Green tea and anticancer perspectives: updates from last decade

PCL/Locust bean gum nanofibers loaded with HP-β-CD/Epicatechin clathrate compounds for fruit packaging

In this work, the hydroxypropyl-β-cyclodextrin (HP-β-CD)/Epicatechin (EC) clathrate compounds were rapidly prepared based on an ultrasound-mediated method, and Polycaprolactone (PCL)/Locust bean gum (LBG) nanofibers loaded clathrate compounds were fabricated by electrostatic spinning (ELS) for fruit packaging. The results of infrared spectrum and crystal type analysis proved that clathrate compounds were successfully prepared. With the addition of clathrate compounds, the diameter of fibers increased from 553.43 to 1273.47 nm, and hydrogen bonds were formed between clathrate compounds and fibrous membranes, which improved the thermal stability, reduced the crystallinity, and enhanced the hydrophilicity and gas permeability of fibrous membranes. The fibrous membranes indicated sustained release of EC for 240 h, retaining the activity of EC and demonstrating good bacteriostatic ability in vitro and in vivo. The test results showed that the antibacterial fibrous membranes prepared in this work have a positive application prospect for fruit packaging.

Exploration of the molecular mechanism of tea polyphenols against pulmonary hypertension by integrative approach of network pharmacology, molecular docking, and experimental verification

Pulmonary hypertension, a common complication of chronic obstructive pulmonary disease, is a major global health concern. Green tea is a popular beverage that is consumed all over the world. Green tea's active ingredients are epicatechin derivatives, also known as "polyphenols," which have anti-carcinogenic, anti-inflammatory, and antioxidant properties. This study aimed to explore the possible mechanism of green tea polyphenols in the treatment of pulmonary hypertension using network pharmacology, molecular docking, and experimental verification. A total of 316 potential green tea polyphenols-related targets were obtained from the PharmMapper, SwissTargetPrediction, and TargetNet databases. A total of 410 pulmonary hypertension-related targets were predicted by the CTD, DisGeNET, pharmkb, and GeneCards databases. Green tea polyphenols-related targets were hit by the 49 targets associated with pulmonary hypertension. AKT1 and HIF1-α were identified through the FDA drugs-target network and PPI network combined with GO functional annotation and KEGG pathway enrichment. Molecular docking results showed that green tea polyphenols had strong binding abilities to AKT1 and HIF1-α. In vitro experiments showed that green tea polyphenols inhibited the proliferation and migration of hypoxia stimulated pulmonary artery smooth muscle cells by decreasing AKT1 phosphorylation and downregulating HIF1α expression. Collectively, green tea polyphenols are promising phytochemicals against pulmonary hypertension.

Effects of natural extract interventions in prostate cancer: A systematic review and network meta-analysis

BACKGROUND

Over years, there has been a widespread quest for effective dietary patterns and natural extracts to mitigate prostate cancer risk. However, despite numerous experimental studies conducted on various natural extracts, the evidence substantiating their efficacy remains largely insufficient. This dearth of compelling evidence presents a significant challenge in advocating for their widespread use as preventive measures against prostate cancer.

OBJECTIVE

Our study endeavors to undertake a network meta-analysis to evaluate the influence of natural extracts on prostate cancer.

METHODS

Researchers systematically searched through Embase, PubMed, Cochrane Library, and Web of Science databases until December 2023. The main focus was on assessing primary outcomes comprising prostate-specific antigen (PSA), insulin-like growth factor-binding protein-3 (IGFBP-3), insulin-like growth factor-1 (IGF-1). We conducted data analysis utilizing StataMP 15.0 software. Therapeutic effects were ranked based on the probability values derived from Surface Under the Cumulative Ranking curve (SUCRA). Additionally, cluster analysis was employed to assess the impacts of natural extracts on three distinct outcomes.

RESULTS

Following screening procedures, the 28 eligible studies were incorporated, the selected studies encompassed 1,566 prostate cancer patients and evaluated 16 different natural extract treatments. Specifically, 24 trials included PSA indicators, 10 included IGF-1 indicators, and 8 included IGFBP-3 indicators. The findings revealed that, based on the SUCRA values, the combined therapy of silybin with selenium (74%) appears to be the most effective approach for reducing serum PSA levels. Simultaneously, silybin alone (84.6%) stands out as the most promising option for decreasing serum IGF-1 levels. Lastly, concerning IGFBP-3, silybin alone (67.7%) emerges as the optimal choice. Twelve studies provided comprehensive information on adverse drug reactions/events (ADR/ADE), whereas five articles did not report any significant ADR/ADE.

CONCLUSION

The NMA suggests that, compared to placebo, utilizing silybin either alone or in combination with selenium has been shown to enhance therapeutic effects, offering potential benefits to patients with prostate cancer. This study can offer valuable insights for prostate patients considering natural extract treatments. Further evidence is required to confirm the safety profile of these treatments.

Genipin's potential as an anti-cancer agent: from phytochemical origins to clinical prospects

This comprehensive review delves into the multifaceted aspects of genipin, a bioactive compound derived from medicinal plants, focusing on its anti-cancer potential. The review begins by detailing the sources and phytochemical properties of genipin, underscoring its significance in traditional medicine and its transition into contemporary cancer research. It then explores the intricate relationship between genipin's chemical structure and its observed anti-cancer activity, highlighting the molecular underpinnings contributing to its therapeutic potential. This is complemented by a thorough analysis of preclinical studies, which investigates genipin's efficacy against various cancer cell lines and its mechanisms of action at the cellular level. A crucial component of the review is the examination of genipin's bioavailability and pharmacokinetics, providing insights into how the compound is absorbed, distributed, metabolized, and excreted in the body. Then, this review offers a general and updated overview of the anti-cancer studies of genipin and its derivatives based on its basic molecular mechanisms, induction of apoptosis, inhibition of cell proliferation, and disruption of cancer cell signaling pathways. We include information that complements the genipin study, such as toxicity data, and we differentiate this review by including commercial status, disposition, and regulation. Also, this review of genipin stands out for incorporating information on proposals for a technological approach through its load in nanotechnology to improve its bioavailability. The culmination of this information positions genipin as a promising candidate for developing novel anti-cancer drugs capable of supplementing or enhancing current cancer therapies.

An efficient artificial intelligence algorithm for predicting the sensory quality of green and black teas based on the key chemical indices

The key components dominating the quality of green tea and black tea are still unclear. Here, we respectively produced green and black teas in March and June, and investigated the correlations between sensory quality and chemical compositions of dry teas by multivariate statistics, bioinformatics and artificial intelligence algorithm. The key chemical indices were screened out to establish tea sensory quality-prediction models based on the result of OPLS-DA and random forest, namely 4 flavonol glycosides of green tea and 8 indices of black tea (4 pigments, epigallocatechin, kaempferol-3-O-rhamnosyl-glucoside, ratios of caffeine/total catechins and epi/non-epi catechins). Compared with OPLS-DA and random forest, the support vector machine model had good sensory quality-prediction performance for both green tea and black tea (F1-score > 0.92), even based on the indices of fresh tea leaves. Our study explores the potential of artificial intelligence algorithm in classification and prediction of tea products with different sensory quality.

