New cancer treatment strategy using combination of green tea catechins and anticancer drugs

Catechin-Functionalized Cationic Lipopolymer Based Multicomponent Nanomicelles for Lung-Targeting Delivery

Catechins from green tea are one of the most effective natural compounds for cancer chemoprevention and have attracted extensive research. Cancer cell-selective apoptosis-inducing properties of catechins depend on efficient intracellular delivery. However, the low bioavailability limits the application of catechins. Herein, a nano-scaled micellar composite composed of catechin-functionalized cationic lipopolymer and serum albumin is constructed. Cationic liposomes tend to accumulate in the pulmonary microvasculature due to electrostatic effects and are able to deliver the micellar system intracellularly, thus improving the bioavailability of catechins. Albumin in the system acts as a biocompatible anti-plasma absorbent, forming complexes with positively charged lipopolymer under electrostatic interactions, contributing to prolonged in vivo retention. The physicochemical properties of the nano-micellar complexes are characterized, and the antitumor properties of catechin-functionalized materials are confirmed by reactive oxygen species (ROS), caspase-3, and cell apoptosis measurements. The role of each functional module, cationic polymeric liposome, and albumin is revealed by cell penetration, in vivo animal assays, etc. This multicomponent micellar nanocomposite has the potential to become an effective vehicle for the treatment of lung diseases such as pneumonia, lung tumors, sepsis-induced lung injury, etc. This study also demonstrates that it is a great strategy to create a delivery system that is both tissue-targeted and biologically active by combining cationic liposomes with the native bioactive compound catechins.

Transcriptomic, 16S ribosomal ribonucleic acid and network pharmacology analyses shed light on the anticoccidial mechanism of green tea polyphenols against Eimeria tenella infection in Wuliangshan black-boned chickens

BACKGROUND

Eimeria tenella is an obligate intracellular parasitic protozoan that invades the chicken cecum and causes coccidiosis, which induces acute lesions and weight loss. Elucidating the anticoccidial mechanism of action of green tea polyphenols could aid the development of anticoccidial drugs and resolve the problem of drug resistance in E. tenella.

METHODS

We constructed a model of E. tenella infection in Wuliangshan black-boned chickens, an indigenous breed of Yunnan Province, China, to study the efficacy of green tea polyphenols against the infection. Alterations in gene expression and in the microbial flora in the cecum were analyzed by ribonucleic acid (RNA) sequencing and 16S ribosomal RNA (rRNA) sequencing. Quantitative real-time polymerase chain reaction was used to verify the host gene expression data obtained by RNA sequencing. Network pharmacology and molecular docking were used to clarify the interactions between the component green tea polyphenols and the targeted proteins; potential anticoccidial herbs were also analyzed.

RESULTS

Treatment with the green tea polyphenols led to a reduction in the lesion score and weight loss of the chickens induced by E. tenella infection. The expression of matrix metalloproteinase 7 (MMP7), MMP1, nitric oxide synthase 2 and ephrin type-A receptor 2 was significantly altered in the E. tenella infection plus green tea polyphenol-treated group and in the E. tenella infection group compared with the control group; these genes were also predicted targets of tea polyphenols. Furthermore, the tea polyphenol (-)-epigallocatechin gallate acted on most of the targets, and the molecular docking analysis showed that it has good affinity with interferon induced with helicase C domain 1 protein. 16S ribosomal RNA sequencing showed that the green tea polyphenols had a regulatory effect on changes in the fecal microbiota induced by E. tenella infection. In total, 171 herbs were predicted to act on two or three targets in MMP7, MMP1, nitric oxide synthase 2 and ephrin type-A receptor 2.

CONCLUSIONS

Green tea polyphenols can directly or indirectly regulate host gene expression and alter the growth of microbiota. The results presented here shed light on the mechanism of action of green tea polyphenols against E. tenella infection in chickens, and have implications for the development of novel anticoccidial products.

