Tea polyphenols: prevention of cancer and optimizing health

Catechins induced acute promyelocytic leukemia cell apoptosis and triggered PML-RARα oncoprotein degradation

Background

It has recently been reported that the extracts of green tea polyphenol have cancer preventive effects. In this study, we investigated the effect of the natural composition from green tea leaves Catechins on acute promyelocytic leukemia (APL).

Methods

In vitro, APL cell lines NB4, retinoic acid-resistant NB4-R1 and NB4-R2 were treated with different concentrations of Catechins. Cell viability and cell apoptosis were analyzed using MTT assay and flow cytometric assay, respectively. Expression of proteins related to apoptosis and PML-RARα oncoprotein were assessed by Western blot. In vivo anti-tumor activity of Catechins was examined in nude mice xenografted with NB4 cells and in situ cell apoptosis was detected by terminal deoxytransferase-catalyzed DNA nick-end labeling assay.

Results

Catechins at micromolar concentration levels significantly inhibited APL cell proliferation and induced cell apoptosis, in association with mitochondria damage, ROS production and caspase activation. The anti-apoptotic Bcl-2 family member Bcl-xL was down regulated, with pro-apoptotic member Bax remaining unchanged. Moreover, Catechins induced the degradation of PML-RARα oncoprotein. Catechins-mediated apoptotic effect was also observed in primary APL cells without affecting normal hematopoietic progenitor cells. In the murine xenograft model, Catechins remarkably inhibited tumor growth and induced in situ leukemic cell apoptosis.

Conclusions

Catechins might be a potential candidate for APL treatment by activating intrinsic apoptotic pathway and targeting PML-RARα oncoprotein.

Reorganisation of the salivary mucin network by dietary components: insights from green tea polyphenols

The salivary mucins that include MUC5B (gel-forming) and MUC7 (non-gel-forming) are major contributors to the protective mucus barrier in the oral cavity, and it is possible that dietary components may influence barrier properties. We show how one dietary compound, the green tea polyphenol epigallocatechin gallate (EGCG), can substantially alter the properties of both the polymeric MUC5B network and monomeric MUC7. Using rate-zonal centrifugation, MUC5B in human whole saliva and MUC5B purified from saliva sedimented faster in the presence of EGCG. The faster sedimentation by EGCG was shown to be greater with increasing MUC5B concentration. Particle tracking microrheology was employed to determine the viscosity of purified MUC5B solutions and showed that for MUC5B solutions of 200-1600 µg/mL, EGCG caused a significant increase in mucin viscosity, which was greater at higher MUC5B concentrations. Visualisation of the changes to the MUC5B network by EGCG was performed using atomic force microscopy, which demonstrated increased aggregation of MUC5B in a heterogeneous manner by EGCG. Using trypsin-resistant, high-molecular weight oligosaccharide-rich regions of MUC5B and recombinant N-terminal and C-terminal MUC5B proteins, we showed that EGCG causes aggregation at the protein domains of MUC5B, but not at the oligosaccharide-rich regions of the mucin. We also demonstrated that EGCG caused the majority of MUC7 in human whole saliva to aggregate. Furthermore, purified MUC7 also underwent a large increase in sedimentation rate in the presence of EGCG. In contrast, the green tea polyphenol epicatechin caused no change in the sedimentation rate of either MUC5B or MUC7 in human whole saliva. These findings have demonstrated how the properties of the mucin barrier can be influenced by dietary components. In the case of EGCG, these interactions may alter the function of MUC5B as a lubricant, contributing to the astringency (dry puckering sensation) of green tea.

Black tea polyphenols: a mechanistic treatise

Dietary interventions are among the emerging trends to curtail physiological malfunctioning like cancer, diabetes, cardiac complications, etc. The essence of phytonutrients has developed the concept of nutraceuticals at the junction of diet health linkages. In this context, theaflavin & thearubigins are the oxidized derivatives of black tea catechins during fermentation having nutraceutical potential owing to esterification of hydroxyl ring with digallate esters. Theaflavin may influence activation of transcription factors such as NFnB or AP-1 that ultimately hinder the formation of nitric oxide expression gene. Likewise, black tea contains a unique amino acid theanine acts as neurotransmitter owing to its ability to cross the blood-brain barrier. Moreover, it boasts immunity by enhancing the disease-fighting ability of gamma delta T cells. Theaflavin & thearubigins act as safeguard against oxidative stress thereby effective in the cardiac functioning. The mechanistic approach of these antioxidants is likely to be associated with inhibition of redox sensitive transcription factors & pro-oxidant enzymes such as xanthine oxidase or nitric oxide synthase. However, their involvement in antioxidative enzyme induction as in glutathione-S-transferases is also well documented. They act as curative agent against numerous pathological disorders by disrupting the electron chain thus inhibiting the progression of certain ailments. Black tea polyphenols established themselves as strong antioxidants due to their standard one-electron potential, and their vitality is dependent on the concentration of polyphenols and pH for their inclusive execution. Present review is an attempt to enrich the readers regarding the health promoting aspects of black tea polyphenols. Concomitantly, it needs core attention of researchers for the exploitations of black tea flavanols as an important dietary constituent for the vulnerable segment.

Epigenetic regulation by selected dietary phytochemicals in cancer chemoprevention

The growing interest in cancer epigenetics is largely due to the reversible nature of epigenetic changes which tend to alter during the course of carcinogenesis. Major epigenetic changes including DNA methylation, chromatin modifications and miRNA regulation play important roles in tumorigenic process. There are several epigenetically active synthetic molecules such as DNA methyltransferase (DNMTs) and histone deacetylases (HDACs) inhibitors, which are either approved or, are under clinical trials for the treatment of various cancers. However, most of the synthetic inhibitors have shown adverse side effects, narrow in their specificity and also expensive. Hence, bioactive phytochemicals, which are widely available with lesser toxic effects, have been tested for their role in epigenetic modulatory activities in gene regulation for cancer prevention and therapy. Encouragingly, many bioactive phytochemicals potentially altered the expression of key tumor suppressor genes, tumor promoter genes and oncogenes through modulation of DNA methylation and chromatin modification in cancer. These bioactive phytochemicals either alone or in combination with other phytochemicals showed promising results against various cancers. Here, we summarize and discuss the role of some commonly investigated phytochemicals and their epigenetic targets that are of particular interest in cancer prevention and cancer therapy.

Analysis of the effect of the active compound of green tea (EGCG) on the proliferation of peripheral blood mononuclear cells

Background

Cancer immunotherapy requires proper manipulation of the immune system, lymphocytes in particular, in order to identify and destroy the cancer cells as non-self. In this study we investigated the effect of the flavonoid present in green tea, namely epigallocatechin-3-gallate (EGCG), on the proliferation of, and IFN-γ production by, peripheral blood mononuclear cells (PBMC) from breast cancer patients stimulated with a mitogen, anti-CD3 and the common breast cancer peptides Her-2/neu, and p53.

Methods

Blood samples were collected from 25 patients with breast cancer at the Kuwait Cancer Control Centre (KCCC). The patients were newly diagnosed, and had not undergone any treatment or surgery at the time of sample collection. The control group consisted of 25 healthy women age-matched (±5 years) to the patients. PBMC were isolated from the patients and controls, and were cultured separately with the mitogen PHA, anti-CD3 antibodies, and Her-2/neu and p53 in the presence or absence of standardized doses of EGCG. The degree of proliferation and interferon-γ [IFN-γ) release were then analyzed.

