(-)-Epigallocatechin-3-gallate suppresses cigarette smoke-induced inflammation in human cardiomyocytes via ROS-mediated MAPK and NF-κB pathways

Epigallocatechin-3-Gallate Inhibits Oxidative Stress Through the Keap1/Nrf2 Signaling Pathway to Improve Alzheimer Disease

Alzheimer disease (AD) is a common neurodegenerative disease with an intricate pathophysiological mechanism. Oxidative stress has been shown in several investigations as a significant factor in AD progression. For instance, studies have confirmed that oxidative stress inhibition may considerably improve AD symptoms, with potent antioxidants being touted as a possible interventional strategy in the search for AD treatment. Epigallocatechin-3-gallate (EGCG) acts as a natural catechin that has antioxidant effect. It activates the kelch-like epichlorohydrin-associated proteins (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway to inhibit oxidative stress. The Keap1/Nrf2 signal pathway is not only an upstream signaling target for a variety of antioxidant enzymes, but also minimizes high levels of reactive oxygen species. This report analyzes the antioxidant effect of EGCG in AD, elaborates its specific mechanism of action, and provides a theoretical basis for its clinical application in AD.

The Preventive Effect of Theabrownin from Ya'an Tibetan Tea Against UVB-Induced Skin Photodamage in BALB/c Mice via the MAPK/NF-κB and Nrf2 Signaling Pathways

Ya'an Tibetan tea, renowned as a mysterious tea, has been used as a traditional remedy for disease prevention among ethnic minorities in the Qinghai-Tibet Plateau region, which experiences the highest levels of UVB radiation in the world, for over 1000 years. Theabrownin (TB) from Ya'an Tibetan tea exhibits various health benefits. In this study, the preventive effects of TB on UVB-induced skin damage were investigated. The results showed that TB pretreatment significantly alleviated visible skin damage, epidermal hyperplasia, and collagen destruction in BALB/c mice. The mechanism of action involved increasing the mRNA and protein levels of Nrf2 and enhancing SOD enzyme activity, thereby reducing MDA content and improving the body's antioxidant capacity. TB also inhibited the protein synthesis of inflammatory factors such as TNF-α, IL-1β, and IL-6, as well as the expression of NF-κB mRNA and protein, thereby reducing skin inflammation. Furthermore, it suppressed the overexpression of p38 MAPK, ERK, and AP-1 mRNA and protein, along with the downstream MMP-1 protein, to prevent collagen destruction in the skin. Additionally, TB pretreatment prevented cell apoptosis by reducing Caspase-3 overexpression. These results suggest that TB can prevent UVB-induced photodamage and exert its preventive effects in a dose-dependent manner by downregulating the MAPK/NF-κB signaling pathway while promoting the Nrf2 signaling pathway in the skin. Consequently, TB holds promising potential for future applications in skin photodamage prevention and skin health promotion.

Biological potential and mechanisms of Tea's bioactive compounds: An Updated review

BACKGROUND

Tea (Camellia sinensis) has a rich history and is widely consumed across many countries, and is categorized into green tea, white tea, oolong tea, yellow tea, black tea, and dark tea based on the level of fermentation. Based on a review of previous literature, the commonly recognized bioactive substances in tea include tea polyphenols, amino acids, polysaccharides, alkaloids, terpenoids, macro minerals, trace elements, and vitamins, which have been known to have various potential health benefits, such as anticancer, antioxidant, anti-inflammatory, anti-diabetes, and anti-obesity properties, cardiovascular protection, immune regulation, and control of the intestinal microbiota. Most studies have only pointed out the characteristics of tea's bioactivities, so a comprehensive summary of the pharmacological characteristics and mechanisms of tea's bioactivities and their use risks are vital.

AIM OF REVIEW

This paper aims to summarize tea's bioactive substances of tea and their pharmacological characteristics and mechanisms, providing a scientific basis for the application of bioactive substances in tea and outlining future research directions for the study of bioactive substances in tea.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review summarizes the main biologically active substances, pharmacological effects, and mechanisms and discusses the potential risks. It may help researchers grasp more comprehensive progress in the study of tea bioactive substances to further promote the application of tea as a natural bioactive substance in the medical field.

The Galloyl Group Enhances the Inhibitory Activity of Catechins against LPS-Triggered Inflammation in RAW264.7 Cells

The galloyl group in catechins was confirmed to be crucial for their health benefits. However, whether the catechins' galloyl group had a contribution to their anti-inflammation remains unclear. This study investigated the anti-inflammation properties and mechanisms of catechins in RAW264.7 cells by using ELISA, fluorometry, flow cytometer, Western blot, and molecular docking. Results showed that the galloyl group enhanced the inhibitory abilities of catechins on inflammatory cytokines (NO, PGE2, IL-1β, and TNF-α) and ROS release in LPS-induced cells. This suppression was likely mediated by delaying cells from the G0/G1 to the S phase, blocking COX-2 and iNOS via the TLR4/MAPK/NF-κB pathway with PU.1 as an upstream target. The research proved that the existence of galloyl groups in catechins was indispensable for their anti-inflammatory capacities and offered a theoretical basis for the anti-inflammatory mechanism of galloylated catechins. Future research is needed to verify the anti-inflammatory effects of catechins in various sources of macrophages or the Caco-2/RAW264.7 cell co-culture system.

