Implication of Akt, ERK1/2 and alternative p38MAPK signalling pathways in human colon cancer cell apoptosis induced by green tea EGCG

Herbal Therapies for Cancer Treatment: A Review of Phytotherapeutic Efficacy

Natural products have proven to be promising anti-cancer agents due to their diverse chemical structures and bioactivity. This review examines their central role in cancer treatment, focusing on their mechanisms of action and therapeutic benefits. Medicinal plants contain bioactive compounds, such as flavonoids, alkaloids, terpenoids and polyphenols, which exhibit various anticancer properties. These compounds induce apoptosis, inhibit cell proliferation and cell cycle progression, interfere with microtubule formation, act on topoisomerase targets, inhibit angiogenesis, modulate key signaling pathways, improve the tumor microenvironment, reverse drug resistance and activate immune cells. Herbal anti-cancer drugs offer therapeutic advantages, particularly selective toxicity against cancer cells, reducing the adverse side effects associated with conventional chemotherapy. Recent studies and clinical trials highlight the benefits of herbal medicines in alleviating side effects, improving tolerance to chemotherapy and the occurrence of synergistic effects with conventional treatments. For example, the herbal medicine SH003 was found to be safe and potentially effective in the treatment of solid cancers, while Fucoidan showed anti-inflammatory properties that are beneficial for patients with advanced cancer. The current research landscape on herbal anticancer agents is extensive. Numerous studies and clinical trials are investigating their efficacy, safety and mechanisms of action in various cancers such as lung, prostate, breast and hepatocellular carcinoma. Promising developments include the polypharmacological approach, combination therapies, immunomodulation and the improvement of quality of life. However, there are still challenges in the development and use of natural products as anti-cancer drugs, such as the need for further research into their mechanisms of action, possible drug interactions and optimal dosage. Standardizing herbal extracts, improving bioavailability and delivery, and overcoming regulatory and acceptance hurdles are critical issues that need to be addressed. Nonetheless, the promising anticancer effects and therapeutic benefits of natural products warrant further investigation and development. Multidisciplinary collaboration is essential to advance herbal cancer therapy and integrate these agents into mainstream cancer treatment.

QM-CSA: A Novel Quantum Mechanics-Based Protocol for Evaluation of the Carcinogen-Scavenging Activity of Polyphenolic Compounds

In this study, a novel quantum mechanics-based protocol for the evaluation of carcinogen-scavenging activity (QM-CSA) is developed. The QM-CSA protocol represents a universal and quantitative approach to evaluate and compare the activation-free energies for alkylation reactions between individual polyphenolic compounds and chemical carcinogens of the epoxy type at physiological conditions by applying two scales: the absolute scale allowing for the comparison with guanine and the relative scale allowing the comparison with glutathione as a reference compound. The devised quantum mechanical methodology was validated by comparing the activation-free energies calculated with 14 DFT functionals in conjunction with two implicit solvation models (SMD and CPCM) and the experimental activation-free energies for reactions between nine investigated chemical carcinogens and guanine. According to the obtained results, the best agreement with experimental data was achieved by applying DFT functionals M11-L and MN12-L in conjunction with the flexible 6-311++G(d,p) basis set and implicit solvation model SMD, and the obtained uncertainties were proven to be similar to the experimental ones. To demonstrate the applicability of the QM-CSA protocol, functionals M11-L, and MN12-L in conjunction with the SMD implicit solvation model were applied to calculate activation-free energies for the reactions of nine investigated chemical carcinogens of the epoxy type with three catechins, namely EGCG, EGC, and (+)-catechin. The order of CSA in this series of catechins in comparison to guanine and glutathione was determined as (+)-catechin > EGC > EGCG. The obtained results, for the first time, demonstrated the evaluation and comparison of CSA in a series of selected catechins with respect to glutathione and guanine. Moreover, the presented results provide valuable insights into the reaction mechanisms and configurations of the corresponding transition states. The novel QM-CSA protocol is also expected to expand the kinetic data for alkylation reactions between various polyphenolic compounds and chemical carcinogens of the epoxy type, which is currently lacking in the scientific literature.

Modulation of long noncoding RNAs by polyphenols as a novel potential therapeutic approach in lung cancer: A comprehensive review

Lung cancer stands as a formidable global health challenge, necessitating innovative therapeutic strategies. Polyphenols, bioactive compounds synthesized by plants, have garnered attention for their diverse health benefits, particularly in combating various cancers, including lung cancer. The advent of whole-genome and transcriptome sequencing technologies has illuminated the pivotal roles of long noncoding RNAs (lncRNAs), operating at epigenetic, transcriptional, and posttranscriptional levels, in cancer progression. This review comprehensively explores the impact of polyphenols on both oncogenic and tumor-suppressive lncRNAs in lung cancer, elucidating on their intricate regulatory mechanisms. The comprehensive examination extends to the potential synergies when combining polyphenols with conventional treatments like chemotherapy, radiation, and immunotherapy. Recognizing the heterogeneity of lung cancer subtypes, the review emphasizes the need for the integration of nanotechnology for optimized polyphenol delivery and personalized therapeutic approaches. In conclusion, we collect the latest research, offering a holistic overview of the evolving landscape of polyphenol-mediated modulation of lncRNAs in lung cancer therapy. The integration of polyphenols and lncRNAs into multidimensional treatment strategies holds promise for enhancing therapeutic efficacy and navigating the challenges associated with lung cancer treatment.

pH-Sensitive Nanoparticles of Epigallocatechin-3-Gallate in Enhanced Colorectal Cancer Therapy

AIM

Encapsulating epigallocatechin-3-gallate (EGCG) in pH-sensitive polymeric nanoparticles for targeted delivery of drugs could revolutionize colorectal cancer treatment.

MATERIALS & METHODS

Nanoparticles were synthesized to release drugs at colon pH. Dynamic light scattering measured their average diameter and ζ-potential, while differential scanning calorimetry and x-ray diffraction assessed EGCG encapsulation.

RESULTS

The nanoparticles showed stability and bioavailability in the gastrointestinal tract, efficiently encapsulating and releasing over 93% of EGCG at pH 7.2. They enhanced cytotoxicity against HT-29 cells and demonstrated antibacterial properties, increasing apoptosis and cell cycle arrest.

CONCLUSION

The study underscores the potential of nanoparticles in enhancing EGCG delivery for colorectal cancer therapy, aiming to minimize side effects and improve therapeutic outcomes.