Therapeutic potential of natural products in schistosomiasis-associated liver fibrosis

Schistosomiasis is a parasitic disease that endangers human health and social development. The granulomatous reaction of Schistosoma eggs in the liver is the main cause of hepatosplenomegaly and fibrotic lesions. Anti liver fibrosis therapy is crucial for patients with chronic schistosomiasis. Although Praziquantel is the only clinical drug used, it is limited in insecticide treatment and has a long-term large-scale use, which is forcing the search for cost-effective alternatives. Previous research has demonstrated that plant metabolites and extracts have effective therapeutic effects on liver fibrosis associated with schistosomiasis. This paper summarizes the mechanisms of action of metabolites and some plant extracts in alleviating schistosomiasis-associated liver fibrosis. The analysis was conducted using databases such as PubMed, Google Scholar, and China National Knowledge Infrastructure (CNKI) databases. Some plant metabolites and extracts ameliorate liver fibrosis by targeting multiple signaling pathways, including reducing inflammatory infiltration, oxidative stress, inhibiting alternate macrophage activation, suppressing hepatic stellate cell activation, and reducing worm egg load. Natural products improve liver fibrosis associated with schistosomiasis, but further research is needed to elucidate the effectiveness of natural products in treating liver fibrosis caused by schistosomiasis, as there is no reported data from clinical trials in the literature.

Microbial-Transferred Metabolites and Improvement of Biological Activities of Green Tea Catechins by Human Gut Microbiota

Green tea catechins (GTCs) are dietary polyphenols with broad bioactivities that undergo extensive microbial metabolism in the human gut. However, microbial-transferred metabolites and their health benefits are not fully understood. Herein, the microbial metabolism of GTCs by human fecal microbiota and dynamic alteration of the microbiota were integrally investigated via in vitro anaerobic fermentation. The results showed that the human gut microbiota exhibited a strong metabolic effect on GTCs via UHPLC-MS/MS analysis. A total of 35 microbial-transferred metabolites were identified, far more than were identified in previous studies. Among them, five metabolites, namely EGCG quinone, EGC quinone, ECG quinone, EC quinone, and mono-oxygenated EGCG, were identified for the first time in fermented GTCs with the human gut microbiota. Consequently, corresponding metabolic pathways were proposed. Notably, the antioxidant, α-amylase, and α-glucosidase inhibitory activities of the GTCs sample increased after fermentation compared to those of the initial unfermented sample. The results of the 16S rRNA gene sequence analysis showed that the GTCs significantly altered gut microbial diversity and enriched the abundancy of Eubacterium, Flavonifractor, etc., which may be further involved in the metabolisms of GTCs. Thus, these findings contribute to a better understanding of the interactions between GTCs and gut microbiota, as well as the health benefits of green tea consumption.

Natural compounds against nonalcoholic fatty liver disease: A review on the involvement of the LKB1/AMPK signaling pathway

Although various therapeutic approaches are used to manage nonalcoholic fatty liver disease (NAFLD), the best approach to NAFLD management is unclear. NAFLD is a liver disorder associated with obesity, metabolic syndrome, and diabetes mellitus. NAFLD progression can lead to cirrhosis and end-stage liver disease. Hepatic kinase B1 (LKB1) is an upstream kinase of 5'-adenosine monophosphate-activated protein kinase (AMPK), a crucial regulator in hepatic lipid metabolism. Activation of LKB1/AMPK inhibits fatty acid synthesis, increases mitochondrial β-oxidation, decreases the expression of genes encoding lipogenic enzymes, improves nonalcoholic steatohepatitis, and suppresses NAFLD progression. One potential opening for new and safe chemicals that can tackle the NAFLD pathogenesis through the LKB1-AMPK pathway includes natural bioactive compounds. Accordingly, we summarized in vitro and in vivo studies regarding the effect of natural bioactive compounds such as a few members of the polyphenols, terpenoids, alkaloids, and some natural extracts on NAFLD through the LKB1/AMPK signaling pathway. This manuscript may shed light on the way to finding a new therapeutic agent for NAFLD management.

Laccase-assisted colouration of wool fabric using green tea extract for imparting antioxidant, antibacterial, and UV protection activities

The demand for natural dyes for imparting sustainable dyeing effects to textiles is increasing. Metal mordants generate an unstainable impact in the natural dyeing of textiles. In order to avoid the toxic effect due to the use of metal mordants, the present work uses enzyme for sustainable natural dyeing of wool. The current study is aimed at preparing multifunctional wool fabric using natural dye green tea (Camellia sinensis). Laccase (an enzyme) was used to polymerise the phenolic compounds of Camellia sinensis in situ on wool. The in situ colouration of wool fabric was performed at various varying dyeing conditions (temperature, time, and concentrations) using laccase. Colouration properties (colour values and strength) were examined to estimate the appearance of dyed fabrics. The evaluation of dyed fabrics for functional properties such as antibacterial, antioxidant, and UV protection was done. The efficient functional properties viz, antibacterial activity (> 75%), antioxidant property (> 90%), and excellent UV protection, were obtained. FTIR analysis of separately prepared polymeric dye and the dyed fabric was also done to confirm the laccase-assisted polymerisation. Thus, a novel approach of enzymatic functional natural dyeing of wool was explored.

Nanoparticles loaded with pharmacologically active plant-derived natural products: Biomedical applications and toxicity

Pharmacologically active natural products have played a significant role in the history of drug development. They have acted as sources of therapeutic drugs for various diseases such as cancer and infectious diseases. However, most natural products suffer from poor water solubility and low bioavailability, limiting their clinical applications. The rapid development of nanotechnology has opened up new directions for applying natural products and numerous studies have explored the biomedical applications of nanomaterials loaded with natural products. This review covers the recent research on applying plant-derived natural products (PDNPs) nanomaterials, including nanomedicines loaded with flavonoids, non-flavonoid polyphenols, alkaloids, and quinones, especially their use in treating various diseases. Furthermore, some drugs derived from natural products can be toxic to the body, so the toxicity of them is discussed. This comprehensive review includes fundamental discoveries and exploratory advances in natural product-loaded nanomaterials that may be helpful for future clinical development.

Analysis of metabolites in green tea during the roasting process using non-targeted metabolomics

BACKGROUND

Roasting plays an important role in the formation of flavor of roasted green tea; however, the changes in chemicals during this process have not been systematically studied until now. To reveal the dynamic changes in chemicals in green tea during roasting, non-targeted metabolomics, coupled with chemometrics, was employed.

RESULTS

A total of 101 non-volatile metabolites were identified in tea samples, and 29 metabolites were identified as characteristic metabolites of roasting. A significant increase in catechins and their derivatives, organic acids, and flavonoid glycosides was observed, while the content of some amino acids and their derivatives decreased over 50% during roasting. The content of theanine glucoside increased dramatically (by 21.23-fold at the roasting stage), and Maillard-derived compounds also increased to varying degrees.

CONCLUSION

Glycosylation, oxidative polymerization, and pyrolysis were important reactions responsible for the formation and transformation of flavor compounds in roasted green tea during roasting. © 2022 Society of Chemical Industry.

