Absorption, metabolism and bioavailability of flavonoids: a review

Integrated omics analysis reveals the alteration of gut microbiota and fecal metabolites in Cervus elaphus kansuensis

The gut microbiota is the largest and most complex microecosystem in animals. It is influenced by the host's dietary habits and living environment, and its composition and diversity play irreplaceable roles in animal nutrient metabolism, immunity, and adaptation to the environment. Although the gut microbiota of red deer has been studied, the composition and function of the gut microbiota in Gansu red deer (Cervus elaphus kansuensis), an endemic subspecies of red deer in China, has not been reported. In this study, the composition and diversity of the gut microbiome and fecal metabolomics of C. elaphus kansuensis were identified and compared for the first time by using 16S rDNA sequencing, metagenomic sequencing, and LC-MS/MS. There were significant differences in gut microbiota structure and diversity between wild and farmed C. elaphus kansuensis. The 16S rDNA sequencing results showed that the genus UCRD-005 was dominant in both captive red deer (CRD) and wild red deer (WRD). Metagenomic sequencing showed similar results to those of 16S rDNA sequencing for gut microbiota in CRD and WRD at the phylum and genus levels. 16S rDNA and metagenomics sequencing data suggested that Bacteroides and Bacillus might serve as marker genera for CRD and WRD, respectively. Fecal metabolomics results showed that 520 metabolites with significant differences were detected between CRD and WRD and most differential metabolites were involved in lipid metabolism. The results suggested that large differences in gut microbiota composition and fecal metabolites between CRD and WRD, indicating that different dietary habits and living environments over time have led to the development of stable gut microbiome characteristics for CRD and WRD to meet their respective survival and reproduction needs. KEY POINTS: • Environment and food affected the gut microbiota and fecal metabolites in red deer • Genera Bacteroides and Bacillus may play important roles in CRD and WRD, respectively • Flavonoids and ascorbic acid in fecal metabolites may influence health of red deer.

Investigations of the highly efficient processing technique, chemical constituents, and anti-inflammatory effect of N-ethyl-2-pyrrolidinone-substituted flavan-3-ol (EPSF)-enriched white tea

N-Ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) are a newly discovered compound class in tea with various bioactivities. This study aimed to develop a novel processing technique to enhance EPSF contents in white tea efficiently. Using optimal processing parameters of 125 °C and 30 min in a high-temperature sterilizing oven, total EPSF content significantly increased by 1.42-18.80-fold to 1.57-6.22 mg/g without impacting sensory characteristics. Metabolomics analysis revealed elevated levels of nucleosides, nucleotides, bases, theaflavins, flavonol aglycones, EPSFs, and most flavone-C-glycosides, as well as decreased levels of amino acids, procyanidins, theasinensins, several flavanols, and flavonol-O-glycosides after EPSF-enrichment treatment. Furthermore, the EPSF-enriched white tea exhibited notable anti-inflammatory effects, mitigating xylene-induced ear edema in mice and carrageenan-induced paw edema and cotton ball-induced granulomas in rats. This study developed a new processing technique for highly efficient enhancement of EPSFs in white tea and demonstrated that EPSF-enriched white tea has a potential to serve as effective anti-inflammatory dietary supplement.

Metabolomic analysis reveals the effect of ultrasonic-microwave pretreatment on flavonoids in tribute Citrus powder

In this study, the ultrasonic-microwave pretreatment was defined as a processing technology in the production of tribute citrus powder, and it could increase the flavonoid compounds in the processing fruit powder. A total of 183 upregulated metabolites and 280 downregulated metabolites were obtained by non-targeted metabolomics, and the differential metabolites was mainly involved in the pathways of flavonoid biosynthesis, flavone and flavonol biosynthesis. A total of 8 flavonoid differential metabolites were obtained including 5 upregulated metabolites (6"-O-acetylglycitin, scutellarin, isosakuranin, rutin, and robinin), and 3 downregulated metabolites (astragalin, luteolin, and (-)-catechin gallate) by flavonoids-targeted metabolomics. The 8 flavonoid differential metabolites participated in the flavonoid biosynthesis pathways, flavone and flavonol biosynthesis pathways, and isoflavonoid biosynthesis pathways. The results provide a reference for further understanding the relationship between food processing and food components, and also lay a basis for the development of food targeted-processing technologies.

Bioisosteric heterocyclic analogues of natural bioactive flavonoids by scaffold-hopping approaches: State-of-the-art and perspectives in medicinal chemistry

The flavonoid family is a set of well-known bioactive natural molecules, with a wide range of potential therapeutic applications. Despite the promising results obtained in preliminary in vitro/vivo studies, their pharmacokinetic and pharmacodynamic profiles are severely compromised by chemical instability. To address this issue, the scaffold-hopping approach is a promising strategy for the structural optimization of natural leads to discover more potent analogues. In this scenario, this Perspective provides a critical analysis on how the replacement of the chromon-4-one flavonoid core with other bioisosteric nitrogen/sulphur heterocycles might affect the chemical, pharmaceutical and biological properties of the resulting new chemical entities. The investigated derivatives were classified on the basis of their biological activity and potential therapeutic indications. For each session, the target(s), the specific mechanism of action, if available, and the key pharmacophoric moieties were highlighted, as revealed by X-ray crystal structures and in silico structure-based studies. Biological activity data, in vitro/vivo studies, were examined: a particular focus was given on the improvements observed with the new heterocyclic analogues compared to the natural flavonoids. This overview of the scaffold-hopping advantages in flavonoid compounds is of great interest to the medicinal chemistry community to better exploit the vast potential of these natural molecules and to identify new bioactive molecules.

Combining bioinformatics and multiomics strategies to investigate the key microbiota and active components of Liupao tea ameliorating hyperlipidemia

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperlipidemia as a major health issue has attracted much public attention. As a geographical indication product of China, Liupao tea (LPT) is a typical representative of traditional Chinese dark tea that has shown good potential in regulating glucose and lipid metabolism. LPT has important medicinal value in hyperlipidemia prevention. However, the active ingredients and metabolic mechanisms by which LPT alleviates hyperlipidemia remain unclear.

AIM OF THE STUDY

This study aimed to systematically investigate the metabolic mechanisms and active ingredients of LPT extract in alleviating hyperlipidemia.

MATERIALS AND METHODS

Firstly, we developed a mouse model of hyperlipidemia to study the pharmacodynamics of LPT. Subsequently, network pharmacology and molecular docking were performed to predict the potential key active ingredients and core targets of LPT against hyperlipidemia. LC-MS/MS was used to validate the identity of key active ingredients in LPT with chemical standards. Finally, the effect and metabolic mechanisms of LPT extract in alleviating hyperlipidemia were investigated by integrating metabolomic, lipidomic, and gut microbiome analyses.

RESULTS

Results showed that LPT extract effectively improved hyperlipidemia by suppressing weight gain, remedying dysregulation of glucose and lipid metabolism, and reducing hepatic damage. Network pharmacology analysis and molecular docking suggested that four potential active ingredients and seven potential core targets were closely associated with roles for hyperlipidemia treatment. Ellagic acid, catechin, and naringenin were considered to be the key active ingredients of LPT alleviating hyperlipidemia. Additionally, LPT extract modulated the mRNA expression levels of Fxr, Cyp7a1, Cyp8b1, and Cyp27a1 associated with bile acid (BA) metabolism, mitigated the disturbances of BA and glycerophospholipid (GP) metabolism in hyperlipidemia mice. Combining fecal microbiota transplantation and correlation analysis, LPT extract effectively improved species diversity and abundance of gut microbiota, particularly the BA and GP metabolism-related gut microbiota, in the hyperlipidemia mice.

CONCLUSIONS

LPT extract ameliorated hyperlipidemia by modulating GP and BA metabolism by regulating Lactobacillus and Dubosiella, thereby alleviating hyperlipidemia. Three active ingredients of LPT served as the key factors in exerting an improvement on hyperlipidemia. These findings provide new insights into the active ingredients and metabolic mechanisms of LPT in improving hyperlipidemia, suggesting that LPT can be used to prevent and therapeutic hyperlipidemia.

Dietary flavonoids modulate the gut microbiota: A new perspective on improving autism spectrum disorder through the gut-brain axis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with an unknown etiology. It is associated with various factors and causes great inconvenience to the patient's life. The gut-brain axis (GBA), which serves as a bidirectional information channel for exchanging information between the gut microbiota and the brain, is vital in studying many neurodegenerative diseases. Dietary flavonoids provide anti-inflammatory and antioxidant benefits, as well as regulating the structure and function of the gut microbiota. The occurrence and development of ASD are associated with dysbiosis of the gut microbiota. Modulation of gut microbiota can effectively improve the severity of ASD. This paper reviews the links between gut microbiota, flavonoids, and ASD, focusing on the mechanism of dietary flavonoids in regulating ASD through the GBA.