Camellia sinensis L. alleviates OVA-induced allergic asthma through NF-κB and MMP-9 pathways

Allergic asthma, a type of chronic airway inflammation, is a global health concern because of its increasing incidence and recurrence rates. Camellia sinensis L. yields a variety type of teas, which are also used as medicinal plants in East Asia and are known to have antioxidant, anti-inflammatory, and immune-potentiating properties. Here, we examined the constituents of C. sinensis L. extract (CSE) and evaluated the protective effects of CSE on allergic asthma by elucidating the underlying mechanism. To induce allergic asthma, we injected the sensitization solution (mixture of ovalbumin (OVA) and aluminum hydroxide) into mice intraperitoneally on days 0 and 14. Then, the mice were exposed to 1% OVA by a nebulizer on days 21 to 23, while intragastric administration of CSE (30 and 100 mg/kg) was performed each day on days 18 to 23. We detected five compounds in CSE, including (-)-epigallocatechin, caffeine, (-)-epicatechin, (-)-epigallocatechin gallate, and (-)-epicatechin gallate. Treatment with CSE remarkably decreased the airway hyperresponsiveness, OVA-specific immunoglobulin E level, and inflammatory cell and cytokine levels of mice, with a decrease in inflammatory cell infiltration and mucus production in lung tissue. Treatment with CSE also decreased the phosphorylation of nuclear factor-κB (NF-κB) and the expression of matrix-metalloproteinase (MMP)-9 in asthmatic mice. Our results demonstrated that CSE reduced allergic airway inflammation caused by OVA through inhibition of phosphorylated NF-κB and MMP-9 expression.

Erythrocyte membrane biomimetic EGCG nanoparticles attenuate renal injury induced by diquat through the NF-κB/NLRP3 inflammasome pathway

Diquat (DQ) poisoning can cause multiple organ damage, and the kidney is considered to be the main target organ. Increasing evidence shows that alleviating oxidative stress and inflammatory response has promising application prospects. Epigallocatechin gallate (EGCG) has potent antioxidant and anti-inflammatory effects. In this study, red blood cell membrane (RBCm)-camouflaged polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) were synthesized to deliver EGCG (EGCG-RBCm/NPs) for renal injury induced by DQ. Human renal tubular epithelial cells (HK-2 cells) were stimulated with 600 μM DQ for 12 h and mice were intraperitoneally injected with 50 mg/kg b.w. DQ, followed by 20 mg/kg b.w./day EGCG or EGCG-RBCM/NPs for 3 days. The assessment of cellular vitality was carried out using the CCK-8 assay, while the quantification of reactive oxygen species (ROS) was performed through ROS specific probes. Apoptosis analysis was conducted by both flow cytometry and TUNEL staining methods. Pathological changes in renal tissue were observed. The expressions of NLRP3, IL-1β, IL-18, NFκB and Caspase1 were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunohistochemistry, immunofluorescence, and Western blot. The results showed that the DQ group had increased ROS expression, increased the level of oxidative stress, and increased apoptosis rate compared with the control group. Histopathological analysis of mice in the DQ group showed renal tubular injury and elevated levels of blood urea nitrogen (BUN), serum creatinine (SCr), kidney injury molecule-1 (KIM-1), and cystatin C (Cys C). Furthermore, the DQ group exhibited heightened expression of NLRP3, p-NFκB p65, Caspase1 p20, IL-1β, and IL-18. However, EGCG-RBCm/NPs treatment mitigated DQ-induced increases in ROS, apoptosis, and oxidative stress, as well as renal toxicity and decreases in renal biomarker levels. Meanwhile, the expression of the above proteins were significantly decreased, and the survival rate of mice was ultimately improved, with an effect better than that of the EGCG treatment group. In conclusion, EGCG-RBCm/NPs can improve oxidative stress, inflammation, and apoptosis induced by DQ. This effect is related to the NF-κB/NLRP3 inflammasome pathway. Overall, this study provides a new approach for treating renal injury induced by DQ.

Research progress of procyanidins in repairing cartilage injury after anterior cruciate ligament tear

Anterior cruciate ligament (ACL) tear is a common sports-related injury, and cartilage injury always emerges as a serious complication following ACL tear, significantly impacting the physical and psychological well-being of affected individuals. Over the years, efforts have been directed toward finding strategies to repair cartilage injury after ACL tear. In recent times, procyanidins, known for their anti-inflammatory and antioxidant properties, have emerged as potential key players in addressing this concern. This article focuses on summarizing the research progress of procyanidins in repairing cartilage injury after ACL tear. It covers the roles, mechanisms, and clinical significance of procyanidins in repairing cartilage injury following ACL tear and explores the future prospects of procyanidins in this domain. This review provides novel insights and hope for the repair of cartilage injury following ACL tear.

(-)-Epigallocatechin-3-gallate promotes intestinal epithelial proliferation and barrier function after ischemia/reperfusion injury via activation of Nurr1

CONTEXT

(-)-Epigallocatechin-3-gallate (EGCG) is involved in cell proliferation and ischemia/reperfusion (I/R) injury of several organs.

OBJECTIVE

To identify the role of EGCG in intestinal epithelial proliferation and barrier exposed to I/R injury.

MATERIAL AND METHODS

Fifty Sprague-Dawley rats were divided into sham, I/R, I/R + EGCG (12.5 mg/kg), I/R + EGCG (25 mg/kg) and I/R + EGCG (50 mg/kg). I/R group rats were subjected to intestinal ischemia for 1 h and 6 h reperfusion. The rats were supplemented with EGCG 12.5, 25 and 50 mg/kg daily for 3 days via intraperitoneal injection before surgery. We used IEC-6 to expose to hypoxia/reoxygenation (H/R) injury to mimic I/R in vivo. IEC-6 cells were divided into control, H/R and H/R + EGCG (40 μmol/L). The effects of EGCG and its mechanism was explored.

RESULTS

Pharmacological treatment with EGCG notably improves intestinal epithelial proliferation (12.5 mg/kg, 1.74-fold; 25 mg/kg, 2.93-fold, and 50 mg/kg, 4.33-fold) and barrier function after I/R injury. EGCG promoted cell proliferation (2.99-fold) and increased the expression of occludin (2.36-fold) and ZO-1 (1.64-fold) in IEC-6 cells after H/R injury. EGCG promoted proliferation of IEC-6 cells with ED50 values of 18.16 μmol/L. Further investigations indicated that EGCG activated Nurr1 expression in intestine after I/R injury. EGCG promote cell proliferation and increased the expression of occludin and ZO-1 in IEC-6 cells after H/R injury were abrogated in the knockdown of Nurr1 by siRNA.