Review and Chemoinformatic Analysis of Ferroptosis Modulators with a Focus on Natural Plant Products

Ferroptosis is a regular cell death pathway that has been proposed as a suitable therapeutic target in cancer and neurodegenerative diseases. Since its definition in 2012, a few hundred ferroptosis modulators have been reported. Based on a literature search, we collected a set of diverse ferroptosis modulators and analyzed them in terms of their structural features and physicochemical and drug-likeness properties. Ferroptosis modulators are mostly natural products or semisynthetic derivatives. In this review, we focused on the abundant subgroup of polyphenolic modulators, primarily phenylpropanoids. Many natural polyphenolic antioxidants have antiferroptotic activities acting through at least one of the following effects: ROS scavenging and/or iron chelation activities, increased GPX4 and NRF2 expression, and LOX inhibition. Some polyphenols are described as ferroptosis inducers acting through the generation of ROS, intracellular accumulation of iron (II), or the inhibition of GPX4. However, some molecules have a dual mode of action depending on the cell type (cancer versus neural cells) and the (micro)environment. The latter enables their successful use (e.g., apigenin, resveratrol, curcumin, and EGCG) in rationally designed, multifunctional nanoparticles that selectively target cancer cells through ferroptosis induction.

Tea Polyphenols and Their Preventive Measures against Cancer: Current Trends and Directions

Cancer is exerting an immense strain on the population and health systems all over the world. Green tea because of its higher simple catechin content (up to 30% on dry weight basis) is greatly popular as an anti-cancer agent which is found to reduce the risks of cancer as well as a range of other diseases. In addition, several in vitro and in vivo studies have shown that green tea possesses copious health benefits like anti-diabetic, anti-obese, anti-inflammatory, neuro-protective, cardio-protective, etc. This review highlights the anti-carcinogenic effects of green tea catechins integrating the recent information to gain a clear concept. Special emphasis was given to the effectiveness of green tea polyphenols (GTP) in the prevention of cancer. Overall, green tea has been found to be effective to reduce the risks of breast cancer, ovarian cancer, liver cancer, colorectal cancer, skin cancer, prostate cancer, oral cancer, etc. However, sufficient information was not found to support that green tea consumption reduces the risk of lung cancer, esophageal cancer, or stomach cancer. The exciting data integrated into this article will increase interest in future researchers to garner more fruitful information on the relevant topics.

Influence of Green Tea Added to Cherry Wine on Phenolic Content, Antioxidant Activity and Alpha-Glucosidase Inhibition during an In Vitro Gastrointestinal Digestion

Cherries are a good source of bioactive compounds, with high antioxidant activity as well as nutritional and therapeutic importance. In this study, cherry wines enriched with green tea infusion (mild and concentrated) were produced, and their biological properties were evaluated. During winemaking, the main vinification parameters (alcohol, reducing sugars, acidity, total polyphenol content) as well biological activity (antioxidant activity, alpha-glucosidase inhibition potential) were determined. An in vitro digestion process was also performed to evaluate the impact of the gastrointestinal environment on the biological stability of the wines, and to analyze the interactions of wine-intestinal microflora. The addition of green tea to the cherry wine significantly increased the total polyphenol content (up to 2.73 g GAE/L) and antioxidant activity (up to 22.07 mM TE/L), compared with the control wine. However, after in vitro digestion, a reduction in total polyphenols (53–64%) and antioxidant activity (38–45%) were noted. Wines fortified with green tea expressed a stronger inhibition effect on intestinal microflora growth, of which E. coli were the most sensitive microorganisms. The tea-derived bioactive compounds significantly increased the potential of alpha-glucosidase inhibition. The proposed wines could be a good alternative type of wine, with an increased polyphenol content and the potential to control the insulin response supporting therapy for diabetes.

Efficacy and Safety of Oral Green Tea Preparations in Skin Ailments: A Systematic Review of Clinical Studies

Green-tea-based products and their polyphenols, especially epigallocatechin-3-gallate, have attracted great attention over the years as possible nutraceuticals, due to their promising bioactivities, especially antioxidant and anti-inflammatory, which could be exploited in several diseases, including skin ailments. In this context, the present study aimed at reviewing clinical evidence about the benefits of the oral administration of green tea preparations and its polyphenols to relieve skin disorders, to point out the current knowledge, and to suggest possible novel strategies to effectively exploit the properties of green tea, also managing safety risks. To this end, a systematic review of the existing literature was carried out, using the PRISMA method. Few studies, including five focused on UV-induced erythema and skin alterations, three on photoaging, two on antioxidant skin defenses, and one on acne and genodermatosis, were retrieved. Despite several benefits, clinical evidence only supports the use of oral green tea preparations to protect skin from damage induced by ultraviolet radiation; in other cases, conflicting results and methodological limits of clinical trials do not allow one to clarify their efficacy. Therefore, their application as adjuvant or alternative sunscreen-protective interventions could be encouraged, in compliance with the safety recommendations.

Targeting Oxidative Stress and Inflammation in Intervertebral Disc Degeneration: Therapeutic Perspectives of Phytochemicals

Low back pain is a major cause of disability worldwide that declines the quality of life; it poses a substantial economic burden for the patient and society. Intervertebral disc (IVD) degeneration (IDD) is the main cause of low back pain, and it is also the pathological basis of several spinal degenerative diseases, such as intervertebral disc herniation and spinal stenosis. The current clinical drug treatment of IDD focuses on the symptoms and not their pathogenesis, which results in frequent recurrence and gradual aggravation. Moreover, the side effects associated with the long-term use of these drugs further limit their use. The pathological mechanism of IDD is complex, and oxidative stress and inflammation play an important role in promoting IDD. They induce the destruction of the extracellular matrix in IVD and reduce the number of living cells and functional cells, thereby destroying the function of IVD and promoting the occurrence and development of IDD. Phytochemicals from fruits, vegetables, grains, and other herbs play a protective role in the treatment of IDD as they have anti-inflammatory and antioxidant properties. This article reviews the protective effects of phytochemicals on IDD and their regulatory effects on different molecular pathways related to the pathogenesis of IDD. Moreover, the therapeutic limitations and future prospects of IDD treatment have also been reviewed. Phytochemicals are promising candidates for further development and research on IDD treatment.

Natural therapeutics and nutraceuticals for lung diseases: Traditional significance, phytochemistry, and pharmacology

BACKGROUND

Lung diseases including chronic obstructive pulmonary disease (COPD), infections like influenza, acute respiratory distress syndrome (ARDS), asthma and pneumonia lung cancer (LC) are common causes of sickness and death worldwide due to their remoteness, cold and harsh climatic conditions, and inaccessible health care facilities.

PURPOSE

Many drugs have already been proposed for the treatment of lung diseases. Few of them are in clinical trials and have the potential to cure infectious diseases. Plant extracts or herbal products have been extensively used as Traditional Chinese Medicine (TCM) and Indian Ayurveda. Moreover, it has been involved in the inhibition of certain genes/protiens effects to promote regulation of signaling pathways. Natural remedies have been scientifically proven with remarkable bioactivities and are considered a cheap and safe source for lung disease.

METHODS

This comprehensive review highlighted the literature about traditional plants and their metabolites with their applications for the treatment of lung diseases through experimental models in humans. Natural drugs information and mode of mechanism have been studied through the literature retrieved by Google Scholar, ScienceDirect, SciFinder, Scopus and Medline PubMed resources against lung diseases.

RESULTS

In vitro, in vivo and computational studies have been explained for natural metabolites derived from plants (like flavonoids, alkaloids, and terpenoids) against different types of lung diseases. Probiotics have also been biologically active therapeutics against cancer, anti-inflammation, antiplatelet, antiviral, and antioxidants associated with lung diseases.