Plant-derived flavonoids are a potential source of drugs for the treatment of liver fibrosis

Liver fibrosis is a dynamic pathological process that can be triggered by any chronic liver injury. If left unaddressed, it will inevitably progress to the severe outcomes of liver cirrhosis or even hepatocellular carcinoma. In the past few years, the prevalence and fatality of hepatic fibrosis have been steadily rising on a global scale. As a result of its intricate pathogenesis, the quest for pharmacological interventions targeting liver fibrosis has remained a formidable challenge. Currently, no pharmaceuticals are exhibiting substantial clinical efficacy in the management of hepatic fibrosis. Hence, it is of utmost importance to expedite the development of novel therapeutics for the treatment of this condition. Various research studies have revealed the ability of different natural flavonoid compounds to alleviate or reverse hepatic fibrosis through a range of mechanisms, which are related to the regulation of liver inflammation, oxidative stress, synthesis and secretion of fibrosis-related factors, hepatic stellate cells activation, and proliferation, and extracellular matrix synthesis and degradation by these compounds. This review summarizes the progress of research on different sources of natural flavonoids with inhibitory effects on liver fibrosis over the last decades. The anti-fibrotic effects of natural flavonoids have been increasingly studied, making them a potential source of drugs for the treatment of liver fibrosis due to their good efficacy and biosafety.

The associations between dietary flavonoid intake and hyperlipidemia: data from the national health and nutrition examination survey 2007-2010 and 2017-2018

Background

Hyperlipidemia is a worldwide health problem and a significant risk factor for cardiovascular diseases; therefore, it imposes a heavy burden on society and healthcare. It has been reported that flavonoids can increase energy expenditure and fat oxidation, be anti-inflammatory, and reduce lipid factor levels, which may reduce the risk of hyperlipidemia. However, the relationship between the prevalence of hyperlipidemia and dietary flavonoid intake in the population remains unclear.

Methods

This study included 8,940 adults from the 2007-2010 and 2017-2018 National Health and Nutrition Examination Surveys (NHANES). The relationship between dietary flavonoid intake and the prevalence of hyperlipidemia was analyzed using weighted logistic regression and weighted restricted cubic spline.

Results

We found an inverse relationship between subtotal catechins intake and hyperlipidemia prevalence in the third quartile [0.74 (0.56, 0.98), p = 0.04] compared with the first quartile. The prevalence of hyperlipidemia and total flavan-3-ol intake in the third quartile were inversely correlated [0.76 (0.59, 0.98), p = 0.03]. Total anthocyanin intake was inversely related to the prevalence of hyperlipidemia in the third quartile [0.77 (0.62, 0.95), p = 0.02] and the fourth quartile [0.77 (0.60, 0.98), p = 0.04]. The prevalence of hyperlipidemia was negatively correlated with total flavonols intake in the fourth quartile [0.75 (0.60, 0.94), p = 0.02]. Using restricted cubic splines analysis, we found that subtotal catechins intake and total flavan-3-ol intake had a nonlinear relationship with the prevalence of hyperlipidemia.

Conclusion

Our study may provide preliminary research evidence for personalizing improved dietary habits to reduce the prevalence of hyperlipidemia.

Autoclaving-treated germinated brown rice relieves hyperlipidemia by modulating gut microbiota in humans

Introduction

Germinated brown rice is a functional food with a promising potential for alleviating metabolic diseases. This study aimed to explore the hypolipidemic effects of autoclaving-treated germinated brown rice (AGBR) and the underlying mechanisms involving gut microbiota.

Methods

Dietary intervention with AGBR or polished rice (PR) was implemented in patients with hyperlipidemia for 3 months, and blood lipids were analyzed. Nutritional characteristics of AGBR and PR were measured and compared. Additionally, 16S rDNA sequencing was performed to reveal the differences in gut microbiota between the AGBR and PR groups.

Results

AGBR relieves hyperlipidemia in patients, as evidenced by reduced levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein-B, and elevated levels of high-density lipoprotein cholesterol and apolipoprotein-A1. In terms of nutrition, AGBR had significantly higher concentrations of free amino acids (10/16 species), γ-aminobutyric acid, resistant starch, soluble dietary fiber, and flavonoids (11/13 species) than PR. In addition, higher microbial abundance, diversity, and uniformity were observed in the AGBR group than in the PR group. At the phylum level, AGBR reduced Firmicutes, Proteobacteria, Desulfobacterota, and Synergistota, and elevated Bacteroidota and Verrucomicrobiota. At the genus level, AGBR elevated Bacteroides, Faecalibacterium, Dialister, Prevotella, and Bifidobacterium, and reduced Escherichia-Shigella, Blautia, Romboutsia, and Turicibacter.

Discussion

AGBR contributes to the remission of hyperlipidemia by modulating the gut microbiota.

Sideritis raeseri-Modified Coatings on Ti-6Al-4V as a Carrier for Controlled Delivery Systems of Active Substances

The search for the ideal metallic material for an implant is still a difficult challenge for scientists due to the phenomenon of corrosion and the consequent disruption of the implant structure. Prevention is the application of coatings that protect the implant, activate the tissues for faster regeneration, and also prevent inflammation through antibacterial and antiviral effects. The present study focuses on the selection of components for a Ti-6Al-4V alloy coating. These days, researchers are taking an intense interest in extracts of natural origin. It was decided to take a look at Sideritis raeseri, which contains vitamins and valuable elements and is rich in polyphenols, as well as antioxidants. The composition of coatings based on a PEG polymer reinforced with brushite and the S. raeseri extract with the proteins L-carnosine, fibroin, or sericin was developed. The samples were subjected to detailed physiochemical analysis, including potentiometry and electrical conductivity analysis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and UV-VIS spectroscopy. The study demonstrated that polyphenols were successfully released from the coatings during incubation in vitro. The osteointegration process can be supported by a number of factors, such as the release of polyphenols from implant coatings to prevent bacterial, viral, and fungal infections. Subjecting the samples to 14 days of incubation demonstrated their interactions with the incubation fluids, an ion exchange between the medium and the materials. An analysis of the surface morphology exhibited the presence of brushite crystals and their increased number after incubation, indicating the bioactivity of the formed coatings.

Epigallocatechin gallate alleviated the in vivo toxicity of ZnO nanoparticles to mouse intestine

To evaluate the oral toxicity of nanoparticles (NPs), it is necessary to consider the interactions between NPs and nutrient molecules. Recently, we reported that epigallocatechin gallate (EGCG), a healthy component in green tea, alleviated the toxicity of ZnO NPs to 3D Caco-2 spheroids in vitro. The present study investigated the combined effects of EGCG and ZnO NPs to mice in vivo. Mice were administrated with 35 or 105 mg/kg bodyweight ZnO NPs with or without the presence of 80 mg/kg bodyweight EGCG via gastric route, once a day, for 21 days, and the influences of EGCG on the toxicity of ZnO NPs to intestine were investigated. We found that EGCG altered the colloidal properties of ZnO NPs both in water and artificial intestine juice. As expected, ZnO NPs induced toxicological effects, such as decreased bodyweight, higher Chiu's scores, and ultrastructural changes in intestine, whereas EGCG alleviated these effects. Combined exposure to EGCG and ZnO NPs also changed trace element levels in mouse intestine. For example, the levels of Ti, Co, and Ni were only significantly elevated after co-exposure to EGCG and ZnO NPs, and Fe levels were only significantly decreased by ZnO NPs. Western blot analysis suggested that tight junction (TJ) and endoplasmic reticulum (ER) proteins were elevated by ZnO NPs, but EGCG inhibited this trend. Combined, these data suggested that gastric exposure to ZnO NPs induced intestinal damage, trace element imbalance, and TJ/ER protein expression in mouse intestine, whereas EGCG alleviated these effects of ZnO NPs.

Ethanol Extract of Limonium bicolor Improves Dextran Sulfate Sodium-Induced Ulcerative Colitis by Alleviating Inflammation and Restoring Gut Microbiota Dysbiosis in Mice

Ulcerative colitis (UC) is a kind of inflammatory bowel condition characterized by inflammation within the mucous membrane, rectal bleeding, diarrhea, and pain experienced in the abdominal region. Existing medications for UC have limited treatment efficacy and primarily focus on symptom relief. Limonium bicolor (LB), an aquatic traditional Chinese medicine (TCM), exerts multi-targeted therapeutic effects with few side effects and is used to treat anemia and hemostasis. Nevertheless, the impact of LB on UC and its mechanism of action remain unclear. Therefore, the objective of this study was to investigate the anti-inflammatory effects and mechanism of action of ethanol extract of LB (LBE) in lipopolysaccharide-induced RAW 264.7 macrophages and dextran sulfate sodium (DSS)-induced UC. The results showed that LBE suppressed the secretion of cytokines in LPS-stimulated RAW 264.7 cells in a dose-dependent manner. LBE had protective effects against DSS-induced colitis in mice, decreased the disease activity index (DAI) score, alleviated symptoms, increased colon length, and improved histological characteristics, thus having protective effects against DSS-induced colitis in mice. In addition, it reversed disturbances in the abundance of proteobacteria and probiotics such as Lactobacillus and Blautia in mice with DSS-induced UC. Based on the results of network pharmacology analysis, we identified four main compounds in LBE that are associated with five inflammatory genes (Ptgs2, Plg, Ppar-γ, F2, and Gpr35). These results improve comprehension of the biological activity and functionality of LB and may facilitate the development of LB-based compounds for the treatment of UC.

