The Role of EGCG in Breast Cancer Prevention and Therapy

Homoplantaginin Antagonizes N-Methyl-d-aspartate Receptor and Extracellular Signal-Regulated Kinase Signaling in Aβ Oligomers-Induced Neuropathology/Toxicity

Extracts from plants/herbals are great resources of drugs and nutrients. Baicalein, a component present in Scutellaria baicalensis, was previously found to alleviate the abnormal depolarization brought about by Aβ oligomers. We extended this promising outcome by screening baicalein derivatives, and a natural compound named homoplantaginin was pinpointed. In this study, we aimed to investigate the effects of homoplantaginin on animal behavior and explore its neuronal functioning/mechanism. In behavior tests, impairments of novel object recognition and of spatial learning/memory were reversed by homoplantaginin in a J20 Alzheimer's disease (AD) mouse model. Utilizing primary glutamatergic neurons, homoplantaginin was found to prevent the Aβ oligomer-induced increase in ERK phosphorylation. Furthermore, homoplantaginin inhibits both AMPA-insult and NMDA-insult depolarization; this was assessed using DiBAC4(3), a membrane potential sensitive dye. Finally, homoplantaginin blocks both Aβ oligomer-induced and NMDA-induced calcium influx, which was assessed by intracellular calcium measurement using Fura2/AM. Interestingly, homoplantaginin immediately blunts the steady state calcium influx caused by NMDA. Taken together, homoplantaginin is capable of inhibiting Aβ oligomer-induced pathophysiology, in particular at the receptor level. This pure compound has great potential to be developed as a clinical therapeutic drug.

EGCG inhibits migration, invasion and epithelial-mesenchymal transition of renal cell carcinoma by activating TFEB-mediated autophagy

BACKGROUND

The incidence of renal cell carcinoma (RCC) is already in the top ten of all types of cancers, with more than 4 %. Epigallocatechin gallate (EGCG), a polyphenolic compound extracted from green tea, has been shown to be effective in the treatment of various tumors. However, limited studies have demonstrated the effect of EGCG on RCC and its underlying molecular mechanisms.

METHODS

After exposure to gradient concentration (0,5,10,20,40,60,80,100 μM) of EGCG, the cell viability of RCC cells was determined by MTT assay. The migration and invasion abilities of RCC cells were investigated by wound healing and transwell assays. The expression levels of proteins involved in the epithelial-mesenchymal transition (EMT) and autophagy were explored by Western blotting assays. The formation of autophagosome was detected by electron microscope and LC3 puncta assays. Nude mouse xenograft model was used as the model system in vivo.

RESULTS

In the present study, EGCG significantly inhibited the migration, invasion and EMT of RCC cells in a concentrated manner. Further exploration of its mechanism indicated that autophagy is involved in EGCG-mediated metastasis inhibition and EMT inhibition of RCC cells. In addition, EGCG could significantly up-regulate the transcription factor EB (TFEB) and promotes its nuclear localization. The incorporation of TFEB into the nucleus enhanced the transcriptional levels of molecules associated with autophagy. TFEB knockdown inhibited EGCG-mediated autophagy activation, metastasis and EMT inhibition in RCC cells.

CONCLUSIONS

In conclusion, these findings demonstrate for the first time that EGCG inhibits migration, invasion, and EMT of RCC by activating TFEB-mediated autophagy. Therefore, the combination of EGCG and TFFB activators or EMT inhibitors is expected to be a promising therapeutic strategy for RCC.

Epigallocatechin-3-Gallate Inhibits Atrial Fibrosis and Reduces the Occurrence and Maintenance of Atrial Fibrillation and its Possible Mechanisms

BACKGROUND

Atrial fibrosis is one of the main causes of the onset and recurrence of atrial fibrillation (AF), for which there is no effective treatment. The aim of this study was to investigate the effect and mechanism of epigallocatechin-3-gallate (EGCG) on AF in rats.

METHODS

The rat model of AF was established by rapid pacing induction after angiotensin-II (Ang-II) induced atrial fibrosis to verify the relationship between atrial fibrosis and the AF. The expression levels of TGF-β/Smad3 pathway molecules and lysyl oxidase (LOX) in AF were detected. Subsequently, EGCG was used to intervene Ang-II-induced atrial fibrosis to explore the role of EGCG in the treatment of AF and its inhibitory mechanism on fibrosis. It was further verified that EGCG inhibited the production of collagen and the expression of LOX through the TGF-β/Smad3 pathway at the cellular level.

RESULTS

The results showed that the induction rate and maintenance time of AF in rats increased with the increase of the degree of atrial fibrosis. Meanwhile, the expressions of Col I, Col III, molecules related to TGF-β/Smad3 pathway, and LOX increased significantly in the atrial tissues of rats in the Ang-II induced group. EGCG could reduce the occurrence and maintenance time of AF by inhibiting the degree of Ang-induced rat atrial fibrosis. Cell experiments confirmed that EGCG could reduce the synthesis of collagen and the expression of LOX in cardiac fibroblast induced by Ang-II. The possible mechanism is to down-regulate the expression of genes and proteins related to the TGF-β/Smad3 pathway.

CONCLUSION

EGCG could downregulate the expression levels of collagen and LOX by inhibiting the TGF-β/Smad3 signaling pathway, alleviating Ang-II-induced atrial fibrosis, which in turn inhibited the occurrence and curtailed the duration of AF.

