Multistage carcinogenesis process as molecular targets in cancer chemoprevention by epicatechin-3-gallate

GC-MS/HPLC Profiling and Sono-Maceration Mediated Extraction of Osbeckia Parvifolia Polyphenols: In Silico and In Vitro Analysis on Anti-Proliferative Activity in Ovarian Cancer Cell Lines

Osbeckia parvifolia, an endemic edible plant of Western Ghats, was investigated in the present study for its polyphenolic compounds, including content, constituents, extraction through an ultrasonic-assisted maceration technique and therapeutic potential in biomedical applications. The methanolic extract (OPM) exhibited an IC50 value of 1.25 μg/mL against 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radicals. Furthermore, the ethyl acetate and methanolic extracts also strongly inhibited 5-lipoxygenase, especially OPM (84.93 %), which was comparable to standard curcumin. OPM also elicited cytotoxicity in SKOV3 ovarian cancer cells (93.80 %), surpassing paclitaxel. Bio-accessibility analysis demonstrated that the release of phenolic compounds and antioxidant potential were very high (above 100 %), revealing the possibility of synergistic efficacy of polyphenolic complexes in drug development. Gas Chromatography -Mass Spectrometry (GC-MS) analysis revealed 22 bioactive polyphenolic compounds in OPM, such as epicatechin, quercetin, and psoralidin. This was confirmed by High Performance Liquid Chromatography (HPLC) and High-Pressure Thin Layer Chromatography (HPTLC) analyses, which revealed a high quantity of catechin (37.45 mg/g). Molecular docking revealed the significant binding affinity of these proteins for the ovarian oncoproteins PI3K (-8.52 kcal/mol) and Casp-8 (-8.41 kcal/mol). Adsorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) profiling indicated the favorable pharmacokinetic properties of these compounds, supporting their candidacy in drug formulations against ovarian cancer.

Opportunities and challenges of foodborne polyphenols applied to anti-aging health foods

Abstract

With the increasing proportion of the global aging population, aging mechanisms and anti-aging strategies become hot topics. Nonetheless, the safety of non-natural anti-aging active molecule and the changes in physiological function that occur during aging have not been clarified. There is therefore a need to develop safer pharmaceutical interventions for anti-aging. Numerous types of research have shown that food-derived biomolecules are of great interest due to their unique contribution to anti-aging safety issues and the prevention of degenerative diseases. Among these, polyphenolic organic compounds are widely used in anti-aging research for their ability to mitigate the physiological functional changes that occur during aging. The mechanisms include the free radical theory, immune aging theory, cellular autophagy theory, epigenetic modification theory, gut microbial effects on aging theory, telomere shortening theory, etc. This review elucidates the mechanisms underlying the anti-aging effects of polyphenols found in food-derived bioactive molecules, while also addressing the challenges associated with anti-aging pharmaceuticals. The review concludes by offering insights into the current landscape of anti-aging active molecule research, aiming to serve as a valuable resource for further scholarly inquiry.

Graphical abstract

Phytocompounds and Regulation of Flavonoids in In Vitro-Grown Safflower Plant Tissue by Abiotic Elicitor CdCl2

In this study, a Gas chromatography-mass spectrometry (GC-MS) investigation of embryogenic callus and somatic embryo regenerated shoots of Carthamus tinctorius revealed the presence of a variety of sugars, sugar acids, sugar alcohols, fatty acids, organic acids, and amino acids of broad therapeutic value. The in vitro developed inflorescence contained a wide range of active compounds. In embryogenic calluses, important flavonoids like naringenin, myricetin, kaempferol, epicatechin gallate, rutin, pelargonidin, peonidin, and delphinidin were identified. To augment the synthesis of active compounds, the effect of cadmium chloride (CdCl2) elicitation was tested for various treatments (T1-T4) along with a control (T0). Varying concentrations of CdCl2 [0.05 mM (T1), 0.10 mM (T2), 0.15 mM (T3), and 0.20 mM (T4)] were added to the MS medium, and flavonoid accumulation was quantified through ultra-high-pressure liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS). The flavonoids naringenin, kaempferol, epicatechin gallate, pelargonidin, cyanidin, and delphinidin increased by 6.7-, 1.9-, 3.3-, 2.1-, 1.9-, and 4.4-fold, respectively, at T3, whereas quercetin, myricetin, rutin, and peonidin showed a linear increase with the increase in CdCl2 levels. The impacts of stress markers, i.e., ascorbate peroxidase (APX), catalase (CAT), and superoxide dismutase (SOD), on defense responses in triggering synthesis were also evaluated. The maximum APX and SOD activity was observed at T3, while CAT activity was at its maximum at T2. The impact of elicitor on biochemical attributes like protein, proline, sugar, and malondialdehyde (MDA) content was investigated. The maximum protein, proline, and sugar accumulation was noted at high elicitor dose T4, while the maximum MDA content was noted at T3. These elevated levels of biochemical parameters indicated stress in culture, and the amendment of CdCl2 in media thus could be a realistic approach for enhancing secondary metabolite synthesis in safflower.

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

CONTEXT

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

DISCUSSION AND CONCLUSION

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

Nano Uncaria gambir as Chemopreventive Agent Against Breast Cancer

BACKGROUND

Breast cancer is one of the main causes of death in women. Uncaria gambir is an Indonesian herbal plant that can be used as an anti-cancer. However, herbal medicines have low bioavailability, which affects their bioactivity. Nanoencapsulation can increase bioavailability and stability of bioactive compounds in herbal medicines.

PURPOSE

This recent finding tried to unravel anti-cancer and chemopreventive of U. gambir nano-encapsulated by Na-alginate.