Results

EGCG significantly suppressed the proliferation of PBMC in response to stimulation separately with (i) the mitogen, (ii) anti-CD3, and (iii) the cancer antigen peptides. IFN-γ production was also significantly suppressed by EGCG in vitro.

Conclusions

EGCG appears to have an immunosuppressive effect on the proliferation of PBMC, indicating that EGCG is worth exploring for immunomodulatory effects in autoimmune diseases and tissue transplantation.

Control of Maillard-type off-flavor development in ultrahigh-temperature-processed bovine milk by phenolic chemistry

The application of phenolic compounds to suppress Maillard chemistry and off-flavor development in ultrahigh-termperature (UHT)-processed milk during processing and storage was investigated. Five phenolic compounds were examined for structure-reactivity relationships (catechin, genistein, daidzein, 1,2,3-trihydroxybenzene, and 1,3,5-trihydroxybenzene). The levels of key transient Maillard reaction (MR) intermediates (reactive carbonyl species) and select off-flavor markers (methional, 2-acetyl-2-thiazoline, 2-acetyl-1-pyrroline) were quantified by LC-MS/MS and GC-MS/ToF, respectively. The addition of phenolic compounds prior to UHT processing significantly reduced the concentration of MR intermediates and related off-flavor compounds compared to a control sample (p < 0.05). All phenolic compounds demonstrated unique structure reactivity and, notably, those with a more activated A-ring for aromatic electrophilic substitution (catechin, genistein, and 1,3,5-trihydroxybenzene) showed the strongest suppression effect on the off-flavor markers and reactive carbonyl species. Sensory studies were in agreement with the analytical data. The cooked flavor intensity was rated lower for the recombination model samples of the catechin-treated UHT milk compared to the control UHT milk. Additionally, consumer acceptability studies showed catechin-treated UHT milk to have significantly higher liking scores when compared the control sample (Fisher's LSD = 0.728).

Apoptosis inducing effects of Kuding tea polyphenols in human buccal squamous cell carcinoma cell line BcaCD885

Tea polyphenols are functional substances present in tea. Kuding tea as a traditional drink also contains these compounds. After 25, 50 and 100 μg/mL of Kuding tea polyphenol treatment for 48 h, cell proliferation of human buccal squamous cell carcinoma cell line BcaCD885 was inhibited, and the 100 μg/mL of Kuding tea polyphenol showed the highest inhibitory rate at 72.3%. Compared to the lower concentration, the 100 μg/mL of Kuding tea polyphenols significantly (p < 0.05) induced apoptosis as determined by flow cytometry analysis, the content of sub-G1 cancer cells was 32.7%. By RT-PCR and western blot assays, Kuding tea polyphenol significantly induced apoptosis in BcaCD885 cancer cells (p < 0.05) by upregulating caspase-3, caspase-8, caspase-9, Fas/FasL, Bax, p53, p21, E2F1, p73 and downregulating Bcl-2, Bcl-xL, HIAP-1, and HIAP-2 mRNA and protein expressions. Kuding tea polyphenols thus present apoptosis inducing effects in vitro.

Quantitative analysis of major constituents in green tea with different plucking periods and their antioxidant activity

The objective of this study was to determine the relationship between the plucking periods and the major constituents and the antioxidant activity in green tea. Green tea was prepared from leaves plucked from the end of April 2013 to the end of May 2013 at intervals of one week or longer. The contents of theanine, theobromine, caffeine, catechin (C), and gallocatechin gallate (GCg) were significantly decreased, whereas those of epicatechin (EC), epigallocatechin gallate (EGCg) and epigallocatechin (EGC) were significantly increased along with the period of tea leaf plucking. In addition, antioxidant activity of green tea and standard catechins was investigated using ABTS, FRAP and DPPH assays. The highest antioxidant activity was observed in relatively the oldest leaf, regardless of the assay methods used. Additionally, the order of antioxidant activity of standard catechins was as follows: EGCg ≥ GCg ≥ ECg > EGC ≥ GC ≥ EC ≥ C. Moreover, the cis-catechins contents were the key factor affecting the antioxidant activity of green tea in all assays employed (ABTS, r = 0.731, p < 0.01; FRAP, r = 0.886, p < 0.01; DPPH, r = 0.778, p < 0.01).

Effects of supplementation with dietary green tea polyphenols on parasite resistance and acute phase protein response to Haemonchus contortus infection in lambs

The objective of this study was to determine the effects of supplementation with dietary green tea polyphenols (GTPs) on parasite resistance and acute phase protein (APP) response to Haemonchus contortus infection in lambs. Thirty male Ujumqin lambs were randomly assigned to five treatment groups for an 8-week feeding period. Treatments included: (1) uninfected as control, (2) infected but not given GTP (INFGTP0) and (3)-(5) infected and fed 2, 4, or 6g GTP/kg feed (dry matter basis; INFGTP2, INFGTP4, and INFGTP6, respectively). Fecal and blood samples were collected to determine fecal egg count (FEC), packed cell volume (PCV), and APP concentrations. Live weight was measured once every 2 weeks. At the end of the feeding period, lambs were slaughtered to determine the adult H. contortus burden. The results demonstrated interaction effects between treatment and sampling time on the average daily gain (ADG; P=0.0005), FEC (P<0.0001), PCV (P=0.0005), and concentrations of serum amyloid A (SAA), haptoglobin (Hp), lipopolysaccharide binding protein (LBP), and α1-acid glycoprotein (α1AGP) (P<0.0001). From days 0 to 56, the ADG values for all infected lambs were lower than that of uninfected lambs, but the ADG values for all GTP-fed lambs were higher than that of INFGTP0 lambs, especially from days 28 to 42. The FECs of all GTP-fed lambs were higher than those of uninfected lambs but lower than that of INFGTP0 lambs. The PCVs of all infected lambs were lower than those of uninfected lambs, but PCV increased with increasing amounts of GTP supplementation. Furthermore, supplementation with different concentrations of GTP significantly reduced the numbers of adult H. contortus, including both males and females (P<0.0001), and the H. contortus burden in INFGTP6 lambs was reduced to uninfected levels. Overall, the SAA, Hp, LBP, and α1AGP concentrations of all infected lambs were higher than those of uninfected lambs from days 0 to 56. Two peaks in expression were observed from days 0 to 3 and at day 28, and APP concentrations of all GTP-fed lambs were lower than those of INFGTP0 lambs, except for SAA in INFGTP6 lambs. In conclusion, quantitative measurements of APP responses to H. contortus infection provide valuable diagnostic information for monitoring infection progression and treatment responses in lambs. An appropriate dose of dietary GTP supplementation can increase host resistance by reducing H. contortus burden and weight loss and suppressing blood APP expression.