CONCLUSION

The results of the mentioned natural metabolites repurposed for different lung diseases especially for SARS-CoV-2 should be evaluated more by advance computational applications, experimental models in the biological system, also need to be validated by clinical trials so that we may be able to retrieve potential drugs for most challenging lung diseases especially SARS-CoV-2.

Mycotoxins in raw materials, beverages and supplements of botanicals: A review of occurrence, risk assessment and analytical methodologies

Over recent years, consumer interest in natural products, such as botanicals has increased considerably. One of the factors affecting their quality is the presence of mycotoxins. This review focuses on exploring the mycotoxin occurrence in botanicals (raw material and ready-to-eat forms such as infusions or tablets) and the risk assessment due to their ingestion. Aflatoxins, Ochratoxin A, and Fumonisins are the most commonly studied mycotoxins and data in the literature report levels ranging from traces to 1000 μg/kg in raw materials. In general, the highest contents observed in raw materials decreased to unconcerning levels after the preparation of the infusions, reaching values that generally do not exceed 100 μg/L. Regarding botanical dietary supplements, the levels observed were lower than those reported for other matrices, although higher levels (of up to 1000 μg/kg) have been reported in some cases. Risk assessment studies in botanicals revealed a higher risk when they are consumed as tablets compared to infusions. Analytical methodologies implied in mycotoxin determination have also been contemplated. In this sense, liquid chromatography coupled to fluorescence detection has been the most frequently employed analytical technique, although in recent years tandem mass spectrometry has been widely used.

Exploring the role of senescence inducers and senotherapeutics as targets for anticancer natural products

During the last few decades, cancer has remained one of the deadliest diseases that endanger human health, emphasizing urgent drug discovery. Cellular senescence has gained a great deal of attention in recent years because of its link to the development of cancer therapy. Senescent cells are incapable of proliferating due to irreversibly inhibited the initiation of the cell cycle pathways. However, senescent cells aggregate in tissues and produce a pro-inflammatory secretome called senescence-associated secretory phenotype (SASP) that can cause serious harmful effects if not managed properly. There is mounting evidence that senescent cells lead to various phases of tumorigenesis in various anatomical sites, owing mostly to the paracrine activities of the SASP. Therefore, a new treatment field called senotherapeutics has been established. Senotherapeutics are newly developed anticancer agents that have been demonstrated to inhibit cancer effectively. In light of recent findings, several promising natural products have been identified as senescence inducers and senotherapeutics, including, miliusanes, epigallocatechin gallate, phloretin, silybin, resveratrol, genistein, sulforaphane, quercetin, allicin, fisetin, piperlongumine, berberine, triptolide, tocotrienols and curcumin analogs. Several of them have already been validated through preclinical trials and exert an enormous potential for clinical trials. This review article focuses on and summarises the latest advances on cellular senescence and its potential as a target for cancer treatment and highlights the well-known natural products as senotherapeutics for cancer treatment.

Therapeutic effects of green tea on endometriosis

Endometriosis is a chronic disorder characterized by the presence of endometrial glands and stroma outside the uterine cavity. It affects 8%-10% of women in their reproductive years, and represents a major clinical problem with deleterious social, sexual and reproductive consequences. Current treatment options include pain relief, hormonal intervention and surgical removal. However, these treatments are deemed unsatisfactory owing to varying success, significant side effects and high recurrence rates. Green tea and its major bioactive component, (-)-epigallocatechin gallate (EGCG), possess diverse biological properties, particularly anti-angiogenic, anti-proliferation, anti-metastasis, and apoptosis induction. In recent years, preclinical studies have proposed the use of green tea to inhibit the growth of endometriosis. Herein, the aim of this review is to summarize the potential therapeutic effects of green tea on molecular and cellular mechanism through inflammation, oxidative stress, invasion and adhesion, apoptosis and angiogenesis in endometriosis.

(-)-Epicatechin acts as a potent agonist of the membrane androgen receptor, ZIP9 (SLC39A9), to promote apoptosis of breast and prostate cancer cells

(-)-Epicatechin, a flavonoid present in high concentrations in foods such as green tea and cocoa, exerts beneficial and protective effects in numerous disease models, including anti-tumorigenesis and apoptosis in human breast and prostate cancer cells. Potential interactions of (-)-epicatechin and (+)-catechin with the membrane androgen receptor, ZIP9 (SLC39A9), which mediates androgen induction of apoptosis in these cancer cells, were investigated. Both (-)-epicatechin and (+)-catechin were effective competitors of [³H]-testosterone binding to PC-3 prostate cancer cells (nuclear androgen receptor-negative, nAR-null) overexpressing ZIP9 (PC3-ZIP9), with relative binding affinities of 75 % and 28 % that of testosterone, respectively. (-)-Epicatechin (200 nM) mimicked the effects of 100 nM testosterone in inducing apoptosis of PC3-ZIP9 cells, whereas (+)-catechin (concentration range 200 nM-1000 nM) did not significantly increase apoptosis and instead blocked the apoptotic response to testosterone. (-)-Epicatechin also activated androgen-dependent ZIP9 signaling pathways, inducing decreases in cAMP production and elevating intracellular free zinc levels, while (+)-catechin typically lacked these actions. Both (-)-epicatechin and (+)-catechin also bound to cell membranes of MDA-MB-468 breast cancer cells (nAR-null, high ZIP9 expression). MDA-MB-468 cells showed similar apoptotic, cAMP, and free zinc signaling responses to (-)-epicatechin to those observed in PC3-ZIP9 cells, as well as antagonism by (+)-catechin of testosterone-induced apoptosis and modulation of cAMP and caspase-3 levels. Moreover, knockdown of ZIP9 expression in MDA-MB-468 cells with siRNA decreased specific [³H]-testosterone binding of both catechins and blocked the apoptotic and free zinc responses to testosterone and (-)-epicatechin. The results indicate (-)-epicatechin is a potent ZIP9 agonist in breast and prostate cancer cells.

Green Tea (Camellia sinensis) Extract Increased Topoisomerase IIβ, Improved Antioxidant Defense, and Attenuated Cardiac Remodeling in an Acute Doxorubicin Toxicity Model

Experimental studies have shown the action of green tea in modulating cardiac remodeling. However, the effects of green tea on the cardiac remodeling process induced by doxorubicin (DOX) are not known. Therefore, this study is aimed at evaluating whether green tea extract could attenuate DOX-induced cardiac remodeling, assessed by cardiac morphological and functional changes and associated with the evaluation of different modulators of cardiac remodeling. The animals were divided into four groups: the control group (C), the green tea group (GT), the DOX group (D), and the DOX and green tea group (DGT). Groups C and GT received intraperitoneal sterile saline injections, D and DGT received intraperitoneal injections of DOX, and GT and DGT were fed chow supplemented with green tea extract for 35 days prior to DOX injection. After forty-eight hours, we performed an echocardiogram and euthanasia and collected the materials for analysis. Green tea attenuated DOX-induced cardiotoxicity by increasing cardiac function and decreasing the concentric remodeling. Treatment with DOX increased oxidative stress in the heart, marked by a higher level of lipid hydroperoxide (LH) and lower levels of antioxidant enzymes. Treatment with green tea increased the antioxidant enzymes' activity and decreased the production of LH. Green tea extract increased the expression of Top2-β independent of DOX treatment. The activity of ATP synthase, citrate synthase, and complexes I and II decreased with DOX, without the effects of green tea. Both groups that received DOX presented with a lower ratio of P-akt/T-akt and a higher expression of CD45, TNFα, and intermediate MMP-2, without the effects of green tea. In conclusion, green tea attenuated cardiac remodeling induced by DOX and was associated with increasing the expression of Top2-β and lowering oxidative stress. However, energy metabolism and inflammation probably do not receive the benefits induced by green tea in this model.