Storage stability and degradation mechanism of xanthohumol in Humulus lupulus L. and beer

Xanthohumol (XN), possessing potent physiological activity, is exclusively derived from hops (Humulus lupulus L.) and exhibits high instability. However, its inherent instability often results in degradation during storage, leading to a decline in its activity due to the formation of various products. This study aimed to explore the stability of XN in beer under different storage conditions, establish or clarify degradation kinetic models, and understand the degradation mechanism. Our findings revealed that XN would degrade rapidly when exposed to high temperature and light. Its degradation followed a first-order kinetic model, involving reactions such as isomerization, hydration and ortho-position cyclization, resulting in the formation of five products. These insights shed light on the factors and mechanisms underlying the instability and degradability of XN, serving as a foundation for the development of a stable beer product enriched with functional XN.

Mechanism of Dihydromyricetin-Induced Reduction of Furfural Derived from the Amadori Compound: Formation of Adducts between Dihydromyricetin and Furfural or Its Precursors

Dihydromyricetin (DMY) was employed to reduce the yield of furfural derived from the Amadori rearrangement product of l-threonine and d-xylose (Thr-ARP) by trapping Thr-ARP, 3-deoxyxyosone (3-DX), and furfural to form adducts. The effect of different concentrations of DMY at different pH values and temperatures on the reduction of furfural production was studied, and the results showed that DMY could significantly reduce furfural production at higher pH (pH 5-7) and lower temperature (110 °C). Through the surface electrostatic potential analysis by Gaussian, a significant enhancement of the C6 nucleophilic ability at higher pH (pH ≥ 5) was observed on DMY with hydrogen-dissociated phenol hydroxyl. The nucleophilic ability of DMY led to its trapping of Thr-ARP, 3-DX, and furfural with the generation of the adducts DMY-Thr-ARP, DMY-3-DX, and DMY-furfural. The formation of the DMY-Thr-ARP adduct slowed the degradation of Thr-ARP, caused the decrease of the 3-DX yield, and thereby inhibited the conversion of 3-DX to furfural. Therefore, DMY-Thr-ARP was purified, and the structure was identified by nuclear magnetic resonance (NMR). The results confirmed that C6 or C8 of DMY and carbonyl carbon in Thr-ARP underwent a nucleophilic addition reaction to form the DMY-Thr-ARP adduct. In combination with the analysis results of Gaussian, most of the DMY-Thr-ARP adducts were calculated to be C6-DMY-Thr-ARP. Furthermore, the formation of DMY-furfural caused furfural consumption. The formation of the adducts also shunted the pathway of both Thr-ARP and 3-DX conversion to furfural, resulting in a decrease in the level of furfural production.

Integrated chemical characterization, metabolite profiling, and pharmacokinetics analysis of Zhijun Tangshen Decoction by UPLC-Q/TOF-MS

Diabetic nephropathy (DN) is the main cause of end-stage renal disease worldwide and a major public issue affecting the health of people. Therefore, it is essential to explore effective drugs for the treatment of DN. In this study, the traditional Chinese medicine (TCM) formula, Zhijun Tangshen Decoction (ZJTSD), a prescription modified from the classical formula Didang Decoction, has been used in the clinical treatment of DN. However, the chemical basis underlying the therapeutic effects of ZJTSD in treating DN remains unknown. In this study, compounds of ZJTSD and serum after oral administration in rats were identified and analyzed using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). Meanwhile, a semi-quantitative approach was used to analyze the dynamic changes in the compounds of ZJTSD in vivo. UPLC-Q/TOF-MS analysis identified 190 compounds from ZJTSD, including flavonoids, anthraquinones, terpenoids, phenylpropanoids, alkaloids, and other categories. A total of 156 xenobiotics and metabolites, i.e., 51 prototype compounds and 105 metabolites, were identified from the compounds absorbed into the blood of rats treated with ZJTSD. The results further showed that 23 substances with high relative content, long retention time, and favorable pharmacokinetic characteristics in vivo deserved further investigations and validations of bioactivities. In conclusion, this study revealed the chemical basis underlying the complexity of ZJTSD and investigated the metabolite profiling and pharmacokinetics of ZJTSD-related xenobiotics in rats, thus providing a foundation for further investigation into the pharmacodynamic substance basis and metabolic regulations of ZJTSD.

Tissue distribution and pharmacokinetics of isoxanthohumol from hops in rodents

Vegetables and fruits contain prenylflavonoids with biological functions that might improve human health. The prenylflavonoid isoxanthohumol (IXA) and its derivative, 8-prenylnaringenin (8-PN), have beneficial activities, including anti-cancer effects and suppression of insulin resistance. However, their pharmacokinetic profile is unclear. Previous studies suggested flavonoids have low systemic availability and are excreted via the feces. Therefore, this study investigated the tissue distribution dynamics of high-purity IXA (>90%) from hops administered orally, either singly (50 mg/kg body weight [BW]) or daily for 14 days (30 mg/kg BW), to mice. High-pressure liquid chromatography demonstrated that IXA was absorbed rapidly after a single administration and reached plasma maximum concentration (C max) (3.95 ± 0.81 μmol/L) by 0.5 h. IXA was present at high levels in the liver compared with the kidney, pancreas, lung, skeletal muscle, spleen, thymus, and heart. The highest IXA level after 14 days of IXA ingestion was observed in the liver, followed by the kidney, thymus, spleen, lung, and brain. There was no significant difference in IXA accumulation in tissues between the single and multiple dose groups. Analyses of the livers of rats treated with different concentrations of IXA (112.5-1500 mg/kg BW) once a day for 28 days demonstrated that IXA accumulated dose-dependently with a correlation coefficient of .813. The accumulation of 8-PN was dependent on the intake period but not the intake amount of IXA (correlation coefficient -.255). In summary, IXA and 8-PN were detected in tissues and organs up to 24 h after ingestion, suggesting that orally ingested IXA might have health benefits as a nutraceutical.

Rheumatoid arthritis molecular targets and their importance to flavonoid-based therapy

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune, inflammatory, and systemic condition that primarily affects the synovial joints and adjacent tissues, including bone, muscle, and tendons. The World Health Organization recognizes RA as one of the most prevalent chronic inflammatory diseases. In the last decade, there was an expansion on the available RA therapeutic options which aimed to improve patient's quality of life. Despite the extensive research and the emergence of new therapeutic approaches and drugs, there are still significant unwanted side effects associated to these drugs and still a vast number of patients that do not respond positively to the existing therapeutic strategies. Over the years, several references to the use of flavonoids in the quest for new treatments for RA have emerged. This review aimed to summarize the existing literature about the flavonoids' effects on the major pathogenic/molecular targets of RA and their potential use as lead compounds for the development of new effective molecules for RA treatment. It is demonstrated that flavonoids can modulate various players in synovial inflammation, regulate immune cell function, decrease synoviocytes proliferation and balance the apoptotic process, decrease angiogenesis, and stop/prevent bone and cartilage degradation, which are all dominant features of RA. Although further investigation is necessary to determine the effectiveness of flavonoids in humans, the available data from in vitro and in vivo models suggest their potential as new disease-modifying anti-rheumatic drugs. This review highlights the use of flavonoids as a promising avenue for future research in the treatment of RA.

Research Progress on Extraction and Detection Technologies of Flavonoid Compounds in Foods

Flavonoid compounds have a variety of biological activities and play an essential role in preventing the occurrence of metabolic diseases. However, many structurally similar flavonoids are present in foods and are usually in low concentrations, which increases the difficulty of their isolation and identification. Therefore, developing and optimizing effective extraction and detection methods for extracting flavonoids from food is essential. In this review, we review the structure, classification, and chemical properties of flavonoids. The research progress on the extraction and detection of flavonoids in foods in recent years is comprehensively summarized, as is the application of mathematical models in optimizing experimental conditions. The results provide a theoretical basis and technical support for detecting and analyzing high-purity flavonoids in foods.

