Green tea polyphenols mitigate the plant lectins-induced liver inflammation and immunological reaction in C57BL/6 mice via NLRP3 and Nrf2 signaling pathways

Serial Extraction of Pectin and Polyphenols From Watermelon Rind for Use in Strawberry Preservation Film

The aim of this study was to extract watermelon rind (WR) pectin (WRP) and watermelon rind polyphenols (WRE) and evaluate the effect of pectin/sodium alginate composite films (WRPSA) with or without WRE on strawberry preservation. WRP was extracted using citric acid, whereas WRE was obtained through ethyl acetate extraction. The extracted WRP was characterized for composition and structural properties, multi-angle laser light scattering (MALLS), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), x-ray diffraction (XRD), ζ-potential analysis, and rheological measurements. The pectin/SA film (WRPSA) and pectin/SA composite film containing WRE (WRPESA) were prepared. Both films were analyzed for physical properties and structurally characterized. Strawberries were wrapped with either WRPSA, WRPESA, or no treatment (exposed) and stored under lightproof conditions at 4°C for 12 days. The results showed that WRP was a low-ester pectin (degree of methylation [DM] = 38.7%) with a molecular weight of 683 kDa. WRP had typical polysaccharide characteristic peaks and good thermal stability that could be used as a film-forming substrate. WRPESA showed better mechanical strength and antioxidant capacity than that of WRPSA, indicating that WRE showed synergistic effects on the improvement of composite films. Additionally, WRPESA effectively reduced strawberry softening, color deterioration, and weight loss, in addition to the delay in the dynamic changes in sugar content and pH and accumulation of malondialdehyde (MDA). WRPESA also helped maintain the total phenolic content of the strawberries. These findings suggest that watermelon byproducts could be valorized for sustainable food packaging, reducing both agricultural waste and reliance on synthetic materials. Practical Application: This article confirmed the feasibility of a sequential extraction process for watermelon rind pectin and polyphenols, which can later be applied to industrial production lines to increase the utilization rate of watermelon rind. The practical application value of this research lies in the development of biodegradable packaging materials. By extracting pectin and polyphenols from watermelon rind, the resulting films can effectively extend the shelf life of strawberries and reduce food waste. Furthermore, this study promotes the utilization of agricultural waste, enhances the nutritional value of food, and provides new opportunities for local economic development. Additionally, it offers a scientific basis for advancing sustainable packaging technology and food preservation innovations, which is significant for environmental protection and healthy consumption.

Bridging the gap: Integrating exercise mimicry into chronic disease management through suppressing chronic inflammation

BACKGROUND

Chronic inflammation is a common hallmark of many chronic diseases. Although exercise holds paramount importance in preventing and managing chronic diseases, adherence to exercise programs can be challenging for some patients. Consequently, there is a pressing need to explore alternative strategies to emulate the anti-inflammatory effects of exercise for chronic diseases.

AIM OF REVIEW

This review explores the emerging role of green tea bioactive components as potential mitigators of chronic inflammation, offering insights into their capacity to mimic the beneficial effects of exercise. We propose that bioactive components in green tea are promising agents for suppressing chronic inflammation, suggesting their unique capability to replicate the health benefits of exercise.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review focuses on several key concepts, including chronic inflammation and its role in chronic diseases, the anti-inflammatory effects of regular exercise, and bioactive components in green tea responsible for its health benefits. It elaborates on scientific evidence supporting the anti-inflammatory properties of green tea bioactive components, such as epigallocatechin gallate (EGCG), and theorizes how these bioactive components might replicate the effects of exercise at a molecular level. Through a comprehensive analysis of current research, this review proposes a novel perspective on the application of green tea as a potential intervention strategy to suppress chronic inflammation, thereby extending the benefits akin to those achieved through exercise.

Callistephus A from Callistephus chinensis Nees alleviates concanavalin A-induced immunological liver injury in mice by inhibiting the activation of JAK/STAT1 and MAPK signaling pathways