Antioxidants in smokers

Cigarette smoke (CS) is likely the most common preventable cause of human morbidity and mortality worldwide. Consequently, inexpensive interventional strategies for preventing CS-related diseases would positively impact health systems. Inhaled CS is a powerful inflammatory stimulus and produces a shift in the normal balance between antioxidants and oxidants, inducing oxidative stress in both the respiratory system and throughout the body. This enduring and systemic pro-oxidative state within the body is reflected by increased levels of oxidative stress and inflammation biomarkers seen in smokers. Smokers might benefit from consuming antioxidant supplements, or a diet rich in fruit and vegetables, which can reduce the CS-related oxidative stress. This review provides an overview of the plasma profile of antioxidants observable in smokers and examines the heterogeneous literature to elucidate and discuss the effectiveness of interventional strategies based on antioxidant supplements or an antioxidant-rich diet to improve the health of smokers. An antioxidant-rich diet can provide an easy-to-implement and cost-effective preventative strategy to reduce the risk of CS-related diseases, thus being one of the simplest ways for smokers to stay in good health for as long as possible. The health benefits attributable to the intake of antioxidants have been observed predominantly when these have been consumed within their natural food matrices in an optimal antioxidant-rich diet, while these preventive effects are rarely achieved with the intake of individual antioxidants, even at high doses.

Untargeted metabolomics coupled with chemometrics approach for Xinyang Maojian green tea with cultivar, elevation and processing variations

The quality and flavor of green tea can be affected by various factors, which are closely related to the metabolite composition of tea. In this study, 66 Xinyang Maojian tea (XYMJ) samples produced by four cultivars, grown in different elevations and manufactured by different processing methods were analyzed by untargeted ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry and chemometrics. 1912 ion features were detected and 95 metabolites were identified tentatively through a customized in-house library. Projection to latent structures discriminate analysis showed high capability to explain the cultivar variation. 54 metabolites were found to be responsible for the differentiation of the four cultivars. 27 metabolites including epigallocatechin gallate, epicatechin gallate, theanine, theogallin showed close correlation with elevation, resulting enhanced umami flavor of the high elevation tea. The differences between manual and mechanical tea were not significant. This comprehensive study is of great reference value for other types of tea.

Inhibition effect of epigallocatechin-3-gallate on the pharmacokinetics of calcineurin inhibitors, tacrolimus, and cyclosporine A, in rats

BACKGROUND

Epigallocatechin-3-gallate (EGCG) is the most biologically active catechin of green tea. Tacrolimus (TAC) and cyclosporine A (CsA) are immunosuppressive agents commonly used in clinical organ transplantation. The present study investigated the effect of EGCG on the pharmacokinetics of TAC and CsA in rats and its underlying mechanisms.

RESEARCH DESIGN AND METHODS

Either TAC or CsA was administered to rats intravenously or orally with or without concomitant EGCG. Polymerase Chain Reaction and Western Blot were used to determine the effect of EGCG on drug-metabolizing enzymes (DMEs), drug transporters (DTs) and nuclear receptors (NRs).

RESULTS

The C_max and AUC of TAC were reduced, and V/F and CL/F of TAC were enhanced after co-administration of EGCG. EGCG increased the Cmax, AUC of CsA at 3 ~ 30 mg∙kg-1 dosages, while decreased those parameters at the dosage of 100 mg∙kg-1. EGCG inhibited the mRNA and protein expressions of DMEs and DTs, such as CYP3A1, A2, UGT1A1, Mdr1 and Mrp2, but upregulated the expressions of Car, Pxr and Fxr.

CONCLUSIONS

These results revealed consumption of high dose EGCG may cause a significant alteration in pharmacokinetics of TAC and distribution/elimination profiles of CsA through the regulation of DMEs, DTs and NRs.

Effects of green tea extract supplementation and endurance training on irisin, pro-inflammatory cytokines, and adiponectin concentrations in overweight middle-aged men

PURPOSE

Green tea extract (GTE) supplementation has been proposed to possess anti-inflammatory properties. This study assessed the effects of GTE on endurance training (ET) induced changes on irisin, pro-inflammatory cytokines, adiponectin and anthropometric indices in overweight middle-aged males.

METHODS

Participants were randomly assigned to three groups (n = 15): endurance training + placebo (ET + P), endurance training + green tea extract supplementation (ET + GTE), and no endurance training + placebo (P). The ET intervention consisted of an 8-week training program that included circuit training, fast walking or jogging performed three times/week at a moderate intensity (40-59% of the heart rate reserve). Participants received 500 mg/day GTE using a green tea capsule. Serum concentrations of interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), irisin, adiponectin, and high-sensitivity C-reactive protein (hs-CRP) were measured prior to and after the 8-week training intervention.

RESULTS

Both exercise interventions decreased IL-6 and hs-CRP (p < 0.05), and increased adiponectin (p < 0.01) levels; changes in these variables were greater in the ET + GTE group compared to the ET + P and P groups (p < 0.01). Irisin concentrations increased only in the ET + GTE group and were different from the ET + P and P groups (p < 0.01). There were no changes in TNF-α concentrations in any of the groups. Both exercise interventions (ET + GTE and ET + P) decreased bodyweight, body mass index (BMI), body fat percentage (BFP), and visceral fat area (VFA) (p < 0.05), with greater changes in these variables occurring in the ET + GTE group compared to ET + P and P groups (p < 0.01).

CONCLUSION

The combination of GTE supplementation and ET produces beneficial anti-inflammatory and metabolic effects, which were greater than those produced by ET alone.

Nutritional applications and beneficial health applications of green tea and l-theanine in some animal species: A review

Green tea (Camellia sinensis) is a popular herbal plant with abundant health benefits, and thus, it has been used as a potent antioxidant for a long time. Based on the available literature, the diversity and the availability of multifunctional compounds in green tea offer its noteworthy potential against many diseases such as liver and heart diseases, inflammatory conditions and different metabolic syndromes. Owing to its bioactive constituents including caffeine, amino acids, l-theanine, polyphenols/flavonoids and carbohydrates among other potent molecules, green tea has many pharmacological and physiological effects. The effects of green tea include anti-oxidative, anti-inflammatory, anti-arthritic, anti-stress, hypolipidaemic, hypocholesterolaemic, skin/collagen protective, hepatoprotective, anti-diabetic, anti-microbial, anti-infective, anti-parasitic, anti-cancerous, inhibition of tumorigenesis and angiogenesis, anti-mutagenic, and memory and bone health-improving activities. Apart from its utilization in humans, green tea has also played a significant role in livestock production such as in dairy, piggery, goatry and poultry industries. Supplementation of animal feeds with green tea and its products is in line with the modern concepts of organic livestock production. Hence, incorporating green tea or green tea by-products into the diet of poultry and other livestock can enhance the value of the products obtained from these animals. Herein, an effort is made to extend the knowledge on the importance and useful applications of green tea and its important constituents in animal production including poultry. This review will be a guideline for researchers and entrepreneurs who want to explore the utilization of feeds supplemented with green tea and green tea by-products for the enhancement of livestock production.

