Green tea and its polyphenolic catechins: medicinal uses in cancer and noncancer applications

Niosomes Consisting of Tween-60 and Cholesterol Improve the Chemical Stability and Antioxidant Activity of (-)-Epigallocatechin Gallate under Intestinal Tract Conditions

In order to improve the chemical stability and antioxidant activity of (-)-epigallocatechin gallate (EGCG) in the gastrointestinal tract, niosomes composed of Tween-60 and cholesterol were developed to encapsulate EGCG in this investigation. EGCG loaded niosomes with encapsulation efficiency around 76% exhibited a small Z-average diameter about 60 nm. Compared to free EGCG, the EGCG remaining in dialysis tubes was significantly improved for niosomes at pH 2 and 7.4. Meanwhile, the residual EGCG for niosomes increased from 3% to 49% after 2 h incubation in simulated intestinal fluid (SIF). Pancreatin was found to impact the stability of niosomes in SIF mainly. Furthermore, the results from ferric reducing antioxidant power and cellular antioxidant activity tests indicated that EGCG loaded niosomes exhibited stronger antioxidant ability than free EGCG during intestinal digestion. Thus, we can infer that niosomal encapsulation might be a promising approach to improve the oral bioavailability of EGCG in the body.

Green tea polyphenols require the mitochondrial iron transporter, mitoferrin, for lifespan extension in Drosophila melanogaster

Green tea has been found to increase the lifespan of various experimental animal models including the fruit fly, Drosophila melanogaster. High in polyphenolic content, green tea has been shown to reduce oxidative stress in part by its ability to bind free iron, a micronutrient that is both essential for and toxic to all living organisms. Due to green tea's iron-binding properties, we questioned whether green tea acts to increase the lifespan of the fruit fly by modulating iron regulators, specifically, mitoferrin, a mitochondrial iron transporter, and transferrin, found in the hemolymph of flies. Publicly available hypomorph mutants for these iron regulators were utilized to investigate the effect of green tea on lifespan and fertility. We identified that green tea could not increase the lifespan of mitoferrin mutants but did rescue the reduced male fertility phenotype. The effect of green tea on transferrin mutant lifespan and fertility were comparable to w¹¹¹⁸ flies, as observed in our previous studies, in which green tea increased male fly lifespan and reduced male fertility. Expression levels in both w¹¹¹⁸ flies and mutant flies, supplemented with green tea, showed an upregulation of mitoferrin but not transferrin. Total body and mitochondrial iron levels were significantly reduced by green tea supplementation in w¹¹¹⁸ and mitoferrin mutants but not transferrin mutant flies. Our results demonstrate that green tea may act to increase the lifespan of Drosophila in part by the regulation of mitoferrin and reduction of mitochondrial iron.

Ellagic acid inhibits proliferation and induces apoptosis in human glioblastoma cells

PURPOSE

To investigate the anticancer activity of ellagic acid (EA) in U251 human glioblastoma cells and its possible molecular mechanism.

METHODS

The cells were treated with EA at various concentrations for different time periods. Cell viability and cell proliferation were detected by cell counting kit-8(CCK-8) assay and live/dead assay respectively. Cell apoptosis were measured with Annexin V-FITC/PI double staining method by flow cytometry and Mitochondrial membrane potential assay separately. Cell cycle was measured with PI staining method by flow cytometry. The expressions of Bcl-2, Survivin, XIAP, Caspase-3, Bax, JNK, p-JNK, ERK1/2, p-ERK1/2, p38, p-p38, DR4, DR5, CHOP and GRP78-related proteins were detected by western blot after EA treatment.

RESULTS

Cell viability and proliferation of glioblastoma cells treated with EA were significantly lower than the control group. EA caused robust apoptosis of the glioblastoma cells compared to the control group. EA significantly decreased the proportion at G0/G1 phases of cell cycling accompanied by increased populations at S phase in U251 cell lines. And the expressions of anti-apoptotic proteins were dramatically down-regulated.

CONCLUSION

Ellagic acid potentially up-regulated DR4, DR5 and MAP kinases (JNK, ERK1/2 and p38). EA also caused significant increase in the expressions of CHOP and GRP78. Our findings suggest that EA would be beneficial for the treatment of glioblastoma.