STUDY DESIGN

U. gambir bioactive compounds were isolated and characterized using UV-Vis spectrometer, FTIR, NMR and HR-MS. U. gambir extract was nanoencapsulated using Na-alginate. Anti-cancer effect was assessed by MTT assay towards T47D cell. Meanwhile, a chemopreventive analysis was carried out in breast cancer mice-induced benzo[α]pyrene. The healthy mice were divided into 8 groups comprising control and treatment.

RESULTS

Elucidation of U. gambir ethyl acetate extract confirmed high catechin content, 89.34% (w/w). Successful nanoencapsulation of U. gambir (G-NPs) was indicated. The particle size of G-NPs was 78.40 ± 12.25 nm. Loading efficiency (LE) and loading amount (LA) of G-NPs were 97.56 ± 0.04% and 32.52 ± 0.01%, respectively. G-NPs had an EC50 value of 10.39 ± 3.50 µg/mL, which was more toxic than the EC50 value of extract towards the T47D cell line. Administration of 200 mg/kg BW G-NPs to mice induced by benzo[α]pyrene exhibited SOD and GSH levels of 13.69 ng/mL and 455.6 ng/mL. In addition, the lowest TNF-α level was 27.96 ng/mL. A dose of 100 mg/kg BW G-NPs could best increase CAT levels by 7.18 ng/mL. There was no damage or histological abnormalities found in histological analysis of the breast tissue in the group given 200 mg/kg BW G-NPs.

Insight into the Biological Roles and Mechanisms of Phytochemicals in Different Types of Cancer: Targeting Cancer Therapeutics

Cancer is a hard-to-treat disease with a high reoccurrence rate that affects health and lives globally. The condition has a high occurrence rate and is the second leading cause of mortality after cardiovascular disorders. Increased research and more profound knowledge of the mechanisms contributing to the disease’s onset and progression have led to drug discovery and development. Various drugs are on the market against cancer; however, the drugs face challenges of chemoresistance. The other major problem is the side effects of these drugs. Therefore, using complementary and additional medicines from natural sources is the best strategy to overcome these issues. The naturally occurring phytochemicals are a vast source of novel drugs against various ailments. The modes of action by which phytochemicals show their anti-cancer effects can be the induction of apoptosis, the onset of cell cycle arrest, kinase inhibition, and the blocking of carcinogens. This review aims to describe different phytochemicals, their classification, the role of phytochemicals as anti-cancer agents, the mode of action of phytochemicals, and their role in various types of cancer.

Anti-colorectal cancer of Ardisia gigantifolia Stapf. and targets prediction via network pharmacology and molecular docking study

BACKGROUND

Ardisia gigantifolia Stapf. (AGS), a Chinese folk medicine widely grows in the south of China and several studies reported that AGS could inhibit the proliferation of breast cancer, liver cancer, and bladder cancer cell lines. However, little is known about its anti-colorectal cancer (CRC) efficiency.

METHODS

In the present study, a combination of MTT assay, network pharmacological analysis, bioinformatics, molecular docking, and molecular dynamics simulation study was used to investigate the active ingredients, and targets of AGS against CRC, as well as the potential mechanism.

RESULTS

MTT assay showed that three kinds of fractions from AGS, including the n-butanol extract (NBAGS), ethyl acetate fraction (EAAGS), and petroleum ether fraction (PEAGS) significantly inhibited the proliferation of CRC cells, with the IC₅₀ values of 197.24, 264.85, 15.45 µg/mL on HCT116 cells, and 523.6, 323.59, 150.31 µg/mL on SW620 cells, respectively. Eleven active ingredients, including, 11-O-galloylbergenin, 11-O-protocatechuoylbergenin, 11-O-syringylbergenin, ardisiacrispin B, bergenin, epicatechin-3-gallate, gallic acid, quercetin, stigmasterol, stigmasterol-3-o-β-D-glucopyranoside were identified. A total of 173 targets related to the bioactive components and 21,572 targets related to CRC were picked out through database searching. Based on the crossover targets of AGS and CRC, a protein-protein interaction network was built up by the String database, from which it was concluded that the core targets would be SRC, MAPK1, ESR1, HSP90AA1, MAPK8. Besides, GO analysis showed that the numbers of biological process, cellular component, and molecular function of AGS against CRC were 1079, 44, and 132, respectively, and KEGG pathway enrichment indicated that 96 signaling pathways in all would probably be involved in AGS against CRC, among which MAPK signaling pathway, lipid, and atherosclerosis, proteoglycans in cancer, prostate cancer, adherens junction would probably be the major pathways. The docking study verified that AGS had multiple ingredients and multiple targets against CRC. Molecular dynamics (MD) simulation analysis showed that the binding would be stable via forming hydrogen bonds.

CONCLUSION

Our study showed that AGS had good anti-CRC potency with the characteristics of multi-ingredients, -targets, and -signaling pathways.

Active Compounds in Fruits and Inflammation in the Body

Inflammation plays an important role in the pathogenesis of many diseases, including cardiovascular diseases, atherosclerosis, diabetes, asthma, and cancer. An appropriate diet and the active compounds contained in it can affect various stages of the inflammatory process and significantly affect the course of inflammatory diseases. Recent reports indicate that polyphenolic acids, vitamins, minerals, and other components of fruits may exhibit activity stimulating an anti-inflammatory response, which may be of importance in maintaining health and reducing the risk of disease. The article presents the latest data on the chemical composition of fruits and the health benefits arising from their anti-inflammatory and antioxidant effects. The chemical composition of fruits determines their anti-inflammatory and antioxidant properties, but the mechanisms of action are not fully understood.

Green tea catechins inhibit Porphyromonas gulae LPS-induced inflammatory responses in human gingival epithelial cells: Running title

OBJECTIVES

To determine the anti-inflammatory effects of green tea catechins in immortalized human gingival epithelial cells (Ca9-22) stimulated with Porphyromonas gulae lipopolysaccharide (LPS).

