Potentiation of growth inhibition and epigenetic modulation by combination of green tea polyphenol and 5-aza-2′-deoxycytidine in human breast cancer cells

Potentiating Gilteritinib Efficacy Using Nanocomplexation with a Hyaluronic Acid-Epigallocatechin Gallate Conjugate

Acute myeloid leukemia carrying FMS-like tyrosine kinase receptor-3 (FLT3) mutations is a fatal blood cancer with a poor prognosis. Although the FLT3 inhibitor gilteritinib has recently been approved, it still suffers from limited efficacy and relatively high nonresponse rates. In this study, we report the potentiation of gilteritinib efficacy using nanocomplexation with a hyaluronic acid-epigallocatechin gallate conjugate. The self-assembly, colloidal stability, and gilteritinib loading capacity of the nanocomplex were characterized by reversed-phase high-performance liquid chromatography and dynamic light scattering technique. Flow cytometric analysis revealed that the nanocomplex efficiently internalized into FLT3-mutated leukemic cells via specific interactions between the surface-exposed hyaluronic acid and CD44 receptor overexpressed on the cells. Moreover, this nanocomplex was found to induce an eradication of the leukemic cells in a synergistic manner by elevating the levels of reactive oxygen species and caspase-3/7 activities more effectively than free gilteritinib. This study may provide a useful strategy to design nanomedicines capable of augmenting the therapeutic efficacy of FLT3 inhibitors for effective leukemia therapy.

The Potential Role of Epigallocatechin-3-Gallate (EGCG) in Breast Cancer Treatment

Breast cancer is one of the most diagnosed cancers worldwide, with an incidence of 47.8%. Its treatment includes surgery, radiotherapy, chemotherapy, and antibodies giving a mortality of 13.6%. Breast tumor development is driven by a variety of signaling pathways with high heterogeneity of surface receptors, which makes treatment difficult. Epigallocatechin-3-gallate (EGCG) is a natural polyphenol isolated as the main component in green tea; it has shown multiple beneficial effects in breast cancer, controlling proliferation, invasion, apoptosis, inflammation, and demethylation of DNA. These properties were proved in vitro and in vivo together with synergistic effects in combination with traditional chemotherapy, increasing the effectiveness of the treatment. This review focuses on the effects of EGCG on the functional capabilities acquired by breast tumor cells during its multistep development, the molecular and signal pathways involved, the synergistic effects in combination with current drugs, and how nanomaterials can improve its bioavailability on breast cancer treatment.

Epigallocatechin-3-gallate Delivered in Nanoparticles Increases Cytotoxicity in Three Breast Carcinoma Cell Lines

The anticancer activity of epigallocatechin-3-gallate (EGCG), orally administrated, is limited by poor bioavailability, absorption, and unpredictable distribution in human tissues. EGCG charged nanoparticles may represent an opportunity to overcome these limitations. We assayed two different kinds of lipid nanoparticles (LNPs and LNPs functionalized with folic acid) charged with EGCG on three breast carcinoma cell lines (MCF-7, MDA-MB-231, and MCF-7TAM) and the human normal MCF10A mammary epithelial cells. Both LNPs loaded with EGCG, at low concentrations, induced a significant cytotoxicity in the three breast carcinoma cells but not in MCF10A cells. In view of a future application, both LNPs and LNPs-FA were found to be very suitable for in vitro studies and useful to improve EGCG administration in vivo. Since they are produced by inexpensive procedures using bioavailable, biocompatible, and biodegradable molecules, they represent an applicable tool for a more rationale use of EGCG as an anti-cancer agent.