Green tea polyphenols affect invasiveness of human gastric MKN-28 cells by inhibition of LPS or TNF-α induced Matrix Metalloproteinase-9/2

Several studies demonstrated a correlation between green tea consumption and a reduced cancer risk. Among different components, green tea polyphenols have been identified as molecules responsible for the beneficial effects showed by the green tea against oxidative stress and cell invasiveness. In this study, we investigated the effects of green tea polyphenol extracts (GTPs) in human gastric MKN-28 cell line. To this aim, we have first evaluated the effect of GTPs on oxidative stress induced cell injury. The pre-treatment with 10^-4 M catechin equivalents of GTPs exerts a protective effect on xanthine-xanthine oxidase induced cell cytotoxicity, thus confirming the anti-oxidant properties of GTPs. The effect of GTPs was also extended to the invasive ability of MKN-28 cells stimulated with TNF-α or LPS, as pro-inflammatory factors. Migration and matrigel invasion assays demonstrated that GTPs exposure (10^-6 M) prevents the increase in cell invasiveness induced by TNF-α or LPS. Finally, we have analyzed the effect of GTPs on the levels of Matrix Metalloproteinases (MMP)-9/2, whose expression is up-regulated by TNF-α or LPS. Our results indicated that the pre-treatment with GTPs was able to reduce MMP-9/2 expression at both protein and enzyme activity levels in the conditioned media of TNF-α or LPS stimulated MKN-28 cells. In conclusion, our results demonstrated that green tea polyphenol extract reduces the invasiveness of gastric MKN-28 cancer cells through the reduction of TNF-α or LPS induced MMP-9/2 up-regulation. Therefore, these data support the hypothesis that GTPs could exert a protective role against the metastatic process in gastric cancer.

The effects of the aqueous extract and residue of Matcha on the antioxidant status and lipid and glucose levels in mice fed a high-fat diet

Matcha is a kind of powdered green tea produced by grinding with a stone mill. In the present study, the preventive effects of the aqueous extract (water-soluble) and residue (water-insoluble) of Matcha on the antioxidant status and lipid and glucose levels in mice fed a high-fat diet were investigated. Mice were fed seven different experimental diets for 4 weeks: a normal diet control (NC), a high-fat diet (HF), a high-fat diet with 0.025% Matcha (MLD), a high-fat diet with 0.05% Matcha (MMD), a high-fat diet with 0.075% Matcha (MHD), a high-fat diet with 0.05% Matcha aqueous extracts (ME), and a high-fat diet with 0.05% Matcha residues (MR). It was found that serum total cholesterol (TC) and triglyceride (TG) levels of the MHD group were significantly decreased compared to those of the HF group. Furthermore, in the MHD group, the level of high-density lipoprotein-cholesterol (HDL-C) was elevated, on the contrary the level of low-density lipoprotein-cholesterol (LDL-C) was suppressed. Moreover, Matcha could significantly lower the blood glucose levels, and improve the superoxide dismutase (SOD) activity and malondialdehyde (MAD) contents both in serum and liver; besides, the serum GSH-Px activity indicated that the oxidative stress caused by HF could be reversed by administration of Matcha. These findings suggest that Matcha has beneficial effects through the suppression of the blood glucose (BG) accumulation and promotion of the lipid metabolism and antioxidant activities. Moreover, the water-insoluble part of Matcha is suggested to play an important role in the suppression of diet-induced high levels of lipid and glucose.

Therapeutic Effects of Phytochemicals and Medicinal Herbs on Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent adverse effect of neurotoxic anticancer medicines. It leads to autonomic and somatic system dysfunction and decreases the patient's quality of life. This side effect eventually causes chemotherapy non-compliance. Patients are prompted to seek alternative treatment options since there is no conventional remedy for CIPN. A range of medicinal herbs have multifarious effects, and they have shown some evidence of efficacy in various neurological and immunological diseases. While CIPN has multiple mechanisms of neurotoxicity, these phytomedicines might offer neuronal protection or regeneration with the multiple targets in CIPN. Thus far, researchers have investigated the therapeutic benefits of several herbs, herbal formulas, and phytochemicals in preventing the onset and progress of CIPN in animals and humans. Here, we summarize current knowledge regarding the role of phytochemicals, herb extracts, and herbal formulas in alleviating CIPN.

(-)-Epigallocatechin gallate (EGCG)-nanoethosomes as a transdermal delivery system for docetaxel to treat implanted human melanoma cell tumors in mice

(-)-Epigallocatechin-3-O-gallate (EGCG), a versatile natural product in fresh tea leaves and green tea, has been investigated as a preventative treatment for cancers and cardiovascular disease. The objective of this study was to develop EGCG-nanoethosomes for transdermal delivery and to evaluate them for treating subcutaneously implanted human melanoma cell tumors. EGCG-nanoethosomes, composed of 0.2% EGCG, 2% soybean phosphatidylcholine, 30% ethanol, 1% Tween-80 and 0.1% sugar esters, were prepared and characterized using laser transmission electron microscopy. These nanoethosomes were smoother and more compact than basic-nanoethosomes with the same components except for EGCG. The effectiveness of transdermal delivery by EGCG-nanoethosomes was demonstrated in an in vitro permeability assay system using mouse skin. The inhibitory effect of docetaxel (DT) loaded in EGCG-nanoethosomes (DT-EGCG-nanoethosomes) was analyzed by monitoring growth of a subcutaneously implanted tumor from A-375 human melanoma cells in mice. Mice treated with DT-EGCG-nanoethosomes exhibited a significant therapeutic effect, with tumors shrinking, on average, by 31.5% of initial volumes after 14 d treatment. This indicated a potential for treating skin cancer. In a pharmacokinetic study, transdermal delivery by DT-EGCG-nanoethosomes enabled sufficient DT exposure to the tumor. Together, these findings indicated that EGCG-nanoethosomes have great potential as drug carriers for transdermal delivery.