The Protective Role of Dietary Polyphenols in Urolithiasis: Insights into Antioxidant Effects and Mechanisms of Action

Urolithiasis is a common urological disease with increasing prevalence and high recurrence rates around the world. Numerous studies have indicated reactive oxygen species (ROS) and oxidative stress (OS) were crucial pathogenic factors in stone formation. Dietary polyphenols are a large group of natural antioxidant compounds widely distributed in plant-based foods and beverages. Their diverse health benefits have attracted growing scientific attention in recent decades. Many literatures have reported the effectiveness of dietary polyphenols against stone formation. The antiurolithiatic mechanisms of polyphenols have been explained by their antioxidant potential to scavenge free radicals and ROS, modulate the expression and the activity of endogenous antioxidant and prooxidant enzymes, regulate signaling pathways associated with OS, and maintain cell morphology and function. In this review, we first describe OS and its pathogenic effects in urolithiasis and summarize the classification and sources of dietary polyphenols. Then, we focus on the current evidence defining their antioxidant potential against stone formation and put forward challenges and future perspectives of dietary polyphenols. To conclude, dietary polyphenols offer potential applications in the treatment and prevention of urolithiasis.

Green extraction and biological activity of phenolic extracts from cashew nut testa using a combination of enzyme and ultrasound-assisted treatments

BACKGROUND

A combination of enzymes and ultrasound treatment was employed to extract bioactive compounds from cashew nut testa, a by-product of the food industry. The total catechin, flavonoid, and phenolic content of extracts was investigated together with their biological activity.

RESULTS

Enzyme and ultrasound-assisted extraction (E-UAE) was performed by incubation with Viscozyme L (20 mL kg^-1 of testa powder, v/w) for 60 min before sonication for 40 min. Ultrasound and enzyme-assisted extraction (U-EAE) was carried out using sonication for 40 min before incubation with Viscozyme L (20 mL kg^-1 of testa powder) for 60 min. Under appropriate conditions, the total phenolic, flavonoid, catechin, and epigallocatechin gallate content of the extracts from cashew nut testa obtained from a combination method (U-EAE or E-UAE) was significantly higher than that obtained using a single method (EAE or UAE). Extracts of cashew nut testa obtained from E-UAE displayed significantly higher antioxidant and α-amylase inhibitory activity than those from the U-EAE. The E-UAE extract at a concentration of 100 μg mL^-1 had a greater impact on the cell viability of MCF-7 after treatment (22% cell viability) than did the doxorubicin (DOX) at 4 μg mL^-1 (39% cell viability), and the E-UAE extract at 100 μg mL^-1 was considered to be safe for healthy cells because the viability of the bovine aerotic endothelial cells treated with this extract was 91%, which was similar to the DOX treatment.

CONCLUSION

The extract of cashew nut testa obtained from E-UAE is valuable and promising for the development of anti-inflammatory therapeutic drugs. © 2023 Society of Chemical Industry.

Chlorophyll Pigments of Olive Leaves and Green Tea Extracts Differentially Affect Their Antioxidant and Anticancer Properties

Plant-based extracts possess biological potential due to their high content of phytochemicals. Nevertheless, photosynthetic pigments (e.g., chlorophylls) that are also present in plant extracts could produce undesirable pro-oxidant activity that might cause a negative impact on their eventual application. Herein, the phenolic content of olive leaf (OLE) and green tea (GTE) extracts was assayed, and their antioxidant and anticancer activities were evaluated before and after the removal of chlorophylls. Regarding phenolic content, OLE was rich in hydroxytyrosol, tyrosol as well as oleuropein, whereas the main compounds present in GTE were gallocatechin, epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallocatechin gallate, and caffeine. Interestingly, fresh extracts’ antioxidant ability was dependent on phenolic compounds; however, the elimination of chlorophyll compounds did not modify the antioxidant activity of extracts. In addition, both OLE and GTE had high cytotoxicity against HL-60 leukemic cell line. Of note, the removal of chlorophyll pigments remarkably reduced the cytotoxic effect in both cases. Therefore, our findings emphasize the remarkable antioxidant and anticancer potential of OLE and GTE and suggest that chlorophylls are of paramount importance for the tumor-killing ability of such plant-derived extracts.

