The Effect of In Vitro Gastrointestinal Digestion on the Antioxidants, Antioxidant Activity, and Hypolipidemic Activity of Green Jujube Vinegar

A Comprehensive Metabolomic Analysis of Volatile and Non-Volatile Compounds in Folium Artemisia argyi Tea from Different Harvest Times

To develop and utilize Folium Artemisia argyi (FAA) tea resources, UPLC-MS/MS, HS-GC-IMS, and HS-SPME/GC×GC-TOFMS were adopted to analyze its volatile and non-volatile compounds, when harvested from March to June, in combination with its antioxidant activity. Here, 1742 volatile compounds and 8726 non-volatile compounds were identified, with 75 differential volatile metabolites and 36 key flavor compounds screened. Notably, 1-octen-3-one, (E)-2-octenal, (E)-2-undecenal, and heptanal were identified as major contributors to the sweet, fruity, green, and herbal aromas, and the concentration of them was highest in June-harvest FAA tea. Furthermore, metabolomics revealed that there were 154 non-volatile differential metabolites in FAA tea at four harvest times, which were mainly related to amino acid biosynthetic pathways. Samples harvested in June also showed the strongest antioxidant capacity, which was positively correlated with D-xylitol, L-glutamic acid, honokiol, and costunolide. These findings highlight June as the optimal harvest time, providing FAA tea with superior flavor and enhanced antioxidant properties, underscoring its potential as a valuable resource for functional food development.

Lactic Acid Bacteria in Vinegar Fermentation: Diversity, Functionality and Health Benefits

Vinegar, frequently distilled by solid fermentation or liquid processes, was generated through the synergistic effect of a microbial community in open or semi-open environments. Based on the studied raw materials, researchers distributed the vinegar into three classes: grain, fruit and animal, with lactic acid bacteria (LAB) playing a pivotal role in their fermentation and contributing significantly to their functional and sensory qualities. Typically, the natural maturation of fresh vinegar necessitates a long period and vast space, engendering a reduced efficiency. To accelerate the vinegar aging process, some physical methods, viz. micro-oxygenation, ozone, ultrasound, microwave, gamma rays, infrared, electric fields and high pressure, have been developed. Produced or enriched by LAB, key bioactive vinegar components are organic acids, phenolic compounds, melanoidins, and tetramethylpyrazine. These active compounds have antibacterial, antioxidant, anti-inflammatory functions; aid in the regulation of liver protection metabolism and glucose control; and have blood pressure, anti-tumor, anti-fatigue and metabolic regulatory effects. The review explores advancements in vinegar production, including modernized fermentation processes and optimized aging techniques, which enhance these beneficial compounds and ensure product consistency and safety. By examining the LAB variety strains and the bioactive profiles of different vinegar types, this study highlights vinegar's value beyond a culinary product, as a potential therapeutic agent in human nutrition and health. The findings underscore vinegar's relevance not only in dietary and preventive healthcare but also as a potential functional food ingredient. Further research is needed to explore the mechanisms of action through which LAB contribute to the development of several new healthy vinegars.

Polysaccharides from Ziziphus jujuba prolong lifespan and attenuate oxidative stress in Caenorhabditis elegans via DAF-16 and SKN-1

Jujube is a commonly consumed traditional Chinese medicinal food. Recent evidence revealed crude polysaccharides of jujube extract (CPJE) exhibited bioactive properties in vitro; however, its antioxidant capacity in vivo remains unknown. The objectives of this study were to evaluate the effects of CPJE on growth, locomotion, reproduction, lifespan, and antioxidant defense system using Caenorhabditis elegans. Results showed CPJE were not toxic to C. elegans with no effects on bacterial growth. Compared to control, CPJE significantly increased body length and width, head thrashes, body bends, and brood size of nematodes. In addition, CPJE at higher concentrations significantly increased pharyngeal pumping of the nematodes. Moreover, CPJE at 0.25, 0.5, and 1 mg/mL promoted lifespan by 17.9 %, 34.7 % and 46.3 %, respectively. CPJE at higher concentrations reduced level of ROS, increased activities of SOD, CAT, and GSH. CPJE also upregulated the expression of daf-16, skn-1, sod-3, and gcs-1 in N2 nematodes. Meanwhile, results from studies with nematode mutants also suggested that improved stress resistance of CPJE was due to modulation of daf-16 and skn-1. Overall, our results suggest CPJE promote longevity and reduce oxidative stress via DAF-16 and SKN-1. Our findings shed a new light on the utilization of CPJE to attenuate oxidative stress.