Treatment Modalities for Acne

Acne is a common inflammatory skin disease which affects the pilosebaceous units of the skin. It can have severe psychological effects and can leave the patient with severe skin scarring. There are four well-recognized pathological factors responsible for acne which is also the target for acne therapy. In this review, different treatment options are discussed, including topical (i.e., retinoids, and antibiotics) and systemic (i.e., retinoids, antibiotics, and hormonal) treatments. Since the general public has been showing an increasing interest in more natural and generally safer treatment options, the use of complementary and alternative medicines (CAM) for treating acne was also discussed. The use of physical therapies such as comedone extraction, cryoslush therapy, cryotherapy, electrocauterization, intralesional corticosteroids and optical treatments are also mentioned. Acne has been extensively researched with regards to the disease mechanism as well as treatment options. However, due to the increasing resistance of Propionibacterium acnes towards the available antibiotics, there is a need for new treatment methods. Additionally, the lack of necessary evidence on the efficacy of CAM therapies makes it necessary for researchers to investigate these treatment options further.

Polyphenols in dementia: From molecular basis to clinical trials

Dementia is common in the elderly, but there are currently no effective therapies available to prevent or treat this syndrome. In the last decade, polyphenols (particularly curcumin, resveratrol and tea catechins) have been under very close scrutiny as potential therapeutic agents for neurodegenerative diseases, diabetes, inflammatory diseases and aging. Data were collected from Web of Science (ISI Web of Knowledge), Pubmed and Medline (from 2000 to 2015), by searching for the keywords "dementia" AND "curcumin", "resveratrol", "EGCG", "tea catechins". The same keywords were used to investigate the current state of clinical trials recorded in the NIH clinicaltrials.gov registry. Starting from the intrinsic properties of the compounds, we explain their specific action in patients with AD and the most common types of dementia. The pharmacological actions of curcumin, resveratrol and tea catechins have mainly been attributed to their antioxidant activity, interaction with cell signaling pathways, anti-inflammatory effect, chelation of metal ions, and neuroprotection. Evidence from in vitro and in vivo studies on polyphenols have demonstrated that they may play an integral role in preventing and treating diseases associated with neurodegeneration. Furthermore, we critically analyze the clinical trials that we found, which investigate the real pharmacological actions and the possible side effects of these compounds. This review highlights the potential role of polyphenols in the prevention/treatment of dementia and describes the current limitations of research in this field.

Molecular mechanisms underlying attenuation of cisplatin-induced acute kidney injury by epicatechin gallate

Cisplatin, a platinum compound, is used as a first-line agent against various forms of solid cancers. Nephrotoxicity is an important adverse effect of cisplatin therapy, which involves increased oxidative stress, inflammation, apoptosis, and activation of the mitogen-activated protein kinase (MAPK) pathway. It is well known that the bioactive compounds present in green tea are used to treat various disorders due to their biological activities. With this background, the present study was aimed to investigate the effect of epicatechin gallate (ECG), a green tea polyphenol, in cisplatin-induced nephrotoxicity in rats. To achieve this, ECG (1.25, 2.5, and 5 mg/kg; intraperitoneal (i.p.)) was administered to male albino Wistar rats for the period of 10 days. On the 7th day, a single i.p. injection of cisplatin (8 mg/kg) was injected into rats to produce kidney injury and the animals were then killed on the 10th day. Cisplatin toxicity was associated with enhanced oxidative stress, impaired renal function along with marked tubular necrosis in Histopathology. Furthermore, cisplatin activated the MAPK pathway, which contributed to inflammation and apoptosis in the kidney of treated rats. In contrast, ECG (5 mg/kg) pretreatment normalized cisplatin-induced oxidative stress, renal function, and histopathological changes. ECG also prevented the activation of the MAPK pathway, and attenuated inflammation and apoptosis in rats. These findings suggest that ECG prevented cisplatin-induced oxidative stress, inflammation, and apoptosis by downregulating the MAPK pathway and resulted in improved renal function.

Effect of catechins on fattening performance, meat quality, some antioxidant and blood parameters and fattening costs in Japanese quail (Coturnix coturnix japonica)

The aim of this study was to investigate the effect of dietary supplementation of green tea (Camellia sinensis) catechins in quail (Coturnix coturnix japonica). Quail were fed with a basal diet, and the treatment groups were fed on the basal diet with 1.25 or 2.50 g/kg catechin supplementation for 30 d. Fattening performance and meat quality of the quail were estimated. Serum total antioxidant status (TAS), plasma and liver malondialdehyde (MDA) and some serum biochemical parameters were measured. The results showed that catechin supplementation did not affect live weight, feed intake, feed conversion ratio, carcass weight, carcass dressing or the nutrient composition of breast and thigh meats. The water holding capacity (WHC) of breast meat was increased in the 2.50 g/kg catechin treatment. Catechin supplementation increased the serum TAS, but decreased plasma MDA and liver MDA concentration as well as serum glucose and total cholesterol levels. Serum triglyceride and total protein levels were not affected by catechin supplementation. In conclusion, catechins have effective antioxidant hypoglycaemic and hypocholesterolaemic properties, as well as having the potential to increase meat quality in fattening quail. On the other hand, catechin supplementation did not have any negative effect on the fattening performance, meat nutrient composition and fattening costs in fattening quail.