METHODS

Ca9-22 cells were incubated with P. gulae LPS (10 μg/ml) with or without green tea catechins, epigallocatechin-3-gallate (EGCg), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epicatechin (EC) (each at 50 μM), for 6 or 24 hours. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay were used to determine the induction of cyclooxygenase 2 (COX2), tumor necrosis factor alpha (TNF-ɑ), interleukin 6 (IL-6), and IL-8. Furthermore, the expression of toll-like receptors (TLRs) 2 and 4 was examined using real-time PCR and western blotting analysis, and phosphorylation of the p38 and ERK1/2 was examined using western blotting analysis.

RESULTS

At the mRNA and protein levels, EGCg, EGC, ECG, and EC were found to significantly inhibit COX2, TNF-ɑ, IL-6, and IL-8. Furthermore, the levels of ERK1/2 and p38 phosphorylation induced by P. gulae LPS were decreased following the addition of each of the catechins, as well as TLR2 and 4 mRNA and protein.

CONCLUSIONS

These findings indicate that green tea catechins are potent inhibitors of inflammatory responses induced by P. gulae LPS, and may also be useful for prevention and/or attenuation of periodontitis.

A Natural Plant Source-Tea Polyphenols, a Potential Drug for Improving Immunity and Combating Virus

The coronavirus disease 2019 (COVID-19) is still in a global epidemic, which has profoundly affected people’s lives. Tea polyphenols (TP) has been reported to enhance the immunity of the body to COVID-19 and other viral infectious diseases. The inhibitory effect of TP on COVID-19 may be achieved through a series of mechanisms, including the inhibition of multiple viral targets, the blocking of cellular receptors, and the activation of transcription factors. Emerging evidence shows gastrointestinal tract is closely related to respiratory tract, therefore, the relationship between the state of the gut–lung axis microflora and immune homeostasis of the host needs further research. This article summarized that TP can improve the disorder of flora, reduce the occurrence of cytokine storm, improve immunity, and prevent COVID-19 infection. TP may be regarded as a potential and valuable source for the design of new antiviral drugs with high efficiency and low toxicity.

Plant-Based Phytochemical Screening by Targeting Main Protease of SARS-CoV-2 to Design Effective Potent Inhibitors

Currently, a worldwide pandemic has been declared in response to the spread of coronavirus disease 2019 (COVID-19), a fatal and fast-spreading viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The low availability of efficient vaccines and treatment options has resulted in a high mortality rate, bringing the world economy to its knees. Thus, mechanistic investigations of drugs capable of counteracting this disease are in high demand. The main protease (Mpro) expressed by SARS-CoV-2 has been targeted for the development of potential drug candidates due to the crucial role played by Mpro in viral replication and transcription. We generated a phytochemical library containing 1672 phytochemicals derived from 56 plants, which have been reported as having antiviral, antibacterial, and antifungal activity. A molecular docking program was used to screen the top three candidate compounds: epicatechin-3-O-gallate, psi-taraxasterol, and catechin gallate, which had respective binding affinities of -8.4, -8.5, and -8.8 kcal/mol. Several active sites in the targeted protein, including Cys145, His41, Met49, Glu66, and Met165, were found to interact with the top three candidate compounds. The multiple simulation profile, root-mean-square deviation, root-mean-square fluctuation, radius of gyration, and solvent-accessible surface area values supported the inflexible nature of the docked protein-compound complexes. The toxicity and carcinogenicity profiles were assessed, which showed that epicatechin-3-O-gallate, psi-taraxasterol, and catechin gallate had favorable pharmacological properties with no adverse effects. These findings suggest that these compounds could be developed as part of an effective drug development pathway to treat COVID-19.

Immunomodulatory Effects of Green Tea Polyphenols

Green tea and its bioactive components, especially polyphenols, possess many health-promoting and disease-preventing benefits, especially anti-inflammatory, antioxidant, anticancer, and metabolic modulation effects with multi-target modes of action. However, the effect of tea polyphenols on immune function has not been well studied. Moreover, the underlying cellular and molecular mechanisms mediating immunoregulation are not well understood. This review summarizes the recent studies on the immune-potentiating effects and corresponding mechanisms of tea polyphenols, especially the main components of (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG). In addition, the benefits towards immune-related diseases, such as autoimmune diseases, cutaneous-related immune diseases, and obesity-related immune diseases, have been discussed.

Advances in Nanodelivery of Green Tea Catechins to Enhance the Anticancer Activity

Cancer is one of the leading causes of death globally. A variety of phenolic compounds display preventative and therapeutic effects against cancers. Green teas are rich in phenolics. Catechins are the most dominant phenolic component in green teas. Studies have shown that catechins have anticancer activity in various cancer models. The anticancer activity of catechins, however, may be compromised due to their low oral bioavailability. Nanodelivery emerges as a promising way to improve the oral bioavailability and anticancer activity of catechins. Research in this area has been actively conducted in recent decades. This review provides the molecular mechanisms of the anticancer effects of catechins, the factors that limit the oral bioavailability of catechins, and the latest advances of delivering catechins using nanodelivery systems through different routes to enhance their anticancer activity.

Antioxidant Therapy in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) are a group of chronic, incurable diseases of the digestive tract, the etiology of which remains unclear to this day. IBD result in significant repercussions on the quality of patients’ life. There is a continuous increase in the incidence and prevalence of IBD worldwide, and it is becoming a significant public health burden. Pharmaceuticals commonly used in IBD management, for example, mesalamine, sulfasalazine, corticosteroids, and others, expose patients to diverse, potentially detrimental side effects and frequently do not provide sufficient disease control. The chronic inflammation underlies the etiology of IBD and closely associates with oxidative/nitrosative stress and a vast generation of reactive oxygen/nitrogen species. Relative to this, several substances with antioxidant and anti-inflammatory properties are now intensively researched as possible adjunctive or independent treatment options in IBD. Representatives of several different groups, including natural and chemical compounds will be characterized in this dissertation.