Food phenolics and Lactiplantibacillus plantarum

Phenolic compounds are important constituents of plant food products. These compounds play a key role in food characteristics such as flavor, astringency and color. Lactic acid bacteria are naturally found in raw vegetables, being Lactiplantibacillus plantarum the most commonly used commercial starter for the fermentation of plant foods. Hence, the metabolism of phenolic compounds of L. plantarum has been a subject of study in recent decades. Such studies confirm that L. plantarum, in addition to presenting catalytic capacity to transform aromatic alcohols and phenolic glycosides, exhibits two main differentiated metabolic routes that allow the biotransformation of dietary hydroxybenzoic and hydroxycinnamic acid-derived compounds. These metabolic pathways lead to the production of new compounds with new biological and organoleptic properties. The described metabolic pathways involve the action of specialized esterases, decarboxylases and reductases that have been identified through genetic analysis and biochemically characterized. The purpose of this review is to provide a comprehensive and up-to-date summary of the current knowledge of the metabolism of food phenolics in L. plantarum.

Sea Buckthorn Flavonoid Extracted by High Hydrostatic Pressure Inhibited IgE-Stimulated Mast Cell Activation through the Mitogen-Activated Protein Kinase Signaling Pathway

Sea buckthorn (Hippophaë rhamnoides L.), as one of the Elaeagnaceae family, has the significant function of anti-tumor, anti-inflammation, anti-oxidation, and other physiological activities. High hydrostatic pressure (HHP) extraction has the advantages of being easy and efficient, while maintaining biological activity. In this study, sea buckthorn flavonoid (SBF) was extracted with HHP and purified sea buckthorn flavonoid (PSBF) was isolated by AB-8 macroporous resin column. HPLC analysis was used to quantified them. In addition, the effect of anti-allergy in RBL-2H3 cells by SBF, PSBF, and their flavonoid compounds was evaluated. The results demonstrate the conditions for obtaining the maximum flavonoid amount of SBF: 415 MPa for 10 min, 72% ethanol concentration, and a liquid to solid ratio of 40 mL/g, which increased the purity from 1.46% to 13.26%. Both SBF and PSBF included rutin, quercitrin, quercetin, isorhamnetin, and kaempferol. In addition, quercitrin, kaempferol, and SBF could regulate Th1/Th2 cytokine balance. Moreover, extracellular Ca2+ influx was reduced by quercitrin and PSBF. Furthermore, rutin, quercetin, iso-rhamnetin, and SBF could also inhibit P-p38 and P-JNK expression, thereby suppressing the phosphorylation of the MAPK signaling pathways. Overall, SBF is effective for relieving food allergy and might be a promising anti-allergic therapeutic agent.

Screening the components in multi-biological samples and the comparative pharmacokinetic study in healthy and depression model rats of Suan-Zao-Ren decoction combined with a network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Suanzaoren Decoction (SZRD) is a classic traditional Chinese prescription, which has been commonly used for treating insomnia, depression and other nerve system diseases for a long time.

AIM OF THIS STUDY

The present study aimed to explore the metabolic profiles in multi-biological samples and pharmacokinetic mechanism between healthy and depression model rats combined with a network pharmacology approach after administration of SZRD.

MATERIALS AND METHODS

In our study, an ultra-high performance liquid chromatography (UPLC)-Q-Exactive Orbitrap Mass Spectrometry method was firstly used to study the prototype components and metabolites of SZRD in plasma, brain, urine, and feces between healthy and depressed rats. The possible metabolic pathways were also speculated. Then a network pharmacological study was conducted on the components in the plasma of model rats. According to the above components screened by network pharmacology and the other reported representative active components, the comparative pharmacokinetic study was established for the simultaneous determination of mangiferin, spinosin, ferulic acid, liquiritin, formononetin. magnoflorine and isoliquiritin between healthy and depression model rats. Finally, molecular docking was used to validate the binding affinity between key potential targets and active components in pharmacokinetics.

RESULTS

A total of 115 components were identified in healthy rats, and 101 components were identified in model rats. The prototype components and metabolites in plasma, brain, urine, and feces were also distinguished. The main metabolic pathways included phase I and phase II metabolic reactions, such as dehydrogenation, oxidation, hydroxylation, gluconaldehyde conjugation, glutathione conjugation and so on. These results provided a basis for the further study of antidepressive pharmacokinetic and pharmacological action in SZRD. Then, according to the degree value of network pharmacological study, it was predicted that 10 components and 10 core targets, which involved in the critical pathways such as neuroactive ligand-receptor interaction, cyclic adenosine monophosphate (cAMP) signaling pathway, serotonergic synapse, phosphatidylinositol-3 kinase (PI3K)-Akt signaling pathway, etc. Finally, the established pharmacokinetic method was successfully applied to compare the pharmacokinetic behavior of these 7 active components in plasma of healthy and depressed rats after oral administration of SZRD. It showed that except magnoflorine, the pharmacokinetic parameters of each component were different between healthy and depressed rats. Molecular docking analysis also indicated that the active compounds in pharmacokinetics could bind tightly to the key targets of network pharmacological study.

CONCLUSION

This study may provide important information for studying the action mechanism of SZRD in treating depression.

Gut microbiome carbon and sulfur metabolisms support Salmonella during pathogen infection

Salmonella enterica serovar Typhimurium is a pervasive enteric pathogen and an ongoing global threat to public health. Ecological studies in the Salmonella impacted gut remain underrepresented in the literature, discounting the microbiome mediated interactions that may inform Salmonella physiology during colonization and infection. To understand the microbial ecology of Salmonella remodeling of the gut microbiome, here we performed multi-omics approaches on fecal microbial communities from untreated and Salmonella -infected mice. Reconstructed genomes recruited metatranscriptomic and metabolomic data providing a strain-resolved view of the expressed metabolisms of the microbiome during Salmonella infection. This data informed possible Salmonella interactions with members of the gut microbiome that were previously uncharacterized. Salmonella- induced inflammation significantly reduced the diversity of transcriptionally active members in the gut microbiome, yet increased gene expression was detected for 7 members, with Luxibacter and Ligilactobacillus being the most active. Metatranscriptomic insights from Salmonella and other persistent taxa in the inflamed microbiome further expounded the necessity for oxidative tolerance mechanisms to endure the host inflammatory responses to infection. In the inflamed gut lactate was a key metabolite, with microbiota production and consumption reported amongst transcriptionally active members. We also showed that organic sulfur sources could be converted by gut microbiota to yield inorganic sulfur pools that become oxidized in the inflamed gut, resulting in thiosulfate and tetrathionate that supports Salmonella respiration. Advancement of pathobiome understanding beyond inferences from prior amplicon-based approaches can hold promise for infection mitigation, with the active community outlined here offering intriguing organismal and metabolic therapeutic targets.

Flavonoid Metabolites in Serum and Urine after the Ingestion of Selected Tropical Fruits

The serum concentration and urinary excretion of flavonoids after the ingestion of guava, pineapple, and pomelo were determined using liquid chromatography-mass spectroscopy (LC-MS/MS). Each group of healthy volunteers was given 200 g of fresh fruit after overnight fasting and a 24-h flavonoid-free diet. The results demonstrate that only the glucuronic-conjugated metabolites of luteolin, quercetin, kaempferol, and myricetin were detected after fruit ingestion. The metabolites were first detected after 2 h, with the time to maximum concentration (Tmax) at 6 h. The most abundant metabolites for guava, pineapple, and pomelo were the glucuronide metabolites of quercetin (AUC0-8 5.4 ± 1.3 μg·h/mL), kaempferol (AUC0-8 9.9 ± 2.3 μg·h/mL), and luteolin (AUC0-8 6.4 ± 1.1 μg·h/mL), respectively. The flavonoids found in the 24-h urinary excretions were glucuronic- and mainly sulfate-conjugated metabolites. Quercetin metabolites were the most abundant after guava and pineapple ingestion, accounting for 900 and 700 μg, respectively. Luteolin metabolites were the most abundant after pomelo ingestion, accounting for 450 μg. The serum and urinary metabolite profiles suggested that guava and pineapple are good sources of quercetin, pineapple is a good source of kaempferol, and pomelo is a good source of luteolin. The study of flavonoid profiles may provide information for the selection of fruits as functional foods for their health benefits to help with various health conditions.

Metabolic profiles of Fufang Xiling Jiedu capsule in rats by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry

Fufang Xiling Jiedu capsule (FXJC), a traditional Chinese medicine that evolved from "Yinqiao Powder", is widely used for the treatment of cold and influenza. However, due to a lack of in vivo metabolism research, the chemical components responsible for the therapeutic effects still remain unclear. Hence, this study aimed to describe the metabolic profiles of the FXJC in rat plasma, urine, and feces. A combined data mining strategy based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was employed and 201 xenobiotics, including 117 prototype components and 84 metabolites were detected. Phenolic acids, flavonoids, triterpenes, and lignans were prominent ingredients absorbed in vivo, and the major metabolic pathways of the detected metabolites were glucuronidation, sulfation, methylation, and oxidation. This is the first systematic study on the metabolism of the FXJC in vivo, providing valuable information for future studies on the efficacy, toxicity, and mechanism of the FXJC.