Identifying the natural compound Catechin from tropical mangrove plants as a potential lead candidate against 3CLpro from SARS-CoV-2: An integrated in silico approach

SARS-CoV-2, a member of beta coronaviruses, is a single-stranded, positive-sense RNA virus responsible for the COVID-19 pandemic. With global fatalities of the pandemic exceeding 4.57 million, it becomes crucial to identify effective therapeutics against the virus. A protease, 3CL^pro, is responsible for the proteolysis of viral polypeptides into functional proteins, which is essential for viral pathogenesis. This indispensable activity of 3CL^pro makes it an attractive target for inhibition studies. The current study aimed to identify potential lead molecules against 3CL^pro of SARS-CoV-2 using a manually curated in-house library of antiviral compounds from mangrove plants. This study employed the structure-based virtual screening technique to evaluate an in-house library of antiviral compounds against 3CL^pro of SARS-CoV-2. The library was comprised of thirty-three experimentally proven antiviral molecules extracted from different species of tropical mangrove plants. The molecules in the library were virtually screened using AutoDock Vina, and subsequently, the top five promising 3CL^pro-ligand complexes along with 3CL^pro-N3 (control molecule) complex were subjected to MD simulations to comprehend their dynamic behaviour and structural stabilities. Finally, the MM/PBSA approach was used to calculate the binding free energies of 3CLpro complexes. Among all the studied compounds, Catechin achieved the most significant binding free energy (-40.3 ± 3.1 kcal/mol), and was closest to the control molecule (-42.8 ± 5.1 kcal/mol), and its complex with 3CL^pro exhibited the highest structural stability. Through extensive computational investigations, we propose Catechin as a potential therapeutic agent against SARS-CoV-2. Communicated by Ramaswamy H. Sarma.

Potential Properties of Natural Nutraceuticals and Antioxidants in Age-Related Eye Disorders

Eye health is crucial, and the onset of diseases can reduce vision and affect the quality of life of patients. The main causes of progressive and irreversible vision loss include various pathologies, such as cataracts, ocular atrophy, corneal opacity, age-related macular degeneration, uncorrected refractive error, posterior capsular opacification, uveitis, glaucoma, diabetic retinopathy, retinal detachment, undetermined disease and other disorders involving oxidative stress and inflammation. The eyes are constantly exposed to the external environment and, for this reason, must be protected from damage from the outside. Many drugs, including cortisonics and antinflammatory drugs have widely been used to counteract eye disorders. However, recent advances have been obtained via supplementation with natural antioxidants and nutraceuticals for patients. In particular, evidence has accumulated that polyphenols (mostly deriving from Citrus Bergamia) represent a reliable source of antioxidants able to counteract oxidative stress accompanying early stages of eye diseases. Luteolin in particular has been found to protect photoreceptors, thereby improving vision in many disease states. Moreover, a consistent anti-inflammatory response was found to occur when curcumin is used alone or in combination with other nutraceuticals. Additionally, Coenzyme Q10 has been demonstrated to produce a consistent effect in reducing ocular pressure, thereby leading to protection in patients undergoing glaucoma. Finally, both grape seed extract, rich in anthocyanosides, and polynsatured fatty acids seem to contribute to the prevention of retinal disorders. Thus, a combination of nutraceuticals and antioxidants may represent the right solution for a multi-action activity in eye protection, in association with current drug therapies, and this will be of potential interest in early stages of eye disorders.

Anticarcinogenic potentials of tea catechins

Catechins are a cluster of polyphenolic bioactive components in green tea. Anticarcinogenic effects of tea catechins have been reported since the 1980s, but it has been controversial. The present paper reviews the advances in studies on the anticarcinogenic activities of tea and catechins, including epidemiological evidence and anticarcinogenic mechanism. Tea catechins showed antagonistic effects on many cancers, such as gynecological cancers, digestive tract cancers, incident glioma, liver and gallbladder cancers, lung cancer, etc. The mechanism underlying the anticarcinogenic effects of catechins involves in inhibiting the proliferation and growth of cancer cells, scavenging free radicals, suppressing metastasis of cancer cells, improving immunity, interacting with other anticancer drugs, and regulating signaling pathways. The inconsistent results and their causes are also discussed in this paper.