Catechins reduce inflammation in lipopolysaccharide-stimulated dental pulp cells by inhibiting activation of the NF-κB pathway

AIM

To ascertain the anti-inflammation mechanism of catechins in lipopolysaccharide-treated human dental pulp cells (HDPCs).

METHODS

Expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 was measured using quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assays. The anti-inflammatory mechanism was explored by examining activation of nuclear factor-kappa B (NF-κB) signaling using qPCR, Western blotting, and immunofluorescence staining.

RESULTS

Human dental pulp cells proliferation was not affected by treatment with epigallocatechin (ECG) or epigallocatechin 3-gallate (EGCG). mRNA expression of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 was decreased significantly in ECG- and EGCG-treated HDPCs. Subsequently, the effects of ECG and EGCG upon activation of NF-κB signaling were evaluated by Western blotting and immunofluorescence staining. Expression of p-p65 protein in HDPCs treated with ECG, EGCG, or an NF-κB inhibitor (Bay 11-7082) was lower than that in HDPCs treated with lipopolysaccharide, data that were consistent with the location of p65 protein according to immunofluorescence staining.

CONCLUSIONS

Catechin could reduce lipopolysaccharide-stimulated inflammation in HDPCs by inhibiting activation of the NF-κB pathway.

Microwave-Assisted Extraction of Phenolic Compounds from Melastoma sanguineum Fruit: Optimization and Identification

A microwave-assisted extraction (MAE) technology optimized by response surface methodology (RSM) was established to extract phenolic compounds from the fruit of Melastoma sanguineum. The effects of solvent composition, ratio of solvent to material, temperature, time and microwave power on phenol yield were evaluated in single-factor tests. The three parameters exerting main impacts on phenol yield were further optimized by RSM. Under optimal extraction conditions (31.33% ethanol, solvent/material ratio of 32.21 mL/g, 52.24 °C, 45 min and 500 W), the total phenolic content was 39.02 ± 0.73 mg gallic acid equivalent (GAE)/g dry weight (DW). This MAE method performed better in comparison with two conventional methods, those being maceration (25.79 ± 1.03 mg GAE/g DW) and Soxhlet extraction (18.40 ± 1.34 mg GAE/g DW), using lower process temperature, shorter irradiation time, and lower organic solvent consumption. In addition, five flavonoids (epicatechin gallate, epicatechin, rutin, pigallocatechin and quercetin) and two phenolic acids (protocatechuic acid and chlorogenic acid) in the extract were identified and quantified using UPLC-MS/MS.

Cancer chemoprevention and therapy using chinese herbal medicine

Traditional Chinese medicine (TCM) plays an indispensable role in cancer prevention and treatment. Chinese herbal medicine (CHM) is a key component of TCM and has been practiced for thousands of years. A number of naturally occurring products from Chinese herbs extracts exhibit strong inhibitory properties against carcinogenesis, including CHM single-herb extracts, CHM-derived active components, and CHM formulas (the polyherbal combinations), which regulate JAK/STAT, MAPK, and NF-ҡB pathways. The present review aims to report the cancer-preventive effect of CHM with evidence from cell-line, animal, epidemiological, and clinical experiments. We also present several issues that have yet to be resolved. In the future, cancer prevention by CHM will face unprecedented opportunities and challenges.

Pu-erh Tea Water Extract Mediates Cell Cycle Arrest and Apoptosis in MDA-MB-231 Human Breast Cancer Cells

Pu-erh tea is believed to have health benefits, the growth inhibition activity of Pu-erh tea on breast cancer cell has not been investigated. In this study, we examined the activity of Pu-erh tea water extract on apoptosis and cell cycle arrest in the human breast adenocarcinoma cell line MDA-MB-231 and clarified its underlying mechanism of action. We found that Pu-erh tea extract inhibited cell proliferation and induced apoptosis in a dose-dependent manner. We also found that Pu-erh tea extract inhibited tumor cell growth within 24 h via accumulation of cells in S phase. Further experiments showed that at 24 h, Pu-erh tea extract up-regulated the expressions of P-p53 (Ser15), p21 and P-JNK and down-regulated the expressions of PCNA, CyclinD1 and CyclinE at the protein level in MDA-MB-231 cells. In particular, the JNK-specific inhibitor SP600125 restored the induction of P-JNK, P-p53 (Ser15), p21, CyclinD1 and CyclinE by Pu-erh tea extract. Our results indicate that Pu-erh tea water extract inhibits cell proliferation of MDA-MB-231 cells through the induction of apoptosis and the stimulation of cell cycle arrest, which is mediated via activation of the JNK-related pathway.

Catechins and Their Therapeutic Benefits to Inflammatory Bowel Disease

Catechins are natural polyphenolic phytochemicals that exist in food and medicinal plants, such as tea, legume and rubiaceae. An increasing number of studies have associated the intake of catechins-rich foods with the prevention and treatment of chronic diseases in humans, such as inflammatory bowel disease (IBD). Some studies have demonstrated that catechins could significantly inhibit the excessive oxidative stress through direct or indirect antioxidant effects and promote the activation of the antioxidative substances such as glutathione peroxidases (GPO) and glutathione (GSH), reducing the oxidative damages to the colon. In addition, catechins can also regulate the infiltration and proliferation of immune related-cells, such as neutrophils, colonic epithelial cells, macrophages, and T lymphocytes, helping reduce the inflammatory relations and provide benefits to IBD. Perhaps catechins can further inhibit the deterioration of intestinal lesions through regulating the cell gap junctions. Furthermore, catechins can exert their significant anti-inflammatory properties by regulating the activation or deactivation of inflammation-related oxidative stress-related cell signaling pathways, such as nuclear factor-kappa B (NF-κB), mitogen activated protein kinases (MAPKs), transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2), signal transducer and the activator of transcription 1/3 (STAT1/3) pathways. Finally, catechins can also stabilize the structure of the gastrointestinal micro-ecological environment via promoting the proliferation of beneficial intestinal bacteria and regulating the balance of intestinal flora, so as to relieve the IBD. Furthermore, catechins may regulate the tight junctions (TJ) in the epithelium. This paper elaborates the currently known possible molecular mechanisms of catechins in favor of IBD.

