Cardioprotective potentials of myricetin on doxorubicin-induced cardiotoxicity based on biochemical and transcriptomic analysis.

Doxorubicin (DOX) is a commonly used anthracycline in cancer chemotherapy. The clinical application of DOX is constrained by its cardiotoxicity. Myricetin (MYR) is a natural flavonoid widely present in many plants with antioxidant and anti-inflammatory properties. However, MYR's beneficial effects and mechanisms in alleviating DOX-induced cardiotoxicity (DIC) remain unknown. C57BL/6 mice were injected with 15 mg/kg of DOX to establish the DIC, and MYR solutions were administrated by gavage to investigate its cardioprotective potentials. Histopathological analysis, physiological indicators assessment, transcriptomics analysis, and RT-qPCR were used to elucidate the potential mechanism of MYR in DIC treatment. MYR reduced cardiac injury produced by DOX, decreased levels of cTnI, AST, LDH, and BNP, and improved myocardial injury and fibrosis. MYR effectively prevented DOX-induced oxidative stress, such as lowered MDA levels and elevated SOD, CAT, and GSH activities. MYR effectively suppressed NLRP3 and ASC gene expression levels to inhibit pyroptosis while regulating Caspase1 and Bax levels to reduce cardiac cell apoptosis. According to the transcriptomic analysis, glucose and fatty acid metabolism were associated with differential gene expression. KEGG pathway analysis revealed differential gene enrichment in PPAR and AMPK pathways, among others. Following validation, MYR was found to alleviate DIC by regulating glycolipid metabolism and AMPK pathway-related genes. Our findings demonstrated that MYR could mitigate DIC by regulating the processes of oxidative stress, apoptosis, and pyroptosis. MYR is critical in improving DOX-induced myocardial energy metabolism abnormalities mediated by the AMPK signaling pathway. In conclusion, MYR holds promise as a therapeutic strategy for DIC.

Research advances in citrus polyphenols: green extraction technologies, gut homeostasis regulation, and nano-targeted delivery system application.

Citrus polyphenols can modulate gut microbiota and such bi-directional interaction that can yield metabolites such as short-chain fatty acids (SCFAs) to aid in gut homeostasis. Such interaction provides citrus polyphenols with powerful prebiotic potential, contributing to guts' health status and metabolic regulation. Citrus polyphenols encompass unique polymethoxy flavonoids imparting non-polar nature that improve their bioactivities and ability to penetrate the blood-brain barrier. Green extraction technology targeting recovery of these polyphenols has received increasing attention due to its advantages of high extraction yield, short extraction time, low solvent consumption, and environmental friendliness. However, the low bioavailability of citrus polyphenols limits their applications in extraction from citrus by-products. Meanwhile, nano-encapsulation technology may serve as a promising approach to improve citrus polyphenols' bioavailability. As citrus polyphenols encompass multiple hydroxyl groups, they are potential to interact with bio-macromolecules such as proteins and polysaccharides in nano-encapsulated systems that can improve their bioavailability. This multifaceted review provides a research basis for the green and efficient extraction techniques of citrus polyphenols, as well as integrated mechanisms for its anti-inflammation, alleviating metabolic syndrome, and regulating gut homeostasis, which is more capitalized upon using nano-delivery systems as discussed in that review to maximize their health and food applications.

Cereal polyphenols inhibition mechanisms on advanced glycation end products and regulation on type 2 diabetes.

Advanced glycation end products (AGEs), the products of non-enzymatic browning reactions between the active carbonyl groups of reducing sugars and the free amines of amino acids, are largely considered oxidative derivatives resulting from diabetic hyperglycemia, which are further recognized as a potential risk for insulin resistance (IR) and type 2 diabetes (T2D). The accumulation of AGEs can trigger numerous negative effects such as oxidative stress, carbonyl stress, inflammation, autophagy dysfunction and imbalance of gut microbiota. Recently, studies have shown that cereal polyphenols have the ability to inhibit the formation of AGEs, thereby preventing and alleviating T2D. In the meanwhile, phenolics compounds could produce different biological effects due to the quantitative structure activity-relationship. This review highlights the effects of cereal polyphenols as a nonpharmacologic intervention in anti-AGEs and alleviating T2D based on the effects of oxidative stress, carbonyl stress, inflammation, autophagy, and gut microbiota, which also provides a new perspective on the etiology and treatment of diabetes.

Peptide hydrogels: Synthesis, properties, and applications in food science.