Chemoprevention of oral cancer: Green tea experience

Oral cancer has a well characterized progression from premalignant oral epithelial changes to invasive cancer, making oral squamous cell carcinoma an optimal disease for chemoprevention interventions prior to malignant transformation. The primary goal of chemoprevention here is to reverse, suppress, or inhibit the progression of premalignant lesions to cancer. Due to the extended duration of oral pathogenesis, its chemoprevention using natural products has been found promising due to their decreased dose and limited toxicity profiles. This review discusses with an emphasis on the clinical trials using green tea extract (GTE) in chemoprevention of oral premalignant lesions along with use of GTE as a chemopreventive agent in various other cancers as well. It is worthwhile to include green tea extract in an oral screening program for evaluating the premalignant lesions comparing the results between the treated and untreated group. Given the wide acceptance of green tea, its benefits may help in effective chemoprevention oral cancer.

Biosynthesis of catechin components is differentially regulated in dark-treated tea (Camellia sinensis L.)

Tea (Camellia sinensis L.) is a crop with both commercial and medicinal value with remarkably high polyphenol content in the form of catechins. To understand the molecular regulation of catechin biosynthesis in tea, we treated the tea plants with darkness. We used qRT-PCR to validate the expression of genes involved in catechin biosynthesis. It indicated that dark treatment displayed different effects on the genes participating in tea flavonoid (FL) pathway. The early genes of FL biosynthesis pathway, CHSI, F3H and DFR, remained at steady expression levels when treated by darkness. It is noteworthy that the expression level of LAR increased and the level of ANS decreased under dark conditions. The vanillin assay showed that the dark-treated plants contained lower levels of total catechins than those grown under normal conditions. The HPLC analysis further demonstrated the changes in biosynthesis of catechins under these conditions. In accordance with the gene expression pattern, the content of epicatechins (ECs) declined and that of catechins (Cs) was elevated in response to the darkness. Our study uncovered the molecular mechanisms and biochemical changes of shading in tea cultivation.

Reduced risk of dyslipidaemia with oolong tea consumption: a population-based study in southern China

Experimental studies have suggested that tea consumption could lower the risk of dyslipidaemia. However, epidemiological evidence is limited, especially in southern China, where oolong tea is the most widely consumed beverage. We conducted a population-based case-control study to evaluate the association between consumption of tea, especially oolong tea, and risk of dyslipidaemia in Shantou, southern China, from 2010 to 2011. Information on tea consumption, lifestyle characteristics and food consumption frequency of 1651 patients with newly diagnosed dyslipidaemia and 1390 controls was obtained using a semi-quantitative questionnaire. Anthropometric variables and serum biochemical indices were determined. Drinking more than 600 ml (2 paos) of green, oolong or black tea daily was found to be associated with the lowest odds of dyslipidaemia risk (P< 0.001) when compared with non-consumption, but only oolong tea consumption was found to be associated with low HDL-cholesterol levels. A dose-response relationship between duration of tea consumption and risk of dyslipidaemia (OR 0.10, 95% CI 0.06, 0.16), as well as that between amount of dried tea leaves brewed and risk of dyslipidaemia (OR 0.34, 95% CI 0.24, 0.48), was found. Moreover, consumption of oolong tea for the longest duration was found to be associated with 3.22, 11.99 and 6.69% lower blood total cholesterol, TAG and LDL-cholesterol levels, respectively. In conclusion, the present study indicates that long-term oolong tea consumption may be associated with a lower risk of dyslipidaemia in the population of Shantou in southern China.

Effect of green tea supplementation on blood pressure among overweight and obese adults: a protocol for a systematic review

INTRODUCTION

Emerging randomised controlled trials (RCTs) exploring the effect of green tea (GT) supplementation or GT extract (GTE) on blood pressure (BP) among overweight and obese adults yielded inconclusive results. We aim to conduct a systematic review to summarise the evidence of RCTs until now, to clarify the efficacy of GT supplementation or GTE in BP in overweight and obese populations.

METHODS AND ANALYSIS

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and ClinicalTrials.gov will be searched to retrieve potential RCTs. Unpublished studies will be identified by searching the abstract books or websites of the three major conference proceedings: the International Society of Hypertension, the Nutrition & Health Conference and the World Congress of Nutrition and Health. A random-effects meta-analysis will be performed to pool the mean difference for the change in BP from baseline (ie, postintervention BP minus baseline BP) between intervention groups and placebo groups of the included studies, presenting the pooled results with 95% CIs. Subgroups analyses will be conducted according to different doses of GT or GTE, trial duration, geographic regions, overweight versus obese participants, and participants with versus without change in body weight after intervention. Sensitivity analysis will be performed by excluding studies classified as having a high risk of bias, applying a fixed-effects model, using the postintervention BP for analyses and excluding trials with non-study cointerventions.

ETHICS AND DISSEMINATION

This systematic review will be published in a peer-reviewed journal. It will be disseminated electronically and in print. Summarising the RCT evidence to clarify the efficacy in BP among overweight and obese adults will aid in making the dietary recommendation of GT and improving the clinical management of hypertension.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42014007273.

Protective effect of (-)-epigallocatechin-3-gallate against cisplatin-induced ototoxicity

Objective: Ototoxicity due to cisplatin therapy interferes with treatment and often forces a reduction in the dosage, duration and frequency of the cisplatin therapy. (-)-Epigallocatechin-3-gallate is known to have the highest antioxidant potency among all tea catechins. This study aimed to investigate the effect of (-)-epigallocatechin-3-gallate on cisplatin ototoxicity in an auditory cell line: House Ear Institute-Organ of Corti 1 cells. Methods: Cultured House Ear Institute-Organ of Corti 1 cells were exposed to cisplatin with or without pre-treatment with (-)-epigallocatechin-3-gallate. Cell viability was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Hoechst 33258 staining was used to identify cells undergoing apoptosis. Western blot analysis was conducted to determine whether (-)-epigallocatechin-3-gallate inhibited cisplatin-induced caspase activation. Intracellular reactive oxygen species production was examined to investigate whether (-)-epigallocatechin-3-gallate was capable of scavenging cisplatin-induced reactive oxygen species accumulation. Results: Cell viability significantly increased in cells pre-treated with (-)-epigallocatechin-3-gallate compared with cells exposed to cisplatin alone. Cisplatin increased cleaved caspase-3 on Western blot analysis; however, pre-treatment with (-)-epigallocatechin-3-gallate inhibited the expression of caspase-3. (-)-Epigallocatechin-3-gallate attenuated reactive oxygen species production and apoptosis in House Ear Institute-Organ of Corti 1 cells. Conclusion: (-)-Epigallocatechin-3-gallate protected against cisplatin cytotoxicity through anti-apoptotic and anti-oxidative effects. Therefore, (-)-epigallocatechin-3-gallate could play a preventive role in cisplatin-induced ototoxicity.