Induction of Endoplasmic Reticulum Stress Pathway by Green Tea Epigallocatechin-3-Gallate (EGCG) in Colorectal Cancer Cells: Activation of PERK/p-eIF2α/ATF4 and IRE1α

Epigallocatechin-3-gallate (EGCG) is the most abundant bioactive polyphenolic compound among the green tea constituents and has been identified as a potential anticancer agent in colorectal cancer (CRC) studies. This study was aimed to determine the mechanism of actions of EGCG when targeting the endoplasmic reticulum (ER) stress pathway in CRC. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay was performed on HT-29 cell line and normal cell line (3T3) to determine the EGCG toxicity. Next, western blot was done to observe the expression of the related proteins for the ER stress pathway. The Caspase 3/7 assay was performed to determine the apoptosis induced by EGCG. The results demonstrated that EGCG treatment was toxic to the HT-29 cell line. EGCG induced ER stress in HT-29 by upregulating immunoglobulin-binding (BiP), PKR-like endoplasmic reticulum kinase (PERK), phosphorylation of eukaryotic initiation factor 2 alpha subunit (eIF2α), activating transcription 4 (ATF4), and inositol-requiring kinase 1 alpha (IRE1α). Apoptosis was induced in HT-29 cells after the EGCG treatment, as shown by the Caspase 3/7 activity. This study indicates that green tea EGCG has the potential to inhibit colorectal cancer cells through the induction of ER stress.

Evaluation of Anti-cancer and Pro-apoptotic Activities of Iranian Green Tea Extract Against A549,PC3, and MCF-7 Cancer Cell Lines

Introduction: Green tea contains active polyphenols including catechins. The goal of the current study was to evaluate anti-cancer effects of Iranian green tea extract (IGTE) on 3 human cancer cell lines including A549, PC3, and MCF-7. Methods: First, Camellia sinensis was obtained from Lahijan, a city in the north of Iran and then IGTE was prepared. Next, catechins of IGTE were determined using high-performance liquid chromatography (HPLC). Finally, the cell viability of different cancer cells was evaluated by treatment with IGTE at concentration between 100 and 1000 µg/mL for 72 hours using MTT assay. Cell death of treated cancer cells was assessed by DAPI staining and RT-PCR method. Results: Our results demonstrated the potential anti-tumor activity of IGTE on MCF-7 cells (IC50= 400 µM), A549 cells (IC50= 500 µM), and PC3 cells (IC50= 600 µM), respectively. Chromatin damages within the nucleus of the treated cancer cells were shown. In addition, we found that IGTE induced apoptosis by up-regulation of Bax (a pro-apoptotic protein) and down-regulation of Bcl2 (an anti-apoptotic protein). Conclusion: Herein, we showed that IGTE is a potent natural product with anti-tumor activity on breast, lung, and prostate cancer cells. The efficacy of current therapies against cancer is limited by a range of adverse effects, toxicity, and drug resistance; therefore, new therapeutic strategies and more effective agents, particularly with natural origin, are desired and green tea may be a potent candidate in the field of cancer therapy

Phytochemicals as potential candidates to combat obesity via adipose non-shivering thermogenesis

Obesity is a chronic metabolic disease caused by a long-term imbalance between energy intake and expenditure. The discovery of three different shades of adipose tissues has implications in terms of understanding the pathogenesis and potential interventions for obesity and its related complications. Fat browning, as well as activation of brown adipocytes and new beige adipocytes differentiated from adipogenic progenitor cells, are emerging as interesting and promising methods to curb obesity because of their unique capacity to upregulate non-shivering thermogenesis. This capacity is due to catabolism of stored energy to generate heat through the best characterized thermogenic effector uncoupling protein 1 (UCP1). A variety of phytochemicals have been shown in the literature to contribute to thermogenesis by acting as chemical uncouplers, UCP1 inducers or regulators of fat differentiation and browning. In this review, we summarize the mechanisms and strategies for targeting adipose-mediated thermogenesis and highlight the role of phytochemicals in targeting adipose thermogenesis to fight against obesity. We also discuss proposed targets for how these phytochemical molecules promote BAT activity, WAT browning and beige cell development, thereby offering novel insights into interventional strategies of how phytochemicals may help prevent and manage obesity via adipose thermogenesis.

Green tea consumption and risk of breast cancer: A systematic review and updated meta-analysis of case-control studies

BACKGROUND

As the most popular beverage in East Asia, green tea (GT) has various biological activities effects such as anti-mutation, anti-oxidation, and anti-tumor. In this study, we aimed to evaluate whether GT consumption could be an effective way to decrease the risk of breast cancer.

METHODS

We had performed a systematic review and updated meta-analysis of published case-control studies to evaluate the association between GT intake and the risk of breast cancer. Searching strategies were performed by the following keywords "Breast cancer," "breast neoplasm," and "green tea," with derivations and different combinations. The following databases were searched: PubMed, Cochrane Library, EMBASE, Web of science, China National Knowledge Infrastructure, WanFang, and China Biology Medicine disc. Studies published in both English and Chinese were considered for inclusion. Risk of bias was assessed through the Newcastle-Ottawa Scale (NOS). All data were analyzed through using Review Manager 5.1 software.

RESULTS

Fourteen studies fulfilled inclusion criteria for meta-analysis, yielding a total of 14,058 breast cancer patients and 15,043 control subjects. Individuals with the habit of drinking GT were found to have a negative association with the risk of future breast cancer (odds ratio 0.83; 95% confidence interval: 0.72-0.96) despite significant heterogeneity. In subgroup analyses, the negative correlation was still found in studies using registry-based controls, NOS grades ≥6 and the number of cases <500.

CONCLUSIONS

GT consumption may have a decreased incidence of breast cancer despite significant heterogeneity. However, owing to the quality of available studies, more properly designed trials are warranted to clarify the association between GT consumption and breast cancer.

Catechins-Modified Selenium-Doped Hydroxyapatite Nanomaterials for Improved Osteosarcoma Therapy Through Generation of Reactive Oxygen Species

Osteosarcoma is the most common bone cancer with limited therapeutic options. It can be treated by selenium-doped hydroxyapatite owing to its known antitumor potential. However, a high concentration of Se is toxic toward normal and stem cells whereas its low concentration cannot effectively remove cancer cells. Therefore, the current study was aimed to improve the anticancer activity of Se-HAp nanoparticles through catechins (CC) modification owing to their high cancer therapeutic value. The sequentially developed catechins modified Se-HAp nanocomposites (CC/Se-HAp) were characterized for various physico-chemical properties and antitumor activity. Structural analysis showed the synthesis of small rod-like single phase HAp nanoparticles (60 ± 15 nm), which effectively interacted with Se and catechins and formed agglomerated structures. TEM analysis showed the internalization and degradation of CC/Se-HAp nanomaterials within MNNG/HOS cells through a non-specific endocytosis process. Cell toxicity analysis showed that catechins modification improved the antitumor activity of Se-HAp nanocomposites by inducing apoptosis of human osteosarcoma MNNG/HOS cell lines, through generation of reactive oxygen species (ROS) which in turn activated the caspase-3 pathway, without significantly affecting the growth of human normal bone marrow stem cells (hBMSCs). qPCR and western blot analyses revealed that casp3, p53, and bax genes were significantly upregulated while cox-2 and PTK-2 were slightly downregulated as compared to control in CC/Se-HAp-treated MNNG/HOS cell lines. The current study of combining natural biomaterial (i.e., catechins) with Se and HAp, can prove to be an effective therapeutic approach for bone cancer therapy.

