Redox balance is essential to maintain the body’s normal metabolism. Once disrupted, it may lead to various chronic diseases, such as diabetes, neurodegenerative diseases, cardiovascular diseases, inflammatory diseases, cancer, aging, etc. Oxidative stress can cause or aggravate a series of pathological processes. Inhibition of oxidative stress and related pathological processes can help to ameliorate these chronic diseases, which have been found to be associated with Nrf2 activation. Nrf2 activation can not only regulate the expression of a series of antioxidant genes that reduce oxidative stress and its damage, but also directly regulate genes related to the above-mentioned pathological processes to counter the corresponding changes. Therefore, targeting Nrf2 has great potential for the prevention or treatment of chronic diseases, and many natural phytochemicals have been reported as Nrf2 activators although the defined mechanisms remain to be elucidated. This review article focuses on the possible mechanism of Nrf2 activation by natural phytochemicals in the prevention or treatment of chronic diseases and the regulation of oxidative stress. Moreover, the current clinical trials of phytochemical-originated drug discovery by targeting the Nrf2-ARE pathway were also summarized; the outcomes or the relationship between phytochemicals and chronic diseases prevention are finally analyzed to propose the future research strategies and prospective.

As a possible alternative to hydrogels, eutectogels are formed by gelling natural deep eutectic solvents (NADESs) that may be closer to the intracellular environment than pure water. This study successfully prepared highly biodegradable and thermostable eutectogels based on polysaccharides and NADESs, and studied the possible mechanism of eutectogel formation. The results show that these eutectogels displayed excellent thermostability as both the G′ and G′′ values remained constant in the temperature range of 60–110 °C, and the weight of the eutectogels remained almost unchanged when held at 80 °C for 10 hours. Similar to the formation of xanthan gum-based hydrogels, water addition and annealing treatment are necessary for the preparation of xanthan gum-based eutectogels. XRD, DSC and FT-IR results show that the existence of xanthan gum affects the original hydrogen bonding network of the NADESs, which further indicate that the hydrogen bond interaction between xanthan gum and NADESs is an important cause of eutectogel formation and changes in gel properties. Rheological results show that the eutectogel is a weak gel with excellent thermostability and structure recovery. As it is more stable than hydrogels and greener than ion gels, the polysaccharide-based eutectogel is expected to be widely used in the fields of food, medicine and materials.

The natural deep eutectic solvent (NADES) is an excellent solvent for insoluble natural products and medicines. Eutectogels formed by gelation of NADESs are interesting materials that deserve attention. In this study, xanthan gum was used as a gelator to gel choline chloride-xylitol with different water contents in virtue of the excellent solubility of choline chloride-xylitol (1:1) to quercetin. We observed that water was critical to the formation of eutectogels. An MTT assay indicated that our eutectogel had excellent biocompatibility as its corresponding hydrogel. According to rheological tests, xanthan gum-based eutectogels had better viscoelastic properties, higher thermal stability, and more defined shear thinning behavior than its corresponding hydrogel. Texture profile analysis showed that eutectogels with less water content had higher hardness and adhesiveness. Meanwhile, Differential scanning calorimeter (DSC) results suggested that the various rheological and texture properties of eutectogels could be attributed to changes in the water state, which was influenced by the hydrogen bonding network of NADES. This biocompatible eutectogel with tunable properties was expected to find applications in novel drug delivery vehicles, which are widely used in the fields of medicine and food.

In recent years, many natural foods and herbs rich in phytochemicals have been proposed as health supplements for patients with metabolic syndrome (MetS). Theaflavins (TFs) are a polyphenol hydroxyl substance with the structure of diphenol ketone, and they have the potential to prevent and treat a wide range of MetS. However, the stability and bioavailability of TFs are poor. TFs have the marvelous ability to alleviate MetS through antiobesity and lipid-lowering (AMPK-FoxO3A-MnSOD, PPAR, AMPK, PI3K/Akt), hypoglycemic (IRS-1/Akt/GLUT4, Ca²⁺/CaMKK2-AMPK, SGLT1), and uric-acid-lowering (XO, GLUT9, OAT) effects, and the modulation of the gut microbiota (increasing beneficial gut microbiota such as Akkermansia and Prevotella). This paper summarizes and updates the bioavailability of TFs, and the available signaling pathways and molecular evidence on the functionalities of TFs against metabolic abnormalities in vitro and in vivo, representing a promising opportunity to prevent MetS in the future with the utilization of TFs.

Extracting ursolic acid (UA) from plant resources using organic solvents is incompatible with food applications. To address this, in this study, 15 edible hydrophobic deep eutectic solvents (HDESs) were prepared to extract UA from apple peel, the extraction conditions were optimized, and the optimization strategies were compared. It was found that the solubility of UA in the HDESs can be 9 times higher than the traditional solvent such as ethanol. The response surface optimization concluded that temperature had the greatest effect on the extraction and the optimized test conditions obtained as follows: temperature of 49 °C, time of 32 min, solid–liquid ratio of 1:16.5 g/mL, respectively. Comparing the response surface methodology (RSM) and artificial neural networks (ANN), it was concluded that ANN has more accurate prediction ability than RSM. Overall, the HDESs are more effective and environmentally friendly than conventional organic solvents to extract UA. The results of this study will facilitate the further exploration of HDES in various food and pharmaceutical applications.