The Potential of Plant-Derived Extracts and Compounds to Augment Anticancer Effects of Chemotherapeutic Drugs

Plant extracts comprise a complex mixture of natural compounds with diverse biological activities including anticancer activities. This has made the use of plant extracts a trending strategy in cancer treatment. In addition, plants' active constituents such as polyphenols could confer protective effects on normal cells against damage by free radicals as well as lessen the toxicity of chemotherapeutic drugs. Recently, many emerging studies revealed the combinatory uses of plant extracts and individual therapeutic compounds that could be a promising panacea in hampering multiple signaling pathways involved in cancer development and progression. Besides enhancing the therapeutic efficacy, this has also been proven to reduce the dosage of chemotherapeutic drugs used, and hence overcome multiple drug resistance and minimize treatment side effects. Notably, combined use of plant extracts with chemotherapeutics drugs was shown to enhance anticancer effects through modulating various signaling pathways, such as P13K/AKT, NF-κB, JNK, ERK, WNT/β-catenin, and many more. Hence, this review aims to comprehensively summarize both In Vitro and In Vivo mechanisms of actions of well-studied plant extracts, such as Ganoderma Lucidum, Korean red ginseng, Garcinia sp., curcumin, and luteolin extracts in augmenting anticancer properties of the conventional chemotherapeutic drugs from an extensive literature search of recent publications.

The Role of Epigenetic Modifications in Human Cancers and the Use of Natural Compounds as Epidrugs: Mechanistic Pathways and Pharmacodynamic Actions

Cancer is a complex disease resulting from the genetic and epigenetic disruption of normal cells. The mechanistic understanding of the pathways involved in tumor transformation has implicated a priori predominance of epigenetic perturbations and a posteriori genetic instability. In this work, we aimed to explain the mechanistic involvement of epigenetic pathways in the cancer process, as well as the abilities of natural bioactive compounds isolated from medicinal plants (flavonoids, phenolic acids, stilbenes, and ketones) to specifically target the epigenome of tumor cells. The molecular events leading to transformation, angiogenesis, and dissemination are often complex, stochastic, and take turns. On the other hand, the decisive advances in genomics, epigenomics, transcriptomics, and proteomics have allowed, in recent years, for the mechanistic decryption of the molecular pathways of the cancerization process. This could explain the possibility of specifically targeting this or that mechanism leading to cancerization. With the plasticity and flexibility of epigenetic modifications, some studies have started the pharmacological screening of natural substances against different epigenetic pathways (DNA methylation, histone acetylation, histone methylation, and chromatin remodeling) to restore the cellular memory lost during tumor transformation. These substances can inhibit DNMTs, modify chromatin remodeling, and adjust histone modifications in favor of pre-established cell identity by the differentiation program. Epidrugs are molecules that target the epigenome program and can therefore restore cell memory in cancerous diseases. Natural products isolated from medicinal plants such as flavonoids and phenolic acids have shown their ability to exhibit several actions on epigenetic modifiers, such as the inhibition of DNMT, HMT, and HAT. The mechanisms of these substances are specific and pleiotropic and can sometimes be stochastic, and their use as anticancer epidrugs is currently a remarkable avenue in the fight against human cancers.

Molecular mechanisms underlying health benefits of tea compounds

Tea is one of the three most widely consumed beverages in the world, not only because of its unique flavor but also due to its various health benefits. The bioactive components in tea, such as polyphenols, polysaccharides, polypeptides, pigments, and alkaloids, are the main contributors to its health functions. Based on epidemiological surveys, the consumption of tea and its compounds in daily life has positive effects on cardiovascular diseases, cancers, hepatopathy, obesity, and diabetes mellitus. In experimental studies, the antioxidant, anti-inflammatory, anti-cancer, anti-obesity, cardiovascular protective, liver protective, and hypoglycemic activities of tea and the related mechanisms of action have been widely investigated. The regulation of several classical signaling pathways, such as nuclear factor-κB (NF-κB), AMP activated protein kinase (AMPK), and wingless/integrated (Wnt) signaling, is involved. Clinical trials have also demonstrated the potential of tea products to be applied as dietary supplements and natural medicines. In this paper, we reviewed and discussed the recent literature on the health benefits of tea and its compounds, and specifically explored the molecular mechanisms involved.