Modulation of PPAR Expression and Activity in Response to Polyphenolic Compounds in High Fat Diets

Peroxisome proliferator-activated receptors (PPAR) are transcription factors that modulate energy metabolism in liver, adipose tissue and muscle. High fat diets (HFD) can negatively impact PPAR expression or activity, favoring obesity, dyslipidemia, insulin resistance and other conditions. However, polyphenols (PP) found in vegetable foodstuffs are capable of positively modulating this pathway. We therefore focused this review on the possible effects that PP can have on PPAR when administered together with HFD. We found that PP from diverse sources, such as coffee, olives, rice, berries and others, are capable of inducing the expression of genes involved in a decrease of adipose mass, liver and serum lipids and lipid biosynthesis in animal and cell models of HFD. Since cells or gut bacteria can transform PP into different metabolites, it is possible that a synergistic or antagonistic effect ultimately occurs. PP molecules from vegetable sources are an interesting option to maintain or return to a state of energy homeostasis, possibly due to an adequate PPAR expression and activity.

Enhancement of antioxidant activity of green tea epicatechins in β-cyclodextrin cavity: Single-crystal X-ray analysis, DFT calculation and DPPH assay

Green tea catechins are potent antioxidant for prevention of various free radical-related diseases. Their antioxidant properties can be improved by encapsulation in cyclodextrins (CDs). Four inclusion complexes of β-CD with (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) have been investigated using single-crystal X-ray diffraction analysis combined with full geometry optimization by DFT/B3LYP calculation and the DPPH assay, aiming to deepen the understanding on their structure-antioxidant activity relationship. Scrutinizing the inclusion structures and conformational changes of the four encapsulated epicatechins reveals the common host-guest stabilization scheme and the epicatechin conformational flexibility facilitating the enhancement of activity. Thermodynamic stability order derived from DFT calculation in vacuum fairly agrees with the order of improved antioxidant capacity deduced from the DPPH assay, β-CD-EGCG>β-CD-ECG>β-CD-EGC≈β-CD-EC.

Antimicrobial activity of tea catechin against canine oral bacteria and the functional mechanisms

Epigallocatechin gallate (EGCG) is the major polyphenolic compound of green tea. Polyphenolic compounds were extracted from the leaf of Camellia sinensis (Japanese green tea), and the minimum inhibitory concentration against canine oral bacteria was measured. Subsequently, we investigated the inhibitory effects of polyphenolic compounds and EGCG on the growth of canine oral bacteria. EGCG showed antimicrobial activity against a model bacterium, Streptococcus mutans. Our results indicate that EGCG can inhibit the growth and biofilm formation of S. mutans and that EGCG does not interact with streptococcal lipoteichoic acid (LTA). Furthermore, our findings suggest that EGCG interacts with other component(s) of the bacterial membrane aside from streptococcal LTA to inhibit biofilm formation and damage biofilms.

Selection and Verification of Candidate Reference Genes for Mature MicroRNA Expression by Quantitative RT-PCR in the Tea Plant (Camellia sinensis)

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) is a rapid and sensitive method for analyzing microRNA (miRNA) expression. However, accurate qRT-PCR results depend on the selection of reliable reference genes as internal positive controls. To date, few studies have identified reliable reference genes for differential expression analysis of miRNAs among tissues, and among experimental conditions in plants. In this study, three miRNAs and four non-coding small RNAs (ncRNA) were selected as reference candidates, and the stability of their expression was evaluated among different tissues and under different experimental conditions in the tea plant (Camellia sinensis) using the geNorm and NormFinder programs. It was shown that miR159a was the best single reference gene in the bud to the fifth leaf, 5S rRNA was the most suitable gene in different organs, miR6149 was the most stable gene when the leaves were attacked by Ectropis oblique and U4, miR5368n and miR159a were the best genes when the leaves were treated by methyl jasmonate (MeJA), salicylic acid (SA) and abscisic acid (ABA), respectively. Our results provide suitable reference genes for future investigations on miRNA functions in tea plants.