New insights of flavonoid glycosidases and their application in food industry

Flavonoids are significant natural nutraceuticals and a key component of dietary supplements. Given that flavonoid glycosides are more plentiful in nature and less beneficial to human health than their aglycone counterparts, they serve as potential precursors for flavonoid production. Glycosidases have shown substantial potential within the food industry, particularly in enhancing the organoleptic properties of juice, wine, and tea. When applied to food resources, glycosidases can amplify their biological activities, thereby improving the performance of functional foods. This review provides up-to-date information on flavonoid glycosidases, including their catalytic mechanisms, biochemical properties, and natural sources, as well as their applications within the food industry. The use of flavonoid glycosidases in improving food quality is also reviewed.

Divergent metabolism of two lychee (Litchi chinensis Sonn.) pulp flavonols and their modulatory effects on gut microbiota: Discovery of hydroxyethylation in vitro colonic fermentation

Quercetin 3-O-rutinose-7-O-α-l-rhamnoside (QRR), a characteristic lychee pulp flavonoid, has been linked to diverse bioactivities involving microbial metabolism. By integrating colonic fermentation and mass spectrometry, the catabolites including 7-O-hydroxyethyl-isorhamnetin and 3'-amino-4'-O-methyl-7-O-hydroxyethyl-isorhamnetin were unprecedently identified and unique to QRR metabolism, relative to the structural analog quercetin 3-O-rutinoside (QR) metabolism. These above-described metabolites highlighted a special biotransformation hydroxyethylation in QRR catabolism. QRR was partially deglycosylated into quercetin 3-O-glucoside-7-O-α-l-rhamnoside potentially catalyzed by Bacteroides. QR was more directly degradable to aglycone during colonic fermentation than are QRR. Unlike with QR fermentation, equivalent QRR effectively upregulated concentrations of propionic and butyric acids that were highly relevant with Faecalibacterium and Coprococcus. After fermentation, the relative abundances of Bacteroides uniformis (0.03%) and Akkermansia muciniphila (0.13%) were only upregulated by QRR among all fermentation groups, leading to the enrichments of the corresponding genera. These results further reveal the relationship between flavonoid structures and metabolic characteristics.

The role of Caenorhabditis elegans in the discovery of natural products for healthy aging

Covering: 2012 to 2023The human population is aging. Thus, the greatest risk factor for numerous diseases, such as diabetes, cancer and neurodegenerative disorders, is increasing worldwide. Age-related diseases do not typically occur in isolation, but as a result of multi-factorial causes, which in turn require holistic approaches to identify and decipher the mode of action of potential remedies. With the advent of C. elegans as the primary model organism for aging, researchers now have a powerful in vivo tool for identifying and studying agents that effect lifespan and health span. Natural products have been focal research subjects in this respect. This review article covers key developments of the last decade (2012-2023) that have led to the discovery of natural products with healthy aging properties in C. elegans. We (i) discuss the state of knowledge on the effects of natural products on worm aging including methods, assays and involved pathways; (ii) analyze the literature on natural compounds in terms of their molecular properties and the translatability of effects on mammals; (iii) examine the literature on multi-component mixtures with special attention to the studied organisms, extraction methods and efforts regarding the characterization of their chemical composition and their bioactive components. (iv) We further propose to combine small in vivo model organisms such as C. elegans and sophisticated analytical approaches ("wormomics") to guide the way to dissect complex natural products with anti-aging properties.

Huangqin Tea Total Flavonoids-Gut Microbiota Interactions: Based on Metabolome and Microbiome Analysis

Huangqin tea (HQT), a Non-Camellia Tea derived from the aerial parts of Scutellaria baicalensis, is widely used in the north of China. The intervention effects of HQT on intestinal inflammation and tumors have been found recently, but the active ingredient and mechanism of action remain unclear. This study aimed to investigate the interactions between the potential flavonoid active components and gut microbiota through culture experiments in vitro combined with HPLC-UV, UPLC-QTOF-MS, and 16S rDNA sequencing technology. The results showed that the HQT total flavonoids were mainly composed of isocarthamidin-7-O-β-D-glucuronide, carthamidin-7-O-β-D-glucuronide, scutellarin, and others, which interact closely with gut microbiota. After 48 h, the primary flavonoid glycosides transformed into corresponding aglycones with varying degrees of deglycosylation. The composition of the intestinal microbiota was changed significantly. The beneficial bacteria, such as Enterococcus and Parabacteroides, were promoted, while the harmful bacteria, such as Shigella, were inhibited. The functional prediction results have indicated notable regulatory effects exerted by total flavonoids and scutellarin on various pathways, including purine metabolism and aminoacyl-tRNA biosynthesis, among others, to play a role in the intervention of inflammation and tumor-related diseases. These findings provided valuable insights for further in-depth research and investigation of the active ingredients, metabolic processes, and mechanisms of HQT.

Flavonoids with Anti-Herpes Simplex Virus Properties: Deciphering Their Mechanisms in Disrupting the Viral Life Cycle

The herpes simplex virus (HSV) is a double-stranded DNA human virus that causes persistent infections with recurrent outbreaks. HSV exists in two forms: HSV-1, responsible for oral herpes, and HSV-2, primarily causing genital herpes. Both types can lead to significant complications, including neurological issues. Conventional treatment, involving acyclovir and its derivatives, faces challenges due to drug resistance. This underscores the imperative for continual research and development of new drugs, with a particular emphasis on exploring the potential of natural antivirals. Flavonoids have demonstrated promise in combating various viruses, including those within the herpesvirus family. This review, delving into recent studies, reveals the intricate mechanisms by which flavonoids decode their antiviral capabilities against HSV. By disrupting key stages of the viral life cycle, such as attachment to host cells, entry, DNA replication, latency, and reactivation, flavonoids emerge as formidable contenders in the ongoing battle against HSV infections.

Dietary flavonoid myricetin 3-O-galactoside suppresses α-melanocyte stimulating hormone-induced melanogenesis in B16F10 melanoma cells by regulating PKA and ERK1/2 activation

Melanogenesis is the process where skin pigment melanin is produced through tyrosinase activity. Overproduction of melanin causes skin disorders such as freckles, spots, and hyperpigmentation. Myricetin 3-O-galactoside (M3G) is a dietary flavonoid with reported bioactivities. M3G was isolated from Limonium tetragonum and its anti-melanogenic properties were investigated in α-melanocyte stimulating hormone-stimulated B16F10 melanoma cells. The in vitro anti-melanogenic capacity of M3G was confirmed by inhibited tyrosinase and melanin production. M3G-mediated suppression of melanogenic proteins, tyrosinase, microphthalmia-associated transcription factor (MITF), and tyrosinase-related proteins (TRP)-1 and TRP-2, were confirmed by mRNA and protein levels, analyzed by RT-qPCR and Western blot, respectively. Furthermore, M3G suppressed Wnt signaling through the inhibition of PKA phosphorylation. M3G also suppressed the consequent phosphorylation of CREB and nuclear levels of MITF. Analysis of MAPK activation further revealed that M3G increased the activation of ERK1/2 while p38 and JNK activation remained unaffected. Results showed that M3G suppressed melanogenesis in B16F10 cells by decreasing tyrosinase production and therefore inhibiting melanin formation. A possible action mechanism was the suppression of CREB activation and upregulation of ERK phosphorylation which might cause the decreased nuclear levels of MITF. In conclusion, M3G was suggested to be a potential nutraceutical with anti-melanogenic properties.

Enzymatic β-elimination in natural product O- and C-glycoside deglycosylation

Biological degradation of natural product glycosides involves, alongside hydrolysis, β-elimination for glycosidic bond cleavage. Here, we discover an O-glycoside β-eliminase (OGE) from Agrobacterium tumefaciens that converts the C3-oxidized O-β-D-glucoside of phloretin (a plant-derived flavonoid) into the aglycone and the 2-hydroxy-3-keto-glycal elimination product. While unrelated in sequence, OGE is structurally homologous to, and shows effectively the same Mn2+ active site as, the C-glycoside deglycosylating enzyme (CGE) from a human intestinal bacterium implicated in β-elimination of 3-keto C-β-D-glucosides. We show that CGE catalyzes β-elimination of 3-keto O- and C-β-D-glucosides while OGE is specific for the O-glycoside substrate. Substrate comparisons and mutagenesis for CGE uncover positioning of aglycone for protonic assistance by the enzyme as critically important for C-glycoside cleavage. Collectively, our study suggests convergent evolution of active site for β-elimination of 3-keto O-β-D-glucosides. C-Glycoside cleavage is a specialized feature of this active site which is elicited by substrate through finely tuned enzyme-aglycone interactions.