Nutraceuticals in the Mediterranean Diet: Potential Avenues for Breast Cancer Treatment

The traditional Mediterranean Diet constitutes a food model that refers to the dietary patterns of the population living in countries bordering the Mediterranean Sea in the early 1960s. A huge volume of literature data suggests that the Mediterranean-style diet provides several dietary compounds that have been reported to exert beneficial biological effects against a wide spectrum of chronic illnesses, such as cardiovascular and neurodegenerative diseases and cancer including breast carcinoma. Among bioactive nutrients identified as protective factors for breast cancer, natural polyphenols, retinoids, and polyunsaturated fatty acids (PUFAs) have been reported to possess antioxidant, anti-inflammatory, immunomodulatory and antitumoral properties. The multiple anticancer mechanisms involved include the modulation of molecular events and signaling pathways associated with cell survival, proliferation, differentiation, migration, angiogenesis, antioxidant enzymes and immune responses. This review summarizes the anticancer action of some polyphenols, like resveratrol and epigallocatechin 3-gallate, retinoids and omega-3 PUFAs by highlighting the important hallmarks of cancer in terms of (i) cell cycle growth arrest, (ii) apoptosis, (iii) inflammation and (iv) angiogenesis. The data collected from in vitro and in vivo studies strongly indicate that these natural compounds could be the prospective candidates for the future anticancer therapeutics in breast cancer disease.

Protective Effects of Epigallocatechin Gallate (EGCG) on Endometrial, Breast, and Ovarian Cancers

Green tea and its major bioactive component, (-)-epigallocatechin gallate (EGCG), possess diverse biological properties, particularly antiproliferation, antimetastasis, and apoptosis induction. Many studies have widely investigated the anticancer and synergistic effects of EGCG due to the side effects of conventional cytotoxic agents. This review summarizes recent knowledge of underlying mechanisms of EGCG on protective roles for endometrial, breast, and ovarian cancers based on both in vitro and in vivo animal studies. EGCG has the ability to regulate many pathways, including the activation of nuclear factor erythroid 2-related factor 2 (Nrf2), inhibition of nuclear factor-κB (NF-κB), and protection against epithelial-mesenchymal transition (EMT). EGCG has also been found to interact with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which affect epigenetic modifications. Finally, the action of EGCG may exert a suppressive effect on gynecological cancers and have beneficial effects on auxiliary therapies for known drugs. Thus, future clinical intervention studies with EGCG will be necessary to more and clear evidence for the benefit to these cancers.

[Epigallocatechin gallate induces CHD5 gene demethylation to promote acute myeloid leukemia cell apoptosis in vitro by regulating p19Arf-p53-p21Cip1 signaling pathway]

OBJECTIVE

To investigate the mechanism by which epigallocatechin gallate (EGCG) induces CHD5 gene demethylation and promotes the apoptosis of acute myeloid leukemia KG-1 and THP-1 cell lines.

METHODS

KG-1 and THP-1 cells treated with 25, 50, 75, 100 or 150 μg/mL EGCG for 48 h were examined for CHD5 gene methylation using MSP and for cell proliferation using MTT assay. The changes in cell cycle and apoptosis of the two cell lines after treatment with EGCG for 48 h were detected using flow cytometry. The mRNA and protein expressions of DNMT1, CHD5, p19Arf, p53 and p21Cip1 in the cells were detected using RT-quantitative PCR and Western blot.

RESULTS

EGCG dose-dependently reversed hypermethylation of CHD5 gene and reduced the cell viability in both KG-1 and THP-1 cells (P < 0.05). EGCG treatment caused obvious cell cycle arrest in G1 phase, significantly increased cell apoptosis, downregulated the expression of DNMT1 and upregulated the expressions of CHD5, p19Arf, p53 and p21Cip1 in KG-1 and THP-1 cells (P < 0.05).

CONCLUSIONS

EGCG reduces hypermethylation of CHD5 gene in KG-1 and THP-1 cells by downregulating DNMT1 to restore its expression, which results in upregulated expressions of p19Arf, p53 and p21Cip1 and induces cell apoptosis.