Callistephus chinensis Nees is an herbaceous plant in the Asteraceae family that has various traditional effects, especially in preventing liver disease. Callistephus A (CA) is a sesquiterpene compound with a rare 6/7 ring skeleton, which has been isolated only from the Callistephus chinensis Nees, but whether CA protects the liver is unknown. Immunological liver injury (ILI) is a common liver disease mediated by the immune system. Therefore, this study investigated whether CA had a protective effect on ILI and uncovered its molecular mechanisms. To study the impact, target, and signal pathway of CA in preventing ILI, we hope to find active components from plants to avoid ILI. In this study, CA regulated the differentiation balance of CD4 + T cells (Th1/Th2 and Th17/Treg balance) and the secretion of inflammatory factors (tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interferon-gamma (IFN-γ), interleukin-4 (IL-4), interleukin-17A (IL-17A) and transforming growth factor-β (TGF-β). CA improves liver inflammation by regulating IFN-γ-induced JAK/STAT1 signaling pathways. CA reduced hepatocyte apoptosis by decreasing protein expression of BCL2-associated X (Bax), cleaved caspase-3, and cleaved Poly (ADP-ribose) polymerase 1 (PARP-1), but increased Bcl-2 protein expression, which was achieved by regulating the MAPK pathway. To investigate the role of CA in immune liver injury, we performed in vitro cell experiments using alpha mouse liver 12 (AML12) cells. The cell experiments showed that CA potently inhibited LPS-mediated AML12 cell damage. After adding CA, damaged mitochondria are cleared through mitochondrial autophagy and reduced production of intracellular reactive oxygen species (ROS). Finally, molecular docking results showed that CA had a strong affinity for five essential target proteins (JAK1, JAK2, STAT1, JNK, and p38). CA regulates the differentiation, anti-inflammatory, and anti-apoptosis of CD4 + T cells. The mechanism of CA against ILI is related to inhibiting the activation of JAK/STAT1 and MAPK signaling pathways.

Hepatoprotective Effect of Tea Composite Solid Beverage on Alcohol-Caused Rat Liver Injury

Alcoholic liver disease (ALD) remains a major cause of liver-related morbidity and mortality worldwide. Tea polyphenols (TPs) possess strong antioxidant activity; cassia seed extract (CSE) has the effect of brightening the eyes; and Ampelopsis grossedentata extract (AGE) has the function of protecting the liver. However, the synergistic hepatoprotective effect of TP, AGE and CSE as a joint formulation is unknown. This study aimed to investigate the role of a tea solid beverage, composed of TP, AGE and CSE, on chronic alcoholic liver injury in rats and its underlying mechanisms via the analysis of transcriptomics and gut microbiota. The histopathological findings revealed that the tea solid beverage could reduce the production of fat vacuoles and inflammatory cell infiltration. Additionally, the tea solid beverage was found to effectively relieve the increase in the AST (from 424.85 U/L to 180.17 U/L), ALT (from 139.95 U/L to 85.88 U/L) and LDH (from 21.16 U/L to 13.35 U/L) enzyme activities and the expression of the inflammatory factors TNF-α (from 394.02 pg/mL to 214.44 pg/mL) and IL-6 (from 208.46 pg/mL to 116.59 pg/mL) caused by alcohol consumption. Further, it significantly enhanced the GSH concentration (from 4.53 pg/mL to 8.08 pg/mL) and SOD activity (from 84.70 U/mL to 156.94 U/mL) and decreased the MDA (from 58.61 mmol/mL to 36.58 mmol/mL) and TG (from 7.07 mmol/L to 3.43 mmol/L)) concentrations in the liver of rats. The analysis and identification of transcriptomics showed that the tea solid beverage intervention primarily protected the liver of rats with chronic alcoholic injury by up-regulating the differential gene Hmgcs1 in order to increase the synthesis of ketone bodies and by down-regulating the differential gene Pfkfb1 for the purpose of decreasing the glucose metabolism. Additionally, it was found that the tea solid beverage could significantly change the composition of intestinal flora in drinking rats by regulating mineral absorption, the pathways of bile secretion, the adipocytokine signaling pathway and the peroxisome balance of the intestinal flora, in order to protect alcohol-drinking rats' livers. In conclusion, the tea solid beverage, consisting of TP, AGE and CSE, is a functional drink that prevents ketone metabolism, glucose metabolism and microbiome disorders induced by alcohol intake.

Beneficial effects of phenolic compounds: native phenolic compounds vs metabolites and catabolites

In the human body, the positive effects of phenolic compounds are increasingly observed through their presence in tissues and organs in their native form or in the form of metabolites or catabolites formed during digestion, microbial metabolism, and host biotransformation. The full extent of these effects is still unclear. The aim of this paper is to review the current knowledge of beneficial effects of native phenolic compounds or their metabolites and catabolites focusing on their role in the health of the digestive system, including disorders of the gastrointestinal and urinary tracts and liver. Studies are mostly connecting beneficial effects in the gastrointestinal and urinary tract to the whole food rich in phenolics, or to the amount of phenolic compounds/antioxidants in food. Indeed, the bioactivity of parent phenolic compounds should not be ignored due to their presence in the digestive tract, and the impact on the gut microbiota. However, the influence of their metabolites and catabolites might be more important for the liver and urinary tract. Distinguishing between the effects of parent phenolics vs metabolites and catabolites at the site of action are important for novel areas of food industry, nutrition and medicine.

