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

Multifunctional sericin-based biomineralized nanoplatforms with immunomodulatory and angio/osteo-genic activity for accelerated bone regeneration in periodontitis

Periodontitis is a chronic inflammation caused by dental plaque. It is characterized by the accumulation of excessive reactive oxygen species (ROS) and inflammatory mediators in the periodontal area. This affects the function of host cells, activates osteoclasts, and destroys periodontal tissue. Treatments such as local debridement or antibiotic therapy for ameliorating the overactive inflammatory microenvironment and repairing periodontal tissues are challenging. This paper reports multifunctional nanoplatforms (Se-CuSrHA@EGCG) based on sericin with ROS-scavenging, immunomodulatory, angiogenic, and osteogenic capabilities. The natural protein sericin, derived from silk cocoons, is used in water/oil emulsification and cross-linking processes to create sericin nanoparticles (Se NPs). Numerous binding sites are present on the surface of Se NPs. Ion-doped hydroxyapatite nanoparticles (Se-CuSrHA NPs) can be constructed using the force between positive and negative charges. After mineralization, an antioxidant coating is formed on the surface using polyethyleneimine (PEI)/epigallocatechin gallate (EGCG). Research conducted both in vitro and in vivo demonstrates that Se-CuSrHA@EGCG NPs can efficiently scavenge ROS, regulate macrophage polarization, increase the secretion of anti-inflammatory cytokines, and balance the immune microenvironment. In addition, Se-CuSrHA@EGCG stimulates angiogenesis, inhibits osteoclasts, and accelerates periodontal tissue repair. Therefore, this is a preferable strategy to accelerate bone regeneration in patients with periodontitis.

Epigallocatechin-3-gallate at the nanoscale: a new strategy for cancer treatment

CONTEXT

Epigallocatechin-3-gallate (EGCG), the predominant catechin in green tea, has shown the potential to combat various types of cancer cells through its ability to modulate multiple signaling pathways. However, its low bioavailability and rapid degradation hinder its clinical application.

OBJECTIVE

This review explores the potential of nanoencapsulation to enhance the stability, bioavailability, and therapeutic efficacy of EGCG in cancer treatment.

METHODS

We searched the PubMed database from 2019 to the present, using 'epigallocatechin gallate', 'EGCG', and 'nanoparticles' as search terms to identify pertinent literature. This review examines recent nano-engineering technology advancements that encapsulate EGCG within various nanocarriers. The focus was on evaluating the types of nanoparticles used, their synthesis methods, and the technologies applied to optimize drug delivery, diagnostic capabilities, and therapeutic outcomes.

RESULTS

Nanoparticles improve the physicochemical stability and pharmacokinetics of EGCG, leading to enhanced therapeutic outcomes in cancer treatment. Nanoencapsulation allows for targeted drug delivery, controlled release, enhanced cellular uptake, and reduced premature degradation of EGCG. The studies highlighted include those where EGCG-loaded nanoparticles significantly inhibited tumor growth in various models, demonstrating enhanced penetration and efficacy through active targeting mechanisms.

CONCLUSIONS

Nanoencapsulation of EGCG represents a promising approach in oncology, offering multiple therapeutic benefits over its unencapsulated form. Although the results so far are promising, further research is necessary to fully optimize the design of these nanosystems to ensure their safety, efficacy, and clinical viability.

Epigallocatechin gallate improves oleic acid-induced hepatic steatosis in laying hen hepatocytes via the MAPK pathway

Fatty liver disease in laying hens, characterized by excessive lipid accumulation in hepatocytes, poses significant challenges to poultry health and production efficiency. In this study, we investigated the therapeutic potential of epigallocatechin gallate (EGCG), a bioactive compound found in green tea, in mitigating oleic acid (OA)-induced hepatic steatosis in primary chicken hepatocytes. Treatment with EGCG effectively attenuated lipid deposition by downregulating lipid synthesis-related genes. Moreover, EGCG mitigated oxidative stress, inflammation, DNA damage, and apoptosis induced by OA, thereby preserving hepatocyte viability. Mechanistically, EGCG exerted its protective effects by modulating the p38 MAPK signaling pathway. Our findings suggest that EGCG holds promise as a therapeutic agent for managing fatty liver disease in poultry, offering insights into novel strategies for improving poultry health and production outcomes.

Silk fibroin microneedles loaded with epigallocatechin gallate mitigate atrazine-induced testicular toxicity

Atrazine (ATZ), a commonly used herbicide, disrupts male endocrine systems, impacting reproductive health. Epigallocatechin gallate (EGCG) possesses potent antioxidant properties and shows promise in alleviating testicular dysfunction induced by endocrine disruptors. However, its clinical utility is hindered by poor physicochemical stability and low oral bioavailability. Herein, we first developed a silk fibroin microneedles (MNs) patch loaded with EGCG, enabling EGCG to directly target the testes through transdermal administration. Our findings revealed that EGCG-loaded silk fibroin microneedles (EGCG-SF-MNs) exhibited excellent biocompatibility with no observed cytotoxicity in vitro or in vivo. In vitro assays revealed that EGCG-SF-MN patches significantly reduced ATZ-induced apoptosis and oxidative stress in GC-1 spg cells by modulating the Bcl-2/Bax ratio and ROS levels. In vivo studies in rats further confirmed the therapeutic potential of these patches, as they reversed ATZ-induced testicular dysfunction, sperm abnormalities, and blood-testis barrier disruption. Proteomics analysis highlighted the beneficial effects of EGCG-SF-MN patches on restoring protein expression altered by ATZ, particularly in necroptosis and lysosome pathways. Collectively, the development of EGCG-SF-MNs demonstrates enhanced therapeutic and targeted delivery efficacy for potential clinical applications in treating male reproductive disorders induced by environmental endocrine disruptor ATZ.

Lipophilic derivatives of EGCG as potent α-amylase and α-glucosidase inhibitors ameliorating oxidative stress and inflammation

Uncontrolled hyperglycemia leads to increased oxidative stress, chronic inflammation, and insulin resistance, rendering diabetes management harder to accomplish. To tackle these myriads of challenges, researchers strive to explore innovative multifaceted treatment strategies, including inhibiting carbohydrate hydrolases. Herein, we report alkyl-ether EGCG derivatives as potent α-amylase and α-glucosidase inhibitors that could simultaneously ameliorate oxidative stress and inflammation. 4″-C18 EGCG, the most promising compound, showed multifold improvement in glycaemic management compared to acarbose, with 230-fold greater inhibition (competitive) of α-glucosidase (IC50 0.81 µM) and 3-fold better inhibition of α-amylase (IC50 3.74 µM). All derivatives showed stronger antioxidant activity (IC50 6.16-15.76 µM) than vitamin C, while acarbose showed none. 4″-C18 EGCG also downregulated pro-inflammatory cytokines and showed no significant cytotoxicity up to 50 µM in primary human peripheral blood mononuclear cells (PBMC), non-cancerous cell line, 3T3-L1 and HEK 293. The in silico binding affinity analysis of 4″-C18 EGCG with α-amylase and α-glucosidase was found to exhibit a good extent of interaction as compared to acarbose. In comparison to EGCG, 4″-Cn EGCG derivatives were found to remain stable in the physiological conditions even after 24 h. Together, the reported molecules demonstrated multifaceted antidiabetic potential inhibiting carbohydrate hydrolases, reducing oxidative stress, and inflammation, which are known to aggravate diabetes.