Due to the unique and excellent biological, physical, and chemical properties of peptide hydrogels, their application in the biomedical field is extremely wide. The applications of peptide hydrogels are closely related to their unique responsiveness and excellent properties. However, its defects in mechanical properties, stability, and toxicity limit its application in the food field. In this review, we focus on the fabrication methods of peptide hydrogels through the physical, chemical, and biological stimulations. In addition, the functional design of peptide hydrogels by the incorporation with materials is discussed. Meanwhile, the excellent properties of peptide hydrogels such as the stimulus responsiveness, biocompatibility, antimicrobial properties, rheology, and stability are reviewed. Finally, the application of peptide hydrogel in the food field is summarized and prospected.

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms.

Cognitive, mood and sleep disorders are common and intractable disorders of the central nervous system, causing great inconvenience to the lives of those affected. The gut-brain axis plays a vital role in studying neurological disorders such as neurodegenerative diseases by acting as a channel for a bidirectional information exchange between the gut microbiota and the nervous system. Dietary polyphenols have received widespread attention because of their excellent biological activity and their wide range of sources, structural diversity and low toxicity. Dietary intervention through the increased intake of dietary polyphenols is an emerging strategy for improving circadian rhythms and treating metabolic disorders. Dietary polyphenols have been shown to play an essential role in regulating intestinal flora, mainly by maintaining the balance of the intestinal flora and enhancing host immunity, thereby suppressing neurodegenerative pathologies. This paper reviewed the bidirectional interactions between the gut microbiota and the brain and their effects on the central nervous system, focusing on dietary polyphenols that regulate circadian rhythms and maintain the health of the central nervous system through the gut-brain axis.

Research advance of non-thermal processing technologies on ovalbumin properties: The gelation, foaming, emulsification, allergenicity, immunoregulation and its delivery system application.

Ovalbumin (OVA) is the most abundant protein in egg white, with excellent functional properties (e.g., gelling, foaming, emulsifying properties). Nevertheless, OVA has strong allergenicity, which is usually mediated by specific IgE thus results in gut microbiota dysbiosis and causes atopic dermatitis, asthma, and other inflammation actions. Processing technologies and the interactions with other active ingredients can influence the functional properties and allergic epitopes of OVA. This review focuses on the non-thermal processing technologies effects on the functional properties and allergenicity of OVA. Moreover, the research advance about immunomodulatory mechanisms of OVA-mediated food allergy and the role of gut microbiota in OVA allergy was summarized. Finally, the interactions between OVA and active ingredients (such as polyphenols and polysaccharides) and OVA-based delivery systems construction are summarized. Compared with traditional thermal processing technologies, novel non-thermal processing techniques have less damage to OVA nutritional value, which also improve OVA properties. OVA can interact with various active ingredients by covalent and non-covalent interactions during processing, which can alter the structure or allergic epitopes to affect OVA/active components properties. The interactions can promote OVA-based delivery systems construction, such as emulsions, hydrogels, microencapsulation, nanoparticles to encapsulate bioactive components and monitor freshness for improving foods quality and safety.

The positive correlation of antioxidant activity and prebiotic effect about oat phenolic compounds.

The correlation of antioxidant activity and prebiotic effect about oat phenolic compounds was invested, while there exists limited studies. Free and bound phenolic compounds were separated from ethyl acetate, n-butanol and aqueous fractions. Fluorescence in situ hybridization was used to investigate gut microbiota of in vitro fermentation samples. The results showed that ethyl acetate fraction possesses higher total phenolics contents than that of aqueous fraction (p < 0.01). The bound-n-butanol and free-ethyl acetate fraction exhibited the higher antioxidant capacity (p < 0.01). The phenolic compounds with more powerful antioxidant capacity could promote the proliferation of gut microbiota (Lactobacillus/Enterococcus spp. and Bifidobacterium spp.) (p < 0.05) and inhibit the growth of gut microbiota (Bacteroides spp. and Clostridium/histolyticum group). There is a positive correlation of antioxidant activity and prebiotic effect about oat phenolic compounds. This study provides a basis for the correlation between antioxidant stress and gut microbiota regulation in vivo.

Dietary flavonoids: a novel strategy for the amelioration of cognitive impairment through intestinal microbiota.

The chances of people suffering from cognitive impairments increase gradually with age. Diet and lifestyle are closely related to the occurrence and development of cognitive function. Dietary flavonoid supplementation has been shown to be one of the protective factors against cognitive decline. Flavonoids belong to a class of polyphenols that have been proposed for the treatment of cognitive decline. Recent evidence has shown that intestinal flora in the human body can interact with flavonoids. Intestinal microbiota can modify the chemical structure of flavonoids, producing new metabolites, the pharmacological activities of which may be different from those of the parent; meanwhile, flavonoids and their metabolites can, in turn, regulate the composition and structure of intestinal flora. Notably, intestinal flora affect host nervous system activity through the gut-brain axis, ultimately causing changes in cognitive function. This review therefore summarizes the interaction of dietary flavonoids and intestinal flora, and their protective effect against cognitive decline through the gut-brain axis, indicating that dietary flavonoids may ameliorate cognitive impairment through their interaction with intestinal microbiota. © 2022 Society of Chemical Industry.