The hepatoprotective effects of Herbt Tea Essences on phenanthrene-induced liver damage in mice

Phenanthrene (Phe), one of the most frequently occurring pollutants in nature, can cause substantial damage to the human liver. Herbt Tea Essences (HTE), a kind of black tea extract with strong anti-inflammatory activity, can protect humans against disease. Currently, whether HTE can protect the liver from Phe-induced hepatotoxicity remains unclear. Herein, we explore the protective effects of HTE against Phe-induced hepatotoxicity. Our results showed that Phe exposure could significantly induce liver damage and increase serum hepatic enzyme levels in mice. HTE could prevent liver damage and recover the expression levels of inflammatory factors. Furthermore, we found that HTE suppressed the excessive activation of the nuclear transcription factor kappa-B and transforming growth factor-β/SMAD signaling pathways to alleviate Phe-induced liver inflammation and fibrosis. Overall, our data showed that HTE treatment could be a new preventive means for Phe-induced liver disease.

Self-Propelled Ultrasmall AuNPs-Tannic Acid Hybrid Nanozyme with ROS-Scavenging and Anti-Inflammatory Activity for Drug-Induced Liver Injury Alleviation

Developing nanomedicines with superior reactive oxygen species (ROS) scavenging capability has emerged as a promising strategy in treating ROS-related diseases, for example, drug-induced liver injury. However, designing nanoscavengers with the self-propelling ability to scavenge ROS actively remains challenging. Here, a self-propelled silica-supported ultrasmall gold nanoparticles-tannic acid hybrid nanozyme (SAuPTB) is designed that can effectively alleviate acetaminophen (APAP)-induced liver injury by scavenging excessive ROS and regulating inflammation. SAuPTB exhibits multienzyme activity and displays significantly enhanced diffusion under hydrogen peroxide (H₂ O₂ ). This in vitro research shows that SAuPTB can effectively eliminate ROS, increasing the viability of H₂ O₂ -stimulated cells and reducing the cytotoxicity of APAP/H₂ O₂ -treated AML12 cells. The in vivo studies show that SAuPTB can accumulate at inflammatory sites in mouse liver, resulting in the decrease of alanine aminotransferase, aspartate aminotransferase, and ROS, reduction in pro-inflammatory cytokines and chemokines, hence reduced hepatocyte necrosis, liver injury, and mortality. Furthermore, SAuPTB activates the nuclear erythroid 2-related factor 2 pathway to upregulate antioxidative genes and reduce oxidative stress. Finally, the liver shows decreased high mobility group box 1 and F4/80⁺ macrophages, suggesting an anti-inflammatory response. This work provides a novel design strategy of nanozymes for ROS-related disease treatment.

NLRP3 Inflammasome: A key contributor to the inflammation formation

Inflammation is an important part of the development of various organ diseases. The inflammasome, as an innate immune receptor, plays an important role in the formation of inflammation. Among various inflammasomes, the NLRP3 inflammasome is the most well studied. The NLRP3 inflammasome is composed of skeletal protein NLRP3, apoptosis-associated speck-like protein (ASC) and pro-caspase-1. There are three types of activation pathways: (1) "classical" activation pathway; (2) "non-canonical" activation pathway; (3) "alternative" activation pathway. The activation of NLRP3 inflammasome is involved in many inflammatory diseases. A variety of factors (such as genetic factors, environmental factors, chemical factors, viral infection, etc.) have been proved to activate NLRP3 inflammasome and promote the inflammatory response of the lung, heart, liver, kidney and other organs in the body. Especially, the mechanism of NLRP3 inflammation and its related molecules in its associated diseases remains not to be summarized, namely they may promote or delay inflammatory diseases in different cells and tissues. This article reviews the structure and function of the NLRP3 inflammasome and its role in various inflammations, including inflammations caused by chemically toxic substances.

Effectiveness of targeting the NLRP3 inflammasome by using natural polyphenols: A systematic review of implications on health effects

Globally, inflammation and metabolic disorders pose serious public health problems and are major health concerns. It has been shown that natural polyphenols are effective in the treatment of metabolic diseases, including anti-inflammation, anti-diabetes, anti-obesity, neuron-protection, and cardio-protection. NLRP3 inflammasome, which are multiprotein complexes located within the cytosol, play an important role in the innate immune system. However, aberrant activation of the NLRP3 inflammasome were discovered as essential molecular mechanisms in triggering inflammatory processes as well as implicating it in several major metabolic diseases, such as type 2 diabetes mellitus, obesity, atherosclerosis or cardiovascular disease. Recent studies indicate that natural polyphenols can inhibit NLRP3 inflammasome activation. In this review, the progress of natural polyphenols preventing inflammation and metabolic disorders via targeting NLRP3 inflammasome is systemically summarized. From the viewpoint of interfering NLRP3 inflammasome activation, the health effects of natural polyphenols are explained. Recent advances in other beneficial effects, clinical trials, and nano-delivery systems for targeting NLRP3 inflammasome are also reviewed. NLRP3 inflammasome is targeted by natural polyphenols to exert multiple health effects, which broadens the understanding of polyphenol mechanisms and provides valuable guidance to new researchers in this field.

