Extract.

[Separation and determination of madecassic acid in triterpenic genins of Centella asiatica by high performance liquid chromatography using beta-cyclodextrin as mobile phase additive].

Centella asiatica (L. ) Urban is a tropical medicinal plant with a long history of therapeutic uses. Madecassic acid and terminolic acid, which are a pair of structural isomers, are two constituents of Centella asiatica. A method using reversed-phase high performance liquid chromatography in which beta-cyclodextrin (beta-CD) was the additive in mobile phase has been developed for separation of the structural isomers and determination of madecassic acid. The two compounds can be isolated with high resolution on a C18 reversed-phase column with the addition of beta-CD in the mobile phase. The separation mechanism of the isomers was discussed. It was assumed that the separation of the isomers might have been resulted from different inclusion forces of complexes with beta-CD. The effects of beta-CD concentration and the pH of mobile phase on resolution were investigated. It was found that the resolution of the isomers increased with the increase of beta-CD concentration when the mobile phase consisted of methanol-water (65 : 35, v/v) at pH 4. The correlation coefficient (r2) of the linear calibration curve between peak area and concentration of madecassic acid was 0.998 9 in the range of 0.1 - 5.0 g/L. This method was successfully used to determine the madecassic acid in triterpenic genins of Centella asiatica.