Effects of natural products on angiogenesis in melanoma

Melanoma is the most aggressive form of skin cancer and originates from genetic mutations in melanocytes. The disease is multifactorial, but its main cause is overexposure to UV radiation. Currently, available chemotherapy expresses little to no results, which may justify the extensive use of natural products to treat this cancer. In this study, we reviewed the inhibition of melanoma angiogenesis by natural products and its potential mechanisms using literature from PubMed, EMBASE, Web of Science, Ovid, ScienceDirect and China National Knowledge Infrastructure databases. According to summarizes 27 natural products including alkaloids, polyphenols, terpenoids, flavonoids, and steroids that effectively inhibit angiogenesis in melanoma. In addition to these there are 15 crude extracts that can be used as promising agents to inhibit angiogenesis, but their core components still deserve further investigation. There are current studies on melanoma angiogenesis involving oxidative stress, immune-inflammatory response, cell proliferation and migration and capillary formation. The above natural products can be involved in melanoma angiogenesis through core targets such as VE-cadherin, COX-2, iNOS, VEGF, bFGF, FGF2,MMP2,MMP9,IL-1β,IL-6 play a role in inhibiting melanoma angiogenesis. Effective excavation of natural products can not only clarify the mechanism of drug action and key targets, but also help to promote the preclinical research of natural products for melanoma treatment and further promote the development of new clinical drugs, which will bring the gospel to the vast number of patients who are deeply afflicted by melanoma.

Epigallocatechin-3-gallate attenuates fluoride induced apoptosis via PI3K/FoxO1 pathway in ameloblast-like cells

Fluoride is a double-edged sword. It was widely used for early caries prevention while excessive intake caused a toxicology effect, affected enamel development, and resulted in dental fluorosis. The study aimed to evaluate the protective effect and mechanism of Epigallocatechin-3-gallate (EGCG) on the apoptosis induced by fluoride in ameloblast-like cells. We observed that NaF triggered apoptotic alterations in cell morphology, excessive NaF arrested cell cycle at the G1, and induced apoptosis by up-regulating Bax and down-regulating Bcl-2. NaF activated the insulin-like growth factor receptor (IGFR), and phosphatidylinositol-3-hydroxylase (p-PI3K), while dose-dependently down-regulating the expression of Forkhead box O1 (FoxO1). EGCG supplements reversed the changes in LS8 morphology, the cell cycle, and apoptosis induced by fluoride. These results indicated that EGCG possesses a protective effect against fluoride toxicity. Furthermore, EGCG suppressed the activation of p-PI3K and the down-regulation of FoxO1 caused by fluoride. Collectively, our findings suggested that EGCG attenuated fluoride-induced apoptosis by inhibiting the PI3K/FoxO1 signaling pathway. EGCG may serve as a new alternative method for dental fluorosis prevention, control, and treatment.

Rising potentials of epigallocatechin gallate (EGCG) loaded lipid-based delivery platforms for breast cancer

Breast cancer is a major global health concern that requires the development of innovative treatment strategies. Epigallocatechin gallate (EGCG), a polyphenolic phytocompound found abundantly in green tea, has exhibited potential anti-cancer properties, including anti-inflammatory, anti-oxidant, anti-angiogenic, and anti-proliferative effects. However, the clinical translation of EGCG is hindered by its poor bioavailability and stability. Lipid-based nanocarriers have materialized as an optimistic platform for encapsulating various therapeutics due to their high drug-loading capacity, stability, biocompatibility, and versatility. The rationale for encapsulating EGCG-loaded lipid nanoparticles is to enhance the therapeutic efficacy, bioavailability, and targeted delivery of EGCG for breast cancer treatment. This targeted delivery minimizes off-target effects and enhances the accumulation of EGCG within tumors or diseased tissues in a controlled or sustained manner, reducing systemic toxicity. In addition, co-delivery of EGCG with synergistic agents can enhance therapeutic efficacy through complementary mechanisms of action, overcome biological barriers, and can be combined with other treatment modalities, i.e., radiation therapy, immunotherapy, chemotherapy, etc., to achieve synergistic effectiveness and overcome resistance mechanisms. The advancement of EGCG-loaded lipid nanoparticles exhibits the potential effectiveness of EGCG-based treatments, can overcome the challenges of administering EGCG, and can transform cancer therapy and other biomedical applications.

Graphical abstract

Understanding the potential role of Epigallocatechin gallate (EGCG) in breast cancer treatment through various signaling pathways and further loaded into the lipid-based delivery system for the improvement of mechanical and biological characteristics of the EGCG.

Effects of Green Tea Extract Epigallocatechin-3-Gallate on Oral Diseases: A Narrative Review

OBJECTIVES

Oral diseases are among the most prevalent diseases globally. Accumulating new evidence suggests considerable benefits of epigallocatechin-3-gallate (EGCG) for oral health. This review aims to explore the role and application of EGCG in main oral diseases.

METHODS

This narrative review thoroughly examines and summarizes the most recent literature available in scientific databases (PubMed, Web of Science, Scopus, and Google Scholar) reporting advances in the role and application of EGCG within the dental field. The major keywords used included "EGCG", "green tea extract", "oral health", "caries", "pulpitis", "periapical disease", "periodontal disease", "oral mucosa", "salivary gland", and "oral cancer".

CONCLUSIONS

EGCG prevents and manages various oral diseases through its antibacterial, anti-inflammatory, antioxidant, and antitumor properties. Compared to traditional treatments, EGCG generally exhibits lower tissue irritation and positive synergistic effects when combined with other therapies. Novel delivery systems or chemical modifications can significantly enhance EGCG's bioavailability, prolong its action, and reduce toxicity, which are current hotspots in developing new materials.

CLINICAL SIGNIFICANCE

this review provides an exhaustive overview of the biological activities of EGCG to major oral diseases, alongside an exploration of applications and limitations, which serves as a reference for preventing and managing oral ailments.