Ethyl Acetate Extract from Artemisia argyi Prevents Liver Damage in ConA-Induced Immunological Liver Injury Mice via Bax/Bcl-2 and TLR4/MyD88/NF-κB Signaling Pathways

BACKGROUND

Immunological liver injury (ILI) is a common liver disease and lacks potent drugs for treatment. Artemisia argyi Lévl. et Vant. (A. argyi), a medicinal and edible homologous plant usually used in diet therapy to cure various liver diseases, provides a great option for the prevention of ILI.

PURPOSE

To investigate the effect that ethyl acetate extract of A. argyi (AaEA) on Concanavalin A (ConA)-induced ILI and the mechanism of regulating Bax/Bcl-2 and TLR4/MyD88/NF-κB signaling pathways.

METHODS

The chemical components of AaEA were studied by LC-MS. In animal experiments, the positive control group was administrated diammonium glycyrrhizinate (DIG, 100 mg/kg), while different doses of AaEA groups (AaEA-H, AaEA-M, AaEA-L) were pretreated with AaEA 2.00, 1.00, and 0.50 g/kg, respectively, by intragastric for seven days, once every day. Then, ConA (12.00 mg/kg) was used through tail intravenous injection to establish the ILI model. The blood samples and livers were collected to test the degree of liver dysfunction, inflammation, oxidative stress, histopathological changes, and cell apoptosis. Real-time PCR and Western blotting analysis were used to explain the mechanism of regulating Bax/Bcl-2 and TLR4/MyD88/NF-κB signaling pathways.

RESULTS

The way in which AaEA prevents liver damage in immunological liver injury (ILI) mice caused by ConA was investigated for the first time. Pretreatment with AaEA reduced the expression of ALT, AST, and inflammatory factors (TNF-α and IFN-γ). Meanwhile, AaEA also reduced MDA levels but upregulated the contents of IL-4, SOD, and GSH-px, alleviating oxidative stress induced by ILI. Western blotting and real-time PCR analysis demonstrated that AaEA could regulate the expression level and relative mRNA expression of key proteins on Bax/Bcl-2 and TLR4/MyD88/NF-κB signaling pathways. Finally, 504 components from AaEA were identified by LC-MS analysis, mainly including flavones, phenolic acids, and terpenoids with anti-inflammatory and liver protective activities, which highlights the potential of AaEA for diet treatment of ILI.

CONCLUSION

AaEA can work against ConA-induced ILI in mice by regulating Bax/Bcl-2 and TLR4/MyD88/NF-κB signaling pathways, which has the potential to be a great strategy for the prevention of ILI.

Natural products for migraine: Data-mining analyses of Chinese Medicine classical literature

Background: Treatment effect of current pharmacotherapies for migraine is unsatisfying. Discovering new anti-migraine natural products and nutraceuticals from large collections of Chinese medicine classical literature may assist to address this gap. Methods: We conducted a comprehensive search in the Encyclopedia of Traditional Chinese Medicine (version 5.0) to obtain migraine-related citations, then screened and scored these citations to identify clinical management of migraine using oral herbal medicine in history. Information of formulae, herbs and symptoms were further extracted. After standardisation, these data were analysed using frequency analysis and the Apriori algorithm. Anti-migraine effects and mechanisms of actions of the main herbs and formula were summarised. Results: Among 614 eligible citations, the most frequently used formula was chuan xiong cha tiao san (CXCTS), and the most frequently used herb was chuan xiong. Dietary medicinal herbs including gan cao, bai zhi, bo he, tian ma and sheng jiang were identified. Strong associations were constructed among the herb ingredients of CXCTS formula. Symptoms of chronic duration and unilateral headache were closely related with herbs of chuan xiong, gan cao, fang feng, qiang huo and cha. Symptoms of vomiting and nausea were specifically related to herbs of sheng jiang and ban xia. Conclusion: The herb ingredients of CXCTS which presented anti-migraine effects with reliable evidence of anti-migraine actions can be selected as potential drug discovery candidates, while dietary medicinal herbs including sheng jiang, bo he, cha, bai zhi, tian ma, and gan cao can be further explored as nutraceuticals for migraine.