(-)-Epigallocatechin-3-gallate (EGCG) attenuates arsenic-induced cardiotoxicity in rats

Chronic arsenic exposure in drinking water is associated with the abnormalities of cardiac tissue. Excessive generation of ROS induced by arsenic has a central role in arsenic-induced cardiotoxicity. (-)-Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, possesses a potent antioxidant capacity and exhibits extensive pharmacological activities. This study was aim to evaluate the effect of EGCG on arsenic-induced cardiotoxicity in vivo and in vitro. Treatment with NaAsO2 seriously affected the morphology and ultrastructure of myocardium, and induced cardiac injuries, oxidative stress, intracellular calcium accumulation and apoptosis in rats. In consistent with in vivo study, the injuries, oxidative stress and apoptosis were also observed in NaAsO2-treated H9c2 cells. All of these effects induced by NaAsO2 were attenuated by EGCG. These results suggest EGCG could attenuate NaAsO2-induced cardiotoxicity, and the mechanism may involve its potent antioxidant capacity.

Natural cures for breast cancer treatment

For centuries, herbs and plants have been used for medicinal purposes and as food as well. This review concerns about different types of plants that retain the immune stimulating and anti-tumor properties. Large variety of active phytochemicals such as carotenoids, flavonoids, ligands, polyphenolics, terpenoids, sulfides, lignans and plant sterols has been identified in different types of herbs. These phytochemicals have different mechanisms of action. They either stimulate the protective enzyme like glutathione transferase or prevent the cell proliferation. This review has centered on the biochemical properties of Allium sativum, Echinacea, Curcuma longa, Arctium lappa, Camellia sinensis, Panax ginseng and Flax seed. Extracts and juices of Withania somnifera, Amoora rohituka, Dysoxylum binectariferum and Vaccinium macrocarpon, respectively also used as anti-breast cancer. The volatile oils and extracts of these herbs and plants inhibit the synthesis of mevalonate that lessen the tumor growth and cholesterol synthesis.

Genetic Divergence between Camellia sinensis and Its Wild Relatives Revealed via Genome-Wide SNPs from RAD Sequencing

Tea is one of the most popular beverages across the world and is made exclusively from cultivars of Camellia sinensis. Many wild relatives of the genus Camellia that are closely related to C. sinensis are native to Southwest China. In this study, we first identified the distinct genetic divergence between C. sinensis and its wild relatives and provided a glimpse into the artificial selection of tea plants at a genome-wide level by analyzing 15,444 genomic SNPs that were identified from 18 cultivated and wild tea accessions using a high-throughput genome-wide restriction site-associated DNA sequencing (RAD-Seq) approach. Six distinct clusters were detected by phylogeny inferrence and principal component and genetic structural analyses, and these clusters corresponded to six Camellia species/varieties. Genetic divergence apparently indicated that C. taliensis var. bangwei is a semi-wild or transient landrace occupying a phylogenetic position between those wild and cultivated tea plants. Cultivated accessions exhibited greater heterozygosity than wild accessions, with the exception of C. taliensis var. bangwei. Thirteen genes with non-synonymous SNPs exhibited strong selective signals that were suggestive of putative artificial selective footprints for tea plants during domestication. The genome-wide SNPs provide a fundamental data resource for assessing genetic relationships, characterizing complex traits, comparing heterozygosity and analyzing putatitve artificial selection in tea plants.

Syntheses of methylated catechins and theaflavins using 2-nitrobenzenesulfonyl group to protect and deactivate phenol

An efficient and versatile synthetic method for labile polyphenols was established using 2-nitrobenzenesulfonate (Ns) as a protecting group for phenol. This methodology provides regio- and stereoselective access to a range of methylated catechins, such as methylated epigallocatechin gallates, that are not readily available from natural sources. In addition, biomimetic synthesis of theaflavins from catechins was accomplished using Ns protection to minimize undesired side reactions of electron-rich aromatic rings during oxidation, enabling construction of the complex benzotropolone core in a single-step oxidative coupling reaction. Availability of these compounds will aid detailed structure-biological activity relationship studies of catechins.

Anticancer Inhibitors of Hsp90 Function: Beyond the Usual Suspects

The 90-kDa heat-shock protein (Hsp90) is a molecular chaperone responsible for the stability and function of a wide variety of client proteins that are critical for cell growth and survival. Many of these client proteins are frequently mutated and/or overexpressed in cancer cells and are therefore being actively pursued as individual therapeutic targets. Consequently, Hsp90 inhibition offers a promising strategy for simultaneous degradation of several anticancer targets. Currently, most Hsp90 inhibitors under clinical evaluation act by blocking the binding of ATP to the Hsp90 N-terminal domain and thereby, induce the degradation of many Hsp90-dependent oncoproteins. Although, they have shown some promising initial results, clinical challenges such as induction of the heat-shock response, retinopathy, and gastrointestinal tract toxicity are emerging from human trials, which constantly raise concerns about the future development of these inhibitors. Novobiocin derivatives, which do not bind the chaperone's N-terminal ATPase pocket, have emerged over the past decade as an alternative strategy to inhibit Hsp90, but to date, no derivative has been investigated in the clinical setting. In recent years, a number of natural or synthetic compounds have been identified that modulate Hsp90 function via various mechanisms. These compounds not only offer new chemotypes for the development of future Hsp90 inhibitors but can also serve as chemical probes to unravel the biology of Hsp90. This chapter presents a synopsis of inhibitors that directly, allosterically, or even indirectly alters Hsp90 function, and highlights their proposed mechanisms of action.