Epigallocatechin-3-gallate and cancer: focus on the role of microRNAs

MicroRNAs (miRNAs) are a group of small non-coding RNAs that affect gene expression. The role of miRNAs in different types of cancers has been published and it was shown that several miRNAs are inappropriately expressed in different cancers. Among the mechanisms that can cause this lack of proper expression are epigenetics, chromosomal changes, polymorphisms or defects in processing proteins. Recent research shows that phytochemicals, including epigallocatechin-3-gallate (EGCG), exert important epigenetic-based anticancer effects such as pro-apoptotic or anti proliferative through miRNA gene silencing. Given that EGCG is able to modulate a variety of cancer-related process i.e., angiogenesis, proliferation, metastasis and apoptosis via targeting various miRNAs such as let-7, miR-16, and miR-210. The discovery of new miRNAs and the differences observed in their expression when exposed to EGCG provides evidence that targeting these miRNAs may be beneficial as a form of treatment. In this review, we aim to provide an overview, based on current knowledge, on how phytochemicals, including epigallocatechin-3-gallate, can be considered as potential miRNAs modulator to improve efficacy of current cancer treatments.

Bioactive Compounds of Dietary Origin and Their Influence on Colorectal Cancer as Chemoprevention

Colorectal cancer (CRC) is one of the most common causes of death and the third most diagnosed cancer worldwide. The tumor microenvironment and cancer stem cells participate in colorectal tumor progression and can dictate malignancy. Nutrition status affects treatment response and the progression or recurrence of the tumor. This review summarizes the main bioactive compounds against the molecular pathways related to colorectal carcinogenesis. Moreover, we focus on the compounds with chemopreventive properties, mainly polyphenols and carotenoids, which are highly studied dietary bioactive compounds present in major types of food, like vegetables, fruits, and seeds. Their proprieties are antioxidant and gut microbiota modulation, important in the intestine because they decrease reactive oxygen species and inflammation, both principal causes of cancer. These compounds can promote apoptosis and inhibit cell growth, proliferation, and migration. Combined with oncologic treatment, a sensitization to first-line colorectal chemotherapy schemes, such as FOLFOX and FOLFIRI, is observed, making them an attractive and natural support in the oncologic treatment of CRC.

Anticancer Therapeutic Effects of Green Tea Catechins (GTCs) When Integrated with Antioxidant Natural Components

After decades of research and development concerning cancer treatment, cancer is still at large and very much a threat to the global human population. Cancer remedies have been sought from all possible directions, including chemicals, irradiation, nanomaterials, natural compounds, and the like. In this current review, we surveyed the milestones achieved by green tea catechins and what has been accomplished in cancer therapy. Specifically, we have assessed the synergistic anticarcinogenic effects when green tea catechins (GTCs) are combined with other antioxidant-rich natural compounds. Living in an age of inadequacies, combinatorial approaches are gaining momentum, and GTCs have progressed much, yet there are insufficiencies that can be improvised when combined with natural antioxidant compounds. This review highlights that there are not many reports in this specific area and encourages and recommends research attention in this direction. The antioxidant/prooxidant mechanisms of GTCs have also been highlighted. The current scenario and the future of such combinatorial approaches have been addressed, and the lacunae in this aspect have been discussed.

Therapeutic Effects of Green Tea Polyphenol (‒)-Epigallocatechin-3-Gallate (EGCG) in Relation to Molecular Pathways Controlling Inflammation, Oxidative Stress, and Apoptosis

(‒)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea. Thanks to multiple interactions with cell surface receptors, intracellular signaling pathways, and nuclear transcription factors, EGCG possesses a wide variety of anti-inflammatory, antioxidant, antifibrotic, anti-remodelation, and tissue-protective properties which may be useful in the treatment of various diseases, particularly in cancer, and neurological, cardiovascular, respiratory, and metabolic disorders. This article reviews current information on the biological effects of EGCG in the above-mentioned disorders in relation to molecular pathways controlling inflammation, oxidative stress, and cell apoptosis.

Natural Polyphenols for Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a prevalent and serious gastrointestinal malignancy with high mortality and morbidity. Chemoprevention refers to a newly emerged strategy that uses drugs with chemopreventive properties to promote antioxidation, regulate cancer cell cycle, suppress proliferation, and induce cellular apoptosis, so as to improve cancer treatment outcomes. Natural polyphenols are currently recognized as a class of chemopreventive agents that have shown remarkable anticarcinogenic properties. Numerous in vitro and in vivo studies have elucidated the anti-CRC mechanisms of natural polyphenols, such as regulation of various molecular and signaling pathways. Natural polyphenols are also reportedly capable of modulating the gut microbiota and cancer stem cells (CSCs) to suppress tumor formation and progression. Combined use of different natural polyphenols is recommended due to their low bioavailability and instability, and combination treatment can exert synergistical effects, reduce side effects, and avoid drug resistance in CRC treatment. In summary, the application of polyphenols in the chemoprevention and treatment of CRC is promising. Further clinical evaluation of their effectiveness is warranted and anticipated.

Inhibition and potential treatment of colorectal cancer by natural compounds via various signaling pathways

Colorectal cancer (CRC) is a common type of malignant digestive tract tumor with a high incidence rate worldwide. Currently, the clinical treatment of CRC predominantly include surgical resection, postoperative chemotherapy, and radiotherapy. However, these treatments contain severe limitations such as drug side effects, the risk of recurrence and drug resistance. Some natural compounds found in plants, fungi, marine animals, and bacteria have been shown to inhibit the occurrence and development of CRC. Although the explicit molecular mechanisms underlying the therapeutic effects of these compounds on CRC are not clear, classical signaling transduction pathways such as NF-kB and Wnt/β-catenin are extensively regulated. In this review, we have summarized the specific mechanisms regulating the inhibition and development of CRC by various types of natural compounds through nine signaling pathways, and explored the potential therapeutic values of these natural compounds in the clinical treatment of CRC.

Combination Therapy Using Polyphenols: An Efficient Way to Improve Antitumoral Activity and Reduce Resistance

Polyphenols represent a structural class of mainly natural organic chemicals that contain multiple phenol structural units. The beneficial properties of polyphenols have been extensively studied for their antitumor, anti-inflammatory, and antibacterial effects, but nowadays, their medical applications are starting to be extended to many other applications due to their prebiotic role and their impact on the microbiota. This review focused on the use of polyphenols in cancer treatment. Their antineoplastic effects have been demonstrated in various studies when they were tested on numerous cancer lines and some in in vivo models. A431 and SCC13 human skin cancer cell lines treated with EGCG presented a reduced cell viability and enhanced cell death due to the inactivation of β-catenin signaling. Additionally, resveratrol showed a great potential against breast cancer mainly due to its ability to exert both anti-estrogenic and estrogenic effects (based on the concentration) and because it has a high affinity for estrogen receptors ERα and Erβ. Polyphenols can be combined with different classical cytostatic agents to enhance their therapeutic effects on cancer cells and to also protect healthy cells from the aggressiveness of antitumor drugs due to their anti-inflammatory properties. For instance, curcumin has been reported to reduce the gastrointestinal toxicity associated with chemotherapy. In the case of 5-FU-induced, it reduced the gastrointestinal toxicity by increasing the intestinal permeability and inhibiting mucosal damage. Co-administration of EGCG and doxorubicin induced the death of liver cancer cells. EGCG has the ability to inhibit autophagic activity and stop hepatoma Hep3B cell proliferation This symbiotic approach is well-known in medical practice including in multiple chemotherapy.