Gandouling Mitigates CuSO4-Induced Heart Injury in Rats

We assessed the protective effects of Gandouling (GDL) on copper sulfate (CuSO4)-induced heart injuries in Sprague−Dawley rats, which were randomly divided into the control, CuSO4, GDL + CuSO4 and penicillamine + CuSO4 groups. The rats received intragastric GDL (400 mg/kg body weight) once per day for 42 consecutive days after 56 days of CuSO4 exposure, and penicillamine was used as a positive control. The levels of plasma inflammatory cytokines (IMA, hFABP, cTn-I and BNP) were determined using the enzyme-linked immunosorbent assay. The histopathological symptoms were evaluated using hematoxylin and eosin staining and transmission electron microscopy. To determine the underlying mechanism, Western blotting was conducted for the detection of the heme oxygenase 1 (HO-1) expression. The results revealed that GDL supplementation alleviated the histopathological symptoms of the rat heart tissue, promoted Cu excretion to attenuate impairment, and significantly decreased inflammatory cytokine levels in the plasma (p < 0.01). In addition, GDL increased the HO-1 expression in the rat hepatic tissue. The protective effect of GDL on the heart was superior to that of penicillamine. Overall, these findings indicate that GDL alleviates hepatic heart injury after a Cu overaccumulation challenge, and GDL supplements can be beneficial for patients with Wilson’s disease.

The role of oxidative stress in ovarian aging: a review

Ovarian aging refers to the process by which ovarian function declines until eventual failure. The pathogenesis of ovarian aging is complex and diverse; oxidative stress (OS) is considered to be a key factor. This review focuses on the fact that OS status accelerates the ovarian aging process by promoting apoptosis, inflammation, mitochondrial damage, telomere shortening and biomacromolecular damage. Current evidence suggests that aging, smoking, high-sugar diets, pressure, superovulation, chemotherapeutic agents and industrial pollutants can be factors that accelerate ovarian aging by exacerbating OS status. In addition, we review the role of nuclear factor E2-related factor 2 (Nrf2), Sirtuin (Sirt), mitogen-activated protein kinase (MAPK), protein kinase B (AKT), Forkhead box O (FoxO) and Klotho signaling pathways during the process of ovarian aging. We also explore the role of antioxidant therapies such as melatonin, vitamins, stem cell therapies, antioxidant monomers and Traditional Chinese Medicine (TCM), and investigate the roles of these supplements with respect to the reduction of OS and the improvement of ovarian function. This review provides a rationale for antioxidant therapy to improve ovarian aging.

The Gut Microbial Metabolite Pyrogallol Is a More Potent Inducer of Nrf2-Associated Gene Expression Than Its Parent Compound Green Tea (-)-Epigallocatechin Gallate

(-)-Epigallocatechin gallate (EGCG) has been associated with multiple beneficial effects. However, EGCG is known to be degraded by the gut microbiota. The present study investigated the hypothesis that microbial metabolism would create major catechol-moiety-containing microbial metabolites with different ability from EGCG to induce nuclear factor-erythroid 2-related factor 2 (Nrf2)-mediated gene expression. A reporter gene bioassay, label-free quantitative proteomics and reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) were combined to investigate the regulation of Nrf2-related gene expression after exposure of U2OS reporter gene or Hepa1c1c7 cells in vitro to EGCG or to its major microbial catechol-moiety-containing metabolites: (-)-epigallocatechin (EGC), gallic acid (GA) and pyrogallol (PG). Results show that PG was a more potent inducer of Nrf2-mediated gene expression than EGCG, with a 5% benchmark dose (BMD₅) of 0.35 µM as compared to 2.45 µM for EGCG in the reporter gene assay. EGC and GA were unable to induce Nrf2-mediated gene expression up to the highest concentration tested (75 µM). Bioinformatical analysis of the proteomics data indicated that Nrf2 induction by PG relates to glutathione metabolism, drug and/or xenobiotics metabolism and the pentose phosphate pathway. Taken together, our findings demonstrate that the microbial metabolite PG is a more potent inducer of Nrf2-associated gene expression than its parent compound EGCG.

Redox and Other Biological Activities of Tea Catechins That May Affect Health: Mechanisms and Unresolved Issues

The beneficial health effects of green tea have been attributed to tea catechins. However, the molecular mechanisms of action, especially those in vivo, remain unclear. This article reviews the redox and other activities of tea catechins, using (-)-epigallocatechin-3-gallate (EGCG), as an example. EGCG is a well-known antioxidant. However, EGCG can be oxidized to generate reactive oxygen species and EGCG quinone. We propose that EGCG quinone can react with Keap-1 to activate Nrf2-regulated cytoprotective enzymes. Tissue levels of catechins are important for their biological activities; a section is devoted to reviewing the biological fates of tea catechins after ingestion. Possible EGCG oxidation in vivo and whether the oligomeric forms are biologically active in animals are discussed. We also review the effects of EGCG on the activities of enzymes, receptors, and other signaling molecules through binding and raise a question about whether the autoxidation of EGCG in vitro may lead to artifacts or misinterpretation in some studies. Finally, we discuss the challenges in the extrapolation of in vitro results to situations in vivo and the translation of laboratory studies to humans.