Cancer Immunotherapy with "Vascular-Immune" Crosstalk as Entry Point: Associated Mechanisms, Therapeutic Drugs and Nano-Delivery Systems

Tumor vessels characterized by abnormal functions and structures hinder the infiltration and immune antigen presentation of immune cells by inducing the formation of an immunosuppressive microenvironment ("cold" environment). Vascular-targeted therapy has been proven to enhance immune stimulation and the effectiveness of immunotherapy by modulating the "cold" microenvironment, such as hypoxia and an acidic microenvironment. Notably, a therapeutic strategy based on "vascular-immune" crosstalk can achieve dual regulation of tumor vessels and the immune system by reprogramming the tumor microenvironment (TME), thus forming a positive feedback loop between tumor vessels and the immune microenvironment. From this perspective, we discuss the factors of tumor angiogenesis and "cold" TME formation. Building on this foundation, some vascular-targeted therapeutic drugs will be elaborated upon in detail to achieve dual regulation of tumor vessels and immunity. More importantly, we focus on cutting-edge nanotechnology in view of "vascular-immune" crosstalk and discuss the rational fabrication of tailor-made nanosystems for efficiently enhancing immunotherapy.

Epigallocatechin gallate protects against fat and muscle atrophy in B16BL6 melanoma-bearing mice on a high-fat diet

AIMS

Epidemiological evidence indicates that there is a substantial association between body mass index (BMI) and at least ten forms of cancer, including melanoma, and BMI imbalance contributes to the poor survival rate of cancer patients before and after therapy. Nevertheless, few pharmacological studies on models of obesity and cancer have been reported. In this study, we administered epigallocatechin gallate (EGCG) to B16BL6 tumor-bearing mice that received a high-fat diet (HFD) to examine its impact.

METHODS

B16BL6 tumor-bearing mice were fed a HFD. Body weight and food intake were documented every week. We conducted a Western blot analysis to examine the protein levels in the tumor, gastrocnemius (GAS), and tibialis anterior (TA) muscles, as well as the inguinal and epididymal white adipose tissues (iWAT and eWAT).

KEY FINDINGS

EGCG has been shown to have anti-cancer effects equivalent to those of cisplatin, a chemotherapy drug. Furthermore, EGCG protected against the loss of epidydimal white adipose tissue by regulating protein levels of lipolysis factors of adipose triglyceride lipase and hormone-sensitive lipase as well as WAT browning factors of uncoupling protein 1, as opposed to cisplatin. EGCG was shown to reduce the protein levels of muscular atrophy factors of muscle RING-finger protein-1, whereas cisplatin did not contribute to rescuing the atrophy of TA and GAS muscles.

CONCLUSION

Taken together, our findings indicate that EGCG has a preventive effect against cachexia symptoms and has anti-cancer effects similar to those of cisplatin in tumor-bearing mice fed a high-fat diet.

Protective effects of EGCG on acrolein-induced Caenorhabditis elegans and its mechanism of life extension

In this study, it was found that epigallocatechin-3-gallate (EGCG) could extend the lifespan of Caenorhabditis elegans (C. elegans) induced by 100 μM acrolein (ACR) at all test concentrations (300, 400, 500, 600, and 700 μM). Notably, 500 μM EGCG exhibited the most significant mean lifespan extension, increasing it by approximately 32.5%. Furthermore, 500 μM EGCG effectively reduced elevated levels of reactive oxygen species (ROS) and lipofuscin production caused by acrolein. It also bolstered the activity of antioxidant enzymes and mitigated malondialdehyde (MDA) levels compared to the ACR-only group. These effects appeared independent of dietary restrictions. Additionally, qPCR results revealed different changes in the transcription levels of 11 genes associated with antioxidative and anti-aging functions following EGCG treatment. At the expression level, GST-4::GFP, SOD-3::GFP and HSP-16.2::GFP exhibited an initial increase with ACR treatment followed by a decrease with EGCG treatment, while the expression pattern of these three GFPs remained consistent with the enzyme activity and transcription regulation level. EGCG treatment also reduced the nuclear localization of SKN-1 and DAF-16 in the MAPK and IIS pathways that were enhanced by ACR. Moreover, the longevity-promoting effects of EGCG were diminished or absent in 13 longevity gene-deletion mutants. In conclusion, EGCG demonstrates protective effects on ACR-induced C. elegans, with the IIS and MAPK pathways playing a critical role in enhancing resilience to ACR.

Comprehensive Review of EGCG Modification: Esterification Methods and Their Impacts on Biological Activities

Epigallocatechin gallate (EGCG), the key constituent of tea polyphenols, presents challenges in terms of its lipid solubility, stability, and bioavailability because of its polyhydroxy structure. Consequently, structural modifications are imperative to enhance its efficacy. This paper comprehensively reviews the esterification techniques applied to EGCG over the past two decades and their impacts on bioactivities. Both chemical and enzymatic esterification methods involve catalysts, solvents, and hydrophobic groups as critical factors. Although the chemical method is cost-efficient, it poses challenges in purification; on the other hand, the enzymatic approach offers improved selectivity and simplified purification processes. The biological functions of EGCG are inevitably influenced by the structural changes incurred through esterification. The antioxidant capacity of EGCG derivatives can be compromised under certain conditions by reducing hydroxyl groups, while enhancing lipid solubility and stability can strengthen their antiviral, antibacterial, and anticancer properties. Additionally, esterification broadens the utility of EGCG in food applications. This review provides critical insights into developing cost-effective and environmentally sustainable selective esterification methods, as well as emphasizes the elucidation of the bioactive mechanisms of EGCG derivatives to facilitate their widespread adoption in food processing, healthcare products, and pharmaceuticals.