Ultrasound-Assisted Extraction and Identification of Natural Antioxidants from the Fruit of Melastoma sanguineum Sims

The fruit of Melastoma sanguineum Sims is an edible and sweet wild fruit. In our previous study, the fruit was found to have a strong antioxidant property. In this study, an ultrasound-assisted extraction (UAE) method was developed to extract natural antioxidants from the fruit of Melastoma sanguineum Sims, and a response surface methodology was used to optimize the conditions of UAE to maximize the extraction efficiency. The influence of five independent extraction parameters (ethanol concentration, solvent/material ratio, extracting time, temperature, and ultrasound power) on the extraction efficiency were investigated using a single factor experiment, and then a central composite rotatable design was used to investigate the interaction of three key parameters. The results showed that the optimal extraction conditions were 42.98% ethanol, 28.29 mL/g solvent/material ratio, 34.29 min extracting time, 60 °C temperature, and 600 W ultrasound power. Under these conditions, the Trolox equivalent antioxidant capacity (TEAC) value of the extracts was 1074.61 ± 32.56 μmol Trolox/g dry weight (DW). Compared with conventional maceration (723.27 ± 11.61 μmol Trolox/g DW) and Soxhlet extraction methods (518.37 ± 23.23 μmol Trolox/g DW), the UAE method improved the extraction efficiency, in a shorter period of time. In addition, epicatechin gallate, epicatechin, rutin, epigallocatechin, protocatechuic acid, chlorogenic acid, and quercetin, were identified and quantified in the fruit extracts of Melastoma sanguineum Sims by UPLC-MS/MS.

Green tea (-)-epigallocatechin gallate inhibits the growth of human villous trophoblasts via the ERK, p38, AMP-activated protein kinase, and protein kinase B pathways

Green tea catechins, especially (-)-epigallocatechin gallate (EGCG), have been reported to circulate in the placenta of animals and blood of humans after consumption. Whether EGCG regulates activity of human villous trophoblasts (HVT) is unknown. This study investigated the pathways involved in EGCG modulation of trophoblast mitogenesis. EGCG inhibited trophoblast proliferation in a dose-dependent and time-dependent manner, as indicated by the number of cells and incorporation of bromodeoxyuridine (BrdU). EGCG was more effective than other green tea catechins in inhibiting cell growth. EGCG also increased the phosphorylation of the MAPK pathway proteins, ERK1/2, and p38, but not JNK. Furthermore, EGCG had no effects on the total amounts of ERK1/2, p38 MAPK, and JNK proteins. This suggests that EGCG selectively affects particular MAPK subfamilies. Pretreatment with specific inhibitors of ERK1/2, p38 MAPK, and AMP-activated protein kinase (AMPK) antagonized EGCG-induced decreases in both cell number and BrdU incorporation. These inhibitors also blocked EGCG-induced increases in the levels of phospho-ERK1/2, phospho-p38, and phospho-AMPK proteins, respectively. Moreover, EGCG was similar to the phosphatidylinositol 3-kinase inhibitors wortmannin and LY-294002 to decrease protein kinase B (AKT) phosphorylation, cell number, and BrdU incorporation. These data imply that EGCG inhibits the growth of HVT through the ERK, p38, AMPK, and AKT pathways.

Directly interact with Keap1 and LPS is involved in the anti-inflammatory mechanisms of (-)-epicatechin-3-gallate in LPS-induced macrophages and endotoxemia

Disruption of the Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid-derived factor 2-related factor 2 (Nrf2) interaction has emerged as a promising strategy to reduce oxidative stress-induced inflammation. However, its roles in regulating downstream events, including the cross talk between Nrf2 and nuclear factor-kappa B (NF-κB), are not well defined. The objective of this study was to elucidate the mechanistic connection between Keap1-Nrf2 signaling and the transcription factor NF-κB and to investigate the function of (-)-epicatechin-3-gallate (ECG) in the repression of multiple inflammatory mediators. ECG attenuated lipopolysaccharide (LPS)-induced inflammatory mediator expression and intracellular reactive oxygen species (ROS) generation through the induction of Nrf2/antioxidant response element (ARE)-driven glutathione (GSH) and hemeoxygenase-1 (HO-1) levels, interference with NF-κB and Nfr2/ARE transcriptional activities, and suppression of the MAPKs (JNK1/2 and p38) and PI3K/Akt signaling pathways. Importantly, anti-inflammatory effects of ECG partly require activation of ERK1/2 signaling to mediate HO-1 expression and Nrf2/ARE signaling activation. Furthermore, ECG may directly interact intracellularly with the Kelch repeat domains of Keap1 and bind to extracellular LPS, thereby promoting the nuclear accumulation of the Nrf2 protein and blockading the activation of LPS-induced downstream target signaling pathways. Consistent with in vitro studies, ECG attenuates pathological syndromes of LPS-induced sepsis and systemic inflammation. Our results identified ECG as a novel Keap1-Nrf2 interaction disruptor and LPS-induced TLR4 activation inhibitor, thereby providing an innovative strategy to prevent or treat immune, oxidative stress and inflammatory-related diseases.