Epigallocatechin Gallate (EGCG) for Parkinson's Disease

In the last couple of decades, we have experienced increased use of nutraceuticals worldwide with a demand for organic foods, which has been elevated to an extent probably unmatched with other periods of our civilization. One of the nutraceuticals that gained attention is epigallocatechin gallate (EGCG), a polyphenol in green tea. It has been suggested that diseases of the central nervous system (CNS) can benefit from consuming some antioxidants, despite current results showing little evidence for their use in preventing and treating these diseases. ECGC may be beneficial in delaying the neurodegeneration of the substantia nigra (SN) regardless of the origin of Parkinson's disease (PD). This review covers the effect of EGCG on vitro and animal models of PD, the potential mechanisms of neuroprotection involved and summaries recent clinical trials in human PD. This review also aims to provide an investigative analysis of the current knowledge in this field and identify putative crucial issues. Environmental factors such as dietary habits, drug use, and social interaction are all factors that influence the evolution of neurodegenerative diseases. Therefore, the use of nutraceuticals requires further investigation. This article is protected by copyright. All rights reserved.

Green Tea (Camellia sinensis): A Review of Its Phytochemistry, Pharmacology, and Toxicology

Objectives Green tea (Camellia sinensis) is a kind of unfermented tea that retains the natural substance in fresh leaves to a great extent. It is regarded as the second most popular drink in the world besides water. In this paper, the phytochemistry, pharmacology, and toxicology of green tea are reviewed systematically and comprehensively. Key findings Green tea has been demonstrated to be good for human health. Nowadays, multiple pharmacologically active components have been isolated and identified from green tea, including tea polyphenols, alkaloids, amino acids, polysaccharides, and volatile components. Recent studies have demonstrated that green tea shows versatile pharmacological activities, such as antioxidant, anticancer, hypoglycemic, antibacterial, antiviral, and neuroprotective. Studies on the toxic effects of green tea extract and its main ingredients have also raised concerns including hepatotoxicity and DNA damage. Summary Green tea can be used to assist the treatment of diabetes, Alzheimer’s disease, oral cancer, and dermatitis. Consequently, green tea has shown promising practical prospects in health care and disease prevention.

Chemical Structure, Sources and Role of Bioactive Flavonoids in Cancer Prevention: A Review

There has been a major shift in the collective mindset around the world in recent decades, both in terms of food and in terms of the treatment of chronic diseases. Increasing numbers of people are choosing to prevent rather than treat, which is why many consumers are choosing plant-based diets, mainly due to their bioactive compounds. A significant case of bioactive compound is flavonoids-a wide subclass of an even wider class of phytochemicals: polyphenols. Flavonoids are a broad topic of study for researchers due to their potential in the prevention and treatment of a broad range of cancers. The aim of this review is to inform/update the reader on the diversity, accessibility and importance of flavonoids as biomolecules that are essential for optimal health, focusing on the potential of these compounds in the prevention of various types of cancer. Along with conventional sources, this review presents some of the possible methods for obtaining significant amounts of flavonoids based on a slightly different approach, genetic manipulation.

Inhibitory Mechanism of Combined Hydroxychavicol With Epigallocatechin-3-Gallate Against Glioma Cancer Cell Lines: A Transcriptomic Analysis

Emerging reports have shown therapeutic potential of hydroxychavicol (HC) and epigallocatechin-3-gallate (EGCG) against cancer cells, however high concentrations are required to achieve the anticancer activity. We reported the synergy of low combination doses of EGCG+HC in glioma cell lines 1321N1, SW1783, and LN18 by assessing the effects of EGCG+HC through functional assays. Using high throughput RNA sequencing, the molecular mechanisms of EGCG+HC against glioma cell lines were revealed. EGCG/HC alone inhibited the proliferation of glioma cell lines, with IC50 values ranging from 82 to 302 µg/ml and 75 to 119 µg/ml, respectively. Sub-effective concentrations of combined EGCG+HC enhanced the suppression of glioma cell growth, with SW1783 showing strong synergism with a combination index (CI) of 0.55 and LN18 showing a CI of 0.51. A moderate synergistic interaction of EGCG+HC was detected in 1321N1 cells, with a CI value of 0.88. Exposure of 1321N1, SW1783, and LN18 cells to EGCG+HC for 24 h induces cell death, with caspase-3 activation rates of 52%, 57%, and 9.4%, respectively. However, the dose for SW1783 is cytotoxic to normal cells, thus this dose was excluded from other tests. EGCG+HC induced cell cycle arrest at S phase and reduced 1321N1 and LN18 cell migration and invasion. Combined EGCG+HC amplified its anticancer effect by downregulating the axon guidance process and metabolic pathways, while simultaneously interfering with endoplasmic reticulum unfolded protein response pathway. Furthermore, EGCG+HC exerted its apoptotic effect through the alteration of mitochondrial genes such as MT-CO3 and MT-RNR2 in 1321N1 and LN18 cells respectively. EGCG+HC dynamically altered DYNLL1 alternative splicing expression in 1321N1 and DLD splicing expression in LN18 cell lines. Our work indicated the pleiotropic effects of EGCG+HC treatment, as well as particular target genes that might be investigated for future glioma cancer therapeutic development.

Epigallocatechin-3-gallate suppresses the growth of human osteosarcoma by inhibiting the Wnt/β-catenin signalling pathway

Osteosarcoma (OS) is one of the most common malignant tumors in adolescents. Due to local invasion, distant metastasis and drug resistance, the clinical treatment efficacy and prognosis of OS have remained almost unchanged for decades. Epigallocatechin-3-gallate (EGCG) is a unique catechin from tea leaves, and some studies have confirmed its antitumour effects on various tumors. Here, cellular experiments showed that EGCG significantly promoted OS cell apoptosis and inhibited proliferation, migration and invasion, and cell and animal experiments demonstrated that the Wnt/β-catenin pathway played an indispensable role in the antitumour effects of EGCG. Moreover, EGCG inhibited the growth of OS cells in vitro while suppressing tumor cell damage to the bone in situ and distant lung metastasis. The results indicate that the antitumour effect of EGCG on human OS may be mediated by regulating the Wnt/β-catenin pathway and that EGCG can be used alone or in combination with other regimens as a potentially effective anticancer treatment.