Exploiting the Achilles' heel of cancer: disrupting glutamine metabolism for effective cancer treatment

Cancer cells have adapted to rapid tumor growth and evade immune attack by reprogramming their metabolic pathways. Glutamine is an important nitrogen resource for synthesizing amino acids and nucleotides and an important carbon source in the tricarboxylic acid (TCA) cycle and lipid biosynthesis pathway. In this review, we summarize the significant role of glutamine metabolism in tumor development and highlight the vulnerabilities of targeting glutamine metabolism for effective therapy. In particular, we review the reported drugs targeting glutaminase and glutamine uptake for efficient cancer treatment. Moreover, we discuss the current clinical test about targeting glutamine metabolism and the prospective direction of drug development.

S100A4/NF-κB axis mediates the anticancer effect of epigallocatechin-3-gallate in platinum-resistant ovarian cancer

Resistance to cisplatin (cis-dichlorodiamineplatinum, DDP) in ovarian cancer is a significant clinical challenge. Epigallocatechin-3-gallate (EGCG) has shown promise in cancer therapy. However, its effects on DDP-resistant ovarian cancer remain understudied. This study aims to assess the impact of EGCG on DDP-resistant cells and elucidate the associated molecular mechanisms. DDP-resistant cell lines were utilized for biological characterization. EGCG effectively inhibited proliferation, mobility, and induced apoptosis in OC/DDP cells. It downregulated the expression of S100A4 and NF-κB while upregulating p53 expression. These effects were reversed upon overexpression of S100A4 or NF-κB. In vivo experiments confirmed tumor inhibition and KI67 inhibition by EGCG. Moreover, EGCG downregulated the expression of S100A4 and NF-κB while upregulating p53 in xenograft mice compared to those without EGCG treatment. This study suggests that EGCG suppresses cancer progression through the S100A4/NF-κB signaling pathway, involving interaction with p53. EGCG holds potential as an anticancer candidate for OC/DDP.

The roles of epigallocatechin gallate in the tumor microenvironment, metabolic reprogramming, and immunotherapy

Cancer, a disease that modern medicine has not fully understood and conquered, with its high incidence and mortality, deprives countless patients of health and even life. According to global cancer statistics, there were an estimated 19.3 million new cancer cases and nearly 10 million cancer deaths in 2020, with the age-standardized incidence and mortality rates of 201.0 and 100.7 per 100,000, respectively. Although remarkable advancements have been made in therapeutic strategies recently, the overall prognosis of cancer patients remains not optimistic. Consequently, there are still many severe challenges to be faced and difficult problems to be solved in cancer therapy today. Epigallocatechin gallate (EGCG), a natural polyphenol extracted from tea leaves, has received much attention for its antitumor effects. Accumulating investigations have confirmed that EGCG can inhibit tumorigenesis and progression by triggering apoptosis, suppressing proliferation, invasion, and migration, altering tumor epigenetic modification, and overcoming chemotherapy resistance. Nevertheless, its regulatory roles and biomolecular mechanisms in the immune microenvironment, metabolic microenvironment, and immunotherapy remain obscure. In this article, we summarized the most recent updates about the effects of EGCG on tumor microenvironment (TME), metabolic reprogramming, and anti-cancer immunotherapy. The results demonstrated EGCG can promote the anti-cancer immune response of cytotoxic lymphocytes and dendritic cells (DCs), attenuate the immunosuppression of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), and inhibit the tumor-promoting functions of tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), and various stromal cells including cancer-associated fibroblasts (CAFs), endothelial cells (ECs), stellate cells, and mesenchymal stem/stromal cells (MSCs). Additionally, EGCG can suppress multiple metabolic reprogramming pathways, including glucose uptake, aerobic glycolysis, glutamine metabolism, fatty acid anabolism, and nucleotide synthesis. Finally, EGCG, as an immunomodulator and immune checkpoint blockade, can enhance immunotherapeutic efficacy and may be a promising candidate for antitumor immunotherapy. In conclusion, EGCG plays versatile regulatory roles in TME and metabolic reprogramming, which provides novel insights and combined therapeutic strategies for cancer immunotherapy.

Prognostic and immune infiltration features of disulfidptosis-related subtypes in breast cancer

Breast cancer (BC) is a prominent cause of cancer incidence and mortality around the world. Disulfidptosis, a type of cell death, can induce tumor cell death. The purpose of this study was to analyze the potential impact of disulfidptosis-related genes (DRGs) on the prognosis and immune infiltration features of BC. Based on DRGs, we conducted an unsupervised clustering analysis on gene expression data of BC in TCGA-BRCA dataset and identified two BC subtypes, cluster1 and cluster2, with cluster1 showing a higher likelihood of favorable survival. Through immune analysis, we found that cluster1 had lower proportions of infiltration in immune-related cells, including aDCs, DCs, NK_cells, Th2_cells, and Treg. Based on the immunophenoscore (IPS) results, we inferred that cluster1 might benefit more from immune checkpoint inhibitors targeting CTLA-4 and PD1. Targeted small molecule prediction results showed that patients with cluster2 BC might respond better to antagonistic small molecule compounds, including clofazimine, lenalidomide, and epigallocatechin. Differentially expressed genes between the two subtypes were found to be enriched in signaling pathways related to steroid hormone biosynthesis, ovarian steroidogenesis, and neutrophil extracellular trap formation, according to enrichment analyses. In conclusion, this study identified BC subtypes based on DRGs so as to help predict patient prognosis and provide valuable tools for guiding clinical management and precise treatment of BC patients.