DISCUSSION AND CONCLUSION

Our findings indicate that EGCG promotes intestinal epithelial cell proliferation and barrier function after I/R injury in vitro and in vivo via activation of Nurr1.

Anti-Inflammatory Effects of Dietary Polyphenols through Inhibitory Activity against Metalloproteinases

Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases that play important roles in a variety of diseases, including cancer, cardiovascular disease, diabetes, obesity, and brain diseases. Dietary polyphenols are thought to have a variety of beneficial effects on these diseases characterized by inflammation. Clinical studies have demonstrated that MMPs are in most cases upregulated in various inflammatory diseases, including osteoarthritis, rheumatoid arthritis, inflammatory bowel disease, and Alzheimer's disease. Studies using patient-derived human samples, animal studies, and cellular experiments have suggested that polyphenols may be beneficial against inflammatory diseases by suppressing MMP gene expression and enzyme activity. One important mechanism by which polyphenols exert their activity is the downregulation of reactive oxygen species that promote MMP expression. Another important mechanism is the direct binding of polyphenols to MMPs and their inhibition of enzyme activity. Molecular docking analyses have provided a structural basis for the interaction between polyphenols and MMPs and will help to explore new polyphenol-based drugs with anti-inflammatory properties.

An integral perspective of canonical cigarette and e-cigarette-related cardiovascular toxicity based on the adverse outcome pathway framework

BACKGROUND

Nowadays, cigarette smoking remains the leading cause of chronic disease and premature death, especially cardiovascular disease. As an emerging tobacco product, e-cigarettes have been advocated as alternatives to canonical cigarettes, and thus may be an aid to promote smoking cessation. However, recent studies indicated that e-cigarettes should not be completely harmless to the cardiovascular system.

AIM OF REVIEW

This review aimed to build up an integral perspective of cigarettes and e-cigarettes-related cardiovascular toxicity.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review adopted the adverse outcome pathway (AOP) framework as a pivotal tool and aimed to elucidate the association between the molecular initiating events (MIEs) induced by cigarette and e-cigarette exposure to the cardiovascular adverse outcome. Since the excessive generation of reactive oxygen species (ROS) has been widely approved to play a critical role in cigarette smoke-related CVD and may also be involved in e-cigarette-induced toxic effects, the ROS overproduction and subsequent oxidative stress are regarded as essential parts of this framework. As far as we know, this should be the first AOP framework focusing on cigarette and e-cigarette-related cardiovascular toxicity, and we hope our work to be a guide in exploring the biomarkers and novel therapies for cardiovascular injury.

Redox Signaling Modulates Activity of Immune Checkpoint Inhibitors in Cancer Patients

Although immunotherapy is already a staple of cancer care, many patients may not benefit from these cutting-edge treatments. A crucial field of research now focuses on figuring out how to improve treatment efficacy and assess the resistance mechanisms underlying this uneven response. For a good response, immune-based treatments, in particular immune checkpoint inhibitors, rely on a strong infiltration of T cells into the tumour microenvironment. The severe metabolic environment that immune cells must endure can drastically reduce effector activity. These immune dysregulation-related tumour-mediated perturbations include oxidative stress, which can encourage lipid peroxidation, ER stress, and T regulatory cells dysfunction. In this review, we have made an effort to characterize the status of immunological checkpoints, the degree of oxidative stress, and the part that latter plays in determining the therapeutic impact of immunological check point inhibitors in different neoplastic diseases. In the second section of the review, we will make an effort to assess new therapeutic possibilities that, by affecting redox signalling, may modify the effectiveness of immunological treatment.

Therapeutic actions of tea phenolic compounds against oxidative stress and inflammation as central mediators in the development and progression of health problems: A review focusing on microRNA regulation

Many health problems including chronic diseases are closely associated with oxidative stress and inflammation. Tea has abundant phenolic compounds with various health benefits including antioxidant and anti-inflammatory properties. This review focuses on the present understanding of the impact of tea phenolic compounds on the expression of miRNAs, and elucidates the biochemical and molecular mechanisms underlying the transcriptional and post-transcriptional protective actions of tea phenolic compounds against oxidative stress- and/or inflammation-mediated diseases. Clinical studies showed that drinking tea or taking catechin supplement on a daily basis promoted the endogenous antioxidant defense system of the body while inhibiting inflammatory factors. The regulation of chronic diseases based on epigenetic mechanisms, and the epigenetic-based therapies involving different tea phenolic compounds, have been insufficiently studied. The molecular mechanisms and application strategies of miR-27 and miR-34 involved in oxidative stress response and miR-126 and miR-146 involved in inflammation process were preliminarily investigated. Some emerging evidence suggests that tea phenolic compounds may promote epigenetic changes, involving non-coding RNA regulation, DNA methylation, histone modification, ubiquitin and SUMO modifications. However, epigenetic mechanisms and epigenetic-based disease therapies involving phenolic compounds from different teas, and the potential cross-talks among the epigenetic events, remain understudied.

Therapeutic Effects of Green Tea Polyphenol (‒)-Epigallocatechin-3-Gallate (EGCG) in Relation to Molecular Pathways Controlling Inflammation, Oxidative Stress, and Apoptosis

(‒)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea. Thanks to multiple interactions with cell surface receptors, intracellular signaling pathways, and nuclear transcription factors, EGCG possesses a wide variety of anti-inflammatory, antioxidant, antifibrotic, anti-remodelation, and tissue-protective properties which may be useful in the treatment of various diseases, particularly in cancer, and neurological, cardiovascular, respiratory, and metabolic disorders. This article reviews current information on the biological effects of EGCG in the above-mentioned disorders in relation to molecular pathways controlling inflammation, oxidative stress, and cell apoptosis.