In vitro and in vivo effects of a nutrient mixture on breast cancer progression

Long-term survival of patients with breast cancer remains poor, due to metastasis and recurrence. We investigated the effects of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline and green tea extract in vitro and in vivo on 4T1 murine breast cancer, a representative model for metastatic breast cancer. After one week of isolation, 5-6-week-old female Balb/C mice were inoculated with 5x10⁵ 4T1 cells into the mammary pad and randomly divided into two groups; the control group was fed a regular diet and the NM group a regular diet supplemented with 0.5% NM. After four weeks, the mice were sacrificed and their tumors, lungs, livers, kidneys, hearts and spleens were excised and processed for histology. Dimensions (length and width) of tumors were measured using a digital caliper, and the tumor burden was calculated using the following formula: 0.5 x length x width. We also tested the effect of NM in vitro on 4T1 cells, measuring cell proliferation by MTT assay, MMP secretion by zymography, invasion through Matrigel, migration by scratch test and morphology by H&E staining. NM inhibited tumor weight and burden of 4T1 tumors by 50% (p=0.02) and 53.4% (p≤0.0001), respectively. Lung metastasis was profoundly inhibited by NM supplementation: mean number of colonies was reduced by 87% (p<0.0001) and mean weight of lungs by 60% (p=0.0001) compared to control mice. Metastasis to liver, spleen, kidney and heart was significantly reduced with NM supplementation. In vitro, NM exhibited 50% toxicity over the control at 250 and 500 µg/ml concentrations. Zymography demonstrated MMP-2 and MMP-9 secretion which was inhibited by NM in a dose-dependent manner, with virtual total inhibition of both at 1,000 µg/ml. Migration by scratch test and invasion through Matrigel were inhibited in a dose-dependent manner with total block of invasion at 250 and of migration at 1,000 µg/ml. These results suggest that NM has therapeutic potential in the treatment of breast cancer.

Epigallocatechin-3-O-(3-O-methyl)-gallate-induced differentiation of human keratinocytes involves klotho-mediated regulation of protein kinase-cAMP responsive element-binding protein signaling

(−)-Epigallocatechin-3-O-gallate (EGCG) has long been known as a potent inducer of keratinocyte differentiation. Although its molecular mechanisms have been extensively studied, its actions on human skin remain to be elucidated. In this study, we demonstrated that methylated EGCG and EGCG increase the expression of klotho, and that klotho functions as a downstream target of EGCG and methylated EGCG in keratinocyte differentiation. We demonstrated that methylated EGCG3 and EGCG induce morphological changes in normal human epidermal keratinocytes (NHEKs) that are related to up-regulation of klotho expression. We also demonstrated that a klotho-induced keratinocyte differentiation marker in NHEKs is inhibited by H-89, a protein kinase (PKA) inhibitor. These results suggest that methylated EGCG and EGCG may function as inducers of keratinocyte differentiation via transcriptional regulation of the klotho protein.

Tea and health: studies in humans

Tea, next to water is the cheapest beverage humans consume. Drinking the beverage tea has been considered a healthpromoting habit since ancient times. The modern medicinal research is providing a scientific basis for this belief. The evidence supporting the health benefits of tea drinking grows stronger with each new study that is published in the scientific literature. Tea plant Camellia sinensis has been cultivated for thousands of years and its leaves have been used for medicinal purposes. Tea is used as a popular beverage worldwide and its ingredients are now finding medicinal benefits. Encouraging data showing cancer-preventive effects of green tea from cell-culture, animal and human studies have emerged. Evidence is accumulating that black tea may have similar beneficial effects. Tea consumption has also been shown to be useful for prevention of many debilitating human diseases that include maintenance of cardiovascular and metabolic health. Various studies suggest that polyphenolic compounds present in green and black tea are associated with beneficial effects in prevention of cardiovascular diseases, particularly of atherosclerosis and coronary heart disease. In addition, anti-aging, antidiabetic and many other health beneficial effects associated with tea consumption are described. Evidence is accumulating that catechins and theaflavins, which are the main polyphenolic compounds of green and black tea, respectively, are responsible for most of the physiological effects of tea. This article describes the evidences from clinical and epidemiological studies in the prevention of chronic diseases like cancer and cardiovascular diseases and general health promotion associated with tea consumption.

Epigallocatechin-3-gallate exerts protective effects against heat stress through modulating stress-responsive transcription factors in poultry

1. The aim of the study was to describe the effect of Epigallocatechin-3-gallate (EGCG), a polyphenol derived from green tea, on activator protein-1 (AP-1) components (phospho-c-Jun and c-Fos), cyclooxygenase-2 (COX-2) and heat shock proteins (HSPs) in the liver of heat-stressed quails. 2. A total of 180 5-week-old female Japanese quails were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (heat stress, HS) for 12 weeks. Birds in both environments were randomly given 1 of 3 diets: basal diet and basal diet with 200 or 400 mg of EGCG added per kilogram of diet. 3. The hepatic c-Jun, c-Fos, COX-2 and HSPs gene expression for quails reared under the HS environment was greater than those reared under the TN environment. Supplemental EGCG decreased hepatic expression of these proteins at a greater extent under HS than TN. 4. In conclusion, suppression of AP-1 COX-2 and HSPs may partly account for the inhibitory effect of EGCG in heat-stressed quail.

Chemoprevention of dietary digitoflavone on colitis-associated colon tumorigenesis through inducing Nrf2 signaling pathway and inhibition of inflammation

Background

Nuclear factor-erythroid 2-related factor 2 (Nrf2) has emerged as a novel target for the prevention of colorectal cancer (CRC). Many chemopreventive compounds associated with Nrf2 activation are effective in preclinical systems and many on-going clinical trials are showing promising findings. In present study we evaluated the cytoprotective effect and chemopreventive properties of dietary digitoflavone.

Method

A cell based Antioxidant Response Element (ARE)-driven luciferase reporter system was applied to screen potential Nrf2 activators. Activation of Nrf2 by digitoflavone was confirmed through mRNA, protein and GSH level assay in Caco-2 cell line. The cytoprotective effect of digitoflavone was evaluated in H₂O₂-induced oxidative stress model and further signaling pathways analysis was used to determine the target of digitoflavone induced Nrf2 activation. An AOM-DSS induced colorectal cancer model was used to assess the chemopreventive effect of digitoflavone.

Result

Micromolarity (10 μM) level of digitoflavone increased Nrf2 expressing, nuclear translocation and expression of downstream phase II antioxidant enzymes. Furthermore, digitoflavone decreased H₂O₂-induced oxidative stress and cell death via p38 MAPK-Nrf2/ARE pathway. In vivo study, 50 mg/kg digitoflavone significantly reduced AOM-DSS induced tumor incidence, number and size.

Conclusion

These observations suggest that digitoflavone is a novel Nrf2 pathway activator, and protects against oxidative stress-induced cell injury. The results of the present study add further evidence of the molecular mechanisms that allow digitoflavone to exert protective effects and reaffirm its potential role as a chemopreventive agent in colorectal carcinogenesis.

Green tea consumption and risk of esophageal cancer: a meta-analysis of published epidemiological studies

We performed a meta-analysis to analyze the association of various levels of green tea consumption with risk of esophageal cancer. We searched MEDLINE, EMBASE, and the Cochrane Library for studies of green tea consumption and esophageal cancer and identified 12 observational studies. For esophageal cancer, the pooled relative risk (RR) was 1.09 [95% confidence interval (CI), 0.76-1.55] for greatest vs. non/least green tea consumption; however, there was significant heterogeneity across studies (P = 0.00, I(2) = 75.5%). Compared with subjects who drank no/least green tea, the pooled RR was 1.14 (95% CI = 0.97-1.35) for moderate drinkers, 0.94 (95% CI = 0.77-1.13) for those who drank little, and 0.97 (95% CI = 0.77-1.22) for all subjects who had ever drunk green tea. Subgroup analysis showed that the RR was 0.46 (95% CI = 0.29-0.73) for female subjects. The results of the present meta-analysis are that any association between green tea and risk of esophageal cancer remains unclear. Subgroup analyses indicated that greater consumption of green tea might reduce the risk of esophageal cancer in female subjects. However, the results are based on limited research. Further research is needed to confirm the results and clarify the likely biological mechanisms.