Epigallocatechin-3-gallate inhibits the growth and increases the apoptosis of human thyroid carcinoma cells through suppression of EGFR/RAS/RAF/MEK/ERK signaling pathway

Background

Thyroid cancer is the most common type of endocrine malignancy and the incidence rate is rapidly increasing worldwide. Epigallocatechin-3-gallate (EGCG) could suppress cancer growth and induce apoptosis in many types of cancer cells. However, the mechanism of action of EGCG on the growth of human thyroid carcinoma cells has not been fully illuminated.

Methods

Cell proliferation and viability were detected by EdU and MTS assays. Cell cycle distribution was measured by flow cytometry. Migration and invasion were evaluated by scratch and transwell assays. Apoptotic levels were detected by TUNEL staining and western blotting. The protein levels of EGFR/RAS/RAF/MEK/ERK signaling pathway were detected by western blotting. The in vivo results were determined by tumor xenografts in nude mice. The in vivo proliferation, tumor microvessel density, and apoptosis were detected by immunohistochemistry.

Results

EGCG inhibited the proliferation, viability, and cell cycle progression in human thyroid carcinoma cells. EGCG decreased the migration and invasion, but increased the apoptosis of human thyroid carcinoma cells. EGCG reduced the protein levels of phospho (p)-epidermal growth factor receptor (EGFR), H-RAS, p-RAF, p-MEK1/2, and p-extracellular signal-regulated protein kinase 1/2 (ERK1/2) in human thyroid carcinoma cells. EGCG inhibited the growth of human thyroid carcinoma xenografts by inducing apoptosis and down-regulating angiogenesis.

Conclusions

EGCG could reduce the growth and increase the apoptosis of human thyroid carcinoma cells through suppressing the EGFR/RAS/RAF/MEK/ERK signaling pathway. EGCG can be developed as an effective therapeutic agent for the treatment of thyroid cancer.

Evidence for the efficacy and safety of herbal weight loss preparations

Rising rates of obesity across the globe have been associated with an increase in the use of herbal preparations for weight control. However, the mechanisms of action for these substances are often not known, as is the potential for interaction with other herbal preparations or prescription pharmaceutical drugs. To investigate the reported efficacy and safety of herbal weight loss preparations, we conducted a review of the literature focusing on herbs that are most commonly used in weight loss preparations, specifically, Garcinia cambogia, Camellia sinensis, Hoodia gordonii, Citrus aurantium and Coleus forskohlii. There was no clear evidence that the above herbal preparations would cause sustained long-term weight loss in humans in the long term. Serious illness and even death have occasionally resulted from the use of herbal weight loss preparations. Few clinical trials have been undertaken to evaluate the efficacy and/or safety of herbal weight loss preparations. In addition, potential issues of herb-herb and herb-drug interactions are often not considered. Regulation of these products is much less rigorous than for prescription medications, despite documented cases of associated hepatotoxicity.

UPLC-Q-TOF/MS-based untargeted metabolomics coupled with chemometrics approach for Tieguanyin tea with seasonal and year variations

The taste and aroma quality of Tieguanyin tea fluctuate seasonally and yearly. However, the compounds responsible for the seasonal and year variations of metabolic pattern and its sensory quality are far from clear. 60 Tieguanyin tea samples harvested in different years and seasons were analyzed by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and chemometrics. Principal component analysis (PCA) explained 33.2% of the total variance, while orthogonal projection to latent structures discriminate analysis (OPLS-DA) can obtain potential metabolites with better discrimination, and with R²X and Q² of cross-validation as 0.974 and 0.937, respectively. Subsequently, heat map analysis (HCA) visualized relationships between Tieguanyin teas with these significantly different potential metabolites by Mann-Whitney U test (p < 0.05). Furthermore, the best discriminate metabolites contributing to different sensory qualities were revealed by stepwise liner discrimination analysis (SLDA) with 100% accuracy rate. The present strategy also exhibited great potential for untargeted metabolomics of other foods.

Anti-tumor activity and the mechanism of a green tea (Camellia sinensis) polysaccharide on prostate cancer

In this study, a homogeneous polysaccharide (GTP), with a molecular weight of 7.0 × 10⁴ Da, was isolated from Green tea, which was only composed of glucose. The antitumor effects of GTP on prostate cancer (PC) cell line along with the possible mechanism was examined. First, we investigate the potential role of microRNA-93 (miR-93) in PC progression. Our results showed that miR-93 was significantly upregulated in human PC tissues and several PC cell lines, and its overexpression was correlated with poor survival in PC patients. Furthermore, functional analysis showed that miR-93 overexpression promoted the migration, invasion and proliferation of PC-3 cells transfected with miR-93 mimics, while its knockdown displayed an opposite result in DU145 cells following miR-93 inhibitor transfection. Additionally, in vivo tumorigenic studies on nude mice confirmed that miR-93 mimic treatment accelerated the growth of PC-3 xenograft tumors. As expected, GTP (25, 50 and 100 μg/ml) inhibited growth of PC-3 cells via inducing apoptosis, which was achieved by elevation of bax/bcl-2 ratio and caspae-3 protein expression, as well as a decrease of miR-93. Thus, miR-93 may be a potential therapeutic target by GTP for PC therapy.

Epigallocatechin-3-O-gallate, the main green tea component, is toxic to Saccharomyces cerevisiae cells lacking the Fet3/Ftr1

Epigallocatechin-3-O-gallate (EGCG), the main green tea component, is intensively studied for its anti-oxidant, anti-inflammatory, anti-microbial and anti-cancer effects. In the present study, a screen on a Saccharomyces cerevisiae gene deletion library was performed to identify conditions under which EGCG had deleterious rather than beneficial effects. Two genes were identified whose deletion resulted in sensitivity to EGCG: FET3 and FTR1, encoding the components of the Fet3/Ftr1 high-affinity iron uptake system, also involved in Cu(I)/Cu(II) balance on the surface of yeast cells. The presence of EGCG in the growth medium induced the production of Cu(I), with deleterious effects on fet3Δ and ftr1Δ cells. Additionally, when combined, physiological surpluses of Cu(II) and EGCG acted in synergy not only against fet3Δ and ftr1Δ, but also against wild type cells, by generating surplus Cu(I) in the growth medium. The results imply that caution should be taken when combining EGCG-rich beverages/nutraceuticals with copper-rich foods.

Epigallocatechin-3-Gallate-Rich Green Tea Extract Ameliorates Fatty Liver and Weight Gain in Mice Fed a High Fat Diet by Activating the Sirtuin 1 and AMP Activating Protein Kinase Pathway

The prevalence of metabolic diseases has risen globally in parallel with the obesity epidemic over the past few decades. Green tea has been reported to have metabolically beneficial effects on obesity; however, the mechanism by which green tea regulates lipid metabolism is not clearly understood. Male c57BL/6 mice were fed a normal chow diet, a high-fat diet (HFD), or an HFD supplemented with various doses of epigallocatechin gallate-rich green tea extract (GTE) for 12 weeks. GTE supplementation reduced body weight gain, prevented hepatic fat accumulation, decreased hypertriglyceridemia, and improved hyperglycemia and insulin resistance in HFD-fed mice. The underlying mechanisms of these beneficial effects of GTE might involve the upregulation of sirtuin 1 and AMP activated protein kinase (AMPK) and the downregulation of enzymes related to de novo lipogenesis. Consistent with the in vivo findings, GTE increased the expression and activity of sirtuin 1, enhanced the binding of sirtuin 1 to liver kinase B1 (LKB1) and subsequent deacetylation of LKB1, and reduced triglyceride accumulation in HepG2 cells. These results suggest the possible therapeutic potential of dietary epigallocatechin gallate-rich GTE supplementation for preventing the development and progression of hepatic steatosis and obesity.