Epigallocatechin-3-gallate (EGCG) attenuates inflammatory responses and oxidative stress in lipopolysaccharide (LPS)-induced endometritis via silent information regulator transcript-1 (SIRT1)/nucleotide oligomerization domain (NOD)-like receptor pyrin domain-containing 3 (NLRP3) pathway

The protective effects of epigallocatechin-3-gallate (EGCG) on lipopolysaccharide (LPS)-induced endometritis in vivo and in vitro will be explored in this study. The endometritis model was induced in female BALB/c mice uterus by perfusion with lipopolysaccharide (LPS) and EGCG were administered at 1 h before LPS induction. The primary bovine endometrial epithelial cells (BEECs) were treated with EGCG for 1 h before LPS stimulation. Uterine histopathological changes, myeloperoxidase (MPO) activity, inflammatory cytokine levels and oxidative stress markers were determined. The extent of Bax, Bcl-2, cleaved caspase-3, silent information regulator transcript-1 (SIRT1), nucleotide oligomerization domain (NOD)-like receptor pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein (ASC) and Caspase1 was detected by Western blot and real-time quantitative PCR assays. The results showed that EGCG significantly reversed the LPS-induced uterine histopathological changes, MPO activity, pro-inflammatory cytokine levels. Additionally, EGCG decreased oxidative stress and reduced cell apoptosis by upregulating SIRT1 expression, downregulating the NLRP3 inflammasome activation. These findings indicated that EGCG exerted its greatest protective effects by blocking inflammatory responses, lowering oxidative stress, and reducing apoptosis via the SIRT1/NLRP3, making its promising candidate treatment for endometritis.

Epigallocatechin gallate as a nutraceutical to potentially target the metabolic syndrome: novel insights into therapeutic effects beyond its antioxidant and anti-inflammatory properties

Epigallocatechin gallate (EGCG) is one of the most abundant and powerful flavonoids contained in green tea. Because of the global increase in green tea consumption, there has been a general interest in understanding its health benefits, including its bioactive compounds like EGCG. Indeed, preclinical evidence already indicates that EGCG demonstrated a strong antioxidant and anti-inflammatory properties that could be essential in protecting against metabolic syndrome. The current review explores clinical evidence reporting on the beneficial effects of EGCG supplementation in obese subjects or patients with diverse metabolic complications that include type 2 diabetes and cardiovascular disease. The discussion incorporates the impact of different formulations of EGCG, as well as the effective doses and treatment duration. Importantly, besides highlighting the potential use of EGCG as a nutraceutical, the current review also discusses crucial evidence related to its pharmaceutical development as an agent to hinder metabolic diseases, including its bioavailability and metabolism profile, as well as its well-known biological properties.

Analysis of the role and mechanism of EGCG in septic cardiomyopathy based on network pharmacology

Background

Septic cardiomyopathy (SC) is a common complication of sepsis that leads to an increase in mortality. The pathogenesis of septic cardiomyopathy is unclear, and there is currently no effective treatment. EGCG (epigallocatechin gallate) is a polyphenol that has anti-inflammatory, antiapoptotic, and antioxidative stress effects. However, the role of EGCG in septic cardiomyopathy is unknown.

Methods

Network pharmacology was used to predict the potential targets and molecular mechanisms of EGCG in the treatment of septic cardiomyopathy, including the construction and analysis of protein-protein interaction (PPI) network, gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and molecular docking. The mouse model of septic cardiomyopathy was established after intraperitoneal injection of LPS (lipopolysaccharide). The myocardial protective effect of EGCG on septic mice is observed by cardiac ultrasound and HE staining. RT-PCR is used to verify the expression level of the EGCG target in the septic cardiomyopathy mouse model.

Results

A total of 128 anti-SC potential targets of EGCGareselected for analysis. The GO enrichment analysis and KEGG pathway analysis results indicated that the anti-SC targets of EGCG mainly participate in inflammatory and apoptosis processes. Molecular docking results suggest that EGCG has a high affinity for the crystal structure of six targets (IL-6 (interleukin-6), TNF (tumor necrosis factor), Caspase3, MAPK3 (Mitogen-activated protein kinase 3), AKT1, and VEGFA (vascular endothelial growth factor)), and the experimental verification result showed levated expression of these 6 hub targets in the LPS group, but there is an obvious decrease in expression in the LPS + EGCG group. The functional and morphological changes found by echocardiography and HE staining show that EGCG can effectively improve the cardiac function that is reduced by LPS.

Conclusion

Our results reveal that EGCG may be a potentially effective drug to improve septic cardiomyopathy. The potential mechanism by which EGCG improves myocardial injury in septic cardiomyopathy is through anti-inflammatory and anti-apoptotic effects. The anti-inflammatory and anti-apoptotic effects of EGCG occur not only through direct binding to six target proteins (IL-6,TNF-α, Caspase3, MAPK3, AKT1, and VEGFA) but also by reducing their expression.

Epigallocatechin-3-Gallate (EGCG): New Therapeutic Perspectives for Neuroprotection, Aging, and Neuroinflammation for the Modern Age

Alzheimer’s and Parkinson’s diseases are the two most common forms of neurodegenerative diseases. The exact etiology of these disorders is not well known; however, environmental, molecular, and genetic influences play a major role in the pathogenesis of these diseases. Using Alzheimer’s disease (AD) as the archetype, the pathological findings include the aggregation of Amyloid Beta (Aβ) peptides, mitochondrial dysfunction, synaptic degradation caused by inflammation, elevated reactive oxygen species (ROS), and cerebrovascular dysregulation. This review highlights the neuroinflammatory and neuroprotective role of epigallocatechin-3-gallate (EGCG): the medicinal component of green tea, a known nutraceutical that has shown promise in modulating AD progression due to its antioxidant, anti-inflammatory, and anti-aging abilities. This report also re-examines the current literature and provides innovative approaches for EGCG to be used as a preventive measure to alleviate AD and other neurodegenerative disorders.