From inflammation to metastasis: The central role of miR-155 in modulating NF-κB in cancer

Cancer is a multifaceted, complex disease characterized by unchecked cell growth, genetic mutations, and dysregulated signalling pathways. These factors eventually cause evasion of apoptosis, sustained angiogenesis, tissue invasion, and metastasis, which makes it difficult for targeted therapeutic interventions to be effective. MicroRNAs (miRNAs) are essential gene expression regulators linked to several biological processes, including cancer and inflammation. The NF-κB signalling pathway, a critical regulator of inflammatory reactions and oncogenesis, has identified miR-155 as a significant participant in its modulation. An intricate network of transcription factors known as the NF-κB pathway regulates the expression of genes related to inflammation, cell survival, and immunological responses. The NF-κB pathway's dysregulation contributes to many cancer types' development, progression, and therapeutic resistance. In numerous cancer models, the well-studied miRNA miR-155 has been identified as a crucial regulator of NF-κB signalling. The p65 subunit and regulatory molecules like IκB are among the primary targets that miR-155 directly targets to alter NF-κB activity. The molecular processes by which miR-155 affects the NF-κB pathway are discussed in this paper. It also emphasizes the miR-155's direct and indirect interactions with important NF-κB cascade elements to control the expression of NF-κB subunits. We also investigate how miR-155 affects NF-κB downstream effectors in cancer, including inflammatory cytokines and anti-apoptotic proteins.

Potential of natural flavonoids to target breast cancer angiogenesis (review)

Angiogenesis is the process by which new blood vessels form and is required for tumour growth and metastasis. It helps in supplying oxygen and nutrients to tumour cells and plays a crucial role in the local progression and distant metastasis of, and development of treatment resistance in, breast cancer. Tumour angiogenesis is currently regarded as a critical therapeutic target; however, anti-angiogenic therapy for breast cancer fails to produce satisfactory results, owing to issues such as inconsistent efficacy and significant adverse reactions. As a result, new anti-angiogenic drugs are urgently needed. Flavonoids, a class of natural compounds found in many foods, are inexpensive, widely available, and exhibit a broad range of biological activities, low toxicity, and favourable safety profiles. Several studies find that various flavonoids inhibit angiogenesis in breast cancer, indicating great therapeutic potential. In this review, we summarize the role of angiogenesis in breast cancer and the potential of natural flavonoids as anti-angiogenic agents for breast cancer treatment. We discuss the value and significance of nanotechnology for improving flavonoid absorption and utilization and anti-angiogenic effects, as well as the challenges of using natural flavonoids as drugs.

The Green Tea Polyphenol Epigallocatechin-Gallate (EGCG) Interferes with Microcin E492 Amyloid Formation

Microcin E492 (MccE492) is an antimicrobial peptide and proposed virulence factor produced by some Klebsiella pneumoniae strains, which, under certain conditions, form amyloid fibers, leading to the loss of its antibacterial activity. Although this protein has been characterized as a model functional amyloid, the secondary structure transitions behind its formation, and the possible effect of molecules that inhibit this process, have not been investigated. In this study, we examined the ability of the green tea flavonoid epigallocatechin gallate (EGCG) to interfere with MccE492 amyloid formation. Aggregation kinetics followed by thioflavin T binding were used to monitor amyloid formation in the presence or absence of EGCG. Additionally, synchrotron radiation circular dichroism (SRCD) and transmission electron microscopy (TEM) were used to study the secondary structure, thermal stability, and morphology of microcin E492 fibers. Our results showed that EGCG significantly inhibited the formation of the MccE492 amyloid, resulting in mainly amorphous aggregates and small oligomers. However, these aggregates retained part of the β-sheet SRCD signal and a high resistance to heat denaturation, suggesting that the aggregation process is sequestered or deviated at some stage but not completely prevented. Thus, EGCG is an interesting inhibitor of the amyloid formation of MccE492 and other bacterial amyloids.

Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.

Chemoprevention and Lifestyle Modifications for Risk Reduction in Sporadic and Hereditary Breast Cancer

Female breast cancer is the most commonly diagnosed malignancy worldwide. Risk assessment helps to identify women at increased risk of breast cancer and allows the adoption of a comprehensive approach to reducing breast cancer incidence through personalized interventions, including lifestyle modification, chemoprevention, intensified surveillance with breast imaging, genetic counseling, and testing. Primary prevention means acting on modifiable risk factors to reduce breast cancer occurrence. Chemoprevention with tamoxifen, raloxifene, anastrozole, and exemestane has already shown benefits in decreasing breast cancer incidence in women at an increased risk for breast cancer. For healthy women carrying BRCA 1 or BRCA 2 pathogenic/likely pathogenic (P/LP) germline variants, the efficacy of chemoprevention is still controversial. Adopting chemoprevention strategies and the choice among agents should depend on the safety profile and risk-benefit ratio. Unfortunately, the uptake of these agents has been low. Lifestyle modifications can reduce breast cancer incidence, and the recommendations for BRCA 1 or BRCA 2 P/LP germline variant carriers are comparable to the general population. This review summarizes the most recent evidence regarding the efficacy of chemoprevention and lifestyle interventions in women with sporadic and hereditary breast cancer.

A Concise Review on Natural Products and Their Derivatives for Breast Cancer Treatment

Cancer is a leading cause of death worldwide. Among other cancers, breast cancer has been found to produce maximum number of cases in 2020. Different factors including geographical, genetic, hormonal, oral contraceptives and modern lifestyle could be responsible for the development of breast cancer and different pathways can be targeted for breast cancer treatment. The various conventional approaches used for the treatment of breast cancer including radiotherapy, chemotherapy, hormone and immunotherapy. But due to the side effects associated with these conventional treatments such as non-selectivity, multidrug resistance and bioavailability, there is a need for the development of better therapeutic agents for breast cancer treatment. Several natural products have been explored for breast cancer treatment. However, many of these natural products suffered from the limitations of poor water solubility and possess toxic side effects. To overcome these limitations, several structural analogs of natural products have been synthesized and possess potent anti-breast cancer effects with less side effects over their precursor molecules. In the present manuscript, we describe the pathogenesis of breast cancer, some potent natural products used in the treatment of breast cancer and their selected structural analogs possessing potent anti-breast cancer effects. Database such as Science direct, Pubmed and Google scholar were searched using keywords 'risk factors', 'screening methods','receptors', and 'natural products and derivatives', Registered clinical trials on selected natural products were also analyzed. Present study concludes that eight selected natural products and their derivatives possess wide potential to exhibit anti-breast cancer effects and could be explored further to develop better chemotherapeutic agents against breast cancer.