The potential of EGCG in modulating the oral-gut axis microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a recurrent chronic intestinal disorder that includes ulcerative colitis (UC) and Crohn's disease (CD). Its pathogenesis involves intricate interactions between pathogenic microorganisms, native intestinal microorganisms, and the intestinal immune system via the oral-gut axis. The strong correlation observed between oral diseases and IBD indicates the potential involvement of oral pathogenic microorganisms in IBD development. Consequently, therapeutic strategies targeting the proliferation, translocation, intestinal colonization and exacerbated intestinal inflammation of oral microorganisms within the oral-gut axis may partially alleviate IBD. Tea consumption has been identified as a contributing factor in reducing IBD, with epigallocatechin gallate (EGCG) being the primary bioactive compound used for IBD treatment. However, the precise mechanism by which EGCG mediates microbial crosstalk within the oral-gut axis remains unclear. In this review, we provide a comprehensive overview of the diverse oral microorganisms implicated in the pathogenesis of IBD and elucidate their colonization pathways and mechanisms. Subsequently, we investigated the antibacterial properties of EGCG and its potential to attenuate microbial translocation and colonization in the gut, emphasizing its role in attenuating exacerbations of IBD. We also elucidated the toxic and side effects of EGCG. Finally, we discuss current strategies for enhancing EGCG bioavailability and propose novel multi-targeted nano-delivery systems for the more efficacious management of IBD. This review elucidates the role and feasibility of EGCG-mediated modulation of the oral-gut axis microbiota in the management of IBD, contributing to a better understanding of the mechanism of action of EGCG in the treatment of IBD and the development of prospective treatment strategies.

Phytomedicine for neurodegenerative diseases: The road ahead

Neurodegenerative disorders (NDs) are among the most common causes of death across the globe. NDs are characterized by progressive damage to CNS neurons, leading to defects in specific brain functions such as memory, cognition, and movement. The most common NDs are Parkinson's, Alzheimer's, Huntington's, and amyotrophic lateral sclerosis (ALS). Despite extensive research, no therapeutics or medications against NDs have been proven to be effective. The current treatment of NDs involving symptom-based targeting of the disease pathogenesis has certain limitations, such as drug resistance, adverse side effects, poor blood-brain barrier permeability, and poor bioavailability of drugs. Some studies have shown that plant-derived natural compounds hold tremendous promise for treating and preventing NDs. Therefore, the primary objective of this review article is to critically analyze the properties and potency of some of the most studied phytomedicines, such as quercetin, curcumin, epigallocatechin gallate (EGCG), apigenin, and cannabinoids, and highlight their advantages and limitations for developing next-generation alternative treatments against NDs. Further extensive research on pre-clinical and clinical studies for developing plant-based drugs against NDs from bench to bedside is warranted.

Therapeutic effects of epigallocatechin-3-gallate for inflammatory bowel disease: A preclinical meta-analysis

BACKGROUND

Epigallocatechin-3-gallate (EGCG), the primary active compound in green tea, is recognized for its significant anti-inflammatory properties and potential pharmacological effects on inflammatory bowel disease (IBD). However, comprehensive preclinical evidence supporting the use of EGCG in treating IBD is currently insufficient.

PURPOSE

To evaluate the efficacy of EGCG in animal models of IBD and explore potential underlying mechanisms, serving as a groundwork for future clinical investigations.

METHODS

A systematic review of pertinent preclinical studies published until September 1, 2023, in databases such as PubMed, Embase, Web of Science, and Cochrane Library was conducted, adhering to stringent quality criteria. The potential mechanisms via which EGCG may address IBD were summarized. STATA v16.0 was used to perform a meta-analysis to assess IBD pathology, inflammation, and indicators of oxidative stress. Additionally, dose-response analysis and machine learning models were utilized to evaluate the dose-effect relationship and determine the optimal dosage of EGCG for IBD treatment.

RESULTS

The analysis included 19 studies involving 309 animals. The findings suggest that EGCG can ameliorate IBD-related pathology in animals, with a reduction in inflammatory and oxidative stress indicators. These effects were observed through significant changes in histological scores, Disease Activity Index, Colitis Macroscopic Damage Index and colon length; a decrease in markers such as interleukin (IL)-1β, IL-6 and interferon-γ; and alterations in malondialdehyde, superoxide dismutase, glutathione, and catalase levels. Subgroup analysis indicated that the oral administration route of EGCG exhibited superior efficacy over other administration routes. Dose-response analysis and machine learning outcomes highlighted an optimal EGCG dosage range of 32-62 mg/kg/day, with an intervention duration of 4.8-13.6 days.

CONCLUSIONS

EGCG exhibits positive effects on IBD, particularly when administered at the dose range of 32 - 62 mg/kg/day, primarily attributed to its ability to regulate inflammation and oxidative stress levels.

Harnessing the Power of Polyphenols: A New Frontier in Disease Prevention and Therapy

There are a wide variety of phytochemicals collectively known as polyphenols. Their structural diversity results in a broad range of characteristics and biological effects. Polyphenols can be found in a variety of foods and drinks, including fruits, cereals, tea, and coffee. Studies both in vitro and in vivo, as well as clinical trials, have shown that they possess potent antioxidant activities, numerous therapeutic effects, and health advantages. Dietary polyphenols have demonstrated the potential to prevent many health problems, including obesity, atherosclerosis, high blood sugar, diabetes, hypertension, cancer, and neurological diseases. In this paper, the protective effects of polyphenols and the mechanisms behind them are investigated in detail, citing the most recent available literature. This review aims to provide a comprehensive overview of the current knowledge on the role of polyphenols in preventing and managing chronic diseases. The cited publications are derived from in vitro, in vivo, and human-based studies and clinical trials. A more complete understanding of these naturally occurring metabolites will pave the way for the development of novel polyphenol-rich diet and drug development programs. This, in turn, provides further evidence of their health benefits.

Biosynthesis of Nanoparticles with Green Tea for Inhibition of β-Amyloid Fibrillation Coupled with Ligands Analysis

Background

Inhibition of amyloid β protein fragment (Aβ) aggregation is considered to be one of the most effective strategies for the treatment of Alzheimer's disease. (-)-Epigallocatechin-3-gallate (EGCG) has been found to be effective in this regard; however, owing to its low bioavailability, nanodelivery is recommended for practical applications. Compared to chemical reduction methods, biosynthesis avoids possible biotoxicity and cumbersome preparation processes.

Materials and Methods

The interaction between EGCG and Aβ42 was simulated by molecular docking, and green tea-conjugated gold nanoparticles (GT-Au NPs) and EGCG-Au NPs were synthesized using EGCG-enriched green tea and EGCG solutions, respectively. Surface active molecules of the particles were identified and analyzed using various liquid chromatography-tandem triple quadrupole mass spectrometry methods. ThT fluorescence assay, circular dichroism, and TEM were used to investigate the effect of synthesized particles on the inhibition of Aβ42 aggregation.