Citrus flavonoids and adhesion molecules: Potential role in the management of atherosclerosis

Atherosclerosis as a chronic inflammatory disorder is accompanied with oxidative stress which causes a high morbidity and mortality. Adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, and E-selectin, are amongst the most important contributors in atherosclerosis. In such cases, dietary interventions with functional foods containing natural antioxidant and anti-inflammatory constituents are of a great interest. Citrus fruits are rich sources of flavonoids as natural pigments with potent antioxidant and anti-inflammatory activities. This study aims to review current evidence regarding the role of citrus flavonoids in the management of atherosclerosis with a focus on their effect on adhesion molecules. Electronic databases including PubMed, Scopus, and Web of Science were searched with the names of adhesion molecules and flavonoids from inception until January 2023. The included articles highly support the beneficial effects of citrus flavonoids in preclinical models of atherosclerosis. Quercetin, naringin and naringenin, hesperidin and hesperetin, nobiletin, rutin, luteolin, apigenin, and kaempferol are the most common flavonoids in citrus fruits which could modulate adhesion molecules including ICAM-1, VCAM-1, E-selectin, and P-selectin. Additionally, markers of chronic inflammation such as interleukins, tumor necrosis factor-α, nuclear factor-κB, and nitric oxide signaling, as well as oxidative stress markers like superoxide dismutase and glutathione were all normalized upon administration of citrus flavonoids. Conclusively, this review confirms the modulatory role of flavonoids on adhesion molecules in atherosclerosis based on the preclinical evaluations. Thus, citrus fruits can be further studied in atherosclerotic patients regarding their activity in reducing adhesion molecules.

Microbial glycosylation of antitubercular agent chlorflavonin

Flavonoids have shown health-benefiting properties, such as antioxidative and anti-inflammatory activities, and are commonly used as nutraceuticals and pharmaceuticals. Although flavonoids are predominantly identified from plants, several filamentous fungal species have also been reported to produce bioactive flavonoids, including chlorflavonin from Aspergillus candidus, a novel halogenated flavonoid with potent antifungal and antitubercular (anti-TB) activities. Unfortunately, the low water-solubility of this molecule may hinder its bioavailability. Glycosylation is an effective method to enhance the polarity of natural products and alter their physicochemical properties. This work focuses on the development of novel water-soluble chlorflavonin derivatives to combat the threat of drug-resistant tuberculosis. In this study, we first increased the production titer of chlorflavonin in A. candidus NRRL 5214 by optimizing the fermentation and purification processes. Next, chlorflavonin-5-O-β-d-glucuronopyranoside (1) and chlorflavonin-7-O-4″-O-methyl-β-d-glucopyranoside (2) were produced from chlorflavonin using Streptomyces chromofuscus ATCC 49982 and Beauveria bassiana ATCC 7159, respectively. Compared to chlorflavonin (4.38 ± 0.54 mg/L in water), the water solubility of the two new glycosides was determined to be 117.86 ± 4.81 mg/L (1) and 124.34 ± 9.13 mg/L (2), respectively. This study provides a promising method to create water-soluble glycosides of chlorflavonin for the development of novel anti-TB drugs.

Plant Polyphenols and Their Potential Benefits on Cardiovascular Health: A Review

Fruits, vegetables, and other food items contain phytochemicals or secondary metabolites which may be considered non-essential nutrients but have medicinal importance. These dietary phytochemicals exhibit chemopreventive and therapeutic effects against numerous diseases. Polyphenols are secondary metabolites found in vegetables, fruits, and grains. These compounds exhibit several health benefits such as immune modulators, vasodilators, and antioxidants. This review focuses on recent studies on using dietary polyphenols to treat cardiovascular disorders, atherosclerosis, and vascular endothelium deficits. We focus on exploring the safety of highly effective polyphenols to ensure their maximum impact on cardiac abnormalities and discuss recent epidemiological evidence and intervention trials related to these properties. Kaempferol, quercetin, and resveratrol prevent oxidative stress by regulating proteins that induce oxidation in heart tissues. In addition, polyphenols modulate the tone of the endothelium of vessels by releasing nitric oxide (NO) and reducing low-density lipoprotein (LDL) oxidation to prevent atherosclerosis. In cardiomyocytes, polyphenols suppress the expression of inflammatory markers and inhibit the production of inflammation markers to exert an anti-inflammatory response. Consequently, heart diseases such as strokes, hypertension, heart failure, and ischemic heart disease could be prevented by dietary polyphenols.

Research Progress of Flavonoids Regulating Endothelial Function

The endothelium, as the guardian of vascular homeostasis, is closely related to the occurrence and development of cardiovascular diseases (CVDs). As an early marker of the development of a series of vascular diseases, endothelial dysfunction is often accompanied by oxidative stress and inflammatory response. Natural flavonoids in fruits, vegetables, and Chinese herbal medicines have been shown to induce and regulate endothelial cells and exert anti-inflammatory, anti-oxidative stress, and anti-aging effects in a large number of in vitro models and in vivo experiments so as to achieve the prevention and improvement of cardiovascular disease. Focusing on endothelial mediation, this paper introduces the signaling pathways involved in the improvement of endothelial dysfunction by common dietary and flavonoids in traditional Chinese medicine and describes them based on their metabolism in the human body and their relationship with the intestinal flora. The aim of this paper is to demonstrate the broad pharmacological activity and target development potential of flavonoids as food supplements and drug components in regulating endothelial function and thus in the prevention and treatment of cardiovascular diseases. This paper also introduces the application of some new nanoparticle carriers in order to improve their bioavailability in the human body and play a broader role in vascular protection.

Research Progress of Protein-Based Bioactive Substance Nanoparticles

Bioactive substances exhibit various physiological activities-such as antimicrobial, antioxidant, and anticancer activities-and have great potential for application in food, pharmaceuticals, and nutraceuticals. However, the low solubility, chemical instability, and low bioavailability of bioactive substances limit their application in the food industry. Using nanotechnology to prepare protein nanoparticles to encapsulate and deliver active substances is a promising approach due to the abundance, biocompatibility, and biodegradability of proteins. Common protein-based nanocarriers include nano-emulsions, nano-gels, nanoparticles, and nano complexes. In this review, we give an overview of protein-based nanoparticle fabrication methods, highlighting their pros and cons. Additionally, we discuss the applications and current issues regarding the utilization of protein-based nanoparticles in the food industry. Finally, we provide perspectives on future development directions, with a focus on classifying bioactive substances and their functional properties.

Unraveling Obesity: Transgenerational Inheritance, Treatment Side Effects, Flavonoids, Mechanisms, Microbiota, Redox Balance, and Bioavailability-A Narrative Review

Obesity is known as a transgenerational vicious cycle and has become a global burden due to its unavoidable complications. Modern approaches to obesity management often involve the use of pharmaceutical drugs and surgeries that have been associated with negative side effects. In contrast, natural antioxidants, such as flavonoids, have emerged as a promising alternative due to their potential health benefits and minimal side effects. Thus, this narrative review explores the potential protective role of flavonoids as a natural antioxidant in managing obesity. To identify recent in vivo studies on the efficiency of flavonoids in managing obesity, a comprehensive search was conducted on Wiley Online Library, Scopus, Nature, and ScienceDirect. The search was limited to the past 10 years; from the search, we identified 31 articles to be further reviewed. Based on the reviewed articles, we concluded that flavonoids offer novel therapeutic strategies for preventing obesity and its associated co-morbidities. This is because the appropriate dosage of flavonoid compounds is able to reduce adipose tissue mass, the formation of intracellular free radicals, enhance endogenous antioxidant defences, modulate the redox balance, and reduce inflammatory signalling pathways. Thus, this review provides an insight into the domain of a natural product therapeutic approach for managing obesity and recapitulates the transgenerational inheritance of obesity, the current available treatments to manage obesity and its side effects, flavonoids and their sources, the molecular mechanism involved, the modulation of gut microbiota in obesity, redox balance, and the bioavailability of flavonoids. In toto, although flavonoids show promising positive outcome in managing obesity, a more comprehensive understanding of the molecular mechanisms responsible for the advantageous impacts of flavonoids-achieved through translation to clinical trials-would provide a novel approach to inculcating flavonoids in managing obesity in the future as this review is limited to animal studies.