Epigallocatechin-3-Gallate Therapeutic Potential in Cancer: Mechanism of Action and Clinical Implications

Cellular signaling pathways involved in the maintenance of the equilibrium between cell proliferation and apoptosis have emerged as rational targets that can be exploited in the prevention and treatment of cancer. Epigallocatechin-3-gallate (EGCG) is the most abundant phenolic compound found in green tea. It has been shown to regulate multiple crucial cellular signaling pathways, including those mediated by EGFR, JAK-STAT, MAPKs, NF-κB, PI3K-AKT-mTOR, and others. Deregulation of the abovementioned pathways is involved in the pathophysiology of cancer. It has been demonstrated that EGCG may exert anti-proliferative, anti-inflammatory, and apoptosis-inducing effects or induce epigenetic changes. Furthermore, preclinical and clinical studies suggest that EGCG may be used in the treatment of numerous disorders, including cancer. This review aims to summarize the existing knowledge regarding the biological properties of EGCG, especially in the context of cancer treatment and prophylaxis.

The potential of epigallocatechin gallate in the chemoprevention and therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most notorious malignancies globally, has a high fatality and poor prognosis. Though remarkable breakthroughs have been made in the therapeutic strategies recently, the overall survival of HCC remains unsatisfactory. Consequently, the therapy of HCC remains a great challenge. Epigallocatechin gallate (EGCG), a natural polyphenol extracted from the leaves of the tea bush, has been extensively investigated for its antitumor effects. In this review, we summarize the previous literature to elucidate the roles of EGCG in the chemoprophylaxis and therapy of HCC. Accumulating evidence has confirmed EGCG prevents and inhibits the hepatic tumorigenesis and progression through multiple biological mechanisms, mainly involving hepatitis virus infection, oxidative stress, proliferation, invasion, migration, angiogenesis, apoptosis, autophagy, and tumor metabolism. Furthermore, EGCG enhances the efficacy and sensitivity of chemotherapy, radiotherapy, and targeted therapy in HCC. In conclusion, preclinical studies have confirmed the potential of EGCG for chemoprevention and therapy of HCC under multifarious experimental models and conditions. Nevertheless, there is an urgent need to explore the safety and efficacy of EGCG in the clinical practice of HCC.

The applications of epigallocatechin gallate (EGCG)-nanogold conjugate in cancer therapy

Cancer has recently increased the death toll worldwide owing to inadequate therapy and decreased drug bioavailability. Long-term and untargeted chemotherapeutic exposure causes toxicity to healthy cells and drug resistance. These challenges necessitate the development of new methods to increase drug efficacy. Nanotechnology is an emerging field in the engineering of new drug delivery platforms. The phytochemical epigallocatechin gallate (EGCG), the main component of green tea extract and its most bioactive component, offers novel approaches to cancer cell eradication. The current review focuses on the nanogold-based carriers containing EGCG, with an emphasis on the chemotherapeutic effects of EGCG in cancer treatment. The nanoscale vehicle may improve the EGCG solubility and bioavailability while overcoming constraints and cellular barriers. This article reviewed the phytochemical EGCG-based gold nanoplatforms and their major anticancer applications, both individually, and in combination therapy in a few cases.

Targeting the NRF2/KEAP1 pathway in cervical and endometrial cancers

Cervical and endometrial cancers are among the most dangerous gynaecological malignancies, with high fatality and recurrence rates due to frequent diagnosis at an advanced stage and chemoresistance onset. The NRF2/KEAP1 signalling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. NRF2, activated by ROS, induces the expression of antioxidant enzymes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase which neutralize ROS, protecting cells against oxidative stress damage. However, activation of NRF2/KEAP1 signalling in cancer cells results in chemoresistance, inactivating drug-mediated oxidative stress and protecting cancer cells from drug-induced cell death. We review the literature on the role of the NRF2/KEAP1 pathway in cervical and endometrial cancers, with a focus on the expression of its components and downstream genes. We also examine the role of the NRF2/KEAP1 pathway in chemotherapy resistance and how this pathway can be modulated by natural and synthetic modulators.

Effects of Green Tea Polyphenol Epigallocatechin-3-Gallate on Markers of Inflammation and Fibrosis in a Rat Model of Pulmonary Silicosis

Inhalation of silica particles causes inflammatory changes leading to fibrotizing silicosis. Considering a lack of effective therapy, and a growing information on the wide actions of green tea polyphenols, particularly epigallocatechin-3-gallate (EGCG), the aim of this study was to evaluate the early effects of EGCG on markers of inflammation and lung fibrosis in silicotic rats. The silicosis model was induced by a single transoral intratracheal instillation of silica (50 mg/mL/animal), while controls received an equivalent volume of saline. The treatment with intraperitoneal EGCG (20 mg/kg, or saline in controls) was initiated the next day after silica instillation and was given twice a week. Animals were euthanized 14 or 28 days after the treatment onset, and the total and differential counts of leukocytes in the blood and bronchoalveolar lavage fluid (BALF), wet/dry lung weight ratio, and markers of inflammation, oxidative stress, and fibrosis in the lung were determined. The presence of collagen and smooth muscle mass in the walls of bronchioles and lung vessels was investigated immunohistochemically. Early treatment with EGCG showed some potential to alleviate inflammation, and a trend to decrease oxidative stress-induced changes, including apoptosis, and a prevention of fibrotic changes in the bronchioles and pulmonary vessels. However, further investigations should be undertaken to elucidate the effects of EGCG in the lung silicosis model in more detail. In addition, because of insufficient data from EGCG delivery in silicosis, the positive and eventual adverse effects of this herbal compound should be carefully studied before any preventive use or therapy with EGCG may be recommended.