Medicinal Herbs Used in Traditional Management of Breast Cancer: Mechanisms of Action

Background: Breast cancer is one of the principal causes of death among women and there is a pressing need to develop novel and effective anti-cancer agents. Natural plant products have shown promising results as anti-cancer agents. Their effectiveness is reported as decreased toxicity in usage, along with safety and less recurrent resistances compared with hormonal targeting anti-cancer agents. Methods: A literature search was conducted for all English-language literature published prior to June 2020. The search was conducted using electronic databases, including PubMed, Embase, Web of Science, and Cochrane Library. The search strategy included keywords such as breast cancer, herbs, anti-cancer biologically active components, clinical research, chemotherapy drugs amongst others. Results: The literature provides documented evidence of the chemo-preventative and chemotherapeutic properties of Ginseng, garlic (Allium sativum), Black cohosh (Actaea racemose), Tumeric (Curcuma longa), Camellia sinenis (green tea), Echinacea, Arctium (burdock), Flaxseed (Linum usitatissimum) and Black Cumin (Nigella sativa). Conclusions: The nine herbs displayed anti-cancer properties and their outcomes and mechanisms of action include inhibition of cell proliferation, angiogenesis and apoptosis as well as modulation of key intracellular pathways. However, more clinical trials and cohort human studies should be conducted to provide key evidence of their medical benefits.

Molecular mechanisms of action of epigallocatechin gallate in cancer: Recent trends and advancement

Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is an ester of epigallocatechin and gallic acid. EGCG, abundantly found in tea, is a polyphenolic flavonoid that has the potential to affect human health and disease. EGCG interacts with various recognized cellular targets and inhibits cancer cell proliferation by inducing apoptosis and cell cycle arrest. In addition, scientific evidence has illustrated the promising role of EGCG in inhibiting tumor cell metastasis and angiogenesis. It has also been found that EGCG may reverse drug resistance of cancer cells and could be a promising candidate for synergism studies. The prospective importance of EGCG in cancer treatment is owed to its natural origin, safety, and low cost which presents it as an attractive target for further development of novel cancer therapeutics. A major challenge with EGCG is its low bioavailability which is being targeted for improvement by encapsulating EGCG in nano-sized vehicles for further delivery. However, there are major limitations of the studies on EGCG, including study design, experimental bias, and inconsistent results and reproducibility among different study cohorts. Additionally, it is important to identify specific EGCG pharmacological targets in the tumor-specific signaling pathways for development of novel combined therapeutic treatments with EGCG. The present review highlights the ongoing development to identify cellular and molecular targets of EGCG in cancer. Furthermore, the role of nanotechnology-mediated EGCG combinations and delivery systems will also be discussed.

Preclinical Pharmacological Activities of Epigallocatechin-3-gallate in Signaling Pathways: An Update on Cancer

Epigallocatechin gallate (EGCG) is the main bioactive component of catechins predominantly present in svarious types of teas. EGCG is well known for a wide spectrum of biological activity as an anti-oxidative, anti-inflammatory, and anti-tumor agent. The effect of EGCG on cell death mechanisms via the induction of apoptosis, necrosis, and autophagy has been documented. Moreover, its anti-proliferative and chemopreventive action has been demonstrated in many cancer cell lines. It was also involved in the modulation of cyclooxygenase-2, in oxidative stress and inflammation of different cell processes. EGCG has been reported as a promising target for plasma membrane proteins, such as epidermal growth factor receptor (EGFR). In addition, it has been demonstrated a mechanism of action relying on the inhibition of ERK1/2, p38 MAPK, NF-κB, and vascular endothelial growth factor (VEGF). EGCG and its derivatives were used in proteasome inhibition and they were involved in epigenetic mechanisms. In summary, EGCG is the most predominant and bioactive constituent of teas and it has a pivotal role in cancer prevention. Its preclinical pharmacological activities are associated with complex molecular mechanisms that involve numerous signaling pathways.