N-Acetylcysteine Slows Down Cardiac Pathological Remodeling by Inhibiting Cardiac Fibroblast Proliferation and Collagen Synthesis

Objective

By observing the effect of N-acetylcysteine (NAC) on the proliferation and collagen synthesis of rat cardiac fibroblasts (CFs) to explore the effect of NAC on cardiac remodeling (CR).

Methods

In vivo, first, the Sprague Dawley (SD) rat myocardial hypertrophy model was constructed, and the effect of NAC on cardiac structure and function was detected by echocardiography, serological testing, and Masson staining. Western blotting (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression level of antioxidant enzymes, and flow cytometry was used to detect the intracellular reactive oxygen species (ROS) content. In vitro, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and 5-ethynyl-2′-deoxyuridine (EdU) staining were used to detect cell proliferation, and the expression level of the NF-κB signaling pathway was detected.

Results

Compared with the control group, the model group had disordered cardiac structure, reduced cardiac function, and obvious oxidative stress (OS) response. However, after NAC treatment, it could obviously improve the rat cardiac structure and cardiac function and alleviate redox imbalance and cardiology remodeling. At the same time, NAC can inhibit the activation of the NF-κB signaling pathway and reduce the proliferation level of CFs and the amount of ³H proline incorporated.

Conclusions

NAC can inhibit AngII-induced CF proliferation and collagen synthesis through the NF-κB signaling pathway, alleviate the OS response of myocardial tissue, inhibit the fibrosis of myocardial tissue, and thus slow down the pathological remodeling of the heart.

Epigallocatechin gallate (EGCG) attenuates staphylococcal alpha-hemolysin (Hla)-induced NLRP3 inflammasome activation via ROS-MAPK pathways and EGCG-Hla interactions

Alpha-hemolysin (Hla), the virulence factor secreted by Staphylococcus aureus (S. aureus), plays a critical role in infection and inflammation, which is a severe health burden worldwide. Therefore, it is necessary to develop a drug against Hla. Epigallocatechin gallate (EGCG), a polyphenol extracted from green tea, has excellent anti-inflammatory activity. In this study, we investigated the inhibitory effect of EGCG on Hla-induced NLRP3 inflammasome activation in vitro and in vivo and elucidated the potential molecular mechanism. We found that EGCG attenuated the hemolysis of Hla by inhibiting its secretion. Besides, EGCG significantly decreased overproduction of ROS and activation of MAPK signaling pathway induced by Hla, thereby markedly attenuating the expression of NLRP3 inflammasome-related proteins in THP-1 cells. Notably, EGCG could spontaneously bind to Hla with affinity constant of 1.71 × 10-4 M, thus blocking the formation of the Hla heptamer. Moreover, Hla-induced expression of NLRP3, ASC and caspase-1 protein and generation of IL-1β and IL-18 in the damaged liver tissue of mice were also significantly suppressed by EGCG in a dose-dependent manner. Collectively, EGCG could be a promising candidate for alleviating Hla-induced the activation of NLRP3 inflammasome, depending on ROS mediated MAPK signaling pathway, and inhibition of Hla secretion and heptamer formation. These findings will enlighten the applications of EGCG to reduce the S. aureus infection by targeting Hla in food and related pharmaceutical fields.

Comprehensive Mechanism, Novel Markers and Multidisciplinary Treatment of Severe Acute Pancreatitis-Associated Cardiac Injury - A Narrative Review

Acute pancreatitis (AP) is one of the common acute abdominal inflammatory diseases in clinic with acute onset and rapid progress. About 20% of the patients will eventually develop into severe acute pancreatitis (SAP) characterized by a large number of inflammatory cells infiltration, gland flocculus flaky necrosis and hemorrhage, finally inducing systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Pancreatic enzyme activation, intestinal endotoxemia (IETM), cytokine activation, microcirculation disturbance, autonomic nerve dysfunction and autophagy dysregulation all play an essential role in the occurrence and progression of SAP. Organ dysfunction is the main cause of early death in SAP. Acute kidney injury (AKI) and acute lung injury (ALI) are common, while cardiac injury (CI) is not, but the case fatality risk is high. Many basic studies have observed obvious ultrastructure change of heart in SAP, including myocardial edema, cardiac hypertrophy, myocardial interstitial collagen deposition. Moreover, in clinical practice, patients with SAP often presented various abnormal electrocardiogram (ECG) and cardiac function. Cases complicated with acute myocardial infarction and pericardial tamponade have also been reported and even result in stress cardiomyopathy. Due to the molecular mechanisms underlying SAP-associated cardiac injury (SACI) remain poorly understood, and there is no complete, unified treatment and sovereign remedy at present, this article reviews reports referring to the pathogenesis, potential markers and treatment methods of SACI in recent years, in order to improve the understanding of cardiac injury in severe pancreatitis.