Contents and compositions of policosanols in green tea (Camellia sinensis) leaves

Policosanol (PC) is a mixture of health promoting bioactive long-chain aliphatic alcohols. Here, we report that green tea (Camellia sinensis) leaves are the exceptionally rich plant-sources of PC. Young and tender leaves and old and turf leaves of C. sinensis were hand-picked in spring and autumn. The total contents of PC in the leaves were in the range of 726.2-1363.6mg/kg as determined by a GC-MS/MS. The compositions of PC in the leaves were different with harvest season and types. The total contents of PC in commercial green tea leaves were found to be in the range of 856.7-1435.1mg/kg. Interestingly, the infused green tea leaves contained the higher PC than the non-infused green tea product, reaching to 1629.4mg/kg. This represents the first report on the contents and compositions of PC in green tea leaves, showing unambiguous evidence of their potential as rich sources of PC.

Biotechnological advances in tea (Camellia sinensis [L.] O. Kuntze): a review

This article presents a comprehensive review on the success and limitations of biotechnological approaches aimed at genetic improvement of tea with a purpose to explore possibilities to address challenging areas. Tea is a woody perennial tree with a life span of more than 100 years. Conventional breeding of tea is slow and limited primarily to selection which leads to narrowing down of its genetic base. Harnessing the benefits of wild relatives has been negligible due to low cross-compatibility, genetic drag and undesirable alleles for low yield. Additionally, being a recalcitrant species, in vitro propagation of tea is constrained too. Nevertheless, maneuvering with tissue/cell culture techniques, a considerable success has been achieved in the area of micropropagation, somatic embryogenesis as well as genetic transformation. Besides, use of molecular markers, "expressomics" (transcriptomics, proteomics, metabolomics), map-based cloning towards construction of physical maps, generation of expressed sequenced tags (ESTs) have facilitated the identification of QTLs and discovery of genes associated with abiotic or biotic stress tolerance and agronomic traits. Furthermore, the complete genome (or at least gene space) sequence of tea is expected to be accessible in the near future which will strengthen combinational approaches for improvement of tea. This review presents a comprehensive account of the success and limitations of the biotechnological tools and techniques hitherto applied to tea and its wild relatives. Expectedly, this will form a basis for making further advances aimed at genetic improvement of tea in particular and of economically important woody perennials in general.

Dietary Intervention of Artemisia and Green Tea Extracts to Rejuvenate Helicobacter pylori-Associated Chronic Atrophic Gastritis and to Prevent Tumorigenesis

OBJECT

As nonmicrobial dietary approach is capable of controlling Helicobacter pylori infection, we evaluated the efficacy of long-term dietary administration of Artemisia and/or green tea extracts on H. pylori-initiated, high-salt-promoted chronic atrophic gastritis and gastric tumorigenesis mouse model.

METHODS

Helicobacter pylori-infected and high-salt-diet-administered C57BL/6 mice were administered with Artemisia extracts (MP group) and/or green tea extracts (GT group) for 36 weeks in addition to the control group (ES group, gastroprotective drug, ecabet sodium 30 mg/kg, diet pellet). Gross and pathological gastric lesions were evaluated after 24 and 36 weeks, respectively, and their underlying molecular changes were measured in gastric homogenates. Detailed mechanisms were further evaluated in in vitro cell models.

RESULTS

The erythematous and nodular changes and mucosal ulcerative and erosive lesions were noted in the control group at 24 weeks. MP, GT, MPGT, and ES groups all showed significantly ameliorated pathologic lesion compared to the control group (p < .05). After the 36 weeks, scattered nodular masses with some central ulcers and thin gastric surface were noted in the control stomach, whereas no tumorous lesion and milder atrophic changes were observed in all MP, GT, and MPGT groups except ES group (p < .05). On molecular analysis, increased expressions of COX-2, TNF-α, IL-6, lipid peroxide, and activated STAT3 relevant to H. pylori infection were significantly decreased with MPGT administration (p < .01), whereas HSP70 was significantly increased. PGDH expressions, core tumor suppressor involved in carcinogenesis, were significantly decreased with H. pylori infection (p < .05), but significantly increased in MPGT group (p < .05). Increased mucosal apoptotic index noted in the control group was significantly decreased with MP and/or GT along with significantly preserved gastric gastroprotective mediators (p < .01) such as mucins, HSP27, and HSP70. H. pylori-induced serum TNF-α and NF-κB activations were significantly decreased with MPGT administration (p < .05).

CONCLUSION

Long-term dietary intake of MP and/or GT can be an effective strategy either to rejuvenate H. pylori atrophic gastritis or to suppress tumorigenesis.

