DZ2002 alleviates corneal angiogenesis and inflammation in rodent models of dry eye disease via regulating STAT3-PI3K-Akt-NF-κB pathway.

Dry eye disease (DED) is a prevalent ocular disorder with a multifactorial etiology. The pre-angiogenic and pre-inflammatory milieu of the ocular surface plays a critical role in its pathogenesis. DZ2002 is a reversible type III S-adenosyl-L-homocysteine hydrolase (SAHH) inhibitor, which has shown excellent anti-inflammatory and immunosuppressive activities in vivo and in vitro. In this study, we evaluated the therapeutic potential of DZ2002 in rodent models of DED. SCOP-induced dry eye models were established in female rats and mice, while BAC-induced dry eye model was established in female rats. DZ2002 was administered as eye drops (0.25%, 1%) four times daily (20 µL per eye) for 7 or 14 consecutive days. We showed that topical application of DZ2002 concentration-dependently reduced corneal neovascularization and corneal opacity, as well as alleviated conjunctival irritation in both DED models. Furthermore, we observed that DZ2002 treatment decreased the expression of genes associated with angiogenesis and the levels of inflammation in the cornea and conjunctiva. Moreover, DZ2002 treatment in the BAC-induced DED model abolished the activation of the STAT3-PI3K-Akt-NF-κB pathways in corneal tissues. We also found that DZ2002 significantly inhibited the proliferation, migration, and tube formation of human umbilical endothelial cells (HUVECs) while downregulating the activation of the STAT3-PI3K-Akt-NF-κB pathway. These results suggest that DZ2002 exerts a therapeutic effect on corneal angiogenesis in DED, potentially by preventing the upregulation of the STAT3-PI3K-Akt-NF-κB pathways. Collectively, DZ2002 is a promising candidate for ophthalmic therapy, particularly in treating DED.

Intelligent packaging based on chitosan/fucoidan incorporated with coleus grass (Plectranthus scutellarioides) leaves anthocyanins and its application in monitoring the spoilage of salmon (Salmo salar L.).

The innovation of this study was to develop a novel biodegradable intelligent packaging based on chitosan/fucoidan combined with different amounts (1, 3 and 5 wt% on chitosan basis) of coleus grass (Plectranthus scutellarioides) leaves anthocyanins (CGL) to monitor the spoilage of salmon (Salmo salar L.). The addition of fucoidan improved the barrier and mechanical properties of the chitosan films (CS) due to hydrogen bonds and intermolecular electrostatic interactions. Moreover, the addition of CGL not only improved the physical properties but also improved the biological activity of chitosan/fucoidan film (CF). The DPPH and ABTS radical scavenging activity of CF contained 5 wt% CGL was 1.83 and 1.75 times than CF, respectively. The inhibition zone size of CF films containing 5 wt% CGL (CF-5%CGL) was approximately 2.04 (Escherichia coli) and 2.16 (Staphylococcus aureus) times higher than that of CF. Moreover, CF-CGL displayed obvious color changes in different pH environments and is highly sensitive to ammonia gas. The CF-CGL has visible color changes during the monitoring of salmon spoilage and extended the shelf life of salmon. According to our findings, CF-CGL film might be employed as a possible intelligent packaging material for monitoring and preserving salmon in the future.

Chitosan/esterified chitin nanofibers nanocomposite films incorporated with rose essential oil: Structure, physicochemical characterization, antioxidant and antibacterial properties.

Active films were developed based on chitosan, esterified chitin nanofibers and rose essential oil (REO). The joint effects of chitin nanofibers and REO on structure and physicochemical properties of chitosan film were investigated. Scanning electron microscopy and Fourier transform infrared spectroscopy showed that the chitin nanofibers and REO had significant effects on the morphology and chemical structure of chitosan composite films. The negatively charged esterified chitin nanofibers formed a compact network structure through intermolecular hydrogen bonding and electrostatic interactions with the positively charged chitosan matrix. Chitin nanofibers and REO synergistically enhanced the water resistance, mechanical properties and UV resistance of chitosan-based films, but the addition of REO increased the oxygen permeability. Furthermore, the addition of REO enhanced the inhibition of ABTS and DPPH free radicals and microorganisms by chitosan-based film. Therefore, chitosan/chitin nanofiber-based active films containing REO as food packaging materials can potentially provide protection to extend food shelf life.

Development and characterization of active packaging based on chitosan/chitin nanofibers incorporated with scallion flower extract and its preservation in fresh-cut bananas.

The aim of this study was to develop a novel active packaging using chitosan (CS) and esterified chitin nanofibers (CF) combined with different contents (1, 2 and 4 wt% on CS basis) of scallion flower extract (SFE) to protect banana samples. The addition of CF significantly improved the barrier and mechanical properties of the CS films (p < 0.05) due to hydrogen bonds and electrostatic interactions. Moreover, the addition of SFE not only improved the physical properties of the CS film but also improved the CS film biological activity. The oxygen barrier property and antibacterial ability of CF-4%SFE were approximately 5.3 and 1.9 times higher than those of the CS film, respectively. In addition, CF-4%SFE had strong DPPH radical scavenging activity (74.8 ± 2.3 %) and ABTS radical scavenging activity (84.06 ± 2.08 %). Fresh-cut bananas stored in CF-4%SFE showed less weight loss, starch loss, color and appearance change than those stored in traditional polyethylene film, which indicated that CF-4%SFE was much better at storing fresh-cut bananas than conventional plastic packaging. For these reasons, CF-SFE films have great potential as a candidate to replace traditional plastic packaging and extend the shelf life of packaged foods.