Research Advances of Lactoferrin in Electrostatic Spinning, Nano Self-Assembly, and Immune and Gut Microbiota Regulation.

Lactoferrin (LF) is a naturally present iron-binding globulin with the structural properties of an N-lobe strongly positively charged terminus and a cage-like structure of nano self-assembly encapsulation. These unique structural properties give it potential for development in the fields of electrostatic spinning, targeted delivery systems, and the gut-brain axis. This review will provide an overview of LF's unique structure, encapsulation, and targeted transport capabilities, as well as its applications in immunity and gut microbiota regulation. First, the microstructure of LF is summarized and compared with its homologous ferritin, revealing both structural and functional similarities and differences between them. Second, the electrostatic interactions of LF and its application in electrostatic spinning are summarized. Its positive charge properties can be applied to functional environmental protection packaging materials and to improving drug stability and antiviral effects, while electrostatic spinning can promote bone regeneration and anti-inflammatory effects. Then the nano self-assembly behavior of LF is exploited as a cage-like protein to encapsulate bioactive substances to construct functional targeted delivery systems for applications such as contrast agents, antibacterial dressings, anti-cancer therapy, and gene delivery. In addition, some covalent and noncovalent interactions of LF in the Maillard reaction and protein interactions and other topics are briefly discussed. Finally, LF may affect immunological function via controlling the gut microbiota. In conclusion, this paper reviews the research advances of LF in electrostatic spinning, nano self-assembly, and immune and gut microbiota regulation, aiming to provide a reference for its application in the food and pharmaceutical fields.

Tea Polyphenols as Prospective Natural Attenuators of Brain Aging.

No organism can avoid the process of aging, which is often accompanied by chronic disease. The process of biological aging is driven by a series of interrelated mechanisms through different signal pathways, including oxidative stress, inflammatory states, autophagy and others. In addition, the intestinal microbiota play a key role in regulating oxidative stress of microglia, maintaining homeostasis of microglia and alleviating age-related diseases. Tea polyphenols can effectively regulate the composition of the intestinal microbiota. In recent years, the potential anti-aging benefits of tea polyphenols have attracted increasing attention because they can inhibit neuroinflammation and prevent degenerative effects in the brain. The interaction between human neurological function and the gut microbiota suggests that intervention with tea polyphenols is a possible way to alleviate brain-aging. Studies have been undertaken into the possible mechanisms underpinning the preventative effect of tea polyphenols on brain-aging mediated by the intestinal microbiota. Tea polyphenols may be regarded as potential neuroprotective substances which can act with high efficiency and low toxicity.

Potential Application of Tea Polyphenols to the Prevention of COVID-19 Infection: Based on the Gut-Lung Axis.

Coronavirus disease 2019 (COVID-19) disrupts the intestinal micro-ecological balance, and patients often develop the intestinal disease. The gut is the largest immune organ in the human body; intestinal microbes can affect the immune function of the lungs through the gut-lung axis. It has been reported that tea polyphenols (TPs) have antiviral and prebiotic activity. In this review, we discussed TPs reduced lung-related diseases through gut-lung axis by inhibiting dysbiosis. In addition, we also highlighted the preventive and therapeutic effects of TPs on COVID-19 complications, further demonstrating the importance of research on TPs for the prevention and treatment of COVID-19 in humans. Based on this understanding, we recommend using TPs to regulate the gut microbiota to prevent or alleviate COVID-19 through the gut-lung axis.

Mechanisms Underlying the Interaction Between Chronic Neurological Disorders and Microbial Metabolites via Tea Polyphenols Therapeutics.

The number of hydroxyl groups and existence of characteristic structural groups in tea polyphenols (TP) make them have antioxidant activity, which gives TP anti-inflammatory effects, toward protecting the intestinal flora and brain neurons. Host-associated microbial metabolites are emerging as dominant modifiers of the central nervous system. As yet, the investigations on host-microbiota crosstalking remain challenging, studies focusing on metabolites such as serotonin, short-chain fatty acids, and others have pinpointed multiple actionable signaling pathways relevant to host health. However, there are still complexities and apparent limitations inherent in transforming complex human diseases to corresponding animal models. Here, we choose to discuss several intestinal metabolites with research value, as crucial areas for assessing TP-mediated chronic brain diseases interactions with microbial.