Results

EGCG as well as apigenin, quercetin, baicalin, and glutathione were identified as capping ligands stabilized on the surface of GT-Au NPs. They more or less inhibited Aβ42 aggregation or promoted fibril disaggregation, with EGCG being the most effective, which bound to Aβ42 through hydrogen bonding, hydrophobic interactions, etc. resulting in 39.86% and 88.50% inhibition of aggregation and disaggregation effects, respectively. EGCG-Au NPs were not as effective as free EGCG, whereas multiple thiols and polyphenols in green tea accelerated and optimized heavy metal detoxification. The synthesized GT-Au NPs conferred the efficacy of diverse ligands to the particles, with inhibition of aggregation and disaggregation effects of 54.69% and 88.75%, respectively, while increasing the yield, enhancing water solubility, and decreasing cost.

Conclusion

Biosynthesis of nanoparticles using green tea is a promising simple and economical drug-carrying approach to confer multiple pharmacophore molecules to Au NPs. This could be used to design new drug candidates to treat Alzheimer's disease.

EGCG Disrupts the LIN28B/Let-7 Interaction and Reduces Neuroblastoma Aggressiveness

Neuroblastoma (NB) is the most commonly diagnosed extracranial solid tumor in children, accounting for 15% of all childhood cancer deaths. Although the 5-year survival rate of patients with a high-risk disease has increased in recent decades, NB remains a challenge in pediatric oncology, and the identification of novel potential therapeutic targets and agents is an urgent clinical need. The RNA-binding protein LIN28B has been identified as an oncogene in NB and is associated with a poor prognosis. Given that LIN28B acts by negatively regulating the biogenesis of the tumor suppressor let-7 miRNAs, we reasoned that selective interference with the LIN28B/let-7 miRNA interaction would increase let-7 miRNA levels, ultimately leading to reduced NB aggressiveness. Here, we selected (-)-epigallocatechin 3-gallate (EGCG) out of 4959 molecules screened as the molecule with the best inhibitory activity on LIN28B/let-7 miRNA interaction and showed that treatment with PLC/PLGA-PEG nanoparticles containing EGCG (EGCG-NPs) led to an increase in mature let-7 miRNAs and a consequent inhibition of NB cell growth. In addition, EGCG-NP pretreatment reduced the tumorigenic potential of NB cells in vivo. These experiments suggest that the LIN28B/let-7 miRNA axis is a good therapeutic target in NB and that EGCG, which can interfere with this interaction, deserves further preclinical evaluation.

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.

Novel molecular hybrids of EGCG and quinoxaline: Potent multi-targeting antidiabetic agents that inhibit α-glucosidase, α-amylase, and oxidative stress

Diabetes mellitus is a multifactorial disease and its effective therapy often demands several drugs with different modes of action. Herein, we report a rational design and synthesis of multi-targeting novel molecular hybrids comprised of EGCG and quinoxaline derivatives that can effectively inhibit α-glucosidase, α-amylase as well as control oxidative stress by scavenging ROS. The hybrids showed superior inhibition of α-glucosidase along with similar α-amylase inhibition as compared to standard drug, acarbose. Most potent compound, 15c showed an IC50 of 0.50 μM (IC50 of acarbose 190 μM) against α-glucosidase. Kinetics studies with 15c revealed a competitive inhibition against α-glucosidase. Binding affinity of 15c (-9.5 kcal/mol) towards α-glucosidase was significantly higher than acarbose (-7.7 kcal/mol). 15c exhibited remarkably high antioxidant activity (IC50 = 18.84 μM), much better than vitamin C (IC50 = 33.04 μM). Of note, acarbose shows no antioxidant activity. Furthermore, α-amylase activity was effectively inhibited by 15c with an IC50 value of 16.35 μM. No cytotoxicity was observed for 15c (up to 40 μM) in MCF-7 cells. Taken together, we report a series of multi-targeting molecular hybrids capable of inhibiting carbohydrate hydrolysing enzymes as well as reducing oxidative stress, thus representing an advancement towards effective and novel therapeutic approaches for diabetes.

Microfluidics-enabled fluorinated assembly of EGCG-ligands-siTOX nanoparticles for synergetic tumor cells and exhausted t cells regulation in cancer immunotherapy

Immune checkpoint inhibitor (ICI)-derived evolution offers a versatile means of developing novel immunotherapies that targets programmed death-ligand 1 (PD-L1)/programmed death-1 (PD-1) axis. However, one major challenge is T cell exhaustion, which contributes to low response rates in "cold" tumors. Herein, we introduce a fluorinated assembly system of LFNPs/siTOX complexes consisting of fluorinated EGCG (FEGCG), fluorinated aminolauric acid (LA), and fluorinated polyethylene glycol (PEG) to efficiently deliver small interfering RNA anti-TOX (thymus high mobility group box protein, TOX) for synergistic tumor cells and exhausted T cells regulation. Using a microfluidic approach, a library of LFNPs/siTOX complexes were prepared by altering the placement of the hydrophobe (LA), the surface PEGylation density, and the siTOX ratio. Among the different formulations tested, the lead formulation, LFNPs3-3/siTOX complexes, demonstrated enhanced siRNA complexation, sensitive drug release, improved stability and delivery efficacy, and acceptable biosafety. Upon administration by the intravenous injection, this formulation was able to evoke a robust immune response by inhibiting PD-L1 expression and mitigating T cell exhaustion. Overall, this study provides valuable insights into the fluorinated assembly and concomitant optimization of the EGCG-based delivery system. Furthermore, it offers a promising strategy for cancer immunotherapy, highlighting its potential in improving response rates in ''cold'' tumors.

Therapeutic strategy of biological macromolecules based natural bioactive compounds of diabetes mellitus and future perspectives: A systematic review

High blood glucose levels are a hallmark of the metabolic syndrome known as diabetes mellitus. More than 600 million people will have diabetes by 2045 as the global prevalence of the disease continues to rise. Contemporary antidiabetic drugs reduce hyperglycemia and its consequences. However, these drugs come with undesirable side effects, so it's encouraging that research into plant extracts and bioactive substances with antidiabetic characteristics is on the rise. Natural remedies are preferable to conventional anti-diabetic drugs since they are safer for the body, more affordable and have fewer potential adverse effects. Biological macromolecules such as liposomes, niosomes, polymeric nanoparticles, solid lipid nanoparticles, nanoemulsions and metallic nanoparticles are explored in this review. Current drug restrictions have been addressed, and the effectiveness of plant-based antidiabetic therapies has enhanced the merits of these methods. Plant extracts' loading capacity and the carriers' stability are the primary obstacles in developing plant-based nanocarriers. Hydrophilic, hydrophobic, and amphiphilic drugs are covered, and a brief overview of the amphipathic features of liposomes, phospholipids, and lipid nanocarriers is provided. Metallic nanoparticles' benefits and attendant risks are highlighted to emphasize their efficiency in treating hyperglycemia. Researchers interested in the potential of nanoparticles loaded with plant extracts as antidiabetic therapeutics may find the current helpful review.