Tea polyphenols alleviates acetochlor-induced apoptosis and necroptosis via ROS/MAPK/NF-κB signaling in Ctenopharyngodon idellus kidney cells

Overuse of acetochlor pollutes soil and rivers, causing threats to the ecosystem. Studies found that acetochlor exposure could damage multiple organs and tissues in fish and mammal. Tea polyphenols (TP), a natural antioxidant that extracted from tea, has been widely used in food and feed additions. However, the mechanism by which acetochlor causes tissue damage is unclear, and its mitigating agent has yet to be developed. Therefore, we established acetochlor exposure and TP mitigation models by treating Ctenopharyngodon idellus kidney (CIK) cells with 20 μM acetochlor and/or 2.5 μg/mL TP for 24 h, and detected the programmed cell death and its related pathways. The results showed that acetochlor exposure modified antioxidant enzyme activities, induced oxidative stress, resulted in the decline of MMP and ATP levels, enhanced glycolysis and lactate accumulation, and triggered apoptosis and necroptosis in CIK cells. However, TP could inhibit CYP450s expression, activate Nrf2 pathway, enhance antioxidant capacity, further effectively alleviate acetochlor-induced CIK cell death. Overall, the present study proved that acetochlor exposure triggered mitochondrial damage and lactate accumulation-mediated apoptosis and necroptosis through CYP450s/ROS/MAPK/NF-κB pathway. Furthermore, TP could alleviate effectively cell death through relieving oxidative stress and lightening Warburg-like effect.

Green Tea Polyphenols Upregulate the Nrf2 Signaling Pathway and Suppress Oxidative Stress and Inflammation Markers in D-Galactose-Induced Liver Aging in Mice

The beneficial effects of green tea polyphenols (GTPs) on D-galactose (D-Gal)-induced liver aging in male Kunming mice were investigated. For this purpose, 40 adult male Kunming mice were divided into four groups. All animals, except for the normal control and GTPs control, were intraperitoneally injected with D-galactose (D-Gal; 300 mg/kg/day for 5 days a week) for 12 consecutive weeks, and the D-Gal-treated mice were allowed free access to 0.05% GTPs (w/w) diet or normal diet for 12 consecutive weeks. Results showed that GTP administration improved the liver index and decreased transaminases and total bilirubin levels. Furthermore, GTPs significantly increased hepatic glutathione and total antioxidant levels, and the activities of superoxide dismutase, catalase, and glutathione S-transferase (GST). Furthermore, GTPs downregulated 8-hydroxy-2-deoxyguanosine, advanced glycation end products, and hepatic oxidative stress markers, such as malondialdehyde and nitric oxide. Additionally, GTPs abrogated dysregulation in hepatic Kelch-like ECH-associated protein 1 and nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target gene expression [heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1, and GST] and inhibited tumor necrosis factor-α, transforming growth factor-β, and interleukin (IL)-1β and IL-6 in the liver of treated mice. Finally, GTPs effectively attenuated D-Gal-induced edema, vacuole formation, and inflammatory cell infiltration. In conclusion, GTPs showed antioxidant and anti-inflammatory properties in D-Gal-induced aging mice, and may be considered a natural alternative to the effects of hepatic aging.

Tea polyphenols alleviate hydrogen peroxide-induced oxidative stress damage through the Mst/Nrf2 axis and the Keap1/Nrf2/HO-1 pathway in murine RAW264.7 cells

Tea polyphenols (TPs) are the major bioactive extract from green tea that have been extensively reported to prevent and treat oxidative stress damage. In previous studies, TPs have been demonstrated to protect cells against oxidative injury induced by hydrogen peroxide (H₂O₂). However, the underlying mechanism remains unclear. The aim of the current study was to investigate whether the protective and regulatory effects of TPs on oxidative stress damage were dependent on the mammalian STE20-like protein kinase (Mst)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2) axis and the Kelch-like ECH-associated protein 1 (Keap1)/Nrf2/heme oxygenase 1 (HO-1) pathway in RAW264.7 cells, a murine macrophage cell line. Maintaining a certain range of intracellular reactive oxygen species (ROS) levels is critical to basic cellular activities, while excessive ROS generation can override the antioxidant capacity of the cell and result in oxidative stress damage. The inhibition of ROS generation offers an effective target for preventing oxidative damage. The results of the present study revealed that pretreatment with TPs inhibited the production of intracellular ROS and protected RAW264.7 cells from H₂O₂-induced oxidative damage. TPs was also demonstrated to attenuate the production of nitric oxide and malondialdehyde and increase the levels of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase). In addition, following TPs treatment, alterations in Mst1/2 at the mRNA and protein level inhibited the production of ROS and promoted the self-regulation of antioxidation. TPs-induced Keap1 gene downregulation also increased the expression of Nrf2 and HO-1. Collectively, the results of the present study demonstrated that TPs provided protection against H₂O₂-induced oxidative injury in RAW264.7 cells.