RNA-Seq Transcriptomic Analysis of Green Tea Polyphenols Modulation of Differently Expressed Genes in Enterococcus faecalis Under Bile Salt Stress.

Enterococcus faecalis (E. faecalis) belongs to lactic acid bacteria which can be used as a probiotic additive and feed, bringing practical value to the health of humans and animals. The prebiotic function of tea polyphenols lays a foundation for green tea polyphenols (GTP) to repair the adverse changes of E. faecalis under stress conditions. In this study, RNA-sequence analysis was used to explore the protective effect of GTP on E. faecalis under bile salt stress. A total of 50 genes were found to respond to GTP under bile salts stress, containing 18 up-regulated and 32 down-regulated genes. The results showed that multiple genes associated with cell wall and membrane, transmembrane transport, nucleotide transport and metabolism were significantly differentially expressed (P < 0.05), while GTP intervention can partly alleviate the detrimental effects of bile salt on amino acid metabolism and transport. The present study provides the whole genome transcriptomics of E. faecalis under bile salt stress and GTP intervention which help us understand the growth and mechanism of continuous adaptation of E. faecalis under stress conditions.

A Natural Plant Source-Tea Polyphenols, a Potential Drug for Improving Immunity and Combating Virus.

The coronavirus disease 2019 (COVID-19) is still in a global epidemic, which has profoundly affected people's lives. Tea polyphenols (TP) has been reported to enhance the immunity of the body to COVID-19 and other viral infectious diseases. The inhibitory effect of TP on COVID-19 may be achieved through a series of mechanisms, including the inhibition of multiple viral targets, the blocking of cellular receptors, and the activation of transcription factors. Emerging evidence shows gastrointestinal tract is closely related to respiratory tract, therefore, the relationship between the state of the gut-lung axis microflora and immune homeostasis of the host needs further research. This article summarized that TP can improve the disorder of flora, reduce the occurrence of cytokine storm, improve immunity, and prevent COVID-19 infection. TP may be regarded as a potential and valuable source for the design of new antiviral drugs with high efficiency and low toxicity.

Tea polyphenols-loaded nanocarriers: preparation technology and biological function.

Tea polyphenols (TP) have various biological functions including anti-oxidant, anti-bacterial, anti-apoptotic, anti-inflammatory and bioengineered repair properties. However, TP exhibit poor stability and bioavailability in the gastrointestinal tract. Nanoencapsulation techniques can be used to protect TP and to uphold their original characteristics during processing, storage and digestion, improve their physiochemical properties and enhance their health promoting effects. Nano-embedded TP show higher antioxidant, antibacterial and anticancer properties than TP, allowing TP to play a better role in bioengineering restoration after embedding. In this review, recent advances in nanoencapsulation of TP with biopolymeric nanocarriers (polysaccharides and proteins), lipid-based nanocarriers and innovative developments in preparation strategies were mainly discussed. Additionally, the strengthening biological functions of stability and bioavailability, antioxidant, antibacterial, anticancer activities and bioengineering repair properties activities after the nano-embedding of TP have been considered. Finally, further studies could be conducted for exploring the application of nanoencapsulated systems in food for industrial applications.

Tea Polyphenols: A Natural Antioxidant Regulates Gut Flora to Protect the Intestinal Mucosa and Prevent Chronic Diseases.

The intestinal tract of a healthy human body hosts many microorganisms that are closely linked to all aspects of people's lives. The impact of intestinal flora on host health is no longer limited to the gut but can also affect every organ in the body through various pathways. Studies have found that intestinal flora can be altered by external factors, which provides new ideas for treating some diseases. Tea polyphenols (TP), a general term for polyphenols in tea, are widely used as a natural antioxidant in various bioactive foods. In recent years, with the progress of research, there have been many experiments that provide strong evidence for the ability of TP to regulate intestinal flora. However, there are very few studies on the use of TP to modify the composition of intestinal microorganisms to maintain health or treat related diseases, and this area has not received sufficient attention. In this review, we outline the mechanisms by which TP regulates intestinal flora and the essential role in maintaining suitable health. In addition, we highlighted the protective effects of TP on intestinal mucosa by regulating intestinal flora and the preventive and therapeutic effects on certain chronic diseases, which will help further explore measures to prevent related chronic diseases.

Tea Polyphenols Prevent and Intervene in COVID-19 through Intestinal Microbiota.