Characterization of the Composition of Bioactive Fractions from Dendrobium officinale Flowers That Protect against H2O2-Induced Oxidative Damage through the PI3K/AKT/Nrf2 Pathway

Dendrobium officinale flowers (DOF) have previously been established as a promising source of natural antioxidants, and it is ideally suited for processing to prepare functional foods and food additives. The precise extraction processes employed, however, can alter the composition and antioxidant properties of the resultant products, and the characteristic compounds associated with the active fractions prepared from DOF or their mechanisms of action have yet to be reported. To clarify the molecular mechanisms through which these active fractions function for the first time, chromatography was used to separate DOF extracts, yielding five fractions (Fr. (a-e)). Analyses of the antioxidant activity for these different fractions revealed that Fr. (d) presented with the most robust bioactivity. Levels of total flavonoids were then measured, revealing that antioxidant activity levels were positively correlated with total flavonoid content. Fr. (d) was found to contain 20 flavonoids in HPLC-Triple-TOF-MS/MS analyses. At the cellular level, Fr. (d) was found to induce increases in the levels of protective antioxidant factors (SOD and GSH-Px) while reducing the levels of reactive oxygen species (ROS), damage-associated factors (MDA, NO, TNF-α, IL-1β, and IL-6), and inducible nitric oxide synthase (iNOS) expression in C2C12 cells that had been stimulated with H2O2. These data thus provided support for Fr. (d) prevention of oxidative stress and inflammation. Network pharmacology analyses further suggested that Fr. (d) can help protect against oxidative stress through its effects on PI3K/Akt-related signaling activity. Fr. (d) was subsequently found to upregulate PI3K/Akt pathway-related proteins, nuclear transcription factor 2 (Nrf2), and heme oxygenase 1 (HO-1) in addition to suppressing Kelch-like epoxide-related protein 1 (Keap1) expression. In summary, Fr. (d) was found to suppress PI3K/Akt/Nrf2 pathway activation, ultimately alleviating inflammation and oxidative stress as predicted with a network pharmacology approach. Future studies aimed at clarifying the composition and mechanistic activity of DOF Fr. (d) will likely help establish it as a functional food capable of promoting health and longevity.

Functional Nutrients and Jujube-Based Processed Products in Ziziphus jujuba

Jujube (Ziziphus jujuba Mill.) is the first tree species in China, with a long history and abundant yield. However, fresh jujubes have a short shelf-life and are not resistant to storage. Therefore, more and more processed jujube products are being studied. These processed products can extend the shelf-life of jujubes and attract widespread attention for their rich functional nutrients. This review summarized changes in nutrients of fresh jujube and processed products and the research progress of different preparation methods of jujubes. Meanwhile, the pharmacological effects of bioactive components in jujube-based products were concluded. Jujube and its processed products contain rich polysaccharides, vitamin C, and other functional nutrients, which are beneficial to humans. As the initial processing method for jujubes, vacuum freezing or microwave drying have become the most commonly used and efficient drying methods. Additionally, processed jujube products cannot be separated from the maximum retention of nutrients and innovation of flavor. Fermentation is the main deep-processing method with broad development potential. In the future, chemical components and toxicological evaluation need to be combined with research to bring consumers higher quality functional jujube products and ensure the sustainable development of the jujube industry.

Current applications of solid lipid nanoparticles and nanostructured lipid carriers as vehicles in oral delivery systems for antioxidant nutraceuticals: A review

Antioxidant nutraceuticals can be found in several dietary sources and have been utilized for various medical benefits including health promotion, disease prevention, and support for treatment of acute and/or chronic diseases. Nonetheless, there are some limitations in delivering antioxidants via oral administration such as low solubility and permeability, pH and enzyme degradation, and instability of the compounds along the gastrointestinal tract leading to low bioavailability. In order to tackle these challenges, the utilization of lipid nanoparticles has numerous advantages to the escalating delivery system of antioxidants in nutraceuticals across the gastrointestinal tract barrier. Nowadays, several types of lipid nanoparticles can be used in antioxidant nutraceutical delivery systems through the oral route, namely solid lipid nanoparticles and nanostructured lipid carriers. This review article aims to provide notable information on the importance and applications of lipid nanoparticles in antioxidant delivery systems from nutraceuticals by an oral route. The mechanism in enhancing antioxidant compound transport across the gastrointestinal tract can occur by elevating loading capacity, improving chemical and physical stability, and increasing its bioavailability. To date, lipid nanoparticle vehicles have been developed to improve the delivery of antioxidant compounds to enhance bioavailability via oral routes. Lipid nanoparticles have remarkable benefits in delivering antioxidant nutraceuticals via oral administration. Hence, scale-up and commercialization of antioxidant nutraceutical-loaded lipid nanoparticles have been a potential technology in recent years. Subsequently, several vegetable and natural oils with antioxidant activity can also be utilized for nanoparticle formulation lipid components to increase nutraceuticals' antioxidant properties and bioavailability.