The Inhibitory Effect of (-)-Epigallocatechin-3-Gallate on Breast Cancer Progression via Reducing SCUBE2 Methylation and DNMT Activity

Epigenetic modifications are important mechanisms responsible for cancer progression. Accumulating data suggest that (-)-epigallocatechin-3-gallate (EGCG), the most abundant catechin of green tea, may hamper carcinogenesis by targeting epigenetic alterations. We found that signal peptide-CUB (complement protein C1r/C1s, Uegf, and Bmp1)-EGF (epidermal growth factor) domain-containing protein 2 (SCUBE2), a tumor suppressor gene, was hypermethylated in breast tumors. However, it is unknown whether EGCG regulates SCUBE2 methylation, and the mechanisms remain undefined. This study was designed to investigate the effect of EGCG on SCUBE2 methylation in breast cancer cells. We reveal that EGCG possesses a significantly inhibitory effect on cell viability in a dose- and time-dependent manner and presents more effects than other catechins. EGCG treatment resulted in enhancement of the SCUBE2 gene, along with elevated E-cadherin and decreased vimentin expression, leading to significant suppression of cell migration and invasion. The inhibitory effect of EGCG on SCUBE2 knock-down cells was remarkably alleviated. Further study demonstrated that EGCG significantly decreased the SCUBE2 methylation status by reducing DNA methyltransferase (DNMT) expression and activity. In summary, this study reported for the first time that SCUBE2 methylation can be reversed by EGCG treatment, finally resulting in the inhibition of breast cancer progression. These results suggest the epigenetic role of EGCG and its potential implication in breast cancer therapy.

Effects and mechanisms of tea for the prevention and management of cancers: An updated review

Tea is a traditional and popular beverage worldwide, and the consumption of tea has been demonstrated to possess many health benefits, such as cardiovascular protection, anti-obesity, anti-diabetes, and anticancer. Epidemiological studies have shown that the consumption of tea is inversely associated with the risk of several cancers. In addition, experimental studies have revealed that the anticancer actions of tea are mainly attributed to tea polyphenols, such as epigallocatechin-3-gallate and theaflavins. Both in vitro and in vivo studies have demonstrated that the possible anticancer mechanisms are the inhibition on proliferation, anti-angiogenesis, induction of apoptosis, suppression on metastasis, inhibition on cancer stem cells, and modulation on gut microbiota. Its synergetic anticancer effects with drugs or other compounds could promote anticancer therapies. Furthermore, clinical trials have elucidated that intervention of tea phytochemicals is effective in the prevention of several cancers. This paper is an updated review for the prevention and management of cancers by tea based on the findings from epidemiological, experimental and clinical studies, and special attention is paid on the mechanisms of action.

Epigenetic reprogramming of epithelial mesenchymal transition in triple negative breast cancer cells with DNA methyltransferase and histone deacetylase inhibitors

Background

Triple negative breast cancer (TNBC) is an aggressive neoplasia with no effective therapy. Our laboratory has developed a unique TNBC cell model presenting epithelial mesenchymal transition (EMT) a process known to be important for tumor progression and metastasis. There is increasing evidence showing that epigenetic mechanisms are involved in the activation of EMT. The objective of this study is to epigenetically reverse the process of EMT in TNBC by using DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi).

Methods

We evaluated the antitumor effect of three DNMTi and six HDACi using our TNBC cell model by MTT assay, migration and invasion assay, three dimensional culture, and colony formation assay. We then performed the combined treatment both in vitro and in vivo using the most potent DNMTi and HDACi, and tested the combined treatment in a panel of breast cancer cell lines. We investigated changes of EMT markers and potential signaling pathways associated with the antitumor effects.

Results

We showed that DNMTi and HDACi can reprogram highly aggressive TNBC cells that have undergone EMT to a less aggressive phenotype. SGI-110 and MS275 are superior to other seven compounds being tested. The combination of SGI with MS275 exerts a greater effect than single agent alone in inhibiting cell proliferation, motility, colony formation, and stemness of cancer cells. We also demonstrated that MS275 and the combination of SGI with MS275 exert in vivo antitumor effect. We revealed that the combined treatment synergistically reverses EMT through inhibiting EpCAM cleavage and WNT signaling, suppressing mutant p53, ZEB1, and EZH2, and inducing E-cadherin, apoptosis, as well as histone H3 tri-methylation.