Prussian Blue Nanozymes Prevent Anthracycline-Induced Liver Injury by Attenuating Oxidative Stress and Regulating Inflammation

Anthracycline-induced liver injury (AILI) is becoming an increasingly serious and potential clinical complication and is linked to reactive oxygen species (ROS) production and subsequent inflammatory response. Herein, we demonstrated that artificial Prussian blue nanozymes (PBZs) prevented daunorubicin-induced liver injury, a prototype of AILI, by attenuating ROS production and regulating inflammation. PBZs exhibited multienzyme activity and could scavenge ROS and free radicals. At the cellular level, PBZs could effectively eliminate ROS, suppress hepatocyte apoptosis, reduce deoxyribonucleic acid damage, and decrease the levels of inflammatory cytokines and chemokines. According to the results of the in vivo study, pretreatment with PBZs also resulted in a desirable protective effect against AILI, as indicated by both a decrease in biochemical indicator levels and hepatocyte necrosis. PBZs upregulated antioxidative genes by activating the Nrf2 pathway to reduce oxidative stress. Meanwhile, PBZs counteracted the inflammatory response based on the decreased expression levels of myeloperoxidase and F4/80 in the liver. Collectively, our findings indicate that PBZ-based nanotherapy is a novel strategy for protecting against AILI.

Technological applications of phenolic-rich extracts for the development of non-dairy foods and beverages

Fruits and other vegetables are sources of bioactive compounds, especially carotenoids, terpenoids, and phenolic compounds. With the focus on sustainability, these compounds' recovery has become a research trend in the last 20 years. However, the correct use of solvents and the steps required to assess the extracts' suitability to be added in food models have been poorly described. Thus, in this review, we attempt to show the pathways and provide guidance on the tailored-made use of solvents for recovering bioactive polyphenolic compounds from food matrices. Special attention is given to the toxicological safety of polyphenol-rich extracts and also their impacts on bioactivity and sensory acceptance of foods and beverages. Practical examples are described and commented on the applications of polyphenol-rich extracts in non-dairy foods and beverages. In summary, the alliance among food science, food technologies, biochemistry, and pharmacology are required to make the development of non-dairy polyphenol-rich foods feasible.

Multifaceted role of phyto-derived polyphenols in nanodrug delivery systems

As naturally occurring bioactive products, several lines of evidence have shown the potential of polyphenols in the medical intervention of various diseases, including tumors, inflammatory diseases, and cardiovascular diseases. Notably, owing to the particular molecular structure, polyphenols can combine with proteins, metal ions, polymers, and nucleic acids providing better strategies for polyphenol-delivery strategies. This contributes to the inherent advantages of polyphenols as important functional components for other drug delivery strategies, e.g., protecting nanodrugs from oxidation as a protective layer, improving the physicochemical properties of carbohydrate polymer carriers, or being used to synthesize innovative functional delivery vehicles. Polyphenols have emerged as a multifaceted player in novel drug delivery systems, both as therapeutic agents delivered to intervene in disease progression and as essential components of drug carriers. Although an increasing number of studies have focused on polyphenol-based nanodrug delivery including epigallocatechin-3-gallate, curcumin, resveratrol, tannic acid, and polyphenol-related innovative preparations, these molecules are not without inherent shortcomings. The active biochemical characteristics of polyphenols constitute a prerequisite to their high-frequency use in drug delivery systems and likewise to provoke new challenges for the design and development of novel polyphenol drug delivery systems of improved efficacies. In this review, we focus on both the targeted delivery of polyphenols and the application of polyphenols as components of drug delivery carriers, and comprehensively elaborate on the application of polyphenols in new types of drug delivery systems. According to the different roles played by polyphenols in innovative drug delivery strategies, potential limitations and risks are discussed in detail including the influences on the physical and chemical properties of nanodrug delivery systems, and their influence on normal physiological functions inside the organism.