4″-Alkyl EGCG Derivatives Induce Cytoprotective Autophagy Response by Inhibiting EGFR in Glioblastoma Cells

Epidermal growth factor receptor (EGFR)-targeted therapy has been proven vital in the last two decades for the treatment of multiple cancer types, including nonsmall cell lung cancer, glioblastoma, breast cancer and head and neck squamous cell carcinoma. Unfortunately, the majority of approved EGFR inhibitors fall into the drug resistance category because of continuous mutations and acquired resistance. Recently, autophagy has surfaced as one of the emerging underlying mechanisms behind resistance to EGFR-tyrosine kinase inhibitors (TKIs). Previously, we developed a series of 4″-alkyl EGCG (4″-Cn EGCG, n = 6, 8, 10, 12, 14, 16, and 18) derivatives with enhanced anticancer effects and stability. Therefore, the current study hypothesized that 4″-alkyl EGCG might induce cytoprotective autophagy upon EGFR inhibition, and inhibition of autophagy may lead to improved cytotoxicity. In this study, we have observed growth inhibition and caspase-3-dependent apoptosis in 4″-alkyl EGCG derivative-treated glioblastoma cells (U87-MG). We also confirmed that 4″-alkyl EGCG could inhibit EGFR in the cells, as well as mutant L858R/T790M EGFR, through an in vitro kinase assay. Furthermore, we have found that EGFR inhibition with 4″-alkyl EGCG induces cytoprotective autophagic responses, accompanied by the blockage of the AKT/mTOR signaling pathway. In addition, cytotoxicity caused by 4″-C10 EGCG, 4″-C12 EGCG, and 4″-C14 EGCG was significantly increased after the inhibition of autophagy by the pharmacological inhibitor chloroquine. These findings enhance our understanding of the autophagic response toward EGFR inhibitors in glioblastoma cells and suggest a potent combinatorial strategy to increase the therapeutic effectiveness of EGFR-TKIs.

Bibliometric and visual analysis in the field of tea in cancer from 2013 to 2023

Objective

Tea has been utilized in cancer research and is progressively gaining wider recognition, with its roles in cancer prevention and treatment being increasingly affirmed. The objective of this study is to investigate the current state and research hotspots in the field of tea's involvement in cancer research from 2013 to 2023, aiming to offer reference and direction for future studies.

Methods

We analyzed 4,789 articles published between 2013 and 2022 from the Web of Science database using VOSviewer, R software, and CiteSpace software.

Result

Tea-related cancer research showed an overall upward trend, with China leading in publications, followed by the United States, India, Japan, and Italy. China also had significant international collaborations, notably with Harvard University and the Egyptian Knowledge Bank. The 'Journal of Agricultural and Food Chemistry' was the most cited journal. Key topics included 'green tea,' 'cancer,' 'in vitro,' 'oxidative stress,' and 'apoptosis.' Research focused on tea's pharmacological effects, anticancer properties, mechanisms of natural compounds (e.g., polyphenols and EGCG), antioxidant and antimicrobial properties, and molecular mechanisms in cancer treatment.

Conclusion

Tea's potential as an anti-cancer medication is gaining global recognition. Our study provides a comprehensive analysis of tea-related cancer research from 2013 to 2023, guiding future investigations in this field.

Implantable Epigallocatechin Gallate Sustained-Release Nanofibers for the Prevention of Immobilization-Induced Muscle Atrophy

Long-term immobilization of joints can lead to disuse atrophy of the muscles in the joints. Oral nutrients are used clinically for rehabilitation and therapeutic purposes, but bioavailability and targeting are limited. Here, we report tea polyphenols (dietary polyphenols), sustained-release nanofilms that release tea polyphenols through slow local degradation of core-shell nanofibers in muscles. This dietary polyphenol does not require gastrointestinal consumption and multiple doses and can directly remove inflammatory factors and superoxide generated in muscle tissue during joint fixation. The quality of muscles is increased by 30%, and muscle movement function is effectively improved. Although nanofibers need to be implanted into muscles, they can improve bacterial infections after joint surgery. To investigate the biological mechanism of this core-shell nanomembrane prevention, we conducted further transcriptomic studies on muscle, confirming that in addition to achieving antioxidation and anti-inflammation by inhibiting TNF-α and NF-κB signaling pathways, tea polyphenol core-shell nanofibers can also promote muscle formation by activating the p-Akt signaling pathway.

Combination of Nanodelivery Systems and Constituents Derived from Novel Foods: A Comprehensive Review

Novel Food is a new category of food, regulated by the European Union Directive No. 2015/2283. This latter norm defines a food as "Novel" if it was not used "for human consumption to a significant degree within the Union before the date of entry into force of that regulation, namely 15 May 1997". Recently, Novel Foods have received increased interest from researchers worldwide. In this sense, the key areas of interest are the discovery of new benefits for human health and the exploitation of these novel sources of materials in new fields of application. An emerging area in the pharmaceutical and medicinal fields is nanotechnology, which deals with the development of new delivery systems at a nanometric scale. In this context, this review aims to summarize the recent advances on the design and characterization of nanodelivery systems based on materials belonging to the Novel Food list, as well as on nanoceutical products formulated for delivering compounds derived from Novel Foods. Additionally, the safety hazard of using nanoparticles in food products, i.e., food supplements, has been discussed in view of the current European regulation, which considers nanomaterials as Novel Foods.

Mitochondria-targeting EGCG derivatives protect H9c2 cardiomyocytes from H2O2-induced apoptosis: design, synthesis and biological evaluation

Pathologies related to cardiovascular diseases mostly emerge as a result of oxidative stress buildup in cardiomyocytes. The heavy load of mitochondrial oxidative phosphorylation in cardiac tissues corresponds to a surge in oxidative stress leading to mitochondrial dysfunction and cellular apoptosis. Thus, scavenging the reactive oxygen species (ROS) linked to mitochondria can significantly improve cardio-protection. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea has been extensively studied for its profound health-beneficial activities. Herein, we designed and synthesized a series of mitochondrial-targeting EGCG derivatives, namely MitoEGCGn (n = 4, 6, 8) by incorporating triphenylphosphonium ion onto it using different linkers. MitoEGCGn were found to be non-toxic to H9c2 rat cardiomyocyte cells even at higher doses in comparison to its parent molecule EGCG. Interestingly, MitoEGCG4 and MitoEGCG6 protected the H9c2 cardiomyocyte cells from the oxidative damage induced by H2O2 whereas EGCG was found to be toxic and ineffective in protecting the cells from H2O2 damage. MitoEGCG4 and MitoEGCG6 also protected the cells from the H2O2-induced disruption of mitochondrial membrane potential as well as activation of apoptosis as revealed by pro-caspase 3 expression profile, DNA fragmentation assay, and AO/EtBr staining. Taken together, our study shows that the mitochondria targeting EGCG derivatives were able to effectively combat the H2O2-induced oxidative stress in H9c2 cardiomyocytes. They eventually augmented the mitochondrial health of cardiomyocytes by maintaining the mitochondrial function and attenuating apoptosis. Overall, MitoEGCG4 and MitoEGCG6 could provision a cardioprotective role to H9c2 cardiomyocytes at the time of oxidative insults related to mitochondrial dysfunction-associated injuries.