Conclusions

Our study showed that DNMTi and HDACi exert antitumor activity in TNBC cells partially by epigenetically reprograming EMT. Our findings strongly suggest that TNBC is sensitive to epigenetic therapies. Therefore, we propose a new strategy to treat TNBC by using the combination of SGI-110 with MS275, which exerts superior antitumor effects by simultaneously targeting multiple pathways.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0988-8) contains supplementary material, which is available to authorized users.

Plant natural modulators in breast cancer prevention: status quo and future perspectives reinforced by predictive, preventive, and personalized medical approach

In contrast to the genetic component in mammary carcinogenesis, epigenetic alterations are particularly important for the development of sporadic breast cancer (BC) comprising over 90% of all BC cases worldwide. Most of the DNA methylation processes are physiological and essential for human cellular and tissue homeostasis, playing an important role in a number of key mechanisms. However, if dysregulated, DNA methylation contributes to pathological processes such as cancer development and progression. A global hypomethylation of oncogenes and hypermethylation of tumor-suppressor genes are characteristic of most cancer types. Moreover, histone chemical modifications and non-coding RNA-associated multi-gene controls are considered as the key epigenetic mechanisms governing the cellular homeostasis and differentiation states. A number of studies demonstrate dietary plant products as actively affecting the development and progression of cancer. "Nutri-epigenetics" focuses on the influence of dietary agents on epigenetic mechanisms. This approach has gained considerable attention; since in contrast to genetic alterations, epigenetic modifications are reversible affect early carcinogenesis. Currently, there is an evident lack of papers dedicated to the phytochemicals/plant extracts as complex epigenetic modulators, specifically in BC. Our paper highlights the role of plant natural compounds in targeting epigenetic alterations associated with BC development, progression, as well as its potential chemoprevention in the context of preventive medicine. Comprehensive measures are stated with a great potential to advance the overall BC management in favor of predictive, preventive, and personalized medical services and can be considered as "proof-of principle" model, for their potential application to other multifactorial diseases.

Trichostatin A and 5-Aza-2'-Deoxycytidine influence the expression of cold-induced genes in Arabidopsis

The expression of cold-induced genes is critical for plants to survive under freezing stress. However, the underlying mechanisms for the decision of when, where, and which genes to express are unclear when a plant meets a sudden temperature drop. Previous studies have demonstrated epigenetics to play a central role in the regulation of gene expression in plant responses to environmental stress. DNA methylation and histone deacetylation are the two most important epigenetic modifications. This study was conducted to investigate the effects of inhibiting DNA methylation and histone deacetylation on gene expression, and to explore the potential role of epigenetics in plant responses to cold stress. The results revealed that histone deacetylase inhibitors (trichostatin A) and DNA methylation inhibitors (5-Aza-2'-deoxycytosine) treatment enhanced cold tolerance. DNA microarray analysis and the gene ontology method revealed 76 cold-induced differently expressed genes in Arabidopsis thaliana seedlings that were treated to 0°C for 24 h following Trichostatin A and 5-Aza-2'-Deoxycytidine. Furthermore, analyses of metabolic pathways and transcription factors of 3305 differentially expressed genes were performed. Each four metabolic pathways were significantly affected (p < 0.01) by Trichostatin A and 5-Aza-2'-Deoxycytidine. Finally, 10 genes were randomly selected and verified via qPCR analysis. Our study indicated that Trichostatin A and 5-Aza-2'-Deoxycytidine can improve the plant cold resistance and influence the expression of the cold-induced gene in A. thaliana. This result will advance our understanding of plant freezing responses and may provide a helpful strategy for cold tolerance improvement in crops.

