Optimization of Ultrasonic-Assisted Extraction of Total Phenolics from Citrus aurantium L. Blossoms and Evaluation of Free Radical Scavenging, Anti-HMG-CoA Reductase Activities

Hydrogel loaded with thiolated chitosan modified taxifolin liposome promotes osteoblast proliferation and regulates Wnt signaling pathway to repair rat skull defects

To alleviate skull defects and enhance the biological activity of taxifolin, this study utilized the thin-film dispersion method to prepare paclitaxel liposomes (TL). Thiolated chitosan (CSSH)-modified TL (CTL) was synthesized through charge interactions. Injectable hydrogels (BLG) were then prepared as hydrogel scaffolds loaded with TAX (TG), TL (TLG), and CTL (CTLG) using a Schiff base reaction involving oxidized dextran and carboxymethyl chitosan. The study investigated the bone reparative properties of CTLG through molecular docking, western blot techniques, and transcriptome analysis. The particle sizes of CTL were measured at 248.90 ± 14.03 nm, respectively, with zeta potentials of +36.68 ± 5.43 mV, respectively. CTLG showed excellent antioxidant capacity in vitro. It also has a good inhibitory effect on Escherichia coli and Staphylococcus aureus, with inhibition rates of 93.88 ± 1.59 % and 88.56 ± 2.83 % respectively. The results of 5-ethynyl-2 '-deoxyuridine staining, alkaline phosphatase staining and alizarin red staining showed that CTLG also had the potential to promote the proliferation and differentiation of mouse embryonic osteoblasts (MC3T3-E1). The study revealed that CTLG enhances the expression of osteogenic proteins by regulating the Wnt signaling pathway, shedding light on the potential application of TAX and bone regeneration mechanisms.

Poly (vinyl alcohol)/sodium alginate/carboxymethyl chitosan multifunctional hydrogel loading HKUST-1 nanoenzymes for diabetic wound healing

Bacterial infection, hyperinflammation and hypoxia, which can lead to amputation in severe cases, are frequently observed in diabetic wounds, and this has been a critical issue facing the repair of chronic skin injuries. In this study, a copper-based MOF (TAX@HKUST-1) highly loaded with taxifolin (TAX) with a drug loading of 41.94 ± 2.60 % was prepared. In addition, it has excellent catalase activity, and by constructing an oxygen-releasing hydrogel (PTH) system with calcium peroxide (CaO2), it can be used as a nano-enzyme to promote the generation of oxygen from hydrogen peroxide (H2O2) to provide sufficient oxygen to the wound, and at the same time, solve the problem of the oxidative stress damage caused by excess H2O2 to the cells during the oxygen-releasing process. On the other hand, TAX and HKUST-1 in PTH synergistically promoted antimicrobial and anti-oxidative stress properties, and the bacterial inhibition rate against Staphylococcus aureus and Escherichia coli reached 90 %. In vivo experiments have shown that PTH hydrogel is able to treat diabetic skin repair by inhibiting the expression of inflammation-related proteins and promoting epidermal neogenesis, angiogenesis and collagen deposition.

Semen Ziziphus jujube Saponins Protects HaCaT Cells against UV Damage and Alleviates the Aging of Caenorhabditis elegans

The role of Semen Ziziphus jujube saponins in sedative and hypnosis has attracted much attention. The study aimed to investigate its possible UV damage protection and anti-aging effects. Total saponins (SZR I) and purified saponins (SZR II) were analyzed and compared by infrared spectroscopy and high-performance liquid chromatography (HPLC). The protective effects of SZR I, SZR II, and their three monomers on HaCaT cells damaged by UV were studied, and their anti-aging activities were observed by Caenorhabditis elegans with paraquat-induced oxidative stress. The results showed that SZR I and SZR II differ in chemical composition but both have the same three monomers. The cell survival rate treated with SZR I and SZR II at a concentration of 400 μg/mL increased by 34.45 and 88.98%, respectively, indicating that they could promote the proliferation of UVB-damaged HaCaT cells. Jujuboside A, Jujuboside B, and spinosin from the saponins exhibited similar effects on UVB-damaged HaCaT cells. SZR I and SZR II had little effect on reproductive performance but could delay the senescence caused by heat and oxidative stress of the C. elegans model. These results provide useful data that Semen Z. jujube saponin is a potential natural product with UV damage protection and anti-aging characteristics.