Ellagic acid inhibits proinflammatory intermediary manufacture by suppressing NF-κB/Akt, VEGF and activating Nrf-2/Caspase-3 signaling pathways in rat testicular damage: a new way for testicular damage cure and in silico approach

Ellagic acid (EA) has protective effect on testicular damage and this natural compound decreases oxidative damage. The present study aims to examine the preventive effect of ellagic acid (EA) against carbon tetrachloride (CCl₄)-induced testicular tissue damage in rats. In testicular tissue, tumor necrosis factor-α (TNF-α), Nuclear factor erythroid-2 related factor 2 (Nrf-2), B-cell lymphoma-2 (Bcl-2), vascular endothelial growth factor (VEGF), Nuclear factor-kappa B (NF-κB), cysteine aspartic proteases (caspase-3) and protein kinase B (Akt) synthesis levels were analyzed by western blot method, reactive oxygen species (ROS) was measured by malondialdehyde (MDA) levels, Glutathione (GSH) level and catalase (CAT) by spectrophotometer. As a result, in comparison with the CCl₄ group, caspase-3 and Nrf-2 protein synthesis levels increased in EA + CCl₄ group, however, VEGF, Bcl-2, NF-κB, TNF-α and Akt protein synthesis levels decreased, EA application raised GSH levels and CAT activity, reduced MDA levels. In this study, in silico tools were applied to confirm the activity of EA against the cancer with macromolecules such as the above mentioned transcription factors. EA, turned out to show significant activity similarly to some cocrystal ligands, particularly against cancer. These results points out that EA can be used as a testicular damage cure drug in future.

Warangalone Induces Apoptosis in HeLa Cells via Mitochondria-Mediated Endogenous Pathway

Cervical cancer as one of the major malignant tumors seriously threatens women's health. More than 270,000 women die of cervical cancer each year. Warangalone is an isoflavone compound isolated from Cudrania tricuspidata with excellent antitumor activity. In this research, we investigated the molecular mechanism of warangalone-induced apoptosis in HeLa cells. The results show that warangalone can selectively and effectively inhibit HeLa cells proliferation. Warangalone can effectively inhibit the invasion and migration of HeLa cells. Furthermore, warangalone was confirmed to activate p53 and mitogen-activated protein kinase (MAPK) family signaling pathways to cause apoptosis. In this case, the expression of the B-cell lymphoma-2 (Bcl-2) family is regulated, and caspase-3 is eventually cleaved, finally triggering the mitochondrial apoptosis. In conclusion, warangalone can induce HeLa cells apoptosis via a mitochondria-mediated endogenous pathway, which represented the potential therapeutic effect of warangalone on cervical cancer.

Polyphenols as Antitumor Agents Targeting Key Players in Cancer-Driving Signaling Pathways

Polyphenols constitute an important group of natural products that are traditionally associated with a wide range of bioactivities. These are usually found in low concentrations in natural products and are now available in nutraceuticals or dietary supplements. A group of polyphenols that include apigenin, quercetin, curcumin, resveratrol, EGCG, and kaempferol have been shown to regulate signaling pathways that are central for cancer development, progression, and metastasis. Here, we describe novel mechanistic insights on the effect of this group of polyphenols on key elements of the signaling pathways impacting cancer. We describe the protein modifications induced by these polyphenols and their effect on the central elements of several signaling pathways including PI3K, Akt, mTOR, RAS, and MAPK and particularly those affecting the tumor suppressor p53 protein. Modifications of p53 induced by these polyphenols regulate p53 gene expression and protein levels and posttranslational modifications such as phosphorylation, acetylation, and ubiquitination that influence stability, subcellular location, activation of new transcriptional targets, and the role of p53 in response to DNA damage, apoptosis control, cell- cycle regulation, senescence, and cell fate. Thus, deep understanding of the effects that polyphenols have on these key players in cancer-driving signaling pathways will certainly lead to better designed targeted therapies, with less toxicity for cancer treatment. The scope of this review centers on the regulation of key elements of cancer signaling pathways by the most studied polyphenols and highlights the importance of a profound understanding of these regulations in order to improve cancer treatment and control with natural products.

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.

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

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

EGCG-Mediated Potential Inhibition of Biofilm Development and Quorum Sensing in Pseudomonas aeruginosa

Pseudomonas aeruginosa (P. aeruginosa), one of the dangerous multidrug resistance pathogens, orchestrates virulence factors production through quorum sensing (QS). Since the exploration of QS inhibitors, targeting virulence to circumvent bacterial pathogenesis without causing significant growth inhibition is a promising approach to treat P. aeruginosa infections. The present study has evaluated the anti-QS and anti-infective activity of epigallocatechin-3-gallate (EGCG), a bioactive ingredient of the traditional green tea, against P. aeruginosa. EGCG showed significant inhibitory effects on the development of biofilm, protease, elastase activity, swimming, and swarming motility, which was positively related to the production of C4-AHL. The expression of QS-related and QS-regulated virulence factors genes was also evaluated. Quantitative PCR analysis showed that EGCG significantly reduced the expression of las, rhl, and PQS genes and was highly correlated with the alterations of C4-AHL production. In-vivo experiments demonstrated that EGCG treatment reduced P. aeruginosa pathogenicity in Caenorhabditis elegans (C. elegans). EGCG increased the survival of C. elegans by 23.25%, 30.04%, and 36.35% in a dose-dependent manner. The findings of this study strongly suggest that EGCG could be a potential candidate for QS inhibition as an anti-virulence compound against bacterial infection.

Cumulative tea consumption is inversely associated with colorectal adenomas in adults: A cross-sectional study in a Taiwanese population

PURPOSE

This study examined the association between cumulative tea consumption over time and various colorectal adenomas as well as their pathology, number, and size.

METHODS

7355 eligible subjects who underwent health check-ups with colonoscopies were recruited. They were classified into three groups: polyp-free, having low-risk colorectal adenomas, and having high-risk colorectal adenomas. The adenoma pathology, number, and size were collected. We defined 120 mL for each Chinese traditional teapot as a 'cup', and calculated the average daily cups of tea consumed. A 'cup-year' was defined as the daily cups multiplied by the years of tea consumption and was used to express the cumulative amount of tea consumption over time.