Circular RNA circACSL1 aggravated myocardial inflammation and myocardial injury by sponging miR-8055 and regulating MAPK14 expression

Myocarditis (MC) is a common, potentially life-threatening inflammatory disease of the myocardium. A growing body of evidence has shown that mitogen-activated protein kinase 14 (MAPK14) participates in the pathogenesis of MC. However, the upstream regulators of MAPK14 remain enigmatic. Circular RNAs (circRNAs) have been identified to play vital roles in the pathophysiology of cardiovascular diseases. Nevertheless, the clinical significance, biological function, and regulatory mechanisms of circRNAs in MC remain poorly understood. In this study, we determined a novel circRNA, circACSL1 (ID: hsa_circ_0071542), which was significantly upregulated in the acute phase of MC, and its dynamic change in expression was related to the progression of MC. We used lipopolysaccharide (LPS) to induce the inflammatory responses in the human cardiomyocytes (HCM) line for in vitro and in cellulo experiments. The pro-inflammatory factors (IL-1β, IL-6, and TNF-α), myocardial injury markers (cTnT, CKMB, and BNP), cell viability, and cell apoptosis were measured to evaluate the extent of myocardial inflammation and myocardial injury level. Functional experiments, including gain-of-function and loss-of-function, were then performed to investigate the pro-inflammatory roles of circACSL1. The results revealed that circACSL1 could aggravate inflammation, myocardial injury, and apoptosis in HCM. Mechanistically, circACSL1 acted as a sponge for miR-8055-binding sites to regulate the downstream target MAPK14 expression. Furthermore, overexpression of miR-8055 rescued the pro-inflammatory effects of circACSL1 on HCM, and the upregulation of MAPK14 induced by circACSL1 was attenuated by miR-8055 overexpression. Knockdown of circACSL1 or overexpression of miR-8055 reduced myocardial inflammation and myocardial injury level and these effects were rescued by overexpression of MAPK14. In summary, our study demonstrated that circACSL1 could aggravate myocardial inflammation and myocardial injury through competitive absorption of miR-8055, thereby upregulating MAPK14 expression. Moreover, circACSL1 may represent a potential novel biomarker for the precise diagnosis of MC and offer a promising therapeutic target for MC treatment.

Amelioration of N,N'-dimethylhydrazine induced colon toxicity by epigallocatechin gallate in Wistar rats

Colon cancer is a life-threatening disease all over the world and is linked to constant oxidative stress and inflammation. Epigallocatechin gallate (EGCG), is a naturally occurring flavone possessing health benefiting pharmacological properties including antioxidant, anti-inflammatory and free radical scavenging properties. Our study investigates the role of EGCG on N,N'-dimethylhydrazine (DMH), a toxic environmental pollutant, induced colon toxicity. To investigate the effect of EGCG, Wistar rats were given EGCG for 7 days at the two doses of 10 and 20 mg/kg body weight and DMH was injected on the seventh day in all the group rats except the control. Our results indicate that DMH administration increased the oxidative stress (MDA) and depleted the glutathione and antioxidant enzyme activities (SOD, CAT, GR, GST and GPx) which was significantly ameliorated by EGCG treatment. Additionally DMH treatment upregulated inflammatory markers expression (NF-κB, COX-2 and IL-6) and enhanced mucosal damage in the colon. EGCG treatment significantly reduced inflammation and restored the normal histoarchitecture of the colon. We can conclude from the present study findings that EGCG protects the colon from DMH toxicity through its antioxidant and anti-inflammatory potential.

Eurotium cristatum Fermented Loose Dark Tea Ameliorates Cigarette Smoke-Induced Lung Injury by MAPK Pathway and Enhances Hepatic Metabolic Detoxification by PXR/AhR Pathway in Mice

Cigarette smoke- (CS-) induced oxidative stress and inflammation in the lung are serious health problems. Primary and reprocessed tea products contain multiple antioxidants that have been reported to protect the lung against CS-induced injury. However, the beneficial effects of Eurotium cristatum fermented loose dark tea (ECT) and Eurotium cristatum particle metabolites (ECP) on CS-induced lung injury and its potential hepatic metabolic detoxification are still unclear. Therefore, sixty mice were randomly divided into six equal groups. CS-exposed mice were prevented or treated with ECP or ECT infusions for 12 or 8 weeks to determine the antioxidative stress, anti-inflammatory and potential metabolic detoxification of ECT and ECP. Thirty-six mice were randomly divided into six equal groups to observe the effects on hepatic metabolic detoxification by replacing daily drinking water with ECT. Results showed that CS significantly decreased the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and upregulated the expressions of malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8, and IL-1β in serum. These adverse effects were modulated by ECP and ECT. In addition, ECT upregulated the mRNA expression of pregnane X receptor (PXR) and cytochrome P450 (CYP450) in the liver on daily free drinking ECT mice group. Western blot analysis further revealed that in CS-exposed mice, ECP and ECT significantly decreased the phosphorylation of mitogen-activated protein kinase (MAPK) in the lung but upregulated the protein expressions of PXR and aryl hydrocarbon receptor (AhR) in the liver. Overall, our findings demonstrated that ECT and ECP protected against lung injury induced by CS via MAPK pathway and enhanced hepatic metabolic detoxification via PXR and AhR pathways. Therefore, daily intake of ECT and ECP can potentially protect against CS-induced oxidative and inflammatory injuries.

Inhibition of TLR4/MAPKs Pathway Contributes to the Protection of Salvianolic Acid A Against Lipotoxicity-Induced Myocardial Damage in Cardiomyocytes and Obese Mice

The occurrence of lipotoxicity during obesity-associated cardiomyopathy is detrimental to health. Salvianolic acid A (SAA), a natural polyphenol extract of Salvia miltiorrhiza Bunge (Danshen in China), is known to be cardioprotective. However, its clinical benefits against obesity-associated cardiomyocyte injuries are unclear. This study aimed at evaluating the protective effects of SAA against lipotoxicity-induced myocardial injury and its underlying mechanisms in high fat diet (HFD)-fed mice and in palmitate-treated cardiomyocyte cells (H9c2). Our analysis of aspartate aminotransferase and creatine kinase isoenzyme-MB (CM-KB) levels revealed that SAA significantly reversed HFD-induced myocardium morphological changes and improved myocardial damage. Salvianolic acid A pretreatment ameliorated palmitic acid-induced myocardial cell death and was accompanied by mitochondrial membrane potential and intracellular reactive oxygen species improvement. Analysis of the underlying mechanisms showed that SAA reversed myocardial TLR4 induction in HFD-fed mice and H9c2 cells. Palmitic acid-induced cell death was significantly reversed by CLI-95, a specific TLR4 inhibitor. TLR4 activation by LPS significantly suppressed SAA-mediated lipotoxicity protection. Additionally, SAA inhibited lipotoxicity-mediated expression of TLR4 target genes, including MyD88 and p-JNK/MAPK in HFD-fed mice and H9c2 cells. However, SAA did not exert any effect on palmitic acid-induced SIRT1 suppression and p-AMPK induction. In conclusion, our data shows that SAA protects against lipotoxicity-induced myocardial damage through a TLR4/MAPKs mediated mechanism.