Amelioration of cognitive impairment using epigallocatechin-3-gallate in ovariectomized mice fed a high-fat diet involves remodeling with Prevotella and Bifidobacteriales

Background: Estrogen deficiency and a high-fat diet (HFD) are both risk factors for Alzheimer's disease (AD). HFD can accelerate cognitive impairment in estrogen-deficient patients, but there is currently no effective treatment. Epigallocatechin-3-galate (EGCG) is widely studied for its anti-inflammatory, anti-cancer, and anti-neurodegeneration effects. Nevertheless, whether EGCG can ameliorate cognitive impairment in HFD-fed estrogen-deficient mice has not been studied. Methods and Results: Ovariectomized (OVX) mice fed an HFD (HFOVX) for 8 weeks experienced impaired object recognition and spatial memory, but this damage was significantly attenuated by the administration of EGCG at a dose of 45 mg/kg. Through 16S rRNA gene sequencing, we found that HFOVX changed the diversity and structure of the gut microbiota in mice, which could be restored with EGCG. Further analysis showed that HFOVX exposure not only resulted in a decrease of Alloprevotella in Bacteroidetes, Lactobacillaceae in Firmicutes, and Prevotella in Bacteroidetes but also in an increase of Bifidobacteriales in Actinobacteria. EGCG effectively reversed the decrease of Prevotella and inhibited the increase of Bifidobacteriales but had no effect on the decrease of Alloprevotella or Lactobacillaceae or on the increase of Enterorhabdus in HFOVX mice. Additionally, using Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, we found that EGCG significantly reversed the five functional gut microbiota genes elevated by HFOVX, including iron complex transport system substrate-binding protein, iron complex transport system permease protein, 3-oxoacyl- [acyl-carrier protein] reductase, transketolase, and 8-oxo-dGTP diphosphatase. Conclusions: We concluded that EGCG improved cognitive impairment in mice with estrogen deficiency exacerbated by an HFD involved a rebuilding of the disrupted gut microbiota composition.

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.

Modern aspects of the use of natural polyphenols in tumor prevention and therapy

Polyphenols are secondary plant metabolites or organic compounds synthesized by them. In other words, these are molecules that are found in plants. Due to the wide variety of polyphenols and the plants in which they are found, these compounds are divided according to the source of origin, the function of the polyphenols, and their chemical structure; where the main ones are flavonoids. All the beneficial properties of polyphenols have not yet been studied, since this group of substances is very extensive and diverse. However, most polyphenols are known to be powerful antioxidants and have anti-inflammatory effects. Polyphenols help fight cell damage caused by free radicals and immune system components. In particular, polyphenols are credited with a preventive effect that helps protect the body from certain forms of cancer. The onset and progression of tumors may be related directly to oxidative stress, or inflammation. These processes can increase the amount of DNA damage and lead to loss of control over cell division. A number of studies have shown that oxidative stress uncontrolled by antioxidants or an uncontrolled and prolonged inflammatory process increases the risk of developing sarcoma, melanoma, and breast, lung, liver, and prostate cancer. Therefore, a more in-depth study of the effect of polyphenolic compounds on certain signaling pathways that determine the complex cascade of oncogenesis is a promising direction in the search for new methods for the prevention and treatment of tumors.

Targeting HSP90 as a Novel Therapy for Cancer: Mechanistic Insights and Translational Relevance

Heat shock protein (HSP90), a highly conserved molecular chaperon, is indispensable for the maturation of newly synthesized poly-peptides and provides a shelter for the turnover of misfolded or denatured proteins. In cancers, the client proteins of HSP90 extend to the entire process of oncogenesis that are associated with all hallmarks of cancer. Accumulating evidence has demonstrated that the client proteins are guided for proteasomal degradation when their complexes with HSP90 are disrupted. Accordingly, HSP90 and its co-chaperones have emerged as viable targets for the development of cancer therapeutics. Consequently, a number of natural products and their analogs targeting HSP90 have been identified. They have shown a strong inhibitory effect on various cancer types through different mechanisms. The inhibitors act by directly binding to either HSP90 or its co-chaperones/client proteins. Several HSP90 inhibitors—such as geldanamycin and its derivatives, gamitrinib and shepherdin—are under clinical evaluation with promising results. Here, we review the subcellular localization of HSP90, its corresponding mechanism of action in the malignant phenotypes, and the recent progress on the development of HSP90 inhibitors. Hopefully, this comprehensive review will shed light on the translational potential of HSP90 inhibitors as novel cancer therapeutics.