RESULTS

Compared to those with no habitual tea consumption, the lowest, middle, and highest tertiles of tea consumption were found to be inversely related to low-risk colorectal adenomas. For high-risk colorectal adenomas, a negative association was found only in the group with the highest tertile of tea consumption. An inverse association between the highest tertile of tea consumption and various features of high-risk colorectal adenomas was also found for villous-rich adenomas and the presence of three or more adenomas, but was not found to be related to adenoma size ≥1 cm.

CONCLUSION

Tea drinking was inversely associated with both low-risk and high-risk colorectal adenomas. Only a larger cumulative dose of ≥42 cup-years was negatively associated with high-risk colorectal adenomas, especially adenomas with villous-rich pathology and when three or more adenomas were present.

Epigallocatechin-3-gallate inhibits proliferation and triggers apoptosis in colon cancer via the hedgehog/phosphoinositide 3-kinase pathways

The present study evaluated whether epigallocatechin-3-gallate (EGCG) effectively attenuates tumor growth in colon cancer cells and in the xenografts of nude mice and investigated the underlying mechanisms by focusing on the sonic hedgehog (Shh) and phosphoinositide 3-kinase (PI3K) pathways. Three kinds of colon cancer cells and BALB/c nude mice were used to evaluate the antiproliferative effect of EGCG. The apoptosis, migration, and invasion of colon cancer cells were analyzed to explore the toxicity effect of EGCG on colon cancer cells. Western blotting was used to demonstrate the expression levels of related proteins. The results showed that EGCG exhibited an antiproliferative effect against colon cancer cells in a dose-dependent manner with low toxicity against normal colon epithelial cells. Administration of EGCG caused significant apoptosis and inhibited the migration and invasion of colon cancer cells. The toxic effect of EGCG on colon cancer cells was accompanied by downregulation of the Shh and PI3K/Akt pathways. In addition, EGCG reduced tumor volume and weight without affecting the body weight of nude mice and inhibited the activation of the Shh and PI3K/AKT pathways in tumor tissue. Further study showed that purmorphamine (smoothened (Smo) agonist) or insulin like growth factor-1 (IGF-1, PI3K agonist) partly abolished the effect of EGCG on cell proliferation, migration, and apoptosis. Cyclopamine (Smo inhibitor) and LY294002 (PI3K inhibitor) showed the similar toxic effects as EGCG on colon cancer cells. In conclusion, EGCG inhibited colon tumor growth via downregulation of the Shh and PI3K pathways and may be a potential chemotherapeutic agent against colon cancer.

EGCG binds intrinsically disordered N-terminal domain of p53 and disrupts p53-MDM2 interaction

Epigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG's anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.

Current status and future prospects of p38α/MAPK14 kinase and its inhibitors

P38α (which is also named MAPK14) plays a pivotal role in initiating different disease states such as inflammatory disorders, neurodegenerative diseases, cardiovascular cases, and cancer. Inhibitors of p38α can be utilized for treatment of these diseases. In this article, we reviewed the structural and biological characteristics of p38α, its relationship to the fore-mentioned disease states, as well as the recently reported inhibitors and classified them according to their chemical structures. We focused on the articles published in the literature during the last decade (2011-2020).

Tea polyphenol EGCG inhibited colorectal-cancer-cell proliferation and migration via downregulation of STAT3

Background

Green tea is a popular beverage worldwide and epigallocatechin-3-gallate (EGCG) is the most bioactive polyphenol in green tea. Our study aims to investigate the anti-proliferation and anti-migration effects of EGCG against colorectal-cancer SW480, SW620, and LS411N cells, and elucidate the underlying mechanism.

Methods

The in vitro anti-proliferation and anti-migration effects of EGCG against colon-cancer cells were evaluated using MTT, scratch-wound-healing, and transwell-migration assays. The effects of EGCG on apoptosis were assessed by Annexin V-FITC/PI double staining and JC-1 staining. Besides, Western blotting was employed to detect the protein-expression level and elucidate the underlying pathways. Real-time qPCR and dual-luciferase reporter assay were adopted to determine the mRNA level and promoter activity.

Results

Our results demonstrated that treatment with EGCG resulted in significant inhibition of cell proliferation by the induction of apoptosis. EGCG also inhibited SW480 cell migration in a dose-dependent manner as assessed by wound-healing and transwell-migration assays. Western blot confirmed that EGCG induced apoptosis by the activation of Caspase-3 and PARP. In addition, both STAT3 and phosphorylated STAT3 (p-STAT3) were downregulated significantly by EGCG in three selected colorectal-cancer cell lines. EGCG treatment also resulted in a significant decrease in Bcl-2, MCL-1, and Vimentin, and an increase in E-cadherin. When STAT3 was inhibited, EGCG showed no obvious effect on cell proliferation and migration. Further investigation by luciferase-reporter-activity assay showed that EGCG suppressed the promoter activity of STAT3 and downregulated the transcription of STAT3.

Conclusion

Our study presents evidence on the anti-proliferation and anti-migration effects of EGCG against colorectal-cancer SW480, SW620, and LS411N cells by downregulating the expression of STAT3 and suggests that EGCG could be an effective and natural supplement for colon-cancer treatment.

Flavonoids Regulate Inflammation and Oxidative Stress in Cancer

Cancer is the second leading cause of death globally. Millions of persons die due to cancer each year. In the last two decades, the anticancer effects of natural flavonoids have become a hot topic in many laboratories. Meanwhile, flavonoids, of which over 8000 molecules are known to date, are potential candidates for the discovery of anticancer drugs. The current review summarizes the major flavonoid classes of anticancer efficacy and discusses the potential anti-cancer mechanisms through inflammation and oxidative stress action, which were based on database and clinical studies within the past years. The results showed that flavonoids could regulate the inflammatory response and oxidative stress of tumor through some anti-inflammatory mechanisms such as NF-κB, so as to realize the anti-tumor effect.

Crocetin suppresses the growth and migration in HCT-116 human colorectal cancer cells by activating the p-38 MAPK signaling pathway

Background and purpose:

Crocetin is a natural antioxidant that is found in the crocus flower and Gardenia jasminoides (fruit). Previous studies have reported its anticancer activity both in vivo and in vitro. In addition, crocetin suppresses the growth and migration of human colorectal cancer cells, however, its mechanism of action remains to be elucidated. Therefore, the present study investigated the molecular mechanism of crocetin effect on colorectal cancer cells (HCT-116) in vitro.

Experimental approach:

HCT-116 cells were treated with different concentrations (0, 200, 400, 600, and 800 μM) of crocetin for 24 h. The cell survival rate was measured by MTT assay. Cell migration capacity was evaluated using the wound healing assay. The expression levels of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP-9) was monitored by RT-PCR. Phosphorylation of focal adhesion kinase (FAK) and p38 mitogen-activated protein kinase (MAPK) was determined using western blot.