Isolation of eugenyl β-primeveroside from Camellia sasanqua and its anticancer activity in PC3 prostate cancer cells

Most studies of tea trees have focused on their ornamental properties, there are fewer published studies on their medical values. The purpose of this study was to compare the chemical constituents and the biological potential of the water extract of leaves in eight species of Camellia including Camellia sinensis. Among eight Camellia species, Camellia sasanqua showed potent anticancer activities in prostate cancer PC3 cells. In addition to catechins, the major component, eugenyl β-primeveroside was detected in C. sasanqua. Eugenyl β-primeveroside blocked the progression of cell cycle at G1 phase by inducing p53 expression and further upregulating p21 expression. Moreover, eugenyl β-primeveroside induced apoptosis in PC3 prostate cancer cells. Our results suggest that C. sasanqua may have anticancer potential.

Designing a broad-spectrum integrative approach for cancer prevention and treatment

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.

Effect of (-)-epigallocatechin-3-O-gallate on autophagic signaling in HepG2 cells

AIM: To investigate the changes of autophagy in hepatocellular carcinoma (HCC) HepG2 cells in response to (-)-epigallocatechin-3-O-gallate (EGCG), and to explore its impact on cell proliferation and death.

METHODS: HepG2 cells were routinely cultured and re-plated in Dulbecco's modified eagle's medium (DMEM) in the presence of EGCG of different concentrations. Transmission electron microscopic technique was used to record the formation of autophagosomes in HepG2 cells. Real-time RT-PCR and Western blot were used to detect the mRNA and protein expression of autophagy-related genes, respectively. MTT and trypan blue assays were carried out to determine the cellular proliferation and death. Autophagic intervention experiment was performed to evaluate whether changes in autophagy are involved in the anti-cancer efficacy of EGCG in HCC.

RESULTS: The proliferation of HepG2 cells was significantly inhibited by EGCG and was negatively related to the concentrations of this compound (r = -0.9341, P < 0.001). Doses of EGCG that could effectively inhibit the proliferation of HepG2 cells significantly decreased the mRNA and protein expression of Beclin1 and Atg5, with increments of P62 named autophagic substrate as well as substantially reduced numbers of autophagasomes found in these cells. Moreover, up-regulating autophagy with rapamycin was found to apparently impair the effect of EGCG in killing HepG2 cells (t = 9.95, P < 0.01), while 3-MA, an autophagy inhibitor, dramatically exaggerated the anti-cancer effects of EGCG (t = 22.82, P < 0.01).

CONCLUSION: EGCG substantially inhibits cell proliferation and promotes cell death in HCC cells via down-regulation of autophagy, which indicates a novel critical pharmacological mechanism of EGCG for hepatoma therapy.

Apoptotic effect of novel Schiff based CdCl₂(C₁₄H₂₁N₃O₂) complex is mediated via activation of the mitochondrial pathway in colon cancer cells

The development of metal-based agents has had a tremendous role in the present progress in cancer chemotherapy. One well-known example of metal-based agents is Schiff based metal complexes, which hold great promise for cancer therapy. Based on the potential of Schiff based complexes for the induction of apoptosis, this study aimed to examine the cytotoxic and apoptotic activity of a CdCl2(C14H21N3O2) complex on HT-29 cells. The complex exerted a potent suppressive effect on HT-29 cells with an IC50 value of 2.57 ± 0.39 after 72 h of treatment. The collapse of the mitochondrial membrane potential and the elevated release of cytochrome c from the mitochondria to the cytosol indicate the involvement of the intrinsic pathway in the induction of apoptosis. The role of the mitochondria-dependent apoptotic pathway was further proved by the significant activation of the initiator caspase-9 and the executioner caspases-3 and -7. In addition, the activation of caspase-8, which is associated with the suppression of NF-κB translocation to the nucleus, also revealed the involvement of the extrinsic pathway in the induced apoptosis. The results suggest that the CdCl2(C14H21N3O2) complex is able to induce the apoptosis of colon cancer cells and is a potential candidate for future cancer studies.

Hibiscus sabdariffa leaf polyphenolic extract induces human melanoma cell death, apoptosis, and autophagy

Melanoma is the least common but most fatal form of skin cancer. Previous studies have indicated that an aqueous extract of Hibiscus sabdariffa leaves possess hypoglycemic, hypolipidemic, and antioxidant effects. In this study, we want to investigate the anticancer activity of Hibiscus leaf polyphenolic (HLP) extract in melanoma cells. First, HLP was exhibited to be rich in epicatechin gallate (ECG) and other polyphenols. Apoptotic and autophagic activities of HLP and ECG were further evaluated by DAPI stain, cell-cycle analysis, and acidic vascular organelle (AVO) stain. Our results revealed that both HLP and ECG induced the caspases cleavages, Bcl-2 family proteins regulation, and Fas/FasL activation in A375 cells. In addition, we also revealed that the cells presented AVO-positive after HLP treatments. HLP could increase the expressions of autophagy-related proteins autophagy-related gene 5 (ATG5), Beclin1, and light chain 3-II (LC3-II), and induce autophagic cell death in A375 cells. These data indicated that the anticancer effect of HLP, partly contributed by ECG, in A375 cells. HLP potentially could be developed as an antimelanoma agent.

Gene regulation mediated by microRNAs in response to green tea polyphenol EGCG in mouse lung cancer

BACKGROUND

Epigallocatechin-3-gallate (EGCG) has been demonstrated to inhibit cancer in experimental studies through its antioxidant activity and modulations on cellular functions by binding specific proteins. We demonstrated previously that EGCG upregulates the expression of microRNA (i.e. miR-210) by binding HIF-1α, resulting in reduced cell proliferation and anchorage-independent growth. However, the binding affinities of EGCG to HIF-1α and many other targets are higher than the EGCG plasma peak level in experimental animals administered with high dose of EGCG, raising a concern whether the microRNA regulation by HIF-1α is involved in the anti-cancer activity of EGCG in vivo.