Preparation of nanocomposite membranes loaded with taxifolin liposome and its mechanism of wound healing in diabetic mice

In this study, a new wound dressing was developed to speed up the healing process of diabetic wounds. First of all, taxifolin liposome (TL) was manufactured in this study. Then, taxifolin (TAX) and TL were mixed with polyvinyl alcohol (PVA) and chitosan (CS) by electrostatic spinning to prepare nanocomposite membranes. Finally, the mechanism of nanocomposite membranes to accelerate diabetic wound healing was investigated. The diameter of TL-loaded polyvinyl alcohol/chitosan nanocomposite membranes (PVA/CS/TL) was 429.43 ± 78.07 nm. The results of in vitro experiments demonstrated that the PVA/CS/TL had better water absorption, water vapor transmission rate (WVTR), porosity, hydrophilicity, mechanical properties, slow-release, antioxidant capacity, and antibacterial properties. The results of in vivo experiments demonstrated that the wound healing rate of mice treated with PVA/CS/TL for eighteen days was 98.39 ± 0.34 %. Histopathological staining, immunohistochemical staining, and western blot experiments also demonstrated that PVA/CS/TL could promote wound healing in diabetic mice by inhibiting the activation of inhibitor kappa B alpha (IκBα)/nuclear factor-kappa B (NF-κB) signaling pathway and related pro-inflammatory factors to increase the expression of CD31 and VEGF in skin tissues. These results suggested that PVA/CS/TL could be a potential candidate for wound dressing to promote chronic skin wound healing.

Silk protein/polyvinylpyrrolidone nanofiber membranes loaded with puerarin accelerate wound healing in mice by reducing the inflammatory response

In modern clinical applications, wound healing remains a considerable challenge. Excessive inflammatory response is associated with delayed wound healing. In this study, we prepared composite nanofibrous membranes by mixing the Chinese herbal extract puerarin (PUE) with natural silk protein (SF) and synthetic polymer polyvinylpyrrolidone (PVP) using electrostatic spinning technique, and conducted a series of studies on the structural and biological properties of the fibrous membranes. The results showed that the loading of PUE increased the diameter, porosity and hydrophilicity of nanofibers, which were more favorable for cell adhesion and proliferation. ABTS radical scavenging assay also showed that the loading of PUE enhanced the antioxidant properties of the fibrous membranes. In addition, SF/PVP/PUE nanofibers are non-toxic and can be used as wound dressings. In vitro experiments showed that SF/PVP/PUE nanofibers could effectively alleviate lipopolysaccharide (LPS)-induced inflammation in Immortalized human keratinocytes (HaCaT) cells and down-regulate pro-inflammatory cytokine expression in cells. In vivo studies further showed that the SF/PVP/PUE nanofibers could effectively accelerate wound repair. The mechanism is that SF/PVP/PUE nanofibers can inhibit the activation and transduction of toll-like receptor 4/myeloid differentiation factor88/nuclear factor kappa B (TLR4/MyD88/NF-κB) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathways, thereby reducing the inflammatory response and achieving wound healing.

Citrus aurantium L. Active Constituents, Biological Effects and Extraction Methods. An Updated Review

Citrus genus is a prominent staple crop globally. Long-term breeding and much hybridization engendered a myriad of species, each characterized by a specific metabolism generating different secondary metabolites. Citrus aurantium L., commonly recognized as sour or bitter orange, can exceptionally be distinguished from other Citrus species by unique characteristics. It is a fruit with distinctive flavor, rich in nutrients and phytochemicals which possess different health benefits. This paper presents an overview of the most recent studies done on the matter. It intends to provide an in-depth understanding of the biological activities and medicinal uses of active constituents existing in C. aurantium. Every plant part is first discussed separately with regards to its content in active constituents. All extraction methods, their concepts and yields, used to recover these valuable molecules from their original plant matrix are thoroughly reported.