Delivery of green tea catechin and epigallocatechin gallate in liposomes incorporated into low-fat hard cheese

The encapsulation of green tea catechin and epigallocatechin gallate (EGCG) in soy lecithin liposomes was examined at four concentrations (0%, 0.125%, 0.25% and 0.5% w/v), and inclusion in cheese at 0% and 0.25% w/v. The empty capsules had a mean diameter of 133nm and significantly (p<0.05) increased with the addition of catechin or EGCG. Electron microscopy revealed the lamellae and central core of the liposomes. Addition of antioxidants gave a significant (p<0.05) increase in the size of liposomes. Liposomes had surface potentials of -42.4 to -46.1mV with no significant difference between treatments, suggesting stable liposome systems. High efficiency (>70%) and yield (∼80%) were achieved from the incorporation of catechin or EGCG inside the liposome structure. Addition of either antioxidant increased the liposome phase transition temperature (>50°C). Nanocapsules containing these antioxidants were effectively retained within a low-fat hard cheese, presenting a simple and effective delivery vesicle for antioxidants.

Effect of a nutrient mixture on matrix metalloproteinase-9 dimers in various human cancer cell lines

Strong clinical and experimental evidence demonstrates association of elevated levels of matrix metalloproteinase MMP-9 with cancer progression, metastasis and shortened patient survival, as it plays a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. MMP-9 is secreted in both the monomeric and dimeric form. Although there is little research on MMP-9 dimers, some studies have shown the dimer to be associated with more aggressive tumor progression. Our objective was to study the relative secretion patterns of MMP-9 monomer and dimer in a variety of cancer cell lines and the effect of a nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract on MMP-9 secretion. The cancer cell lines were grown in their respective media, supplemented with 10% FBS, penicillin (100 U/ml) and streptomycin (100 µg/ml) in 24-well tissue culture plates. At near confluence, the cells were treated with NM at 0,10, 50, 100, 500 and 1000 µg/ml. Parallel sets of cultures were treated with PMA (100 ng/ml) for induction of MMP-9. Cell MMP-9 secretion was assayed by gelatinase zymography. MMP-9 dimer secretion patterns of cancer cells fell into different categories. We observed no MMP-9 dimer in prostate DU-145 and PC-3, pancreatic MIA-Pa-Ca2, colon HCT-116, bladder T-24, head and neck FaDu, glioblastoma A-172, T-98 and LN-18 and leukemia HL-60, Jurkat, and Raji cell lines. MMP-dimer secretion only with PMA induction was seen in breast MCF-7 and MDA-MB-231, uterine SK-UT-1, lung A-549, tongue SC-25, melanoma A2058, osteosarcoma U-2OS, rhabdomyosarcoma, fibrosarcoma HT-1080, chondrosarcoma SW-1350 and liposarcoma SW-872. Cervical HeLa and DoTc 2 4510, renal 786-0 and HCC SK-Hep-1 cells exhibited MMP-9 dimer without PMA treatment and increased secretion with PMA treatment. Sarcomas had the highest levels of MMP-9 monomer and dimer with and without PMA among these cancer cell lines. Cervical, uterine and male breast cancer cell lines showed the next highest levels of MMP-9, followed by breast cancer cell lines. Melanoma, renal, lung, head and neck and HCC showed lower levels and prostate, glioblastoma, bladder and leukemia cell lines the lowest. NM showed dose-dependent inhibition of MMP-9 monomer and dimer in all cell lines tested. In conclusion, high MMP-9 and dimer secretion levels correlated with the most aggressive cancer cell lines. NM was effective in inhibiting MMP-9 and dimer secretion in all cell lines tested, suggesting its therapeutic potential as an antimetastatic agent.

Effects of season and plantation on phenolic content of unfermented and fermented Sri Lankan tea

The effects of season and plantation on the polyphenol content of Camellia sinensis (tea) leaves were determined. Aqueous and organic extracts of freeze-dried fresh (unfermented) and black (fully-fermented) tea leaves were prepared for a structured set of samples (fermented and unfermented teas from six high-, mid- and low-grown plantations; fermented and unfermented teas from two harvesting seasons from four highland plantations), collected from the main tea-growing regions in Sri Lanka. Total catechin content and amounts of individual catechins, flavonols and theaflavins were determined by HPLC. Mean values for the phenolic constituents were generally significantly higher (p<0.05) with solvent extraction. The mean values for total catechins, total flavonols and caffeine in the aqueous extracts from unfermented teas were 10.6%, 1.5% and 2.9%, respectively. For both unfermented and fermented tea leaves, a significant (p<0.05) interaction between plantation and season was observed for phenolic constituents. Ferric reducing antioxidant power was positively (p<0.05) correlated with (-)-epicatechin gallate and total phenolic contents.

In vitro modulation of MMP-2 and MMP-9 in pediatric human sarcoma cell lines by cytokines, inducers and inhibitors

The highly aggressive pediatric sarcomas are characterized by high levels of matrix metalloproteinase (MMP)-2 and MMP-9, which play crucial roles in tumor invasion and metastasis by degradation of the extracellular membrane leading to cancer cell spread to distal organs. We examined the effects of cytokines, mitogens, inducers and inhibitors on MMP-2 and -9 expression in osteosarcoma (U2OS) and rhabdomyosarcoma (RD). The selected compounds included natural cytokines and growth factors, as well as chemical compounds applied in therapy of sarcoma and natural compounds that have demonstrated anticancer therapeutic potential. These cell lines were cultured in their respective media to near confluence and the cells were washed with PBS and incubated in serum-free medium with various concentrations of several cytokines, mitogens and inhibitors. After 24 h the media were removed and analyzed for MMP-2 and -9 by gelatinase zymography and quantitated by densitometry. Osteosarcoma and rhabdomyosarcoma showed bands corresponding to MMP-2 and -9 with dose-dependent enhancement of MMP-9 with phorbol 12-myristate 13-acetate (PMA) treatment. Tumor necrosis factor-α, interleukin-1β and LPS enhanced osteosarcoma U2OS MMP-9 secretion but had no effect on MMP-2 secretion. Tumor necrosis factor-α stimulated rhabdomyosarcoma MMP-2 expression, but had no effect on MMP-9 secretion. Doxycycline, epigallocatechin gallate, nutrient mixture (NM), actinomycin-D, cyclohex-amide, retinoic acid and dexamethasone inhibited MMP-2 and -9 in U2OS osteosarcoma cells. PMA-treated RD cells showed dose-response inhibition of MMP-9 by doxycycline and epigallocatechin gallate and both MMPs by NM. Dexamethasone and actinomycin-D showed inhibition of MMP-2 secretion of RD cells. Our results show that cytokines, mitogens and inducers show variable upregulation of U2OS osteosarcoma and RD rhabdomyosarcoma MMP-2 and -9 secretion, and inhibitors demonstrate downregulation under stimulatory conditions, suggesting the application of these agents for the development of effective therapies in pediatric sarcomas.