Brain Mitochondrial Bioenergetics in Genetic Neurodevelopmental Disorders: Focus on Down, Rett and Fragile X Syndromes

Mitochondria, far beyond their prominent role as cellular powerhouses, are complex cellular organelles active as central metabolic hubs that are capable of integrating and controlling several signaling pathways essential for neurological processes, including neurogenesis and neuroplasticity. On the other hand, mitochondria are themselves regulated from a series of signaling proteins to achieve the best efficiency in producing energy, in establishing a network and in performing their own de novo synthesis or clearance. Dysfunctions in signaling processes that control mitochondrial biogenesis, dynamics and bioenergetics are increasingly associated with impairment in brain development and involved in a wide variety of neurodevelopmental disorders. Here, we review recent evidence proving the emerging role of mitochondria as master regulators of brain bioenergetics, highlighting their control skills in brain neurodevelopment and cognition. We analyze, from a mechanistic point of view, mitochondrial bioenergetic dysfunction as causally interrelated to the origins of typical genetic intellectual disability-related neurodevelopmental disorders, such as Down, Rett and Fragile X syndromes. Finally, we discuss whether mitochondria can become therapeutic targets to improve brain development and function from a holistic perspective.

ROS scavenging and immunoregulative EGCG@Cerium complex loaded in antibacterial polyethylene glycol-chitosan hydrogel dressing for skin wound healing

The elevation of oxidative stress and inflammatory response after injury remains a substantial challenge that can deteriorate the wound microenvironment and compromise the success of wound healing. Herein, the assembly of naturally derived epigallocatechin-3-gallate (EGCG) and Cerium microscale complex (EGCG@Ce) was prepared as reactive oxygen species (ROS) scavenger, which was further loaded in antibacterial hydrogels as wound dressing. EGCG@Ce shows superior antioxidation capacity towards various ROS including free radical, O2- and H2O2 through superoxide dismutase-like or catalase-mimicking catalytic activity. Importantly, EGCG@Ce could provide mitochondrial protective effect against oxidative stress damages, reverse the polarization of M1 macrophages and reduce the secretion of pro-inflammatory cytokines. Furtherly, EGCG@Ce was loaded into the PEG-chitosan hydrogel with dynamic, porous, injectable and antibacterial properties as wound dressing, which accelerated the regeneration of both epidermal layer and dermis, resulting in improved healing process of full-thickness skin wounds in vivo. Mechanistically, EGCG@Ce re-shaped the detrimental tissue microenvironment and augmented the pro-reparative response through reducing ROS accumulation, alleviating inflammatory response, enhancing the M2 macrophage polarization and angiogenesis. Collectively, antioxidative and immunomodulatory metal-organic complex-loaded hydrogel is a promising multifunctional dressing for the repair and regeneration of cutaneous wounds without additional drugs, exogenous cytokines, or cells. STATEMENT OF SIGNIFICANCE: (1) We reported an effective antioxidant through self-assembly coordination of EGCG and Cerium for managing the inflammatory microenvironment at the wound site, which not only showed high catalytic capacity towards multiple ROS, but also could provide mitochondrial protective effect against oxidative stress damage, reverse the polarization of M1 macrophages and downregulate pro-inflammatory cytokines. EGCG@Ce was further loaded into porous and bactericidal PEG-chitosan (PEG-CS) hydrogel as a versatile wound dressing, which accelerated wound healing and angiogenesis. (2) The applicability of alleviating sustainable inflammation and regulating macrophage polarization through ROS scavenging is a promising strategy for tissue repair and regeneration without additional drugs, cytokines, or cells.

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.

Extraction, characterization of polyphenols from certain medicinal plants and evaluation of their antioxidant, antitumor, antidiabetic, antimicrobial properties, and potential use in human nutrition

Introduction

Dietary medicinal plants are among the most sought-after topics in alternative medicine today due to their preventive and healing properties against many diseases.

Aim

This study aimed to extract and determine the polyphenols from indigenous plants extracts, i.e., Mentha longifolia, M. arvensis, Tinospora cordifolia, Cymbopogon citratus, Foeniculum vulgare, Cassia absus, Camellia sinensis, Trachyspermum ammi, C. sinensis and M. arvensis, then evaluate the antioxidant, cytotoxicity, and antimicrobial properties, besides enzyme inhibition of isolated polyphenols.

Methods

The antioxidant activity was evaluated by DPPH, Superoxide radical, Hydroxyl radical (OH.), and Nitric oxide (NO.) scavenging activity; the antidiabetic activity was evaluated by enzymatic methods, and anticancer activity using MTT assay, while the antibacterial activity.

Results

The results showed that tested medicinal plants' polyphenolic extracts (MPPE) exhibited the most significant antioxidant activity in DPPH, hydroxyl, nitric oxide, and superoxide radical scavenging methods because of the considerable amounts of total polyphenol and flavonoid contents. UHPLC profile showed twenty-five polyphenol complexes in eight medicinal plant extracts, categorized into phenolic acids, flavonoids, and alkaloids. The main polyphenol was 3-Feroylquinic acid (1,302 mg/L), also found in M. longifolia, C. absus, and C. sinensis, has a higher phenolic content, i.e., rosmarinic acid, vanillic acid, chlorogenic acid, p-coumaric acid, ferulic acid, gallic acid, catechin, luteolin, 7-O-neohesperideside, quercetin 3,7-O-glucoside, hesperidin, rutin, quercetin, and caffeine in the range of (560-780 mg/L). At the same time, other compounds are of medium content (99-312 mg/L). The phenolics in C. sinensis were 20-116% more abundant than those in M. longifolia, C. absus, and other medicinal plants. While T. cordifolia is rich in alkaloids, T. ammi has a lower content. The MTT assay against Caco-2 cells showed that polyphenolic extracts of T. ammi and C. citratus had maximum cytotoxicity. While M. arvensis, C. sinensis, and F. vulgare extracts showed significant enzyme inhibition activity, C. sinensis showed minor inhibition activity against α-amylase. Furthermore, F. vulgare and C. sinensis polyphenolic extracts showed considerable antibacterial activity against S. aureus, B. cereus, E. coli, and S. enterica.

Discussion

The principal component analysis demonstrated clear separation among medicinal plants' extracts based on their functional properties. These findings prove the therapeutic effectiveness of indigenous plants and highlight their importance as natural reserves of phytogenic compounds with untapped potential that needs to be discovered through advanced analytical methods.