New Evidence for Artemisia absinthium as an Alternative to Classical Antibiotics: Chemical Analysis of Phenolic Compounds, Screening for Antimicrobial Activity

Artemisia absinthium, an important herb of the Artemisia genus, was evaluated in this study for its potential as an alternative to classical antibiotics. The antimicrobial activity of methanol extracts of A. absinthium (MEAA) was evaluated using the broth microdilution method, revealing that A. absinthium exhibited broad-spectrum antibacterial and antifungal activity. Ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS) was used to analyze the chemical profile of the MEAA, with a focus on flavonoids, quinic acids, and glucaric acids. A total of 90 compounds were identified, 69 of which were described for the first time in A. absinthium. Additionally, a new class of caffeoyl methyl glucaric acids was identified. The main active compounds were quantified and screened for antimicrobial activity. A. absinthium was found to be rich in quinic acids and flavonoids. The screening for antimicrobial activity also revealed that salicylic acid, caffeic acid, casticin, and 3,4-dicaffeoylquinic acid had varying degrees of antimicrobial activity. The acute toxicity of MEAA was examined following OECD guidelines. The administration of 5000 mg/kg bw of MEAA did not result in mortality in male and female mice. Furthermore, there were no observed effects on the visceral organs or general behavior of the mice, demonstrating the good safety of MEAA. This study provides new evidence for the use of A. absinthium as an alternative to classical antibiotics in addressing the problem of bacterial resistance.

Flavonoids: Overview of Biosynthesis, Biological Activity, and Current Extraction Techniques

Recently, increased attention has been paid to natural sources as raw materials for the development of new added-value products. Flavonoids are a large family of polyphenols which include several classes based on their basic structure: flavanones, flavones, isoflavones, flavonols, flavanols, and anthocyanins. They have a multitude of biological properties, such as anti-inflammatory, antioxidant, antiviral, antimicrobial, anticancer, cardioprotective, and neuroprotective effects. Current trends of research and development on flavonoids relate to identification, extraction, isolation, physico-chemical characterization, and their applications to health benefits. This review presents an up-to-date survey of the most recent developments in the natural flavonoid classes, the biological activity of representative flavonoids, current extraction techniques, and perspectives.

The neuromodulatory effects of flavonoids and gut Microbiota through the gut-brain axis

Recent investigations show that dietary consumption of flavonoids could potentially confer neuroprotective effects through a variety of direct and indirect mechanisms. Numerous flavonoids have been shown to cross the BBB and accumulate within the central nervous system (CNS). Some of these compounds purportedly counteract the accumulation and deleterious effects of reactive oxygen species, fostering neuronal survival and proliferation by inhibiting neuroinflammatory and oxidative stress responses. Moreover, several studies suggest that gut microbiota may participate in regulating brain function and host behavior through the production and modulation of bioactive metabolites. Flavonoids may shape gut microbiota composition by acting as carbon substrates to promote the growth of beneficial bacteria that produce these neuroprotective metabolites, consequently antagonizing or suppressing potential pathogens. By influencing the microbiota-gut-brain axis through this selection process, flavonoids may indirectly improve brain health. This review examines the current state of research into the relationship between bioactive flavonoids, gut microbiota, and the gut-brain axis.

D-α-tocopherol polyethylene glycol 1000 succinate-based microemulsion delivery system: Stability enhancement of physicochemical properties of luteolin

In the present study, D-α-Tocopherol polyethylene glycol 1000 succinate-based self-microemulsifying drug delivery systems (TPGS-SMEDDS) were introduced to enhance the solubility and stability of luteolin. The ternary phase diagrams were constructed to obtain the maximum area of microemulsion and suitable formulations of TPGS-SMEDDS. The particle size distribution and polydispersity index of selected TPGS-SMEDDS were analyzed to be less than 100 nm and 0.4, respectively. The thermodynamic stability results suggested that the TPGS-SMEDDS was stable during the heat-cool and freeze-thaw cycle. Moreover, the TPGS-SMEDDS exhibited excellent encapsulation capacity (51.21 ± 4.39 to 85.71 ± 2.40%) and loading efficiency (61.46 ± 5.27 to 102.86 ± 2.88 mg/g) to luteolin. In addition, the TPGS-SMEDDS showed an admirable vitro release ability with a ratio of more than 88.40 ± 1.14% for luteolin in 24 h. Therefore, TPGS-based SMEDDS might provide an effective role for the oral administration of luteolin and holds promise as a potential delivery for poorly soluble bioactive compounds.

Engineering Escherichia coli for efficient and economic production of C-glycosylflavonoids by deleting YhhW and regulating pH

C-glycosylflavonoids have a number of pharmacological activities. An efficient method for the preparation of C-glycosylflavonoids is through metabolic engineering. Thus, it is important to prevent the degradation of C-glycosylflavonoids for producing C-glycosylflavonoids in the recombinant strain. In this study, two critical factors for the degradation of C-glycosylflavonoids were clarified. The quercetinase (YhhW) gene from Escherichia coli BL21(DE3) was expressed, purified, and characterized. YhhW effectively degraded quercetin 8-C-glucoside, orientin, and isoorientin, while the degradation of vitexin and isovitexin was not significant. Zn²⁺ can significantly reduce the degradation of C-glycosylflavonoids by inhibiting the activity of YhhW. pH was another key factor causing the degradation of C-glycosylflavonoids, and C-glycosylflavonoids were significantly degraded with pH exceeding 7.5 in vitro or in vivo. On this basis, two strategies, deleting YhhW gene from the genome of E. coli and regulating pH during the bioconversion, were developed to relieve the degradation of C-glycosylflavonoids. Finally, the total degradation rates for orientin and quercetin 8-C-glucoside decreased from 100 to 28% and 65% to 18%, respectively. The maximum yield of orientin reached 3353 mg/L with luteolin as substrate, and the maximum yield of quercetin 8-C-glucoside reached 2236 mg/L with quercetin as substrate. Therefore, the method described herein for relieving the degradation of C-glycosylflavonoids may be widely used for the biosynthesis of C-glycosylflavonoids in recombinant strains.

Targeting gut-brain axis by dietary flavonoids ameliorate aging-related cognition decline: Evidences and mechanisms

Aging-related cognitive impairment, mainly Alzheimer's disease (AD), has been widely studied. However, effective prevention and treatment methods are still lacking. In recent years, researchers have observed beneficial effects of plant-based supplements, such as flavonoids, on cognitive protection. This provides a new clue for the prevention of cognitive dysfunction. Studies have shown that dietary flavonoids have neuroprotective effects, but the mechanism is not clear. In this review, we systematically reviewed the research progress on the effects of dietary flavonoids on gut microbes and their metabolites, and concluded that flavonoids could improve cognitive function through the gut-brain axis. Flavonoids can be absorbed through the intestine, cross the blood-brain barrier, and enter the brain tissue. Flavonoids can inhibit the expression and secretion of inflammatory factors in brain tissue, reduce the damage caused by oxidative stress, clear neural damage proteins and inhibit neuronal apoptosis, thereby ameliorating age-related cognitive disorders. Future work will continue to explore the gut-brain axis and target genes regulated by flavonoids. In addition, clinical research and its mechanisms need to be further explored to provide solutions or advise for patients with cognitive impairment.

Nobiletin with AIEE Characteristics for Targeting Mitochondria and Real-Time Dynamic Tracking in Zebrafish

Nobiletin is a natural product with multiple physiological activities and is the main ingredient of Pericarpium Citri Reticulatae. We successfully discovered that nobiletin exhibits aggregation induced emission enhancement (AIEE) properties and it has significant advantages such as a large Stokes shift, good stability and excellent biocompatibility. The increase in methoxy groups endows nobiletin a greater fat-solubility, bioavailability and transport rate than the corresponding unmethoxylated flavones. Ulteriorly, cells and zebrafish were used to explore the application of nobiletin in biological imaging. It emits fluorescence in cells and is specifically targeted at mitochondria. Moreover, it has a noteworthy affinity for the digestive system and liver of zebrafish. Due to the unique AIEE phenomenon and stable optical properties of nobiletin, it paves the way for discovering, modifying and synthesizing more molecules with AIEE characteristics. Furthermore, it has a great prospect with regard to imaging cells and cellular substructures, such as mitochondria, which play crucial roles in cell metabolism and death. Indeed, three-dimensional real-time imaging in zebrafish provides a dynamic and visual tool for studying the absorption, distribution, metabolism and excretion of drugs. In this article, more directions and inspiration can be presented for the exploration of non-invasive pharmacokinetic research and intuitive drug pathways or mechanisms.