Chemical constituents and anticancer activity of yellow camellias against MDA-MB-231 human breast cancer cells

Yellow camellia, with its golden yellow flowers, is rare in the world. Most studies of yellow camellia have focused on its ornamental properties; however, there are fewer published studies on its medical values. The purpose of this study was to define the chemical constituents and the biological potential of the water extract of leaves in six species of yellow camellia. The data showed that Camellia murauchii had significantly higher total catechins and total polyphenol content than others; Camellia euphlebia had the highest total amino acids and γ-aminobutyric acid. The results indicated that Camellia tunghinensis exhibited the highest free radical scavenging capacity and showed potent anticancer activities. Camellia nitidissima had stronger inhibitory effect than other species on fatty acid synthesis. In addition to catechins, 3-p-coumaroylquinic acid, kaempferol-3-O-glucoside, and quercetin-3-O-glucoside were detected in C. tunghinensis using liquid chromatography-tandem mass spectrometry. Taken together, yellow camellias possess biological activity and are worthy of continued study.

Plant polyphenol induced cell death in human cancer cells involves mobilization of intracellular copper ions and reactive oxygen species generation: a mechanism for cancer chemopreventive action

SCOPE

Anticancer polyphenolic nutraceuticals from fruits, vegetables, and spices are generally recognized as antioxidants, but can be prooxidants in the presence of copper ions. We earlier proposed a mechanism for such activity of polyphenols and now we provide data in multiple cancer cell lines in support of our hypothesis.

METHODS AND RESULTS

Through multiple assays, we show that polyphenols luteolin, apigenin, epigallocatechin-3-gallate, and resveratrol are able to inhibit cell proliferation and induce apoptosis in different cancer cell lines. Such cell death is prevented to a significant extent by cuprous chelator neocuproine and reactive oxygen species scavengers. We also show that normal breast epithelial cells, cultured in a medium supplemented with copper, become sensitized to polyphenol-induced growth inhibition.

CONCLUSION

Since the concentration of copper is significantly elevated in cancer cells, our results strengthen the idea that an important anticancer mechanism of plant polyphenols is mediated through intracellular copper mobilization and reactive oxygen species generation leading to cancer cell death. Moreover, this prooxidant chemopreventive mechanism appears to be a mechanism common to several polyphenols with diverse chemical structures and explains the preferential cytotoxicity of these compounds toward cancer cells.

In vitro modulation of MMP-2 and MMP-9 in adult human sarcoma cell lines by cytokines, inducers and inhibitors

The highly aggressive adult sarcomas are characterized by high levels of matrix metalloproteinase (MMP)-2 and -9, which play crucial roles in tumor invasion and metastasis by degradation of the extracellular membrane leading to cancer cell spread to distal organs. We examined the effect of cytokines, mitogens, inducers and inhibitors on MMP-2 and MMP-9 secretion in chondrosarcoma (SW-1353), fibrosarcoma (HT-1080), liposarcoma (SW-872) and synovial sarcoma (SW-982) cell lines. The selected compounds included natural cytokines and growth factors, as well as chemical compounds applied in therapy of sarcoma and natural compounds that have demonstrated anticancer therapeutic potential. MMP-2 and MMP-9 secretions were analyzed by gelatinase zymography following 24-h exposure to the tested agents and quantitated by densitometry. Fibrosarcoma, chondrosarcoma, liposarcoma and synovial sarcoma showed bands corresponding to MMP-2 and MMP-9 with dose-dependent enhancement of MMP-9 with phorbol 12-myristate 13-acetate (PMA) treatment. In chondrosarcoma cells, tumor necrosis factor (TNF)-α had a stimulatory effect on MMP-9 and insignificant effect on MMP-2 and interleukin (IL)-1β stimulated MMP-9 and MMP-2. In fibrosarcoma and liposarcoma cells, TNF-α had a profound stimulatory effect on MMP-9, but no effect on MMP-2 and in synovial sarcoma an inhibitory effect on MMP-2 and no effect on MMP-9. IL-1β had a slight inhibitory effect on fibrosarcoma, liposarcoma and synovial sarcoma MMP-2 and MMP-9 except for MMP-9 in synovial sarcoma which showed slight stimulation. Lipopolysaccharide (LPS) stimulated expression of MMP-2 in fibrosarcoma and chondrosarcoma while inhibited it in liposarcoma. Doxycycline, epigallocatechin gallate and the nutrient mixture inhibited MMP-2 and MMP-9 in all cell lines. Actinomycin-D, cyclohexamide, retinoic acid, and dexamethasone inhibited MMP-2 and -9 in chondrosarcoma and fibrosarcoma cells. Our results show that cytokines, mitogens, inducers and inhibitors have an up or down regulatory effect on MMP-2 and MMP-9 expression in adult sarcoma cell lines, suggesting these agents may be effective strategies to treat these cancers.

Exosome derived from epigallocatechin gallate treated breast cancer cells suppresses tumor growth by inhibiting tumor-associated macrophage infiltration and M2 polarization

Background

Tumor-associated macrophages (TAM) play an important role in tumor microenvironment. Particularly, M2 macrophages contribute to tumor progression, depending on the expression of NF-κB. Tumor-derived exosomes can modulate tumor microenvironment by transferring miRNAs to immune cells. Epigallocatechin gallate (EGCG) has well known anti-tumor effects; however, no data are available on the influence of EGCG on communication with cancer cells and TAM.

Methods

Murine breast cancer cell lines, 4T1, was used for in vivo and ex vivo studies. Exosome was extracted from EGCG-treated 4T1 cells, and the change of miRNAs was screened using microarray. Tumor cells or TAM isolated from murine tumor graft were incubated with exosomes derived from EGCG-treated and/or miR-16 inhibitor-transfected 4T1 cells. Chemokines for monocytes (CSF-1 and CCL-2), cytokines both with high (IL-6 and TGF-β) and low (TNF-α) expression in M2 macrophages, and molecules in NF-κB pathway (IKKα and Iκ-B) were evaluated by RT-qPCR or western blot.

Results

EGCG suppressed tumor growth in murine breast cancer model, which was associated with decreased TAM and M2 macrophage infiltration. Expression of chemokine for monocytes (CSF-1 and CCL-2) were low in tumor cells from EGCG-treated mice, and cytokines of TAM was skewed from M2- into M1-like phenotype by EGCG as evidenced by decreased IL-6 and TGF-β and increased TNF-α. Ex vivo incubation of isolated tumor cells with EGCG inhibited the CSF-1 and CCL-2 expression. Ex vivo incubation of TAM with exosomes from EGCG-treated 4T1 cells led to IKKα suppression and concomitant I-κB accumulation; increase of IL-6 and TGF-β; and, decrease of TNF-α. EGCG up-regulated miR-16 in 4T1 cells and in the exosomes. Treatment of tumor cells or TAM with exosomes derived from EGCG-treated and miR-16-knock-downed 4T1 cells restored the above effects on chemokines, cytokines, and NF-κB pathway elicited by EGCG-treated exosomes.

Conclusions

Our data demonstrate that EGCG up-regulates miR-16 in tumor cells, which can be transferred to TAM via exosomes and inhibits TAM infiltration and M2 polarization. We suggest a novel mechanism by which EGCG exerts anti-tumor activity via regulation of TAM in tumor microenvironment.