Effect of In Vitro Gastrointestinal Digestion on Phytochemicals and Antioxidant Activities in Cherry Tomatoes (Solanum lycopersicum var. cerasiforme)

We investigated the impact of simulated in vitro gastrointestinal digestion on the levels of total polyphenols, total flavonoids, carotenoids, and antioxidant capacity in cherry tomatoes. The initial total polyphenol content of fresh tomatoes was 220.51 μg GAE/g, which decreased to 203.24 μg GAE/g after 120 min of stomach treatment and further decreased to 138.23 μg GAE/g after 120 min of small intestine treatment. Similarly, the initial total flavonoid content in fresh tomatoes was 43.28 μg QE/g, but after 120 min of small intestine digestion, it decreased by approximately 50.72% to 21.33 μg QE/g. Lycopene, lutein, and β-carotene also experienced a decrease of 69.71∼78.38% during the digestion process compared to fresh tomatoes. The antioxidant activity exhibited a reduction of 34.95∼37.67% compared to fresh tomatoes after digestion in the stomach and intestines. The bioactive compounds present in tomatoes undergo decomposition and conversion into other substances during digestion, and these degradation products are believed to inhibit the growth of SK-Hep1 human hepatoma cells while enhancing antioxidant activity within the intracellular environment.

Optimization of the Process for Green Jujube Vinegar and Organic Acid and Volatile Compound Analysis during Brewing

Healthy fruit vinegar has become very popular recently in China. This study aimed to produce fruit vinegar with a good taste, high nutritional value, and strong functional properties from green jujube. This study investigated the optimization of the process for green jujube vinegar using response surface methodology. The optimum fermentation parameters for green jujube vinegar were determined as follows: initial alcoholicity 6%, acetobacter 8%, fermentation temperature 32 °C, and time 7 d. The organic acids of the optimized sample were evaluated by HPLC, and the volatile substances were identified and analyzed by HS-SPME and GC-MS during the fermentation and aging of the green jujube vinegar. The results showed that the variation trends of the different organic acids during the making of the green jujube vinegar were significantly different. Organic acids are the key flavor compounds of green jujube vinegar, and their changes were mainly attributed to microbial metabolism. In particular, the green jujube vinegar stood out in terms of volatile aroma compounds, including a total of 61 volatile compounds whose major components were acetic acid, isoamyl acetate, ethyl acetate, 3-hydroxy-2-butanone, methyl palmitate, and ethanol. The results can provide theoretical support for the production of green jujube vinegar.

Deciphering the mechanism of jujube vinegar on hyperlipoidemia through gut microbiome based on 16S rRNA, BugBase analysis, and the stamp analysis of KEEG

Background

Growing data indicate that the gut microbiome may contribute to the rising incidence of hyperlipoidemia. Jujube vinegar lowers lipids, protects the liver, and reduces oxidant capacity, however, it is unknown whether this is due to the gut flora. To further research the role of the gut microbiome in treating hyperlipidemia with jujube vinegar, we looked into whether the action of jujube vinegar is related to the regulation of the gut microbiome.

Method

Thirty male ICR mice were used. The control group (CON), the high-fat diet (HFD) group, and the vinegar group (VIN) each consisted of ten female ICR mice fed consistently for eight weeks. For each treatment, we kept track of body mass, liver index, blood lipid levels, and oxidative stress state. We also analyzed mouse feces using high-throughput 16srRNA sequencing to examine the relationship between jujube vinegar's hypolipidemic effect and antioxidant activity and how it affects the gut microbiome.

Results

Jujube vinegar reduced body weight by 19.92%, serum TC, TG, and LDL-C by 25.09%, 26.83%, and 11.66%, and increased HDL-C by 1.44 times, serum AST and ALT decreased by 26.36% and 34.87% respectively, the blood levels of SOD and GSH-Px increased 1.35-fold and 1.60-fold, respectively. While blood MDA decreased 33.21%, the liver's SOD and GSH-Px increased 1.32-fold and 1.60-fold, respectively, and the liver's MDA decreased 48.96% in HFD mice. The gut microbiome analysis revealed that jujube vinegar increased the intestinal microbial ASV count by 13.46%, and the F/B (Firmicutes/Bacteroidota) ratio by 2.08-fold in high-fat diet mice, and the proportion was significantly inversely correlated with TC, TG, and LDL-C and positively correlated with HDL-C. Biomarker bacteria in the vinegar group included Lactobacillaceae and Lactobacillus, which correlated favorably with HDL-C, SOD, and GSH-Px and negatively with LDL-C, TC, and TG. Jujube vinegar increased the abundance of the Aerobic, Contains Mobile Elements, and Facultative Aerobic by 2.84 times, 1.45 times, and 2.40 times, while decreased the abundance of Potential pathogens by 44.72%, according to the BugBase study. The KEGG analysis showed that jujube vinegar was predominantly reflected in the biological process of gene function and related to signal transduction pathways, including glucagon signaling system, HIF-1 signaling pathway, adipocytokine signaling pathway, amino sugar, and nucleotide sugar metabolism, and so forth.