EGCG adjuvant chemotherapy: Current status and future perspectives

The resistance of cancer cells to chemotherapeutic drugs greatly reduces the therapeutic effect in cancer patients, and the toxic side effects caused by chemotherapy also seriously affect the quality of life of patients. The combination of epigallocatechin-3-gallate (EGCG), the main active ingredient in tea, with cisplatin, 5-FU, doxorubicin and paclitaxel enhances their sensitizing effect on tumors and combats the drug resistance of cancer cells. These effects seem to be mediated by a variety of mechanisms, including combating drug resistance mediated by cancer stem cells, enhancing drug sensitivity, inducing cell cycle arrest and apoptosis, and blocking angiogenesis. In addition, EGCG can suppress a series of adverse effects caused by chemotherapy, such as gastrointestinal disorders, nephrotoxicity and cardiotoxicity, through its anti-inflammatory and antioxidant effects and improve the quality of life of patients. However, the low bioavailability and off-target effects of EGCG and its reactivity with some chemotherapeutic agents limit its clinical application. The nanomodification of EGCG and chemotherapeutic drugs not only enhances the antitumor activity but also prolongs the survival time of tumor-bearing mice, and has the advantage of low toxicity. Therefore, this review aims to discuss the current status and challenges regarding the use of EGCG in combination with chemotherapy drugs in the treatment of cancer. In general, EGCG is a promising adjuvant for chemotherapy.

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.

In situ global proteomics profiling of EGCG targets using a cell-permeable and Click-able bioorthogonal probe

Despite possessing a wide spectrum of biological activities, molecular targets of EGCG remain elusive and as a result, its precise mode of action is still unknown. Herein, we have developed a novel cell-permeable and Click-able bioorthogonal probe for EGCG, YnEGCG for in situ detection and identification of its interacting proteins. The strategic structural modification on YnEGCG allowed it to retain innate biological activities of EGCG (IC₅₀ 59.52 ± 1.14 μM and 9.07 ± 0.01 μM for cell viability and radical scavenging activity, respectively). Chemoproteomics profiling identified 160 direct EGCG targets, with H:L ratio ≥ 1.10 from the list of 207 proteins, including multiple new proteins that were previously unknown. The targets were broadly distributed in various subcellular compartments suggesting a polypharmacological mode of action of EGCG. GO analysis revealed that the primary targets belonged to the enzymes that regulate key metabolic processes including glycolysis and energy homeostasis, also the cytoplasm (36 %) and mitochondria (15.6 %) contain the majority of EGCG targets. Further, we validated that EGCG interactome was closely associated with apoptosis indicating its role in inducing toxicity in cancer cells. For the first time, this in situ chemoproteomics approach could identify a direct and specific EGCG interactome under physiological conditions in an unbiased manner.

Absorption, metabolism, bioactivity, and biotransformation of epigallocatechin gallate

Epigallocatechin gallate (EGCG), a typical flavone-3-ol polyphenol containing eight free hydroxyl groups, is associated with a variety of bioactivities, such as antioxidant, anti-inflammatory, anti-cancer, and antibacterial activities. However, the poor bioavailability of EGCG restricts its use. In this review, we discuss the processes involved in the absorption and metabolism of EGCG, with a focus on its metabolic interactions with the gut microbiota. Next, we summarize the bioactivities of some key metabolites, describe the biotransformation of EGCG by different microorganisms, and discuss its catabolism by specific bacteria. A deeper understanding of the absorption, metabolism, and biotransformation of EGCG may enable its disease-preventive and therapeutic properties to be better utilized. This review provides a theoretical basis for further development and utilization of EGCG and its metabolites for improving the gut microbiota and physiological health.

Epigallocatechin-3-gallate Mo nanoparticles (EGM NPs) efficiently treat liver injury by strongly reducing oxidative stress, inflammation and endoplasmic reticulum stress

Drug-induced liver injury (DILI) is a serious clinical disease associated with reactive oxygen species (ROS) burst and subsequent inflammatory responses. However, traditional treatments were limited by low efficacy and serious side effects due to the special liver structure. Here, we developed a molybdenum (Mo)-based nanoparticles, EGM NPs, after overall consideration of the pathophysiology of DILI and the advantages of nanodrugs. It demonstrated that EGM NPs treated acetaminophen (APAP)-induced DILI by scavenging ROS and inhibiting inflammation. EGM NPs effectively scavenged various ROS and reduced cell apoptosis at the cellular level. More importantly, EGM NPs can treat APAP-induced DILI in vivo, reducing the levels of liver function indicators in mice with liver injury, scaling down the area of hepatocyte necrosis and successfully inhibiting endoplasmic reticulum (ER) stress in the liver. EGM NPs also showed a certain anti-inflammatory effect by reducing infiltration of macrophages, decreasing pro-inflammatory factors and inhibiting the expression levels of inducible nitric oxide synthase (NOS2) and myeloperoxidase (MPO). Collectively, our findings suggest that EGM NPs-based nanotherapeutic is a novel strategy for the treatment of DILI.

The Anticancer Potential of Plant-Derived Nutraceuticals via the Modulation of Gene Expression

Current studies show that approximately one-third of all cancer-related deaths are linked to diet and several cancer forms are preventable with balanced nutrition, due to dietary compounds being able to reverse epigenetic abnormalities. An appropriate diet in cancer patients can lead to changes in gene expression and enhance the efficacy of therapy. It has been demonstrated that nutraceuticals can act as powerful antioxidants at the cellular level as well as anticarcinogenic agents. This review is focused on the best studies on worldwide-available plant-derived nutraceuticals: curcumin, resveratrol, sulforaphane, indole-3-carbinol, quercetin, astaxanthin, epigallocatechin-3-gallate, and lycopene. These compounds have an enhanced effect on epigenetic changes such as histone modification via HDAC (histone deacetylase), HAT (histone acetyltransferase) inhibition, DNMT (DNA methyltransferase) inhibition, and non-coding RNA expression. All of these nutraceuticals are reported to positively modulate the epigenome, reducing cancer incidence. Furthermore, the current review addresses the issue of the low bioavailability of nutraceuticals and how to overcome the drawbacks related to their oral administration. Understanding the mechanisms by which nutraceuticals influence gene expression will allow their incorporation into an “epigenetic diet” that could be further capitalized on in the therapy of cancer.