Findings/Results:

The proliferation of HCT-116 was inhibited by crocetin at 800 μM (P < 0.001). Crocetin prevented migration of HCT-116 cells (P < 0.05) and suppressed VEGF and MMP-9 mRNA expression (P < 0.001) and increased phosphorylation of p38 (MAPK; P < 0.001). However, no significant change in the phosphorylation of FAK was observed.

Conclusion and implication:

These data suggested that crocetin-induced growth- and migration- suppressing effects on HCT-116 cells may partially depend on the regulation of the p38 (MAPK) signaling pathway.

Epigallocatechin gallate inhibits HeLa cells by modulation of epigenetics and signaling pathways

This study examines the effect of epigallocatechin gallate (EGCG) on signaling pathways, epigenetic modulators and tumour suppressor genes in cervical cancer cells, HeLa. qRT-PCR, ELISA-based enzymatic assays and in silico studies were used to catalogue the modulation of these genes by EGCG treatment. qRT-PCR showed transcriptional modulation of several epigenetic modifiers including DNA methyltransferases and histone modifiers (DNMT1, DNMT3B, DNMT3A, AURKA, AURKC, AURKB, KDM4A, KDM5C, PRMT7, PRMT6, UBE2B, HDAC5, HDAC6, HDAC7 and HDAC11. Furthermore, ELISA-based assays showed that EGCG lowered the activity of DNA methyltransferases, histone deacetylases and histone methyltransferases (H3K9). Molecular docking results suggests that EGCG may competitively inhibit some epigenetic enzymes (DNMT1, DNMT3A, HDAC2, HDAC3, HDAC4, HDAC7 and EZH2). A functional outcome of these epigenetic alterations could be inferred from the reversal of promoter hypermethylation of tumour suppressor genes by quantitative methylation array and transcriptional re-expression of tumour suppressor genes including TP73, PTEN, SOCS1, CDH1, RARβ, and DAPK1 by qRT-PCR. Downregulation of key signaling moieties of PI3K, Wnt and MAPK pathways, cell cycle regulators, metastasis regulators and pro-inflammatory moieties including TERT, CCNB1, CCNB2, MMP2, MMP7. PIK3C2B, PIK3CA, MAPK8 and IL6 was also observed. In silico protein-protein interaction network analysis followed by KEGG analysis discerned the active participation of gene sets towards cancer pathways. This study comprehensively explains EGCG's anti-cancer mechanism via the synchronized transcriptional alteration of several molecular targets across different signaling pathways and reversal of tumour suppressor gene silencing through modulation of epigenetic enzymes.

Epigallocatechin gallate induces chemopreventive effects on rats with diethylnitrosamine‑induced liver cancer via inhibition of cell division cycle 25A

Epigallocatechin gallate (EGCG), the most active monomer in green tea (GT), has demonstrated potential therapeutic and preventive effects on various tumors, including liver cancer. However, the anticancer mechanisms of EGCG in liver cancer remain to be elucidated. The abnormal expression of cell division cycle 25A (CDC25A) has been identified in liver cancer and is closely associated with malignancy and poor prognosis in patients with hepatocellular carcinoma (HCC). The present study used human hepatoma cell lines and rats with diethylnitrosamine (DEN)-induced HCC as models to investigate the association between the effect of EGCG on liver cancer and regulation of the p21waf1/Cip1/CDC25A axis. The results demonstrated that EGCG can inhibit the proliferation of HepG2 and Huh7 cells, reduce the expression of CDC25A and increase the expression of p21waf1/Cip1 in HepG2. In vivo, HCC was induced by DEN in Sprague-Dawley rats. EGCG significantly reduced tumor volume and improved the survival rates of rats with HCC. The expression levels of CDC25A mRNA and protein in liver tissues and the level of serum γ glutamyl transpeptidase in rats treated with EGCG were significantly decreased, while p21waf1/Cip1 mRNA and protein expression levels were increased compared with the HCC group, in the process of DEN-induced HCC. No significant difference in the chemopreventive effects on liver cancer was observed between GT extract and EGCG under an EGCG equivalence condition. Thus, EGCG can suppress human hepatoma cell proliferation and prolong the survival of rats with HCC, and the potential mechanism may be involved in EGCG-induced upregulation of p21waf1/Cip1 and downregulation of CDC25A.

Natural Compounds Targeting Cancer Stem Cells: A Promising Resource for Chemotherapy

BACKGROUND

Cancer Stem Cells (CSCs) are the subpopulation of cancer cells which are directly involved in drug resistance, metastases to distant organ and cancer recurrence.

METHODS

A systematic literature search was conducted through various electronic databases including, Pubmed, Scopus, Google scholar using the keywords "cancer stem cells" and "natural compounds" in the present study. Articles published between 1999 and 2019 were reviewed. All the expositions concerning CSCs associated cancer pathogenesis and therapy resistance, as well as targeting these properties of CSCs by natural compounds were selected for the current study.

RESULTS

Natural compounds have always been thought as a rich source of biologically active principles, which target aberrantly activated signaling pathways and other modalities of CSCs, while tethering painful side effects commonly involved in the first-line and second-line chemo-radiotherapies. In this review, we have described the key signaling pathways activated in CSCs to maintain their survival and highlighted how natural compounds interrupt these signaling pathways to minimize therapy resistance, pathogenesis and cancer recurrence properties of CSCs, thereby providing useful strategies to treat cancer or aid in cancer therapy improvement. Like normal stem cells, CSCs rely on different signaling pathways and other properties for their maintenance. Therefore, the success of cancer treatment depends on the development of proper anti-neoplastic drugs capable of intercepting those signaling pathways as well as other properties of CSCs in order to eradicate this evasive subpopulation of cancer cells.

CONCLUSION

Compounds of natural origin might act as an outstanding source to design novel therapies against cancer stem cells.

EGCG induces β-defensin 3 against influenza A virus H1N1 by the MAPK signaling pathway

Epigallocatechin gallate (EGCG) is the main component of green tea, which has been proven to inhibit a variety of viruses, including influenza A virus. However, the mechanism of EGCG against influenza virus remains to be further explored. The mechanism of EGCG against influenza virus was studied. The results showed that EGCG significantly increased the levels of HBD3 mRNA and protein, while the levels of phosphorylation of (p)-p38 MAPK, ERK and JNK after EGCG treatment were significantly up-regulated. p38 MAPK, ERK and JNK inhibitors significantly inhibited the expression of HBD3 induced by EGCG. On the other hand, EGCG significantly inhibited the expression of HA and NP proteins in influenza A virus H1N1, but attenuated the anti-influenza A virus effect of EGCG after silencing HBD3. Thus, the anti-influenza virus effect of EGCG is related to the induction of HBD3 expression. In addition, the expression of EGCG-induced HBD3 is related to the p38 MAPK, ERK and JNK signaling pathways. The research data show that EGCG can induce HBD3 expression through p38 MAPK, ERK and JNK signaling pathway to inhibit the replication of influenza A virus H1N1, providing a new and effective candidate drug for influenza virus.