Catechins from oolong tea improve uterine defects by inhibiting STAT3 signaling in polycystic ovary syndrome mice

Background

It is showed that inflammation is causative factor for PCOS, leading to a decline in ovarian fertility. Previous studies have reported that tea consumption can reduce the incidence of ovarian cancer. We speculate that catechins from oolong tea (Camellia sinensis (L.) O. Kuntze) may have a potential therapeutic effect on PCOS. This study aims to investigate the effects of oolong tea catechins on the uterus of polycystic ovary syndrome (PCOS) mice induced by insulin combined with human chorionic gonadotropin (hCG).

Methods

Sixty female mice were divided into 6 groups (n = 10): model, model + Metformin 200 mg/kg, model + catechins 25 mg/kg, model + catechins 50 mg/kg, and model + catechins 100 mg/kg. Another forty female mice were divided into 4 groups (n = 10): control, control + catechins 100 mg/kg, model, and model + catechins 100 mg/kg. Ovarian and uterine weight coefficients, sex hormone levels, glucose metabolism and insulin resistance, and ovarian and uterine pathology were examined. Changes in NF-κB-mediated inflammation, MMP2 and MMP9 expressions, and STAT3 signaling were evaluated in the uterus of mice.

Results

Catechins could effectively reduce the ovarian and uterine organ coefficients, reduce the levels of E2, FSH and LH in the blood and the ratio of LH/FSH, and improve glucose metabolism and insulin resistance in PCOS mice induced by insulin combined with hCG. In addition, catechins could significantly down-regulated the expression of p-NF-κB p65 in the uterus and the protein expressions of the pro-inflammatory factors (IL-1β, IL-6, and TNF-α). The expressions of mmp2 and mmp9 associated with matrix degradation in uterine tissue were also significantly down-regulated by catechins. Further, catechins significantly reduced the expression of p-STAT3 and increased the expression of p-IRS1 and p-PI3K in the uterus of PCOS mice.

Conclusion

Catechins from oolong tea can alleviate ovarian dysfunction and insulin resistance in PCOS mice by inhibiting uterine inflammation and matrix degradation via inhibiting p-STAT3 signaling.

N-Ethyl-2-Pyrrolidinone-Substituted Flavan-3-Ols with Anti-inflammatory Activity in Lipopolysaccharide-Stimulated Macrophages Are Storage-Related Marker Compounds for Green Tea

Fresh green tea (GT) is commonly considered to have better sensory flavor and higher commercial value than long-term-stored GT; however, the chemical variations during storage are unclear. In this study, the chemical profiles of stored GT were surveyed among time-series samples from 0 to 19 months using a nontargeted metabolomics method. Seven N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) increased from 0.022 ± 0.019 to 3.212 ± 0.057 mg/g within 19 months (correlation coefficients with storage duration ranging from 0.936 to 0.965), and they were the most significantly increased compounds among the 127 identified compounds. Two representative EPSFs (R-EGCG-cThea and S-EGCG-cThea) possess potential anti-inflammatory properties by suppressing the expression, phosphorylation, and nuclear translocation of nuclear factor kappa-B (NF-κB) p65 in lipopolysaccharide-stimulated macrophages based on western blotting and immunofluorescence results. In conclusion, EPSFs were found to be marker compounds for stored GT and showed potential anti-inflammatory activity by regulating the NF-κB signaling pathway.

Therapeutic potential of ALKB homologs for cardiovascular disease

Cardiovascular diseases (CVDs) are the leading causes of human death. Recently, ALKB homologs, including ALKBH1-8 and FTO, have been found to have a variety of biological functions, such as histone demethylation, RNA demethylation, and DNA demethylation. These functions may regulate the physiological and pathological processes of CVDs, including inflammation, oxidative stress, cell apoptosis, and mitochondrial, endothelial, and fat metabolism dysfunction. In the present review, we summarize the biological functions of ALKB homologs and the relationship between the ALKB homologs and CVDs. Importantly, we discuss the roles of ALKB homologs in the regulation of oxidative stress, inflammation, autophagy, and DNA damage in CVDs, as well as the practical applications of ALKB homologs inhibitors or agonists in treating CVDs. In conclusion, the ALKBH family might be a promising target for CVDs therapy.

Epigallocatechin-3-gallate protects immunity and liver drug-metabolism function in mice loaded with restraint stress

(-)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic compound present in green tea and has been shown to possess bio-activities. In this study, we investigated the protective effects of EGCG against restraint stress (RS)-induced liver injury and immunosuppression. EGCG (10, 20 and 40 mg/kg) was orally administered to mice daily for 7 days before modeling the restraint stress. lood, liver and broncho-alveolar lavage fluid (BALF) samples were collected and tested. We found that EGCG significantly reduced the release of stress hormones to weak restraint stress response. EGCG effectively improved hepatic damage by decreas the serum levels of alanine aminotransaminase (ALT) and aspartate transaminase (AST) in restraint-challenged mice. Furthermore, EGCG also significantly prevented the release of H2O2, NOS and 8-isoprostane, and reduced the levels of interleukin (IL)-1β, IL-2,and IL-6 restrained mice. EGCG can normal the level of cytochrome P450 (CYP450) 1A2, 2D22, 2E1 and 3A11 that induced by restraint stress., the inhibition status of T cells subsets in serum and gA in BALF were significantly relieved EGCG pretreatment. Taken together, our data suggest that EGCG possesse hepatic- and immune-protective properties against restraint stress through its anti-oxidant, anti-inflammatory and immunomodulatory activities.