Bactericidal activity of green tea extracts: the importance of catechin containing nano particles

When we drink green tea infusion, we believe we are drinking the extract of the green tea leaves. While practically each tea bag infused in 300 mL water contains about 50 mg of suspended green tea leaf particles. What is the role of these particles in the green tea effect is the objective of this study. These particles (three different size ranges) were isolated via varying speed centrifugation and their respective inputs evaluated. Live oral bacterial samples from human volunteers have been screened against green tea extracts and macro, micro and nano sized green tea particles. The results showed that the presence/absence of the macro and mico sized tea particles in the green tea extract did not contribute much. However, the nano sized particles were characterized to be nature’s nano stores of the bioactive catechins. Eradication of these nano tea particles resulted in decrease in the bactericidal property of the green tea extracts. This is a curtain raiser investigation, busting the nano as well as green tea leaf particle contribution in green tea extracts.

Green tea and anticancer perspectives: updates from last decade

Green tea is the most widely consumed beverage besides water and has attained significant attention owing to health benefits against array of maladies, e.g., obesity, diabetes mellitus, cardiovascular disorders, and cancer insurgence. The major bioactive molecules are epigallocatechin-3-gallate, epicatechin, epicatechin-3-gallate, epigallocatechin, etc. The anticarcinogenic and antimutagenic activities of green tea were highlighted some years ago. Several cohort studies and controlled randomized trials suggested the inverse association of green tea consumption and cancer prevalence. Cell culture and animal studies depicted the mechanisms of green tea to control cancer insurgence, i.e., induction of apoptosis to control cell growth arrest, altered expression of cell-cycle regulatory proteins, activation of killer caspases, and suppression of nuclear factor kappa-B activation. It acts as carcinoma blocker by modulating the signal transduction pathways involved in cell proliferation, transformation, inflammation, and metastasis. However, results generated from some research interventions conducted in different groups like smokers and nonsmokers, etc. contradicted with aforementioned anticancer perspectives. In this review paper, anticancer perspectives of green tea and its components have been described. Recent findings and literature have been surfed and arguments are presented to clarify the ambiguities regarding anticancer perspectives of green tea and its component especially against colon, skin, lung, prostate, and breast cancer. The heading of discussion and future trends is limelight of the manuscript. The compiled manuscript provides new avenues for researchers to be explored in relation to green tea and its bioactive components.

Thermoreversible gel for intrapocket delivery of green tea catechin as a local drug delivery system: An original research

The periodontal therapies along with systemic antibiotic therapy aim at eliminating the subgingival microbiota to arrest the progression of periodontal diseases. The complete elimination is often difficult, and thus the probability of repopulation after periodontal therapy is also high. The objectives of the study are to develop in situ thermoreversible gelling system of green tea catechins suitable for periodontal pocket administration, which would act as an adjunct to mechanical periodontal therapy. Gel is prepared on a weight basis using a cold process. In vitro drug release pattern is observed through spectrophotometer analysis at 277 nm. The gel is subjected to serial dilution analysis to determine the minimum inhibitory concentration (MIC) and disc diffusion analysis to determine the in vitro antibacterial effectiveness. Release pattern studies showed a complete release of drug from gel occurred by 36 h. A volume of 1.25 mg/ml was determined as MIC required against the periodontal pathogens. Disc diffusion analysis showed a 14 mm zone of inhibition is present around the 75 µl well for all the four species and 12 mm zone of inhibition around the 50 µl well. The advantage of F-127 is its thermoreversible nature that used for in situ gel formulation. Pluronic gel proved to be a promising carrier for prolong and effective release of green tea catechin.

Modulation of hexavalent chromium-induced genotoxic damage in peripheral blood of mice by epigallocatechin-3-gallate (EGCG) and its relationship to the apoptotic activity

This study was conducted to investigate the relationship between modulation of genotoxic damage and apoptotic activity in Hsd:ICR male mice treated with (-)-epigallocatechin-3-gallate (EGCG) and hexavalent chromium [Cr(VI)]. Four groups of 5 mice each were treated with (i) control vehicle only, (ii) EGCG (10 mg/kg) by gavage, (iii) Cr(VI) (20 mg/kg of CrO3) intraperitoneally (ip), and (iv) EGCG in addition to CrO3 (EGCG-CrO3). Genotoxic damage was evaluated by examining presence of micronucleated polychromatic erythrocytes (MN-PCE) obtained from peripheral blood of the caudal vein at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB) staining. EGCG treatment produced no significant changes in frequency of MN-PCE. However, CrO3 treatment significantly increased number of MN-PCE at 24 and 48 h post injection. Treatment with EGCG prior to CrO3 injection decreased number of MN-PCE compared to CrO3 alone. The MN-PCE reduction was greater than when EGCG was administered ip. The frequency of early apoptotic cells was elevated at 48 h following EGCG, CrO3, or EGCG-CrO3 exposure, with highest levels observed in the combined treatment group, while the frequencies of late apoptotic cells and necrotic cells were increased only in EGCG-CrO3 exposure. Our findings support the view that EGCG is protective against genotoxic damage induced by Cr(VI) and that apoptosis may contribute to elimination of DNA-damaged cells (MN-PCE) when EGCG was administered prior to CrO3. Further, it was found that the route of administration of EGCG plays an important role in protection against CrO3-induced genotoxic damage.