Inducers of Senescence, Toxic Compounds, and Senolytics: The Multiple Faces of Nrf2-Activating Phytochemicals in Cancer Adjuvant Therapy

The reactivation of senescence in cancer and the subsequent clearance of senescent cells are suggested as therapeutic intervention in the eradication of cancer. Several natural compounds that activate Nrf2 (nuclear factor erythroid-derived 2-related factor 2) pathway, which is involved in complex cytoprotective responses, have been paradoxically shown to induce cell death or senescence in cancer. Promoting the cytoprotective Nrf2 pathway may be desirable for chemoprevention, but it might be detrimental in later stages and advanced cancers. However, senolytic activity shown by some Nrf2-activating compounds could be used to target senescent cancer cells (particularly in aged immune-depressed organisms) that escape immunosurveillance. We herein describe in vitro and in vivo effects of fifteen Nrf2-interacting natural compounds (tocotrienols, curcumin, epigallocatechin gallate, quercetin, genistein, resveratrol, silybin, phenethyl isothiocyanate, sulforaphane, triptolide, allicin, berberine, piperlongumine, fisetin, and phloretin) on cellular senescence and discuss their use in adjuvant cancer therapy. In light of available literature, it can be concluded that the meaning and the potential of adjuvant therapy with natural compounds in humans remain unclear, also taking into account the existence of few clinical trials mostly characterized by uncertain results. Further studies are needed to investigate the therapeutic potential of those compounds that display senolytic activity.

Addition of milk to tea infusions: Helpful or harmful? Evidence from in vitro and in vivo studies on antioxidant properties

Tea consumption is practised as a tradition, and has shown potential to improve human health. Maximal uptake of tea antioxidants and milk proteins without a negative impact on tea flavor is highly desired by consumers. There is a conflicting evidence of the effect of milk addition to tea on antioxidant activity. Differences in the type of tea, the composition, type and amount of milk, preparation method of tea-milk infusions, the assays used to measure antioxidant activity, and sampling size likely account for different findings. Interactions between tea polyphenols and milk proteins, especially between catechins and caseins, could account for a decrease in antioxidant activity, although other mechanisms are also possible, given the similar effects between soy and bovine milk. The role of milk fat globules and the milk fat globule membrane surface is also important when considering interactions and loss of polyphenolic antioxidant activity, which has not been addressed in the literature.

Tea Consumption Is Associated with Increased Bone Strength in Middle-Aged and Elderly Chinese Women

OBJECTIVES

Previous studies found that tea consumption was related to a reduction in the risks of some chronic diseases, but limited data are available on bone health. This study aimed to examine the associations of tea consumption with hip bone strength in Chinese women.

DESIGN

Cross-sectional study.

SETTING

The participants were from the ongoing Guangzhou Nutrition and Health Study. This was a cohort study started in 2008. The examination data conducted between June 2010 and December 2013 were used.

PARTICIPANTS

A total of 1,495 Chinese women aged more than 40 years were included.

MEASUREMENTS

Tea consumption, socio-demographic information and lifestyle habits were collected by a face-to-face questionnaire. Hip bone mineral density (BMD) and geometric parameters, i.e. cross-sectional area (CSA), section modulus (Z) and buckling ratio (BR), were generated by dual-energy X-ray absorptiometry. The associations of tea consumption with bone phenotypes were detected by analysis of covariance and multiple linear regression models after adjusting for age, body mass index, years since menopause, physical activity, dietary-protein intake, dietary-calcium intake, calcium tablet intake, drinking status and smoking status.

RESULTS

Tea drinkers (n = 732) had approximately 1.9% higher BMD (p < 0.05) and 3.6% lower BR (p < 0.05) than non-tea drinkers (n = 763). The dose-response relationships of BMD, BR or CSA with total tea consumption were identified (p-trend < 0.05). Tea drinking was found to be a significant and independent predictor of BMD (β = 0.068, p < 0.05) or BR (β = -0.079, p < 0.05).

CONCLUSION

Tea consumption was associated with increased bone strength in middle-aged and elderly Chinese women.

Chemopreventive effects of Ku-jin tea against AOM-induced precancerous colorectal lesions in rats and metabolomic analysis

Ku-jin tea (KJT) is a health beverage prepared from the leaves of the plant Acer tataricum subsp. ginnala that has been consumed in some regions of China for thousands of years. KJT contains high levels of anti-inflammatory and antioxidative compounds such as ginnalins, but little is known about the chemopreventive effect of KJT on colon cancer. In this study, we investigated the preventive effects of KJT on colon carcinogenesis using the azoxymethane (AOM)-induced precancerous colorectal lesion model in rats. The results showed that the number of aberrant crypts, aberrant crypt foci (ACF) and crypts/focus in rats of the KJT + AOM group were significantly decreased compared with rats of the AOM group (p < 0.01). Further exploration of the prevention mechanism of KJT by UPLC-QTOF/MS-based urinary metabolomics showed that 5 metabolic pathways were modulated, including purine metabolism and amino acid metabolism, in the group with KJT. In addition, the levels of the immunomodulatory cytokines IL-1α and IL-10 were significantly decreased, and the levels of IL-2 in the serum of AOM rats increased after KJT treatment. Our present data suggest that KJT can inhibit AOM-induced colonic ACF formation and might be a useful chemopreventive agent against colorectal carcinogenesis.

Green tea (Camellia sinensis) and l-theanine: Medicinal values and beneficial applications in humans-A comprehensive review

Green tea (Camellia sinensis) is a famous herb, and its extract has been extensively used in traditional Chinese medicinal system. In this context, several studies have revealed its health benefits and medicinal potentialities for several ailments. With ever increasing scientific knowledge, search for safer, potential and novel type of health-related supplements quest, scientists are re-directing their research interests to explore natural resources i.e. medicinal herbs/plant derived compounds. Green tea consumption has gained a special attention and popularity in the modern era of changing lifestyle. The present review is aimed to extend the current knowledge by highlighting the importance and beneficial applications of green tea in humans for safeguarding various health issues. Herein, we have extensively reviewed, analyzed, and compiled salient information on green tea from the authentic published literature available in PubMed and other scientific databases. Scientific literature evidenced that owing to the bioactive constituents including caffeine, l-theanine, polyphenols/flavonoids and other potent molecules, green tea has many pharmacological and physiological functions. It possesses multi-beneficial applications in treating various disorders of humans. This review also provides in-depth insights on the medicinal values of green tea which will be useful for researchers, medical professionals, veterinarians, nutritionists, pharmacists and pharmaceutical industry. Future research emphasis and promotional avenues are needed to explore its potential therapeutic applications for designing appropriate pharmaceuticals, complementary medicines, and effective drugs as well as popularize and propagate its multidimensional health benefits.