Development of active packaging with chitosan, guar gum and watermelon rind extract: Characterization, application and performance improvement mechanism.

The objective of this study was to make a film matrix containing chitosan (CS) and guar gum (GG), and to improve the physicochemical properties of the film using watermelon rind extract (WRE) as a cross-linker and active substance for the preservation of fresh-cut bananas. The results of Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy showed that the WRE and CG matrix formed intermolecular hydrogen bond interactions, which made the structure of the resulting films more compact. With increasing amounts of WRE, the mechanical properties of the films were significantly increased, but the permeability of water vapor and oxygen was significantly decreased (p < 0.05). Notably, when the amount of extract reached 4 wt%, the DPPH radical scavenging activity of the composite film significantly increased to 83.24 %, and the antibacterial activity also reached its highest value. Fresh-cut bananas were stored at room temperature with polyethylene film, CG and CG-WRE. The CG with 4 wt% WRE effectively inhibited the changes in appearance, firmness, weight, color and total soluble solids content of fresh-cut bananas during storage. Therefore, CG-WRE as a novel active food packaging material, has good physicochemical properties and great potential to extend the shelf life of foods.

Encapsulation of catechin into nano-cyclodextrin-metal-organic frameworks: Preparation, characterization, and evaluation of storage stability and bioavailability.

This study, nanoscale α-, ß-, γ-cyclodextrin (CD)-metal-organic frameworks (MOFs) were successfully prepared using solvothermal assisted ultrasound method. CD-MOFs were used as nanocarriers to encapsulate catechin (CA), and their encapsulation capacities were evaluated. Encapsulation capacities of CD-MOFs to incorporate CA followed the order: ß-CD-MOFs > Î³-CD-MOFs > α-CD-MOFs. CA/CD-MOFs were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). DSC and SEM results provided evidence for the formation of CA/CD-MOFs. XRD results indicated the new solid crystalline phases formed in CA/CD-MOFs complex. Results of FT-IR showed that CA was combined with CD-MOFs through hydrogen bonding and van der Waals forces. Current research demonstrated that encapsulation of CA within CD-MOFs provided it against light, oxygen and temperature. Moreover, encapsulation by CD-MOFs improved storage stability and bioavailability of CA. Thus, these CA/CD-MOFs have potential to be used as nutritional supplements and functional foods.

Development and characterization of chitosan/guar gum active packaging containing walnut green husk extract and its application on fresh-cut apple preservation.

The aim of this work was to develop active packaging film by using chitosan/guar gum (CG) film matrix and walnut green husk extract (WE), for preservation of fresh-cut apple. WE was used as cross-linking agent to improve physicochemical properties, and as active substances to enhance antioxidant activity of CG films. Fourier transform infrared spectroscopy and scanning electron microscopy results showed WE formed intermolecular hydrogen bond interactions with the film matrix, and microstructures of the film were more compact. With the increase of WE content (0-4 wt%), the mechanical properties of composite films were significantly enhanced, while permeability of water vapor and oxygen was significantly decreased (p < 0.05). When the amount of extract reached 4 wt%, the DPPH radical scavenging activity of composite film was significantly increased to 94.59%. CG-WE and CG films were used as active packaging materials to preserve fresh-cut apple. When stored at 4 °C for 10 days, CG-WE films showed better performance in reducing firmness, weight loss, total soluble solids and inhibiting browning and microbial growth of fresh-cut apples. Therefore, as a new type of active food packaging material, CG-WE films have good physical properties, and great potential in ensuring food quality and extending shelf life.

[Electroacupuncture protects septic rats from acute lung injury through the JAK1/STAT3 pathway].

OBJECTIVE: To explore the protective effect of electroacupuncture against acute lung injury (ALI) in septic rats and explore the mechanism. METHODS: Sixty male SD rats were randomly divided into cecal ligation and puncture (CLP)-induced sepsis group (n=45) and sham operation group (n=15; with laparotomy but without CLP). The rat models of sepsis were randomized into ALI group (n=15) without further treatment, ALI + SEA group (n=15) treated with electroacupuncture at the point far from the Zusanli acupoint for 30 min, and ALI + EA group (n=15) with electroacupuncture at Zusanli with identical frequency, intensity and duration of electrical stimulation. All the rats were sacrificed at 12 h after CLP for measurement of the weight and the wet/dry weight (W/D) ratio of the lungs. Pathological changes of the lung tissues were examined using HE staining, and the contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the homogenate of the lung tissues were detected using enzyme-linked immunosorbent assay (ELISA). TUNEL staining was used to detect the apoptotic cells, and the expressions of Bax, caspase-3 and the important proteins in the JAK1/STAT3 signaling pathway (JAK1 and STAT3) were detected with Western blotting. RESULTS: Compared with those in the sham operation group, the rats in ALI group showed obvious lung pathologies with significantly increased lung W/D ratio (P < 0.01), pulmonary expressions of TNF-α and IL-6 (P < 0.01), and obvious up-regulation of JAK1, STAT3, caspase-3, and Bax expressions (P < 0.01); similar changes were also observed in ALI+SEA group (P > 0.05). Compared with those in ALI+SEA group, the rats in ALI+EA group showed significantly milder lung pathologies, lowered lung W/D ratio (P < 0.01) and decreased pulmonary expressions of TNF-α, IL-6, JAK1, STAT3, caspase-3 and Bax (P < 0.01). CONCLUSIONS: Electroacupuncture can inhibit the release of inflammatory mediators and cell apoptosis via the JAK1/STAT3 pathway to reduce lung injuries in septic rats.