Prospective study of the relationship between coffee and tea with colorectal cancer risk: the PLCO Cancer Screening Trial

Background:

Coffee and tea are commonly consumed and carry potential anticancer components that could reduce the risk of colorectal cancer; however, their relationships with colorectal cancer risk remain inconsistent.

Methods:

A prospective analysis was carried out to examine the relationships of coffee and tea intake with colorectal cancer risk in 57 398 men and women in the intervention arm of the National Cancer Institute-Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, a national screening study that limits differential detection biases. Coffee and tea intakes were assessed by food frequency questionnaire.

Results:

Six hundred and eighty-one incident colorectal cancer cases were ascertained during a median follow-up of 11.4 years. Greater coffee intake was not associated with risk of colorectal cancer (relative risk (RR)=1.08, 95% confidence interval (CI)=0.79–1.48, P_trend=0.23). Stratifying by cancer site (P_{heterogeneity}=0.48) or stage (P_{heterogeneity}=0.83) did not alter the relationship. Associations remained unchanged in subsets of participants for either caffeinated or decaffeinated coffee or when stratifying by several colorectal cancer risk factors. Similarly, greater tea intake was not associated with colorectal cancer risk overall (RR=0.77, 95% CI=0.55–1.09, P_trend=0.17) or by cancer site (P_{heterogeneity}=0.14) or stage (P_{heterogeneity}=0.60). These associations were not modified by several colorectal cancer risk factors.

Conclusion:

The findings of this study do not provide evidence to suggest that drinking coffee or tea is beneficial in protecting against colorectal cancer.

A pilot study to evaluate the safety and efficacy of an oral dose of (-)-epigallocatechin-3-gallate-rich polyphenon E in patients with mild to moderate ulcerative colitis

BACKGROUND

Green tea and its main polyphenolic component, (-)-epigallocatechin-3-gallate (EGCG), exert powerful anti-inflammatory effects that are protective against both inflammatory diseases and cancer. Research with animal and human cell lines provide plausible support for these claims. Poor absorption results in low systemic bioavailability of EGCG after oral administration but high colonic mucosal exposure.

METHODS

Patients with mild to moderate ulcerative colitis (UC) were randomized to daily doses of oral Polyphenon E (400 mg or 800 mg of total EGCG daily, administered in split doses) or placebo in a double-blinded, placebo-controlled pilot study. Response was measured by the UC disease activity index and the inflammatory bowel disease questionnaire on day 56.

RESULTS

Twenty patients were randomized to active therapy or placebo in a 4:1 ratio. Nineteen subjects received >1 dose of study medication (15 Polyphenon E, 4 placebo). The mean UC disease activity index score at study entry was 6.5 ± 1.9 in the treatment group and 7.3 ± 1.7 in the placebo group. After 56 days of therapy, the response rate was 66.7% (10 of 15) in the Polyphenon E group and 0% (0 of 4) in the placebo group (P = 0.03). The active treatment remission rate was 53.3% (8 of 15) compared with 0% (0 of 4) for placebo (P = 0.10). Polyphenon E treatment resulted in only minor side effects.

CONCLUSIONS

Administration of Polyphenon E resulted in a therapeutic benefit for patients who were refractory to 5-aminosalicylic and/or azathioprine. This agent holds promise as a novel option for the treatment of patients with UC with mild to moderately active disease.

Modulation of u-PA, MMPs and their inhibitors by a novel nutrient mixture in pediatric human sarcoma cell lines

Pediatric sarcomas are highly aggressive tumors that are characterized by high levels of matrix metalloproteinase (MMP)-2 and -9 secretions that degrade the ECM and basement membrane, allowing cancer cells to spread to distal organs. Proteases play a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. Strong clinical and experimental evidence demonstrates association of elevated levels of u-PA and MMPs with cancer progression, metastasis and shortened patient survival. MMP activities are regulated by specific tissue inhibitors of metalloproteinases (TIMPs). Our main objective was to study the effect of a nutrient mixture (NM) on activity of u-PA, MMPs and TIMPs in various human pediatric sarcomas. Human osteosarcoma MNNG-HOS, osteosarcoma U-2OS and rhabdomyosarcoma RD cell lines (ATCC) were cultured in their respective media and treated at confluence with NM at 0, 50, 100, 250, 500 and 1,000 µg/ml. Analysis of u-PA activity was carried out by fibrin zymography, MMPs by gelatinase zymography and TIMPs by reverse zymography. All sarcoma cell lines studied expressed u-PA, which was inhibited by NM in a dose-dependent manner. On gelatinase zymography, osteosarcoma MNNG-HOS showed a band corresponding to MMP-2 and induction of MMP-9 with PMA (100 ng/ml) treatment. U-2OS osteosarcoma cells showed strong bands corresponding to inactive MMP-2 and MMP-9 and faint bands corresponding to active MMP-2 and MMP-9 dimer; PMA treatment enhanced MMP-9 and MMP-9 dimer activity. Rhabdomyosarcoma showed MMP-2 and faint MMP-9 bands; PMA treatment enhanced MMP-9 expression. NM inhibited their expression in a dose-dependent manner. Activity of TIMPs was upregulated by NM in all cancer cell lines in a dose-dependent manner. Analysis revealed a positive correlation between u-PA and MMPs and a negative correlation between u-PA/MMPs and TIMPs. These findings suggest the therapeutic potential of NM in treatment of pediatric sarcomas.

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.

Anti-metastatic and differential effects on protein expression of epigallocatechin-3-gallate in HCCLM6 hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third highest cause of cancer-related mortality in humans. Epigallocatechin-3-gallate (EGCG) has been shown to inhibit the metastatic activity of certain cancer cells. The aim of this study was to determine the effects and molecular mechanism(s) of action of EGCG in human HCC cells. A migration and invasion assay for the metastatic behavior of HCCLM6 cells was performed. The anti-metastatic effects of EGCG were investigated by RT-PCR and gelatin zymography. A total cellular protein profile was obtained using 2-dimensional gel electrophoresis (2-DE), followed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) analyses of proteins with significant differences in expression following treatment with EGCG. The results revealed that EGCG induced apoptosis and inhibited the metastasis of HCCLM6 cells. The anti-metastatic effects of EGCG were associated with the inhibition of matrix metalloproteinase (MMP)-2 and MMP-9 activity. The expression levels of far upstream element (FUSE) binding protein 1 (FUBP1), heat shock protein beta 1 (HSPB1), heat shock 60 kDa protein 1 (chaperonin) (CH60) and nucleophosmin (NPM) proteins, which are associated with metastasis, were significantly altered in the EGCG-treated HCCLM6 cells. The data from the present study suggest that EGCG has potential as a therapeutic agent for the treatment of HCC.