Immunomodulatory Effects of Natural Feed Additives for Meat Chickens

Broiler chickens are increasingly kept in large numbers in intensive housing conditions that are stressful, potentially depleting the immune system. With the prohibition of the use of antibiotics in poultry feed spreading worldwide, it is necessary to consider the role of natural feed additives and antibiotic alternatives to stimulate the chickens' immune systems. We review the literature to describe phytogenic feed additives that have immunomodulatory benefits in broilers. We initially review the major active ingredients from plants, particularly flavonoids, resveratrol and humic acid, and then describe the major herbs, spices, and other plants and their byproducts that have immunomodulatory effects. The research reviewed demonstrates the effectiveness of many natural feed additives in improving the avian immune system and therefore broiler health. However, some, and perhaps all, additives have the potential to reduce immunocompetence if given in excessive amounts. Sometimes additives are more effective when given in combination. There is an urgent need to determine tolerance levels and optimum doses for additives deemed most suitable to replace antibiotics in the diet of broiler chickens. Effective replacement is most likely with readily available additives, such as olive oil byproducts, olive leaves and alfalfa. It is concluded that effective replacement of antibiotic function with plant-derived additives will be possible, but that further research is necessary to determine optimum doses.

Pharmacological Activity of Flavonoid Quercetin and Its Therapeutic Potential in Testicular Injury

Quercetin is a natural flavonoid widely found in natural fruits and vegetables. Recent studies have shown that quercetin mediates multiple beneficial effects in a variety of organ damage and diseases, and is considered a healthcare supplement with health-promoting potential. Male infertility is a major health concern, and testicular damage from multiple causes is an important etiology. Previous studies have shown that quercetin has a protective effect on reproductive function. This may be related to the antioxidant, anti-inflammatory, and anti-apoptotic biological activities of quercetin. Therefore, this paper reviews the mechanisms by which quercetin exerts its pharmacological activity and its role in testicular damage induced by various etiologies. In addition, this paper compiles the application of quercetin in clinical trials, demonstrating its practical effects in regulating blood pressure and inhibiting cellular senescence in human patients. However, more in-depth experimental studies and clinical trials are needed to confirm the true value of quercetin for the prevention and protection against testicular injury.

Bamboo shoot dietary fiber alleviates gut microbiota dysbiosis and modulates liver fatty acid metabolism in mice with high-fat diet-induced obesity

Introduction

Obesity is a common nutritional disorder characterized by an excessive fat accumulation. In view of the critical role of gut microbiota in the development of obesity and metabolic diseases, novel dietary therapies have been developed to manage obesity by targeting the gut microbiome. In this study, we investigated anti-obesity effects of bamboo shoot dietary fiber (BSDF) and the potential mechanisms.

Methods

After 12 weeks of intervention with BSDF in high-fat mice, we detected obesity-related phenotypic indicators, and made transcriptomic analysis of liver tissue. Then we analyzed the changes of gut microbiota using 16S rRNA gene sequencing, explored the effect of BSDF on gut microbiota metabolites, and finally verified the importance of gut microbiota through antibiotic animal model.

Results and discussion

We found that BSDF was effective in reducing lipid accumulation in liver and adipose tissue and alleviating dyslipidemia and insulin resistance. Liver transcriptome analysis results showed that BSDF could improve lipid metabolism and liver injury by modulating peroxisome proliferator-activated receptor (PPAR) and fatty acid metabolic pathways. The 16S rRNA gene sequencing analysis of gut microbiota composition showed that BSDF significantly enriched beneficial bacteria such as Bifidobacterium, Akkermansia, Dubosiella, and Alloprevotella. Analysis of fecal metabolomics and gut microbiota metabolites revealed that BSDF increased the levels of several short-chain fatty acids and enriched bile acids, which may be important for improving lipid metabolism. Notably, the obesity-related metabolic disorders were abrogated after the abrogation of gut microbiota, suggesting that gut microbiota is a key factor in the beneficial effects of BSDF.

Conclusion

Our study suggests that BSDF as a prebiotic supplement has the potential to improve obesity by improving gut microbiota and modulating host PPAR and fatty acid metabolic pathways.

The Potential of Flavonoids and Flavonoid Metabolites in the Treatment of Neurodegenerative Pathology in Disorders of Cognitive Decline

Flavonoids are a biodiverse family of dietary compounds that have antioxidant, anti-inflammatory, antiviral, and antibacterial cell protective profiles. They have received considerable attention as potential therapeutic agents in biomedicine and have been widely used in traditional complimentary medicine for generations. Such complimentary medical herbal formulations are extremely complex mixtures of many pharmacologically active compounds that provide a therapeutic outcome through a network pharmacological effects of considerable complexity. Methods are emerging to determine the active components used in complimentary medicine and their therapeutic targets and to decipher the complexities of how network pharmacology provides such therapeutic effects. The gut microbiome has important roles to play in the generation of bioactive flavonoid metabolites retaining or exceeding the antioxidative and anti-inflammatory properties of the intact flavonoid and, in some cases, new antitumor and antineurodegenerative bioactivities. Certain food items have been identified with high prebiotic profiles suggesting that neutraceutical supplementation may be beneficially employed to preserve a healthy population of bacterial symbiont species and minimize the establishment of harmful pathogenic organisms. Gut health is an important consideration effecting the overall health and wellbeing of linked organ systems. Bioconversion of dietary flavonoid components in the gut generates therapeutic metabolites that can also be transported by the vagus nerve and systemic circulation to brain cell populations to exert a beneficial effect. This is particularly important in a number of neurological disorders (autism, bipolar disorder, AD, PD) characterized by effects on moods, resulting in depression and anxiety, impaired motor function, and long-term cognitive decline. Native flavonoids have many beneficial properties in the alleviation of inflammation in tissues, however, concerns have been raised that therapeutic levels of flavonoids may not be achieved, thus allowing them to display optimal therapeutic effects. Dietary manipulation and vagal stimulation have both yielded beneficial responses in the treatment of autism spectrum disorders, depression, and anxiety, establishing the vagal nerve as a route of communication in the gut-brain axis with established roles in disease intervention. While a number of native flavonoids are beneficial in the treatment of neurological disorders and are known to penetrate the blood–brain barrier, microbiome-generated flavonoid metabolites (e.g., protocatechuic acid, urolithins, γ-valerolactones), which retain the antioxidant and anti-inflammatory potency of the native flavonoid in addition to bioactive properties that promote mitochondrial health and cerebrovascular microcapillary function, should also be considered as potential biotherapeutic agents. Studies are warranted to experimentally examine the efficacy of flavonoid metabolites directly, as they emerge as novel therapeutic options.

Prospects for the application of traditional Chinese medicine network pharmacology in food science research

There has always been a particular difficulty with in-depth research on the mechanisms of food nutrition and bioactivity. The main function of food is to meet the nutritional needs of the human body, rather than to exert a therapeutic effect. Its relatively modest biological activity makes it difficult to study from the perspective of general pharmacological models. With the popularity of functional foods and the concept of dietary therapy, and the development of information and multi-omics technology in food research, research into these mechanisms is moving towards a more microscopic future. Network pharmacology has accumulated nearly 20 years of research experience in traditional Chinese medicine (TCM), and there has been no shortage of work from this perspective on the medicinal functions of food. Given the similarity between the concept of 'multi-component-multi-target' properties of food and TCM, we think that network pharmacology is applicable to the study of the complex mechanisms of food. Here we review the development of network pharmacology, summarize its application to 'medicine and food homology', and propose a methodology based on food characteristics for the first time, demonstrating its feasibility for food research. © 2023 Society of Chemical Industry.

Biopreservative Effect of the Tunisian Halophyte Lobularia maritima Flavonoid Fraction, Used Alone and in Combination with Linalool in Stored Minced Beef Meat

In the present study, Lobularia maritima (Lm) flavonoid extract (LmFV) was characterized by HPLC analyses and five compounds were detected. Further, to describe the chemical content of the matrix, GC-MS analyses after silylation were performed; the obtained results showed the presence of a large number of components belonging to several chemical classes, mostly sugar alcohols, sugars, fatty acids, and terpenes. Firstly, the antibacterial activities of this fraction and linalool (Lin) were evaluated against eight foodborne pathogenic strains with MIC values between 2.3 and 5.8 mg/mL and 0.23 and 0.7 mg/mL, respectively. Then, the antioxidant activity of both was evaluated by the DPPH antiradical test and the phosphomolybdenum test. Furthermore, the biopreservative effect of LmFV alone and in combination with Lin on minced beef stored at 4 °C for 14 days was evaluated using microbiological and physiochemical tests. LmFV at 4.6% alone significantly reduced microbial spoilage in ground meat (p < 0.05). The combination of LmFV (4.6%) and Lin (0.46%) was more effective than LmFV alone in inhibiting bacterial contamination, reducing TBARS values and the risk of bacterial contamination, and reducing the accumulation of Met myoglobin (MetMb). This combination, therefore, extends the shelf life of the product by about 10 days. Based on these microbiological results and physicochemical parameters, it can be stated that the addition of Lin potentiates the flavonoid fraction of L. maritima more strongly against the deterioration of meat quality by significantly improving its biopreservative effect as a natural conservative.