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.

Mapping Pharmacological Network of Multi-Targeting Litchi Ingredients in Cancer Therapeutics

Considerable pharmacological studies have demonstrated that the extracts and ingredients from different parts (seeds, peels, pulps, and flowers) of Litchi exhibited anticancer effects by affecting the proliferation, apoptosis, autophagy, metastasis, chemotherapy and radiotherapy sensitivity, stemness, metabolism, angiogenesis, and immunity via multiple targeting. However, there is no systematical analysis on the interaction network of “multiple ingredients-multiple targets-multiple pathways” anticancer effects of Litchi. In this study, we summarized the confirmed anticancer ingredients and molecular targets of Litchi based on published articles and applied network pharmacology approach to explore the complex mechanisms underlying these effects from a perspective of system biology. The top ingredients, top targets, and top pathways of each anticancer function were identified using network pharmacology approach. Further intersecting analyses showed that Epigallocatechin gallate (EGCG), Gallic acid, Kaempferol, Luteolin, and Betulinic acid were the top ingredients which might be the key ingredients exerting anticancer function of Litchi, while BAX, BCL2, CASP3, and AKT1 were the top targets which might be the main targets underling the anticancer mechanisms of these top ingredients. These results provided references for further understanding and exploration of Litchi as therapeutics in cancer as well as the application of “Component Formula” based on Litchi’s effective ingredients.

Homeobox B5 suppression attenuates proliferation and elevates apoptosis in hepatoma cell lines through ERK/MDM2 signalling

Homeobox B5 (HOXB5), a member of the HOX gene family, is an important gene in tumourigenesis. However, its role in hepatocellular carcinoma (HCC) cell proliferation and apoptosis remains unclear. In this study, we investigated the role and regulation mechanism of HOXB5 in HCC cell lines Hep3B and LM6. The data indicated high expression of HOXB5 in HCC tissues and cell lines. In HCC cells, inhibition of HOXB5 by transfection with HOXB5 siRNA significantly constrained cell viability, and Bcl-2 levels, and it increased cell apoptosis, cytochrome c levels, BAX levels, and caspase-3 activity. On the contrary, HOXB5 overexpression increased proliferation and Bcl-2 levels but inhibited BAX levels and caspase-3 activity in these cells. HOXB5 downregulation attenuated activation of extracellular signal-regulated kinase (ERK) and expression of the murine double minute 2 (MDM2) oncogene. Incubation with the ERK activator, phorbol 12-myristate 13-acetate (40 μmol/L), for 12 hours reversed the effects of HOXB5 inhibition on MDM2 expression, cell proliferation, and apoptosis in HCC cells. Overall, this study demonstrated that HOXB5 inhibition regulated MDM2 expression by controlling ERK activation and that it modulated proliferation and apoptosis in HCC cells.

Tea polyphenols and their chemopreventive and therapeutic effects on colorectal cancer

Colorectal cancer (CRC), a multifactorial disease, is usually induced and developed through complex mechanisms, including impact of diet and lifestyle, genomic abnormalities, change of signaling pathways, inflammatory response, oxidation stress, dysbiosis, and so on. As natural polyphenolic phytochemicals that exist primarily in tea, tea polyphenols (TPs) have been shown to have many clinical applications, especially as anticancer agents. Most animal studies and epidemiological studies have demonstrated that TPs can prevent and treat CRC. TPs can inhibit the growth and metastasis of CRC by exerting the anti-inflammatory, anti-oxidative or pro-oxidative, and pro-apoptotic effects, which are achieved by modulations at multiple levels. Many experiments have demonstrated that TPs can modulate several signaling pathways in cancer cells, including the mitogen-activated protein kinase pathway, phosphatidylinositol-3 kinase/Akt pathway, Wnt/β-catenin pathway, and 67 kDa laminin receptor pathway, to inhibit proliferation and promote cell apoptosis. In addition, novel studies have also suggested that TPs can prevent the growth and metastasis of CRC by modulating the composition of gut microbiota to improve immune system and decrease inflammatory responses. Molecular pathological epidemiology, a novel multidisciplinary investigation, has made great progress on CRC, and the further molecular pathological epidemiology research should be developed in the field of TPs and CRC. This review summarizes the existing in vitro and in vivo animal and human studies and potential mechanisms to examine the effects of tea polyphenols on CRC.

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.

EGCG regulates CTR1 expression through its pro-oxidative property in non-small-cell lung cancer cells

Copper transporter 1 (CTR1) plays an important role in increasing cisplatin intake. Our previous studies showed that CTR1 expression was upregulated by (-)-epigallocatechin-3-gallate (EGCG), a green tea polyphenol, therefore enhanced cisplatin sensitivity in ovary cancer and non-small-cell lung cancer (NSCLC) cells. In the current study in the non-small-cell lung cancer cells, we uncovered a potential mechanism of EGCG-induced CTR1 through its pro-oxidative property. We found that EGCG increased reactive oxygen species (ROS) generation, while in the presence of ROS scavenger N-acetyl-cysteine (NAC), ROS production was eliminated. Changes of CTR1 expression were consistent with the ROS level. Simultaneously, EGCG downregulated ERK1/2 while upregulated lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) through ROS to induce CTR1 expression. Besides, in a nude mouse xenografts model, EGCG treatment raised ROS level, expression of CTR1 and NEAT1 in tumor tissue. Also, ERK1/2 and p-ERK1/2 were suppressed as well. Taken together, these results suggested a novel mechanism that EGCG mediated ROS to regulate CTR1 expression through the ERK1/2/NEAT1 signaling pathway, which provided more possibilities for EGCG as a natural agent in adjuvant therapy of lung cancer.

Green tea polyphenol epigallocatechin-3-gallate improves the antioxidant capacity of eggs

Dietary supplementation with EGCG led to an increase in egg antioxidant activity and antioxidant chemical substances, tryptophan and carotenoid. This may be associated with its increasing effect on the oxidative stress related regulators expression (P38MAPK, Nrf2 and HO-1).