Green Tea Catechins: Nature’s Way of Preventing and Treating Cancer

Green tea’s (Camellia sinensis) anticancer and anti-inflammatory effects are well-known. Catechins are the most effective antioxidants among the physiologically active compounds found in Camellia sinesis. Recent research demonstrates that the number of hydroxyl groups and the presence of specific structural groups have a substantial impact on the antioxidant activity of catechins. Unfermented green tea is the finest source of these chemicals. Catechins have the ability to effectively neutralize reactive oxygen species. The catechin derivatives of green tea include epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). EGCG has the greatest anti-inflammatory and anticancer potential. Notably, catechins in green tea have been explored for their ability to prevent a variety of cancers. Literature evidence, based on epidemiological and laboratory studies, indicates that green tea catechins have certain properties that can serve as the basis for their consideration as lead molecules in the synthesis of novel anticancer drugs and for further exploration of their role as pharmacologically active natural adjuvants to standard chemotherapeutics. The various sections of the article will focus on how catechins affect the survival, proliferation, invasion, angiogenesis, and metastasis of tumors by modulating cellular pathways.

Epigallocatechin gallate is a potent inhibitor of cystathionine beta-synthase: Structure-activity relationship and mechanism of action

Epigallocatechin gallate (EGCG) is the main bioactive component of green tea. Through screening of a small library of natural compounds, we discovered that EGCG inhibits cystathionine β-synthase (CBS), a major H₂S-generating enzyme. Here we characterize EGCG's mechanism of action in the context of CBS-derived H₂S production. In the current project, biochemical, pharmacological and cell biology approaches were used to characterize the effect of EGCG on CBS in cellular models of cancer and Down syndrome (DS). The results show that EGCG binds to CBS and inhibits H₂S-producing CBS activity almost 30-times more efficiently than the canonical cystathionine formation (IC₅₀ 0.12 versus 3.3 μM). Through screening structural analogs and building blocks, we identified that gallate moiety of EGCG represents the pharmacophore responsible for CBS inhibition. EGCG is a mixed-mode, CBS-specific inhibitor with no effect on the other two major enzymatic sources of H₂S, CSE and 3-MST. Unlike the prototypical CBS inhibitor aminooxyacetate, EGCG does not bind the catalytic cofactor of CBS pyridoxal-5'-phosphate. Molecular modeling suggests that EGCG blocks a substrate access channel to pyridoxal-5'-phosphate. EGCG inhibits cellular H₂S production in HCT-116 colon cancer cells and in DS fibroblasts. It also exerts effects that are consistent with the functional role of CBS in these cells: in HCT-116 cells it decreases, while in DS cells it improves viability and proliferation. In conclusion, EGCG is a potent inhibitor of CBS-derived H₂S production. This effect may contribute to its pharmacological effects in various pathophysiological conditions.

Functional Bacterial Amyloids: Understanding Fibrillation, Regulating Biofilm Fibril Formation and Organizing Surface Assemblies

Functional amyloid is produced by many organisms but is particularly well understood in bacteria, where proteins such as CsgA (E. coli) and FapC (Pseudomonas) are assembled as functional bacterial amyloid (FuBA) on the cell surface in a carefully optimized process. Besides a host of helper proteins, FuBA formation is aided by multiple imperfect repeats which stabilize amyloid and streamline the aggregation mechanism to a fast-track assembly dominated by primary nucleation. These repeats, which are found in variable numbers in Pseudomonas, are most likely the structural core of the fibrils, though we still lack experimental data to determine whether the repeats give rise to β-helix structures via stacked β-hairpins (highly likely for CsgA) or more complicated arrangements (possibly the case for FapC). The response of FuBA fibrillation to denaturants suggests that nucleation and elongation involve equal amounts of folding, but protein chaperones preferentially target nucleation for effective inhibition. Smart peptides can be designed based on these imperfect repeats and modified with various flanking sequences to divert aggregation to less stable structures, leading to a reduction in biofilm formation. Small molecules such as EGCG can also divert FuBA to less organized structures, such as partially-folded oligomeric species, with the same detrimental effect on biofilm. Finally, the strong tendency of FuBA to self-assemble can lead to the formation of very regular two-dimensional amyloid films on structured surfaces such as graphite, which strongly implies future use in biosensors or other nanobiomaterials. In summary, the properties of functional amyloid are a much-needed corrective to the unfortunate association of amyloid with neurodegenerative disease and a testimony to nature's ability to get the best out of a protein fold.

Structure-based design and synthesis of a novel long-chain 4''-alkyl ether derivative of EGCG as potent EGFR inhibitor: in vitro and in silico studies

Herein, we report the discovery of a novel long-chain ether derivative of (-)-epigallocatechin-3-gallate (EGCG), a major green tea polyphenol as a potent EGFR inhibitor. A series of 4''-alkyl EGCG derivatives have been synthesized via regio-selectively alkylating the 4'' hydroxyl group in the D-ring of EGCG and tested for their antiproliferative activities against high (A431), moderate (HeLa), and low (MCF-7) EGFR-expressing cancer cell lines. The most potent compound, 4''-C14 EGCG showed the lowest IC50 values across all the tested cell lines. 4''-C14 EGCG was also found to be significantly more stable than EGCG under physiological conditions (PBS at pH 7.4). Further western blot analysis and imaging data revealed that 4''-C14 EGCG induced cell death in A431 cells with shrunken nuclei, nuclear fragmentation, membrane blebbing, and increased population of apoptotic cells where BAX upregulation and BCLXL downregulation were observed. In addition, autophosphorylation of EGFR and its downstream signalling proteins Akt and ERK were markedly inhibited by 4''-C14 EGCG. MD simulation and the MM/PBSA analysis disclosed the binding mode of 4''-C14 EGCG in the ATP-binding site of EGFR kinase domain. Taken together, our findings demonstrate that 4''-C14 EGCG can act as a promising potent EGFR inhibitor with enhanced stability.

The Potential of Epigallocatechin Gallate (EGCG) in Targeting Autophagy for Cancer Treatment: A Narrative Review

Autophagy is an evolutionarily conserved process for the degradation of redundant or damaged cellular material by means of a lysosome-dependent mechanism, contributing to cell homeostasis and survival. Autophagy plays a multifaceted and context-dependent role in cancer initiation, maintenance, and progression; it has a tumor suppressive role in the absence of disease and is upregulated in cancer cells to meet their elevated metabolic demands. Autophagy represents a promising but challenging target in cancer treatment. Green tea is a widely used beverage with healthy effects on several diseases, including cancer. The bioactive compounds of green tea are mainly catechins, and epigallocatechin-gallate (EGCG) is the most abundant and biologically active among them. In this review, evidence of autophagy modulation and anti-cancer effects induced by EGCG treatment in experimental cancer models is presented. Reviewed articles reveal that EGCG promotes cytotoxic autophagy often through the inactivation of PI3K/Akt/mTOR pathway, resulting in apoptosis induction. EGCG pro-oxidant activity has been postulated to be responsible for its anti-cancer effects. In combination therapy with a chemotherapy drug, EGCG inhibits cell growth and the drug-induced pro-survival autophagy. The selected studies rightly claim EGCG as a valuable agent in cancer chemoprevention.