Association between heart rate variability indices and features of spontaneous ventricular tachyarrhythmias in mice

Direct evidence is limited for the association between heart rate variability (HRV) indices and ventricular tachyarrhythmias (VTAs). While galectin-3 (Gal-3) is regarded as a causal factor for cardiac remodelling and a biomarker for arrhythmias, its regulation on VTAs and HVR is unknown. Using aged transgenic (TG) mice with cardiac overexpression of β2 -adrenoceptors and spontaneous VTAs, we studied whether changes in HRV indices correlated with the severity of VTAs, and whether Gal-3 gene knockout (KO) in TG mice might limit VTA. Body-surface ECG was recorded (10-minute period) in 9- to 10-month-old mice of non-transgenic (nTG), TG and TG × Gal-3 knockout (TG/KO). Time-domain, frequency-domain and nonlinear-domain HRV indices were calculated using the R-R intervals extracted from ECG signals and compared with frequency of VTAs. TG and TG/KO mice developed frequent VTAs and showed significant changes in certain time-domain and nonlinear-domain HRV indices relative to nTG mice. The severity of VTAs in TG and TG/KO mice in combination, estimated by VTA counts and arrhythmia score, was significantly correlated with certain time-domain and nonlinear-domain HRV indices. In conclusion, significant changes in HRV indices were evident and correlated with the severity of spontaneous VTAs in TG mice. The frequency of VTA and HRV indices were largely comparable between TG and TG/KO mice. Deletion of Gal-3 in TG mice altered certain HRV indices implying influence by neuronally localized Gal-3 on autonomic nervous activity.

Coumaroyl Flavonol Glycosides and More in Marketed Green Teas: An Intrinsic Value beyond Much-Lauded Catechins

Marketed green teas (GTs) can highly vary in their chemical composition, due to different origins, processing methods, and a lack of standardization of GT-based products. Consequently, biological activities become difficult to correlate to the presence/content of certain constituents. Herein, ultra-high-performance liquid chromatography (UHPLC) combined with high-resolution tandem mass spectrometry (HR MS/MS) was successfully applied to six commercial GT products, extracted by ethanol sonication, to disclose their polyphenol profile beyond the well-known catechins. The relative abundance of each class of metabolites was correlated to antiradical and antilipoperoxidant data through hierarchical clustering analysis, since it reasonably affects the beneficial properties of the product that reaches the consumer. The thiobarbituric acid reactive substances (TBARS) assay demonstrated that GT extracts effectively counteracted the UV-induced lipoperoxidation of hemp oil, which is highly rich in Polyunsaturated Fatty Acids (PUFAs), and therefore highly unstable. The Relative Antioxidant Capacity Index (RACI) comprehensively emphasized that gunpower and blend in filter GTs appeared to be the less active matrices, and except for a GT-based supplement, the Sencha GT, which was particularly rich in flavonol glycosides, was the most active, followed by Bancha GT.

Preclinical Pharmacological Activities of Epigallocatechin-3-gallate in Signaling Pathways: An Update on Cancer

Epigallocatechin gallate (EGCG) is the main bioactive component of catechins predominantly present in svarious types of teas. EGCG is well known for a wide spectrum of biological activity as an anti-oxidative, anti-inflammatory, and anti-tumor agent. The effect of EGCG on cell death mechanisms via the induction of apoptosis, necrosis, and autophagy has been documented. Moreover, its anti-proliferative and chemopreventive action has been demonstrated in many cancer cell lines. It was also involved in the modulation of cyclooxygenase-2, in oxidative stress and inflammation of different cell processes. EGCG has been reported as a promising target for plasma membrane proteins, such as epidermal growth factor receptor (EGFR). In addition, it has been demonstrated a mechanism of action relying on the inhibition of ERK1/2, p38 MAPK, NF-κB, and vascular endothelial growth factor (VEGF). EGCG and its derivatives were used in proteasome inhibition and they were involved in epigenetic mechanisms. In summary, EGCG is the most predominant and bioactive constituent of teas and it has a pivotal role in cancer prevention. Its preclinical pharmacological activities are associated with complex molecular mechanisms that involve numerous signaling pathways.

Mechanisms Underlying the Anti-Depressive Effects of Regular Tea Consumption

This article is a comprehensive review of the literature pertaining to the antidepressant effects and mechanisms of regular tea consumption. Meta-data supplemented with recent observational studies were first analyzed to assess the association between tea consumption and depression risk. The literature reported risk ratios (RR) were 0.69 with 95% confidence intervals of 0.62-0.77. Next, we thoroughly reviewed human trials, mouse models, and in vitro experiments to determine the predominant mechanisms underlying the observed linear relationship between tea consumption and reduced risk of depression. Current theories on the neurobiology of depression were utilized to map tea-mediated mechanisms of antidepressant activity onto an integrated framework of depression pathology. The major nodes within the network framework of depression included hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, inflammation, weakened monoaminergic systems, reduced neurogenesis/neuroplasticity, and poor microbiome diversity affecting the gut-brain axis. We detailed how each node has subsystems within them, including signaling pathways, specific target proteins, or transporters that interface with compounds in tea, mediating their antidepressant effects. A major pathway was found to be the ERK/CREB/BDNF signaling pathway, up-regulated by a number of compounds in tea including teasaponin, L-theanine, EGCG and combinations of tea catechins and their metabolites. Black tea theaflavins and EGCG are potent anti-inflammatory agents via down-regulation of NF-κB signaling. Multiple compounds in tea are effective modulators of dopaminergic activity and the gut-brain axis. Taken together, our findings show that constituents found in all major tea types, predominantly L-theanine, polyphenols and polyphenol metabolites, are capable of functioning through multiple pathways simultaneously to collectively reduce the risk of depression.