Although all countries have taken corresponding measures, the coronavirus disease 2019 (COVID-19) is still ravaging the world. To consolidate the existing anti-epidemic results and further strengthen the prevention and control measures against the new coronavirus, we are now actively pioneering a novel research idea of regulating the intestinal microbiota through tea polyphenols for reference. Although studies have long revealed the regulatory effect of tea polyphenols on the intestinal microbiota to various gastrointestinal inflammations, little is known about the prevention and intervention of COVID-19. This review summarizes the possible mechanism of the influence of tea polyphenols on COVID-19 mediated by the intestinal microbiota. In this review, the latest studies of tea polyphenols exhibiting their own antibacterial and anti-inflammatory activities and protective effects on the intestinal mucosal barrier are combed through and summarized. Among them, (-)-epigallocatechin-3-gallate (EGCG), one of the main monomers of catechins, may be activated as nuclear factor erythroid 2 p45-related factor 2 (Nrf2). The agent inhibits the expression of ACE2 (a cellular receptor for SARS-CoV-2) and TMPRSS2 to inhibit SARS-CoV-2 infection, inhibiting the life cycle of SARS-CoV-2. Thus, preliminary reasoning and judgments have been made about the possible mechanism of the effect of tea polyphenols on the COVID-19 control and prevention mediated by the microbiota. These results may be of great significance to the future exploration of specialized research in this field.

Omics Analyses of Intestinal Microbiota and Hypothalamus Clock Genes in Circadian Disturbance Model Mice Fed with Green Tea Polyphenols.

Green tea polyphenols (GTP) have similar activities as prebiotics, which effectively regulate the structure of intestinal flora and affect their metabolic pathways. The intestinal flora is closely related to the host's circadian rhythm, and the supplementation with GTP may be an effective way to improve circadian rhythm disorders. In this study, we established a mouse model of circadian rhythm disturbance of anthropogenic flora to investigate the regulation mechanism of GTP on the host circadian rhythms. After 4 weeks of GTP administration, the results showed that GTP significantly alleviated the structural disorder of intestinal microbiota, thus effectively regulating related metabolites associated with brain nerves and circadian rhythms. Moreover, single-cell transcription of the mouse hypothalamus suggested that GTP up-regulated the number of astrocytes and oligodendrocytes and adjusted the expression of core clock genes Csnk1d, Clock, Per3, Cry2, and BhIhe41 caused by circadian disruption. Therefore, this study provided evidence that GTP can improve the physiological health of hosts with the circadian disorder by positively affecting intestinal flora and related metabolites and regulating circadian gene expression.

The interaction effect between tea polyphenols and intestinal microbiota: Role in ameliorating neurological diseases.

Tea polyphenols (TP) are one of the most functional and bioactive substances in tea. The interactions between TP and intestinal microbiota suggest that probiotics intervention is a useful method to ameliorate neurological diseases. Now, numerous researches have suggested that TP plays a significant role in modulating intestinal bacteria, especially in the area of sustaining a stable state of intestinal microbial function and abundance. Furthermore, homeostatic intestinal bacteria can enhance the immunity of the host. The close reciprocity between intestinal microbiota and the central nervous system provides a new chance for TP to modulate neural-related diseases depending on intestinal microbiota. Therefore, based on the bidirectional relationship between the brain and the intestines, this review provides a new clue to solve insomnia symptoms and related neurological diseases that will enable us to better study the bidirectional effects of TP and intestinal microbiota on the improvement of host health. PRACTICAL APPLICATIONS: This review provides a new clue to solve insomnia symptoms and related neurological diseases that will enable us to better study bidirectional effects of TP and intestinal microbiota on the improvement of host health.

The role of the intestinal microbiota in the pathogenesis of host depression and mechanism of TPs relieving depression.

Depression is a prevalent neuropsychiatric disease with a high recurrence rate, affecting over 350 million people worldwide. Intestinal flora disorders and gut-brain-axis (GBA) dysfunction may cause mental disorders. Alterations in the intestinal flora composition could increase the permeability of the gut barrier, activate systemic inflammation and immune responses, regulate the release and efficacy of monoamine neurotransmitters, alter the activity and function of the hypothalamic-pituitary-adrenal (HPA) axis, and modify the abundance of the brain-derived neurotrophic factor (BDNF); all of these showed a close correlation with the occurrence of depression. In addition, the disturbance of the intestinal flora is related to circadian rhythm disorders, which aggravate the symptoms of depression. Tea polyphenols (TPs) have been found to have antidepressant effects. Therefore, the close reciprocity between the intestinal flora and circadian rhythm provides a new opportunity for TPs to regulate depression relying on the intestinal flora. In this review, we discussed the relationship between intestinal flora dysbiosis and the pathogenesis of depression and the mechanism of TPs relieving depression via the GBA.