Artificial Intelligence Assisted Ultrasonic Extraction of Total Flavonoids from Rosa sterilis

Flavonoids in Rosa sterilis were studied. The flavonoids in Rosa sterilis were extracted by ultrasonic method, and the extraction conditions were modeled and optimized by response the surface methodology and the artificial intelligence method. The results show that the ultrasonic method can effectively extract total flavonoids, and the extraction rate is close to the prediction value of ANN-GA algorithm, which proves the rationality of the model. The order of the effects of the parameters on the experiment was material liquid ratio > extraction power > extraction time > ethanol concentration. In addition, the scavenging effects of flavonoids on DPPH, O²⁻· and ·OH were also determined, and these indicated that flavonoids have strong antioxidant activities. The kinetics of the extraction process was studied by using the data of the extraction process, and it was found that the extraction process conformed to Fick’s first law.

Ultrasound-assisted aqueous two-phase extraction of synephrine, naringin, and neohesperidin from Citrus aurantium L. fruitlets

The ultrasound-assisted aqueous two-phase extraction (UA-ATPE) was first employed to develop an effective technique for simultaneous extraction and preliminary purification of synephrine, naringin, and neohesperidin from Citrus aurantium L. fruitlets. Five types of ethanol/salts of aqueous two-phase system (ATPS) were investigated and then the extraction conditions were further optimized using single-factor experiments and response surface methodology (RSM) via Box-Behnken Design (BBD). The optimum process parameters were concluded as follows: 20.60% (w/w) K₂CO₃, 27% (w/w) ethanol, solvent-to-material ratio of 45.17:1 (g:g), 120-mesh particle size of fruitlets powder, extraction temperature of 50 °C, extraction time of 30 min, and ultrasonic power of 80 W. Under these conditions, the extraction yields of synephrine, naringin, and neohesperidin were up to 11.17 mg/g, 7.39 mg/g, and 89.27 mg/g, respectively. The yield of neohesperidin extracted by the optimal UA-ATPE was over eight times higher than that extracted by the ultrasound-assisted extraction (UAE) using conventional solvents, and the total yield of target compounds was over twice higher while the impurity content in the extract was much lower. Therefore, UA-ATPE appeared to be a highly effective and promising approach for the extraction of synephrine, naringin, and neohesperidin from C. aurantium fruitlets.

Velutin, an Aglycone Extracted from Korean Mistletoe, with Improved Inhibitory Activity against Melanin Biosynthesis

The abnormal regulation of melanin synthesis leads to a wide range of pigmentary disorders. Although various melanin biosynthesis inhibitors have been developed, their efficacy and long-term safety needs to be further improved, and thus the goal of this study is to develop promising natural compound inhibitors of melanin biosynthesis. Here, we obtained aglycone flavonoid extract through the microwave-assisted hydrolysis of glycoside extract from Korean mistletoe in acidic condition. The aglycone extract inhibited tyrosinase activity more efficiently with better antioxidant activity than glycoside extract in vitro. The microwave-assisted aglycone extract of mistletoe was further analyzed for in vivo activity, and the results showed the aglycone extract inhibited both early melanocyte development and melanin synthesis more efficiently in zebrafish embryo in a dose-dependent manner. Our in vivo toxicity assay quantitatively measured cell death in zebrafish embryos and showed that the microwave-assisted aglycone extract of mistletoe had no significant effect on cell death (p < 0.001), indicating that aglycone extract is more biocompatible than glycoside extract. Furthermore, our in vitro and in vivo analyses successfully identified and characterized velutin, an aglycone of a homoflavoyadorinin B glycoside, as a major inhibitory component in the microwave-assisted mistletoe extract. Ultimately, this study showed that the novel natural compound inhibitor velutin, which was generated through microwave-assisted extraction from mistletoe, improved the efficacy of melanin biosynthesis inhibition with little toxicity.