Conclusion

Based on these findings, jujube vinegar may reduce hyperlipoidemia by controlling the gut microbiome and enhancing antioxidant capacity.

Comprehensive Analysis of Secondary Metabolites of Four Medicinal Thyme Species Used in Folk Medicine and Their Antioxidant Activities In Vitro

Thyme is a colloquial term for number of aromatic species belonging to the genus Thymus L., known for their expressed biological activities and therefore used worldwide for seasoning and in folk medicine. In the present paper, the content of the total polyphenols (TP), total flavonoids (TF), and antioxidant capacity were assessed in the extracts of four traditionally used thyme species. Moreover, a comprehensive metabolomic study of thyme bioactive compounds was performed, and the obtained data were processed using multivariate statistical tests. The results clearly demonstrated the positive correlation between the content of the TP, TF, and antioxidant activity, and TF was more significant than TP. The findings revealed that four selected thyme species contained 528 secondary metabolites, including 289 flavonoids and 146 phenolic acids. Thymus marschallianus had a higher concentration of active ingredients, which improve its antioxidant capacity. Differentially accumulated metabolites were formed by complex pathways such as flavonoid, flavone, flavonol, isoflavonoid, and anthocyanin biosynthesis. Correlation analysis showed that 59 metabolites (including 28 flavonoids, 18 phenolic acids, and 7 terpenoid compounds) were significantly correlated with obtained values of the antioxidant capacity. The results suggested that selected thyme species exhibit a great diversity in antioxidant-related components, whereas flavonoids may be responsible for the high antioxidant capacity of all studied thyme species. The present study greatly expands our understanding of the complex phytochemical profiles and related applications of selected medicinal plants.

Determination of Changes in Volatile Aroma Components, Antioxidant Activity and Bioactive Compounds in the Production Process of Jujube (Ziziphus jujuba Mill.) Vinegar Produced by Traditional Methods

Jujube has anticancer, diabetic, antimicrobial, anti-inflammatory, cardiovascular, gastrointestinal and immune system effects. In this study, jujube juice, jujube wine and jujube vinegar were investigated in terms of chemical composition, phenolic contents, organic acid contents, volatile compound contents, and antioxidant activity. Antioxidant activity and total phenolic content of jujube vinegar produced by traditional methods were found to be higher than those of jujube juice and wine. Protocatechic acid, chlorogenic acid, phydroxybenzoic acid, caffeic acid, epicatechin, and syringic acid were detected in jujube vinegar. Moreover, oxalic acid, malic acid, tartaric acid, formic acid, ascorbic acid, lactic acid, acetic acid and some other organic acid components were determined in jujube vinegar. Volatile aroma compounds such as ester, aldehyde, alcohol, terpene, acid, and ketone were determined in jujube samples. It was seen that the antioxidant activity and bioactive compounds of jujube vinegar were very rich, and jujube vinegar, which is an alternative product with a high potential produced from jujube fruit, is an important product for the food sector due to its long shelf life. This research is the first detailed study in which the antioxidant activity and bioactive compounds determined during the production stages of jujube vinegar (jujube juice, wine, and vinegar) were evaluated in detail.

Extraction of a Triterpene Solution and Evaluation of the Hypolipidemic Efficacy of the Pleurotus tuber-regium (Fr.) Sing Sclerotium

The total triterpenes in edible mushrooms have high medicinal value, and the sclerotium has various biological activities, such as the regulation of blood pressure and blood glucose. In this study, the total triterpenes of the Pleurotus tuber-regium (Fr.) Sing Sclerotium (PTRSS) were extracted, and their hypolipidemic effects were also investigated. The infrared spectra showed that the total triterpenes were consistent with the characteristic structures of the total triterpenes before and after purification. The binding abilities of total triterpenes to sodium glycocholate, sodium taurocholate, and sodium cholate were investigated, and all of them had a good binding ability to cholate. In vivo experiments showed that zebrafish tolerated the total triterpenes from the mushroom nuclei at a maximum concentration of 500 µg/mL. A correlation analysis showed that the total triterpenes from the mushroom nuclei reduced the lipid accumulation in zebrafish induced by a high-fat diet, and the lipid-lowering effect showed a correlation with dose.