The Potential Role of Polyphenols in Oxidative Stress and Inflammation Induced by Gut Microbiota in Alzheimer's Disease

Gut microbiota (GM) play a role in the metabolic health, gut eubiosis, nutrition, and physiology of humans. They are also involved in the regulation of inflammation, oxidative stress, immune responses, central and peripheral neurotransmission. Aging and unhealthy dietary patterns, along with oxidative and inflammatory responses due to gut dysbiosis, can lead to the pathogenesis of neurodegenerative diseases, especially Alzheimer's disease (AD). Although the exact mechanism between AD and GM dysbiosis is still unknown, recent studies claim that secretions from the gut can enhance hallmarks of AD by disturbing the intestinal permeability and blood-brain barrier via the microbiota-gut-brain axis. Dietary polyphenols are the secondary metabolites of plants that possess anti-oxidative and anti-inflammatory properties and can ameliorate gut dysbiosis by enhancing the abundance of beneficial bacteria. Thus, modulation of gut by polyphenols can prevent and treat AD and other neurodegenerative diseases. This review summarizes the role of oxidative stress, inflammation, and GM in AD. Further, it provides an overview on the ability of polyphenols to modulate gut dysbiosis, oxidative stress, and inflammation against AD.

Molecular mechanisms and applications of tea polyphenols: A narrative review

Tea is a worldwide popular drink with high nutritional and medicinal values as it is rich in nutrients, such as polyphenols, amino acids, vitamins, glycosides, and so on. Among them, tea polyphenols (TPs) are the current research hotspot. TPs are known to have multiple biological activities such as anti-oxidation, anti-tumor, anti-inflammation, anti-bacteria, lowering lipid, and liver protection. By reviewing a large number of literatures, we explained the mechanism of TPs exerting biological activity and a wide range of applications. We also discussed the deficiencies and development potential of TPs, in order to provide theoretical reference and scientific basis for the subsequent development and utilization of TPs. PRACTICAL APPLICATIONS: We summarized the bioactivity mechanisms of TPs in anti-tumor, anti-oxidation, antibacterial, anti-inflammatory, lipid-lowering, and liver protection, focused on its application fields in food and medicine, and discussed the deficiency and development potential of current research on TPs, so as to provide a certain convenient way for scholars studying TPs. It is expected to contribute to the subsequent discovery of biological activity and the broadening of the field of TPs.

Molecular mechanisms underlying health benefits of tea compounds

Tea is one of the three most widely consumed beverages in the world, not only because of its unique flavor but also due to its various health benefits. The bioactive components in tea, such as polyphenols, polysaccharides, polypeptides, pigments, and alkaloids, are the main contributors to its health functions. Based on epidemiological surveys, the consumption of tea and its compounds in daily life has positive effects on cardiovascular diseases, cancers, hepatopathy, obesity, and diabetes mellitus. In experimental studies, the antioxidant, anti-inflammatory, anti-cancer, anti-obesity, cardiovascular protective, liver protective, and hypoglycemic activities of tea and the related mechanisms of action have been widely investigated. The regulation of several classical signaling pathways, such as nuclear factor-κB (NF-κB), AMP activated protein kinase (AMPK), and wingless/integrated (Wnt) signaling, is involved. Clinical trials have also demonstrated the potential of tea products to be applied as dietary supplements and natural medicines. In this paper, we reviewed and discussed the recent literature on the health benefits of tea and its compounds, and specifically explored the molecular mechanisms involved.

Tea polyphenols inhibit the growth and virulence of ETEC K88

Diarrhea caused by Enterotoxigenic Escherichia coli (ETEC) causes high levels of morbidity and mortality in neonatal piglets. Owing to the abuse of antibiotics and emergence of drug resistance, antibiotics are no longer considered only beneficial, but also potentially harmful drugs. Supplements that can inhibit the growth of bacteria are expected to replace antibiotics. Tea polyphenols have numerous important biological functions, including antibacterial, antiviral, antioxidative, anti-inflammatory, and antihypertensive effects. We investigated the role of tea polyphenols in ETEC K88 infection using a mouse model. Pretreating with tea polyphenols attenuated the symptoms induced by ETEC K88. Furthermore, in a cell adherence assay, tea polyphenols inhibited ETEC K88 adherence to IPEC-J2 cells. When cells were infected with ETEC K88, mRNA and protein levels of claudin-1 were significantly decreased compared with those of control cells. However, when cells were pretreated with tea polyphenols, claudin-1 mRNA and protein levels were higher than those in cells without pretreatment upon cell infection with ETEC K88. TLR2 mRNA levels were also higher following cell infection with ETEC K88 when cells were pretreated with tea polyphenols. These data revealed that tea polyphenols could increase the barrier integrity of IPEC-J2 cells by upregulating expression of claudin-1 through activation of TLR2. Tea polyphenols had beneficial effects on epithelial barrier function. Therefore, tea polyphenols could be used as a novel strategy to control and treat pig infections caused by ETEC K88.