Hypotriglyceridemic potential of fermented mixed tea made with third-crop green tea leaves and camellia (Camellia japonica) leaves in Sprague-Dawley rats

Fermented mixed tea made with third-crop green tea leaves and camellia leaves by a tea-rolling process has been developed. The objective of this study was to investigate hypotriglyceridemic potential of the mixed tea in rats. The mixed tea contained theasinensins and theaflavins. Rats fed the mixed tea extract at the level of 1% exerted significantly lower body weight and adipose tissue weight compared to animals fed third-crop green tea or camellia tea extract alone for 4 weeks. Serum and hepatic triglyceride was significantly and dose-dependently decreased by the mixed tea. This decrease was associated with lowered lipogenic enzyme activities in the liver. Furthermore, an oral administration of 4 or 8% of the mixed tea extract followed by fat emulsion suppressed the increment of serum triglyceride level. These results suggest that the mixed tea has hypotriglyceridemic action, partially via delaying triglyceride absorption in the small intestine and repressing hepatic lipogenic enzymes.

Modulation of u-PA, MMPs and their inhibitors by a novel nutrient mixture in adult human sarcoma cell lines

Adult sarcomas are highly aggressive tumors that are characterized by high levels of matrix metalloproteinase (MMP)-2 and -9 secretions that degrade the ECM and basement membrane, allowing cancer cells to spread to distal organs. Proteases play a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. Strong clinical and experimental evidence demonstrates association of elevated levels of u-PA and MMPs with cancer progression, metastasis and shortened patient survival. MMP activities are regulated by specific tissue inhibitors of metalloproteinases (TIMPs). Our main objective was to study the effect of a nutrient mixture (NM) on the activity of u-PA, MMPs and TIMPs in various human adult sarcomas. Human fibrosarcoma (HT-1080), chondrosarcoma (SW-1353), liposarcoma (SW-872), synovial sarcoma (SW-982) and uterine leimyosarcoma (SK-UT-1) cell lines (ATCC) were cultured in their respective media and treated at confluence with NM at 0, 50, 100, 250, 500 and 1,000 μg/ml. Analysis of u-PA activity was carried out by fibrin zymography, MMPs by gelatinase zymography and TIMPs by reverse zymography. Fibrosarcoma, chondrosarcoma, liposarcoma and leiomyosarcoma cancer cell lines expressed u-PA, which was inhibited by NM in a dose-dependent manner. However, no bands corresponding to u-PA were detected for synovial sarcoma cells. On gelatinase zymography, fibrosarcoma, chondrosarcoma, liposarcoma and synovial sarcoma showed bands corresponding to MMP-2 and MMP-9 with enhancement of MMP-9 with PMA (100 ng/ml) treatment. Uterine leiomyosarcoma showed strong bands corresponding to inactive and active MMP-9 and a faint band corresponding to MMP-9 dimer induced with PMA treatment, but no MMP-2 band. NM inhibited their expression in a dose-dependent manner. Activity of TIMPs was upregulated by NM in all cancer cell lines in a dose-dependent manner. Analysis revealed a positive correlation between u-PA and MMPs and a negative correlation between u-PA/MMPs and TIMPs. These findings suggest the therapeutic potential of NM in treatment of adult sarcomas.

Modulation of u-PA, MMPs and their inhibitors by a novel nutrient mixture in human lung cancer and mesothelioma cell lines

Lung cancer, the most prevalent cancer worldwide and malignant mesothelioma are highly aggressive tumors that are characterized by high levels of matrix metalloproteinase (MMP)-2 and -9 secretion. Proteases play a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. Strong clinical and experimental evidence demonstrates association of elevated levels of u-PA and MMPs with cancer progression, metastasis and shortened patient survival. MMP activities are regulated by specific tissue inhibitors of metalloproteinases (TIMPS). Our main objective was to study the effect of a nutrient mixture (NM) on the activity of u-PA, MMPs and TIMPs on human lung and malignant mesothelioma (MM) cell lines. Human lung cancer (A-549 and Calu-3) and malignant mesothelioma (MSTO-211H) cell lines were cultured in their respective media and treated at confluence with NM at 0, 50, 100, 250, 500 and 1000 μg/ml. Analysis of u-PA activity was carried out by fibrin zymography, MMPs by gelatinase zymography and TIMPs by reverse zymography. Both lung cancer cell lines expressed u-PA, which was inhibited by NM in a dose-dependent manner. However, no bands corresponding to u-PA were detected for the MSTO-211H MM cell line. On gelatinase zymography, A-549 cells showed one band corresponding to MMP-2 and induction of MMP-9 with PMA (100 ng/ml) treatment. MSTO-211H showed two bands, an intense band corresponding to MMP-2 and a faint band corresponding to MMP-9; MMP-9 was enhanced significantly with PMA treatment. NM inhibited their expression in both cell lines in a dose-dependent manner. Calu-3 showed no MMP-2 or MMP-9 expression. Activity of TIMPs was upregulated by NM in all cancer cell lines in a dose-dependent manner. Analysis revealed a positive correlation between u-PA and MMPs and a negative correlation between u-PA/MMPs and TIMPs. These findings suggest the therapeutic potential of NM in the treatment of lung and mesothelioma cancers.

Inhibition of the SK-N-MC human neuroblastoma cell line in vivo and in vitro by a novel nutrient mixture

Neuroblastoma, a peripheral nervous system cancer that can be highly invasive and metastatic, accounts for 8–10% of all solid childhood tumors in children under the age of 15 years. Despite multiple clinical efforts, prognosis remains poor for this enigmatic disease. A nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract has shown significant antitumor effects. Using the nude mouse xenograft model, we investigated the efficacy of NM. We also tested the effect of NM in vitro, evaluating cell viability, secretion of the matrix metalloproteinases (MMP)-2 and MMP-9, tissue inhibitor of metalloproteinase (TIMP)-2 secretion, Matrigel invasion and cellular apoptosis and morphology. Athymic nude mice 5–6 weeks of age were inoculated with 3×10⁶ SK-N-MC neuroblastoma cells subcutaneously and randomly divided into two groups. Group A was fed a regular diet and group B a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. We also tested the effect of NM in vitro. NM inhibited the growth of xenograft tumors by 22% (P=0.04); and, in vitro, NM induced dose-dependent inhibition of cell proliferation with a decrease of 27% (P=0.001) and 36% (P=0.002) at 500 and 1000 μg/ml NM compared to the control, respectively. Zymography revealed MMP-2 secretion in normal cells and PMA (100 ng/ml)-induced MMP-9 secretion. NM inhibited the secretion of both MMPs with total blockage at a concentration of 100 μg/ml. Reverse zymography demonstrated a dose-dependent increase in TIMP-2 expression by NM. Notable, SK-N-MC human neuroblastoma cells were not invasive through Matrigel. NM induced dose-dependent apoptosis of SK-N-MC cells. The results suggest that NM may have therapeutic potential in treating neuroblastoma.

Designer foods and their benefits: A review

Designer foods are normal foods fortified with health promoting ingredients. These foods are similar in appearance to normal foods and are consumed regularly as a part of diet. In this article we have reviewed the global regulatory status and benefits of available designer foods such as designer egg, designer milk, designer grains, probiotics, designer foods enriched with micro and macronutrients and designer proteins. Designer foods are produced by the process of fortification or nutrification. With the advances in the biotechnology, biofortification of foods using technologies such as recombinant DNA technology and fermentation procedures are gaining advantage in the industry. The ultimate acceptability and extensive use of designer foods depend on proper regulation in the market by the regulatory authorities of the country and by creating consumer awareness about their health benefits through various nationwide programs.