RESULTS

We employed functional genomic approaches to elucidate the role of microRNA in the EGCG inhibition of tobacco carcinogen-induced lung tumors in A/J mice. By analysing the microRNA profiles, we found modest changes in the expression levels of 21 microRNAs. By correlating these 21 microRNAs with the mRNA expression profiles using the computation methods, we identified 26 potential targeted genes of the 21 microRNAs. Further exploration using pathway analysis revealed that the most impacted pathways of EGCG treatment are the regulatory networks associated to AKT, NF-κB, MAP kinases, and cell cycle, and the identified miRNA targets are involved in the networks of AKT, MAP kinases and cell cycle regulation

CONCLUSIONS

These results demonstrate that the miRNA-mediated regulation is actively involved in the major aspects of the anti-cancer activity of EGCG in vivo.

Chronic exposure to combined carcinogens enhances breast cell carcinogenesis with mesenchymal and stem-like cell properties

Breast cancer is the most common type of cancer affecting women in North America and Europe. More than 85% of breast cancers are sporadic and attributable to long-term exposure to small quantities of multiple carcinogens. To understand how multiple carcinogens act together to induce cellular carcinogenesis, we studied the activity of environmental carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene (B[a]P), and dietary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) using our breast cell carcinogenesis model. Our study revealed, for the first time, that combined NNK and B[a]P enhanced breast cell carcinogenesis chronically induced by PhIP in both non-cancerous and cancerous breast cells. Co-exposure was more potent than sequential exposure to combined NNK and B[a]P followed by PhIP in inducing carcinogenesis. Initiation of carcinogenesis was measured by transient endpoints induced in a single exposure, while progression of carcinogenesis was measured by acquisition of constitutive endpoints in cumulative exposures. Transient endpoints included DNA damage, Ras-Erk-Nox pathway activation, reactive oxygen species elevation, and increased cellular proliferation. Constitutive endpoints included various cancer-associated properties and signaling modulators, as well as enrichment of cancer stem-like cell population and activation of the epithelial-to-mesenchymal transition program. Using transient and constitutive endpoints as targets, we detected that a combination of the green tea catechins ECG and EGCG, at non-cytotoxic levels, was more effective than individual agents in intervention of cellular carcinogenesis induced by combined NNK, B[a]P, and PhIP. Thus, use of combined ECG and EGCG should be seriously considered for early intervention of breast cell carcinogenesis associated with long-term exposure to environmental and dietary carcinogens.

Delivering flavonoids into solid tumors using nanotechnologies

INTRODUCTION

Long-term epidemiological studies have demonstrated that regular ingestion of flavonoids contained in dietary sources is associated with a reduced risk for many chronic diseases including cancer. However, although flavonoids are largely consumed in the diet and high concentrations may exist in the intestine after oral administration, the plasma/tissue concentrations of flavonoids are lower than their effective therapeutic doses due to poor bioavailability, resulting in the limited efficacy of flavonoids in various clinical studies. Therefore, the application of nanotechnology to deliver flavonoids to tumor sites has received considerable attention in recent years.

AREAS COVERED

In this review, after a general review of the potential benefits of flavonoids in cancer therapy and several key factors affecting their bioavailability, the current efforts in improving the delivery efficacy of promising candidates that are particularly important in the human diet, namely quercetin, epigallocatechin-3-gallate (EGCG) and genistein were focused on. Finally, the challenges of developing flavonoid delivery systems that improve flavonoid bioavailability and their anticancer therapy potentials were summarized.

EXPERT OPINION

The design of suitable molecular carriers for flavonoids is an area of research that is in rapid progress. A large number of unheeded promising favonoids are suffering from poor in vivo parameters, their potential benefits deserves further research. Furthermore, more effort should be placed on developing active targeting systems, evaluating the efficacy and toxicity of novel flavonoid delivery systems through small and large scale clinical trials.

Green tea and the risk of gastric cancer: epidemiological evidence

Gastric cancer (GC) is one of the leading causes of cancer death in the world. Numerous efforts are being made to find chemoprotective agents able to reduce its risk. Amongst these, green tea has been reported to have a protective effect against stomach cancer. This article aims to critically evaluate all epidemiological studies reporting an association between green tea consumption and GC risk. MEDLINE, EBSCOHOST and Google Scholar were used to search for clinical trials of green tea and its correlation to stomach cancer. Studies include cohort and case-control studies. Outcome of interests are inverse association, no association, and positive association. Seventeen epidemiologic studies were reviewed. Eleven studies were conducted in Japan, five in China, and one with Japanese descendent in Hawaii. Ten case-control studies and seven cohort studies were included. The relative risks or odds ratio of GC for the highest level of green tea consumption was compared. Seven studies suggested no association, eight an inverse association, and one a positive association. One study had shown a significantly lowered GC risk when tea was served warm to cold. Another study also showed a significantly risk with lukewarm tea. All studies that analyzed men and women separately have suggested a reduced risk in women than in men, albeit no significant difference. This review demonstrates that there is insufficient information to support green tea consumption reduces the risk of GC. More studies on the subject matter are warranted.

Chemoprevention of gastrointestinal cancer: the reality and the dream

Despite substantial progress in screening, early diagnosis, and the development of noninvasive technology, gastrointestinal (GI) cancer remains a major cause of cancer-associated mortality. Chemoprevention is thought to be a realistic approach for reducing the global burden of GI cancer, and efforts have been made to search for chemopreventive agents that suppress acid reflux, GI inflammation and the eradication of Helicobacter pylori. Thus, proton pump inhibitors, statins, monoclonal antibodies targeting tumor necrosis factor-alpha, and nonsteroidal anti-inflammatory agents have been investigated for their potential to prevent GI cancer. Besides the development of these synthetic agents, a wide variety of the natural products present in a plant-based diet, which are commonly called phytoceuticals, have also sparked hope for the chemoprevention of GI cancer. To perform successful searches of chemopreventive agents for GI cancer, it is of the utmost importance to understand the factors contributing to GI carcinogenesis. Emerging evidence has highlighted the role of chronic inflammation in inducing genomic instability and telomere shortening and affecting polyamine metabolism and DNA repair, which may help in the search for new chemopreventive agents for GI cancer.

