Alcoholic liver disease (ALD) threatens human health, so it is imperative that we find ways to prevent or treat it. In recent years, the study of polysaccharides has shown that they have different kinds of bioactivities. Among them are many biological effects that have been attributed to polysaccharide precursors. D-Isofloridoside (DIF) is one of the polysaccharide precursors from the marine red alga Laurencia undulata. This study evaluated the effect of DIF on alcohol-induced oxidative stress in human hepatoma cells (HepG2). As a result, DIF attenuated alcohol-induced cytotoxicity, reduced the amount of intracellular reactive oxygen species (ROS), and effectively reduced alcohol-induced DNA damage in HepG2 cells. In addition, a western blot showed that, after DIF treatment, the expression levels of glutathione (GSH), superoxide dismutase (SOD), and B-cell lymphoma-2 (bcl-2) increased, while the expression levels of γ-glutamyl transferase (GGT), BCL2-associated X (bax), cleaved caspase-3, and mitogen-activated protein kinase (p38 and c-Jun N-terminal kinase) signal transduction proteins reduced. This showed that DIF may protect cells by reducing the amount of intracellular ROS and inhibiting intracellular oxidative stress and apoptotic processes. Finally, molecular docking demonstrated that DIF can bind to SOD, GGT, B-cell lymphoma-2, and bax proteins. These results indicated that DIF can protect HepG2 cells from alcohol-induced oxidative stress damage, making it an effective potential ingredient in functional foods.
Hydrogels based on nanocomposites (NC) structure have acquired a great deal of interest, but they are still limited by relatively low mechanical strength, inevitably losing elasticity when applied below subzero temperatures, due to the formation of ice crystallization. In this study, an anti-freezing and mechanically strong Laponite NC organohydrogel was prepared by a direct solvent replacement strategy of immersing Laponite NC pre-hydrogel into ethylene glycol (EG)/water mixture solution. In the organohydrogel, a part of water molecules was replaced by EG, which inhibited the formation of ice crystallization even at extremely low temperatures. In addition, the formation of hydrogen bonds between Laponite and the monomers of N-isopropylacrylamide (NIPAM) and hydroxyethyl acrylate (HEA) endowed the organohydrogels with high mechanical strength and toughness. The NC organohydrogel can maintain its mechanical flexibility even at −25 °C. The compressive stress, tensile stress, and elongation at the break of N5H5L reached 3871.71 kPa, 137.05 kPa, and 173.39%, respectively, which may be potentially applied as ocean probes in low temperature environment.
To develop a novel asymmetric nanofiber membrane with antioxidant and antibacterial activities, biocompatible polyvinyl pyrrolidone (PVP) and polycaprolactone (PCL) were used as carriers to load water-soluble tea tree extract (TTE) and hydrophobic tea tree oil (TTO) via electrospinning and electrostatic spraying, respectively, which was named as TTE-PVP-3/TTO-PCL. The results show that uniform TTE-PVP nanofibers with an average diameter of 95 ± 27 nm could be obtained when the mass ratio of TTE to PVP was set as 1:3. Homogeneous TTO/PCL microspheres with an average size of 4.38 ± 0.79 µm could be obtained when the propulsion speed was 0.08 mm/min and the voltage was 10 KV. The activity study showed that TTE could only improve the antioxidant activity of TTE-PVP-3/TTO-PCL, while TTO could improve the antibacterial activity effectively. Under experimental conditions, the inhibition zones of TTE-PVP-3/TTO-PCL against Staphylococcus aureus and Escherichia coli were 7.50 ± 0.48 mm and 9.55 ± 0.45 mm, respectively, and its scavenging rates for 2,2-diphenylpicrylhydrazyl (DHPP) and hydroxyl radical were 59.79 ± 4.10% and 61.02 ± 4.95%, respectively. In conclusions, TTE-PVP-3/TTO PCL can be potentially used as a new kind of anti-oxidative and antibacterial wound dressings.