Crystallographic evidence for β-cyclodextrin inclusion complexation facilitating the improvement of antioxidant activity of tea (+)-catechin and (-)-epicatechin

Single-crystal X-ray analysis to 0.6Å resolution using synchrotron radiation of the inclusion complexes of β-cyclodextrin (β-CD) with (+)-catechin (CA) and (-)-epicatechin (EC) has been carried out to gain atomistic insight into how the inclusion complexation helps to improve tea catechin antioxidant activity. The β-CD-CA complex crystallizes in the monoclinic P21 space group, whereas the β-CD-EC complex crystallizes in both the monoclinic P21 and triclinic P1 space groups. In comparing the inclusion structures, the β-CD-EC dimeric structure having higher numbers of OH⋯O hydrogen bonds combined with π⋯π interactions is associated with its greater interaction energy, as derived from DFT/B3LYP single-point energy calculations. Detailed structural analysis of the CA, EC conformation and inclusion geometry reveals that the interplay of the intermolecular OH⋯O hydrogen bond stabilized catechol moiety and the protection of OH groups in the β-CD cavity plays a key role in the improvement of antioxidant capacity upon inclusion complexation.

Polyphenols, antioxidants, and antimutagenic effects of Copaifera langsdorffii fruit

Copaifera langsdorffii (copaiba) is a Brazilian exotic fruit, poorly studied regarding its bioactive composition. The aim of this study was to determine bioactive compounds, antioxidant and antimutagenic activities of copaiba pulp. The samples were extracted with different solvents in order to analyze polyphenol compounds (Folin Ciocalteau and HPLC-DAD), total flavonoids (reaction with AlCl3) and antioxidant capacity (FRAP, ORAC, DPPH). The copaiba fruit showed high polyphenol content and antioxidant capacity. Phenolic compounds, such as gallic acid, epicatechin gallate, catechin, epicatechin and isoquercitrin, were identified in the copaiba pulp. Despite the antioxidant capacity, the highest dose of copaiba showed no antimutagenic effects in the in vivo study. The dose which showed antimutagenic activity was 100 mg kg(-1).

Chemotherapy-induced peripheral neurotoxicity and complementary and alternative medicines: progress and perspective

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a severe and dose-limiting side effect of antineoplastic drugs. It can cause sensory, motor and autonomic system dysfunction, and ultimately force patients to discontinue chemotherapy. Until now, little is understood about CIPN and no consistent caring standard is available. Since CIPN is a multifactorial disease, the clinical efficacy of single pharmacological drugs is disappointing, prompting patients to seek alternative treatment options. Complementary and alternative medicines (CAMs), especially herbal medicines, are well known for their multifaceted implications and widely used in human health care. Up to date, several phytochemicals, plant extractions, and herbal formulas have been evaluated for their potential therapeutic benefit of preventing the onset and progression of CIPN in experimental models. Clinical acupuncture has also been shown to improve CIPN symptoms. In this review, we will give an outline of our current knowledge regrading the advanced research of CIPN, the role of CAMs in alleviating CIPN and possible lacunae in research that needs to be addressed.

Epigallocatechin-3-gallate-induced inhibition of interleukin-6 release and adjustment of the regulatory T/T helper 17 cell balance in the treatment of colitis in mice

Epigallocatechin-3-gallate (EGCG) has a promising therapeutic effect for ulcerative colitis (UC), but the treatment mechanism has yet to be fully elucidated. The aim of the present study was to investigate the mechanism of EGCG in the treatment of UC. Experimental colitis mouse models were prepared. The mice were randomly divided into four groups: Normal control, model (MD), 50 mg/kg/day EGCG treatment and 100 mg/kg/day EGCG treatment. The daily disease activity index (DAI) of the mice was recorded, changes in the organizational structure of the colon were observed and the spleen index (SI) was measured. In addition, levels of interleukin (IL)-6, IL-10, IL-17 and transforming growth factor (TGF)-β1 in the plasma and hypoxia-inducible factor (HIF)-1α and signal transducer and activator of transcription (STAT) 3 protein expression in colon tissues were evaluated. Compared with the MD group, the mice in the two EGCG treatment groups exhibited decreased DAIs and SIs and an attenuation in the colonic tissue erosion. EGCG could reduce the release of IL-6 and IL-17 and regulate the mouse splenic regulatory T-cell (Treg)/T helper 17 cell (Th17) ratio, while increasing the plasma levels of IL-10 and TGF-β1 and decreasing the HIF-1α and STAT3 protein expression in the colon. The experiments confirmed that EGCG treated mice with experimental colitis by inhibiting the release of IL-6 and regulating the body Treg/Th17 balance.