EGCG inhibits transforming growth factor-β-mediated epithelial-to-mesenchymal transition via the inhibition of Smad2 and Erk1/2 signaling pathways in nonsmall cell lung cancer cells

Transforming growth factor-β (TGF-β)-mediated epithelial mesenchymal transition (EMT) of human lung cancer cells may contribute to lung cancer metastasis. It has been reported that EGCG can inhibit tumorigenesis and cancer cell growth in lung cancer; however, the effect of EGCG on EMT in nonsmall cell lung cancer (NSCLC) cells has not been investigated. In this study, we found that NSCLC cells A549 and H1299 were converted to the fibroblastic phenotype in response to TGF-β. Epithelial marker E-cadherin was down-regulated, and mesenchymal marker vimentin was up-regulated simultaneously. Our results illustrated that TGF-β was able to induce EMT in NSCLC cells, and EGCG would reverse TGF-β-induced morphological changes, up-regulate the expression of E-cadherin, and down-regulate the expression of vimentin. Immunofluorescent staining also demonstrated that E-cadherin was up-regulated and that vimentin was down-regulated by EGCG pretreatment. Moreover, wound-healing and the in vitro invasion assay showed that EGCG could inhibit TGF-β-induced migration and invasion of NSCLC cells. By using the dual-luciferase reporter assay, we demonstrated that EGCG inhibited TGF-β-induced EMT at the transcriptional level. EGCG decreased the phosphorylation of Smad2 and Erk1/2, inhibited the nuclear translocation of Smad2, and repressed the expression of transcription factors ZEB1, Snail, Slug, and Twist, and up-regulated the expression of E-cadherin. In summary, our results suggest that EGCG can inhibit TGF-β-induced EMT via down-regulation of phosphorylated Smad2 and Erk1/2 in NSCLC cells.

Inhibitory effect of genistein on the invasive potential of human cervical cancer cells via modulation of matrix metalloproteinase-9 and tissue inhibitors of matrix metalloproteinase-1 expression

BACKGROUND

One of the most challenging stumbling blocks for the treatment of cancer is the ability of cancer cells to break the natural barriers and spread from its site of origin to non-adjacent regional and distant sites, accounting for high cancer mortality rates. Gamut experimental and epidemiological data advocate the use of pharmacological or nutritional interventions to inhibit or delay various stage(s) of cancer such as invasion and metastasis. Genistein, a promising chemopreventive agent, has gained considerable attention for its powerful anti-carcinogenic, anti-angiogenic and chemosensitizing activities.

METHODS

In this study, the cytotoxic potential of genistein on HeLa cells by cell viability assay and the mode of cell death induced by genistein were determined by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Moreover, to establish its inhibitory effect on migration of HeLa cells, scratch wound assay was performed and these results were correlated with the expression of genes involved in invasion and migration (MMP-9 and TIMP-1) by RT-PCR.

RESULTS

The exposure of HeLa cells to genistein resulted in significant dose- and time-dependent growth inhibition, which was found to be mediated by apoptosis and cell cycle arrest at G(2)/M phase. In addition, it induced migration-inhibition in a time-dependent manner by modulating the expression of MMP-9 and TIMP-1.

CONCLUSION

Our results signify that genistein may be an effective anti-neoplastic agent to prevent cancer cell growth and invasion and metastasis. Therefore therapeutic strategies utilizing genistein could be developed to substantially reduce cancer morbidity and mortality.

Aqueous fraction of Nephelium ramboutan-ake rind induces mitochondrial-mediated apoptosis in HT-29 human colorectal adenocarcinoma cells

The aim of this study was to investigate the cytotoxic and apoptotic effects of Nephelium ramboutan-ake (pulasan) rind in selected human cancer cell lines. The crude ethanol extract and fractions (ethyl acetate and aqueous) of N. ramboutan-ake inhibited the growth of HT-29, HCT-116, MDA-MB-231, Ca Ski cells according to MTT assays. The N. ramboutan-ake aqueous fraction (NRAF) was found to exert the greatest cytotoxic effect against HT-29 in a dose-dependent manner. Evidence of apoptotic cell death was revealed by features such as chromatin condensation, nuclear fragmentation and apoptotic body formation. The result from a TUNEL assay strongly suggested that NRAF brings about DNA fragmentation in HT-29 cells. Phosphatidylserine (PS) externalization on the outer leaflet of plasma membranes was detected with annexin V-FITC/PI binding, confirming the early stage of apoptosis. The mitochondrial permeability transition is an important step in the induction of cellular apoptosis, and the results clearly suggested that NRAF led to collapse of mitochondrial transmembrane potential in HT-29 cells. This attenuation of mitochondrial membrane potential (Δψm) was accompanied by increased production of ROS and depletion of GSH, an increase of Bax protein expression, and induced-activation of caspase-3/7 and caspase-9. These combined results suggest that NRAF induces mitochondrial-mediated apoptosis.

Health-promoting effects of green tea

Green tea is manufactured from the leaves of the plant Camellia sinensis Theaceae and has been regarded to possess anti-cancer, anti-obesity, anti-atherosclerotic, anti-diabetic, anti-bacterial, and anti-viral effects. Many of the beneficial effects of green tea are related to the activities of (-)-epigallocatechin gallate (EGCG), a major component of green tea catechins. For about 20 years, we have engaged in studies to reveal the biological activities and action mechanisms of green tea and EGCG. This review summarizes several lines of evidence to indicate the health-promoting properties of green tea mainly based on our own experimental findings.