In vitro Biological Effects of Sulforaphane (SFN), Epigallocatechin-3-gallate (EGCG), and Curcumin on Breast Cancer Cells: A Systematic Review of the Literature

Much of the recent research in neoplasia has been focusing on the epigenetics of cancer cells, particularly as regards the search for potential molecular biomarkers that could be used for early diagnosis, effective treatment, and prognosis of several types of cancer. Carcinogenesis often starts with mutations in oncogenes and tumor suppressor genes, and it leads to anomalies in cellular processes as vital as cell cycle regulation and apoptosis. Because malignant changes arise as a result of genetic as well as epigenetic mechanisms, one possible means of intervention involves reprogramming gene expression, so as to-at least in part-revert the molecular alterations. DNA methylation and demethylation, acetylation and deacetylation of histones, and microRNAs are a few examples of the epigenetic mechanisms responsible for tumor development and progression. Many biologically active compounds present in food-including sulforaphane, curcumin, and epigallocatechin-have been found to modulate those processes. We here systematically review information on the effects of such bioactive dietary compounds on human breast cancer cell lines, and explore the mechanisms underlying those effects with a view to their potential therapeutic application.

Assessing the anticancer effects associated with food products and/or nutraceuticals using in vitro and in vivo preclinical development-related pharmacological tests

This review is part of a special issue entitled "Role of dietary pattern, foods, nutrients and nutraceuticals in supporting cancer prevention and treatment" and describes a pharmacological strategy to determine the potential contribution of food-related components as anticancer agents against established cancer. Therefore, this review does not relate to chemoprevention, which is analysed in several other reviews in the current special issue, but rather focuses on the following: i) the biological events that currently represent barriers against the treatment of certain types of cancers, primarily metastatic cancers; ii) the in vitro and in vivo pharmacological pre-clinical tests that can be used to analyse the potential anticancer effects of food-related components; and iii) several examples of food-related components with anticancer effects. This review does not represent a catalogue-based listing of food-related components with more or less anticancer activity. By contrast, this review proposes an original pharmacological strategy that researchers can use to analyse the potential anticancer activity of any food-related component-e.g., by considering the crucial characteristics of cancer biological aggressiveness. This review also highlights that cancer patients undergoing chemotherapy should restrict the use of "food complements" without supervision by a medical nutritionist. By contrast, an equilibrated diet that includes the food-related components listed herein would be beneficial for cancer patients who are not undergoing chemotherapy.

Breast cancer chemopreventive and chemotherapeutic effects of Camellia Sinensis (green tea): an updated review

Introduction

Camellia sinensis belongs to the plant family of Theaceae, native to East Asia, the Indian Subcontinent and Southeast Asia, but naturalized in many parts of the world. The aim of this study was to overview its anti-breast cancer chemopreventive and chemotherapeutic effects. This review article is aimed to overview breast cancer chemopreventive and chemotherapeutic effects of Camellia sinensis (green tea).

Methods

This review article was carried out by searching studies in PubMed, Medline, Web of Science, and IranMedex databases. The initial search strategy identified around 108 references. In this study, 68 studies were accepted for further screening, and met all our inclusion criteria [in English, full text, chemopreventive and chemotherapeutic effects of Camellia sinensis and dated mainly from the year 1999 to 2016. The search terms were Camellia sinensis, chemopreventive, chemotherapeutic properties, pharmacological effects.

Result

The result of this study suggested that the catechin available in Camellia sinensis has properties which can prevent and treat breast cancer. It has also been shown to inhibit proliferation of breast cancer cells and to block carcinogenesis. It was found that increased Camellia sinensis consumption may lower the risk of breast cancer. Camellia sinensis intake was shown to reduce the risk of breast cancer incidence. In addition, potential breast cancer chemopreventive effect of Camellia sinensis both in vivo and in vitro was highly confirmed. However, the evidence of low effect and no effect was observed. More clinical trial studies are needed to prove its anti-breast cancer activity decisively.

Conclusion

Camellia sinensis is broadly utilized as a part of customary medication since antiquated time because of its cost adequacy, and fewer reaction properties. The studies demonstrated anti-breast cancer activity of Camellia sinensis and its component by adjusting cell signaling pathways such as angiogenesis, apoptosis, and transcription factor. Furthermore, Camellia sinensis and its chemical compound was shown to be extremely useful in the development of novel anticancer medications.