Potential of Anti-inflammatory Molecules in the Chemoprevention of Breast Cancer

Breast cancer is a global issue, affecting greater than 1 million women per annum. Over the past two decades, there have been numerous clinical trials involving the use of various pharmacological substances as chemopreventive agents for breast cancer. Various pre-clinical as well as clinical studies have established numerous anti-inflammatory molecules, including nonsteroidal anti-inflammatory drugs (NSAIDs) and dietary phytochemicals as promising agents for chemoprevention of several cancers, including breast cancer. The overexpression of COX-2 has been detected in approximately 40% of human breast cancer cases and pre-invasive ductal carcinoma in-situ lesions, associated with aggressive elements of breast cancer such as large size of the tumour, ER/PR negative and HER-2 overexpression, among others. Anti-inflammatory molecules inhibit COX, thereby inhibiting the formation of prostaglandins and inhibiting nuclear factor-κBmediated signals (NF-kB). Another probable explanation entails inflammation-induced degranulation, with the production of angiogenesis-regulating factors, such as vascular endothelial growth factor, which can be possibly regulated by anti-inflammatory molecules. Apart from NSAIDS, many dietary phytochemicals have the ability to decrease, delay, or stop the progression and/or incidence of breast cancer by their antioxidant action, regulating inflammatory and proliferative cell signalling pathways as well as inducing apoptosis. The rapid progress in chemoprevention research has also established innovative strategies that can be implemented to prevent breast cancer. This article gives a comprehensive overview of the recent advancements in using antiinflammatory molecules in the chemoprevention of breast cancer along with their mechanism of action, supported by latest preclinical and clinical data. The merits of anti-inflammatory chemopreventive agents in the prevention of cardiotoxicity have been described. We have also highlighted the ongoing research and advancements in improving the efficacy of using antiinflammatory molecules as chemopreventive agents.

Flavonoids as Potential Antiviral Agents for Porcine Viruses

Flavonoids are types of natural substances with phenolic structures isolated from a variety of plants. Flavonoids have antioxidant, anti-inflammatory, anticancer, and antiviral activities. Although most of the research or applications of flavonoids are focused on human diseases, flavonoids also show potential applicability against porcine virus infection. This review focuses on the recent progress in antiviral mechanisms of potential flavonoids against the most common porcine viruses. The mechanism discussed in this paper may provide a theoretical basis for drug screening and application of natural flavonoid compounds and flavonoid-containing herbs to control porcine virus infection and guide the research and development of pig feed additives.

Green Tea Polyphenol (-)-Epigallocatechin-3-Gallate (EGCG): A Time for a New Player in the Treatment of Respiratory Diseases?

(-)-Epigallocatechin-3-gallate (EGCG) is a major polyphenol of green tea that possesses a wide variety of actions. EGCG acts as a strong antioxidant which effectively scavenges reactive oxygen species (ROS), inhibits pro-oxidant enzymes including NADPH oxidase, activates antioxidant systems including superoxide dismutase, catalase, or glutathione, and reduces abundant production of nitric oxide metabolites by inducible nitric oxide synthase. ECGC also exerts potent anti-inflammatory, anti-fibrotic, pro-apoptotic, anti-tumorous, and metabolic effects via modulation of a variety of intracellular signaling cascades. Based on this knowledge, the use of EGCG could be of benefit in respiratory diseases with acute or chronic inflammatory, oxidative, and fibrotizing processes in their pathogenesis. This article reviews current information on the biological effects of EGCG in those respiratory diseases or animal models in which EGCG has been administered, i.e., acute respiratory distress syndrome, respiratory infections, COVID-19, bronchial asthma, chronic obstructive pulmonary disease, lung fibrosis, silicosis, lung cancer, pulmonary hypertension, and lung embolism, and critically discusses effectiveness of EGCG administration in these respiratory disorders. For this review, articles in English language from the PubMed database were used.

Liensinine Inhibits Cell Growth and Blocks Autophagic Flux in Nonsmall-Cell Lung Cancer

Liensinine is a bioactive component of Plumula Nelumbinis extracted from the green embryo of the mature seeds of Nelumbonaceae and exhibits therapeutic functions and noteworthy anti-tumor effects in recent studies. However, the potential anti-tumor property and the underlying mechanisms of liensinine in nonsmall-cell lung cancer (NSCLC) have not been illustrated. In this study, we demonstrated that liensinine has the potential anti-tumor property, and it could inhibit growth of NSCLC in vitro and in vivo. In addition, we found that although it induced significant accumulation of autophagosomes, liensinine could quench them for degradation and blocked autophagic flux. Importantly, we observed that liensinine inhibited the normal function of mitochondrial energy supply and impaired the lysosomal function. This research firstly provides a possibility insight that liensinine could be a novel therapeutic strategy for NSCLC.

Chemico-biological aspects of (-)-epigallocatechin-3-gallate (EGCG) to improve its stability, bioavailability and membrane permeability: Current status and future prospects

Natural products have been a bedrock for drug discovery for decades. (-)-Epigallocatechin-3-gallate (EGCG) is one of the widely studied natural polyphenolic compounds derived from green tea. It is the key component believed to be responsible for the medicinal value of green tea. Significant studies implemented in in vitro, in cellulo, and in vivo models have suggested its anti-oxidant, anti-cancer, anti-diabetic, anti-inflammatory, anti-microbial, neuroprotective activities etc. Despite having such a wide array of therapeutic potential and promising results in preclinical studies, its applicability to humans has encountered with rather limited success largely due to the poor bioavailability, poor membrane permeability, rapid metabolic clearance and lack of stability of EGCG. Therefore, novel techniques are warranted to address those limitations so that EGCG or its modified analogs can be used in the clinical setup. This review comprehensively covers different strategies such as structural modifications, nano-carriers as efficient drug delivery systems, synergistic studies with other bioactivities to improve the chemico-biological aspects (e.g., stability, bioavailability, permeability, etc.) of EGCG for its enhanced pharmacokinetics and pharmacological properties, eventually enhancing its therapeutic potentials. We think this review article will serve as a strong platform with comprehensive literature on the development of novel techniques to improve the bioavailability of EGCG so that it can be translated to the clinical applications.