Cocoa tea (Camellia ptilophylla) induces mitochondria-dependent apoptosis in HCT116 cells via ROS generation and PI3K/Akt signaling pathway

Cocoa tea (Camellia ptilophylla), a natural gallocatechin gallate (GCG)-rich and low caffeine-containing tea species, has been recently reported to possess various bioactivities. However, the anti-colon cancer effects of Cocoa tea and its underlying mechanisms remain virtually unknown. This study aimed to assess the anti-proliferative and pro-apoptotic effects of water extract of Cocoa tea (CWE) on human colon cancer HCT116 cells compared with Yunnan Daye tea (YWE). Primarily, CWE showed stronger anti-proliferation and apoptosis induction than YWE. Moreover, reduction of mitochondrial membrane potential (MMP), up-regulation of Bax/Bcl-2 ratio, release of cytochrome c, activation of caspase-9 and -3, and cleavage of poly (ADP-ribose) polymerase (PARP) were observed, suggesting that mitochondrial apoptotic pathway was activated by CWE. Furthermore, CWE-induced apoptosis in HCT116 cells was dependent on the generation of intracellular reactive oxygen species (ROS) and down-regulation of phosphatidylinositol-3-kinase (PI3K)/Akt pathway. Pretreatment with ROS scavenger N-acetyl cysteine (NAC) attenuated the impact of CWE on mitochondria-related apoptosis proteins, and partially recovered the inhibition of Akt phosphorylation. These results indicated that ROS generation mediated mitochondrial dysfunction and inactivation of PI3K/Akt pathway in CWE-induced HCT116 cell apoptosis. Additionally, CWE significantly inhibited tumor growth in HCT116 tumor-bearing mice, suggesting that Cocoa tea could act as a potential functional beverage to prevent or treat colorectal cancer.

Licochalcone A-Induced Apoptosis Through the Activation of p38MAPK Pathway Mediated Mitochondrial Pathways of Apoptosis in Human Osteosarcoma Cells In Vitro and In Vivo

BACKGROUND

Licochalcone A (LicA) is isolated from the roots of Glycyrrhiza glabra and possesses antitumor and anti-invasive activities against several tumor cells. However, the antitumor effects of LicA on human osteosarcoma cells have yet to be demonstrated either in vitro or in vivo.

METHODS

Cell viability was measured by MTT assay. Apoptosis and mitochondrial dysfunction were detected with Annexin V/PI staining and JC-1 staining by flow cytometry. The expressions of caspase- or mitochondrial-related proteins were demonstrated by western blotting. Antitumor effect of LicA on 143B xenograft mice in vivo.

RESULTS

LicA could inhibit cell proliferation and induce apoptosis in human osteosarcoma cells, as evidenced by a decrease in cell viability, loss of mitochondrial membrane potentials, and activation of caspases. LicA treatment substantially reduced the expression of Bcl-2 and Mcl-1 and increased the expression of cleaved-caspase-3, cleaved-caspase-9, cleaved-PARP, and Bax in HOS and U2OS cells. Moreover, mitochondrial membrane potential and apoptosis suppression mediated by Z-VAD or tauroursodeoxycholic acid significantly reduced LicA-induced mitochondria-dependent apoptosis. The study also determined that LicA treatment induced p38MAPK phosphorylation, but siRNA-p38 or BIRB796 substantially reversed cell viability through the inhibition of mitochondria-dependent apoptosis pathways. Finally, an in vivo study revealed that LicA significantly inhibited 143B xenograft tumor growth.

CONCLUSIONS

These findings demonstrate that LicA has antitumor activities against human osteosarcoma cells through p38MAPK regulation of mitochondria-mediated intrinsic apoptotic pathways in vitro and in vivo.

Combinatorial Epigenetics Impact of Polyphenols and Phytochemicals in Cancer Prevention and Therapy

Polyphenols are potent micronutrients that can be found in large quantities in various food sources and spices. These compounds, also known as phenolics due to their phenolic structure, play a vital nutrient-based role in the prevention of various diseases such as diabetes, cardiovascular diseases, neurodegenerative diseases, liver disease, and cancers. However, the function of polyphenols in disease prevention and therapy depends on their dietary consumption and biological properties. According to American Cancer Society statistics, there will be an expected rise of 23.6 million new cancer cases by 2030. Due to the severity of the increased risk, it is important to evaluate various preventive measures associated with cancer. Relatively recently, numerous studies have indicated that various dietary polyphenols and phytochemicals possess properties of modifying epigenetic mechanisms that modulate gene expression resulting in regulation of cancer. These polyphenols and phytochemicals, when administrated in a dose-dependent and combinatorial-based manner, can have an enhanced effect on epigenetic changes, which play a crucial role in cancer prevention and therapy. Hence, this review will focus on the mechanisms of combined polyphenols and phytochemicals that can impact various epigenetic modifications such as DNA methylation and histone modifications as well as regulation of non-coding miRNAs expression for treatment and prevention of various types of cancer.

Advances in the Antagonism of Epigallocatechin-3-gallate in the Treatment of Digestive Tract Tumors

Due to changes in the dietary structure of individuals, the incidence of digestive tract tumors has increased significantly in recent years, causing a serious threat to the life and health of patients. This has in turn led to an increase in cancer prevention research. Many studies have shown that epigallocatechin-3-gallate (EGCG), an active ingredient in green tea, is in direct contact with the digestive tract upon ingestion, which allows it to elicit a significant antagonizing effect on digestive tract tumors. The main results of EGCG treatment include the prevention of tumor development in the digestive tract and the induction of cell cycle arrest and apoptosis. EGCG can be orally administered, is safe, and combats other resistances. The synergistic use of cancer drugs can promote the efficacy and reduce the anti-allergic properties of drugs, and is thus, favored in medical research. EGCG, however, currently possesses several shortcomings such as poor stability and low bioavailability, and its clinical application prospects need further development. In this paper, we have systematically summarized the research progress on the ability of EGCG to antagonize the activity and mechanism of action of digestive tract tumors, to achieve prevention, alleviation, delay, and even treat human gastrointestinal tract tumors via exogenous dietary EGCG supplementation or the development of new drugs containing EGCG.

Flavonoids in Cancer and Apoptosis

Cancer is the second leading cause of death globally. Although, there are many different approaches to cancer treatment, they are often painful due to adverse side effects and are sometimes ineffective due to increasing resistance to classical anti-cancer drugs or radiation therapy. Targeting delayed/inhibited apoptosis is a major approach in cancer treatment and a highly active area of research. Plant derived natural compounds are of major interest due to their high bioavailability, safety, minimal side effects and, most importantly, cost effectiveness. Flavonoids have gained importance as anti-cancer agents and have shown great potential as cytotoxic anti-cancer agents promoting apoptosis in cancer cells. In this review, a summary of flavonoids and their effectiveness in cancer treatment targeting apoptosis has been discussed.