Fabrication of chitosan-coated epigallocatechin-3-gallate (EGCG)-hordein nanoparticles and their transcellular permeability in Caco-2/HT29 cocultures

Epigallocatechin-3-gallate (EGCG) has gained appreciable attention because of its health benefits. However, the poor permeability across the intestine limits its use. In this study, we have fabricated chitosan-coated EGCG-hordein nanoparticles (Cs-EHNs), with the aim to enhance the intestinal permeability of EGCG. Cs-EHNs were fabricated by layer-by-layer electrostatic stacking method, and its uptake and transcellular permeability were studied in the Caco-2/HT29 co-culture model. The constructed Cs-EHNs had the average diameter of 296 nm, polymer dispersity index (PDI) of 0.30, zeta potential of 59.6 mV, and showed a spherical morphology. Encapsulation efficiency of EGCG was 87.3%. The transcellular permeability experiments indicated that the apparent permeability coefficient (P_app) of Cs-EHNs was higher than that of free EGCG. Furthermore, the cellular uptake of Cs-EHNs was studied by specific endocytosis inhibitors, and results showed that the uptake mechanisms of Cs-EHNs were through caveolae-mediated endocytosis and macropinocytosis. This study demonstrated that encapsulation of EGCG using chitosan-coated hordein nanoparticles could be a promising approach to improve the absorption of EGCG.

Epigallocatechin 3-gallate: From green tea to cancer therapeutics

Epigallocatechin 3-gallate (EGCG) possesses various biological functions, including anti-cancer and anti-inflammatory properties. EGCG is an abundant polyphenolic component originating from green tea extract that has exhibited versatile bioactivities in combating several cancers. This review highlights the pharmacological features of EGCG and its therapeutic implications in cancer and other metabolic diseases. It modulates numerous signaling pathways, regulating cells' undesired survival and proliferation, thus imparting strong tumor chemopreventive and therapeutic effects. EGCG initiates cell death through the intrinsic pathway and causes inhibition of EGFR, STAT3, and ERK pathways in several cancers. EGCG alters and inhibits ERK1/2, NF-κB, and Akt-mediated signaling, altering the Bcl-2 family proteins ratio and activating caspases in tumor cells. This review focuses on anti-cancer, anti-oxidant, anti-inflammatory, anti-angiogenesis, and apoptotic effects of EGCG. We further highlighted the potential of EGCG in different types of cancer, emphasizing clinical trials formulations that further improve our understanding of the therapeutic management of cancer and inflammatory diseases.

EGCG Inhibits Proliferation and Induces Apoptosis Through Downregulation of SIRT1 in Nasopharyngeal Carcinoma Cells

Epigallocatechin-3-gallate (EGCG), a frequently studied catechin in green tea, has been shown involved in the anti-proliferation and apoptosis of human nasopharyngeal carcinoma (NPC) cells. However, the underlying molecular mechanism of the apoptotic effects of EGCG has not been fully investigated. Recent literature emphasized the importance of Sirtuin 1 (SIRT1), an NAD⁺-dependent protein deacetylase, in regulating cellular stress responses, survival, and organismal lifespan. Herein, the study showed that EGCG could significantly inhibit cell proliferation and promote apoptosis of 2 NPC (CNE-2 and 5-8F) cell lines. Moreover, it was also found that SIRT1 is down-regulated by EGCG, and the SIRT1-p53 signaling pathway participates in the effects of EGCG on CNE-2 and 5-8 F cells. Taken together, the findings of this study provided evidence that EGCG could inhibit the growth of NPC cell lines and is linked with the inhibition of the SIRT1-p53 signaling pathway, suggesting the therapeutic potential of EGCG in human NPC.

LC-MS Based Metabolomics Study of the Effects of EGCG on A549 Cells

(−)-Epigallocatechin-3-gallate (EGCG) is the main bioactive catechin in green tea. The antitumor activity of EGCG has been confirmed in various types of cancer, including lung cancer. However, the precise underlying mechanisms are still largely unclear. In the present study, we investigated the metabolite changes in A549 cells induced by EGCG in vitro utilizing liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. The result revealed 33 differentially expressed metabolites between untreated and 80 μM EGCG-treated A549 cells. The altered metabolites were involved in the metabolism of glucose, amino acid, nucleotide, glutathione, and vitamin. Two markedly altered pathways, including glycine, serine and threonine metabolism and alanine, aspartate and glutamate metabolism, were identified by MetaboAnalyst 5.0 metabolic pathway analysis. These results may provide potential clues for the intramolecular mechanisms of EGCG’s effect on A549 cells. Our study may contribute to future molecular mechanistic studies of EGCG and the therapeutic application of EGCG in cancer management.

Vorinostat (SAHA) and Breast Cancer: An Overview

Vorinostat (SAHA), an inhibitor of class I and II of histone deacetylases, is the first histone deacetylase inhibitor (HDI) approved for the treatment of cutaneous T-cell lymphoma in 2006. HDIs are promising anticancer agents that inhibit the proliferation of many types of cancer cells including breast carcinoma (BC). BC is a heterogeneous disease with variable biological behavior, morphological features, and response to therapy. Although significant progress in the treatment of BC has been made, high toxicity to normal cells, serious side effects, and the occurrence of multi-drug resistance limit the effective therapy of BC patients. Therefore, new active agents which improve the effectiveness of currently used regimens are highly needed. This manuscript analyzes preclinical and clinical trials data of SAHA, applied individually or in combination with other anticancer agents, considering different histological subtypes of BC.