Metagenomics Approach to the Intestinal Microbiome Structure and Abundance in High-Fat-Diet-Induced Hyperlipidemic Rat Fed with (-)-Epigallocatechin-3-Gallate Nanoparticles

The effects of nanoparticles (NPs) on microbiota homeostasis and their physiological relevance are still unclear. Herein, we compared the modulation and consequent pharmacological effects of oral administration of (−)-epigallocatechin-3-gallate (EGCG)-loaded β-cyclodextrin (β-CD) NPs (EGCG@β-CD NPs) and EGCG on gut microbiota. EGCG@β-CD NPs were prepared using self-assembly and their influence on the intestinal microbiome structure was analyzed using a metagenomics approach. The “Encapsulation efficiency (EE), particle size, polydispersity index (PDI), zeta potential” of EGCG@β-CD NPs were recorded as 98.27 ± 0.36%, 124.6 nm, 0.313 and –24.3 mV, respectively. Surface morphology of EGCG@β-CD NPs was observed as spherical. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and molecular docking studies confirmed that EGCG could be well encapsulated in β-CD and formed as EGCG@β-CD NPs. After being continuously administered EGCG@β-CD NPs for 8 weeks, the serum cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and liver malondialdehyde (MDA) levels in the rats were significantly decreased, while the levels of catalase (CAT) and apolipoprotein-A1 (apo-A1) in the liver increased significantly in the hyperlipidemia model of rats, when compared to the high-fat-diet group. Furthermore, metagenomic analysis revealed that the ratio of Verrucomicrobia/Bacteroidetes was altered and Bacteroidetes decreased in the high-fat diet +200 mg/kg·bw EGCG@β-CD NPs group, while the abundance of Verrucomicrobia was significantly increased, especially Akkermansia muciniphila in rat feces. EGCG@β-CD NPs could be a promising EGCG delivery strategy to modulate the gut microbiota, enhancing its employment in the prevention of hyperlipidemia.

Green Tea Epigallocatechin-3-Gallate Regulates Autophagy in Male and Female Reproductive Cancer

With a rich abundance of natural polyphenols, green tea has become one of the most popular and healthiest nonalcoholic beverages being consumed worldwide. Epigallocatechin-3-gallate (EGCG) is the predominant catechin found in green tea, which has been shown to promote numerous health benefits, including metabolic regulation, antioxidant, anti-inflammatory, and anticancer. Clinical studies have also shown the inhibitory effects of EGCG on cancers of the male and female reproductive system, including ovarian, cervical, endometrial, breast, testicular, and prostate cancers. Autophagy is a natural, self-degradation process that serves important functions in both tumor suppression and tumor cell survival. Naturally derived products have the potential to be an effective and safe alternative in balancing autophagy and maintaining homeostasis during tumor development. Although EGCG has been shown to play a critical role in the suppression of multiple cancers, its role as autophagy modulator in cancers of the male and female reproductive system remains to be fully discussed. Herein, we aim to provide an overview of the current knowledge of EGCG in targeting autophagy and its related signaling mechanism in reproductive cancers. Effects of EGCG on regulating autophagy toward reproductive cancers as a single therapy or cotreatment with other chemotherapies will be reviewed and compared. Additionally, the underlying mechanisms and crosstalk of EGCG between autophagy and other cellular processes, such as reactive oxidative stress, ER stress, angiogenesis, and apoptosis, will be summarized. The present review will help to shed light on the significance of green tea as a potential therapeutic treatment for reproductive cancers through regulating autophagy.

Rules of Chinese Herbal Intervention of Radiation Pneumonia Based on Network Pharmacology and Data Mining

Objective

To explore the mechanism and principles of traditional Chinese medicine (TCM) in the management of radiation pneumonia.

Methods

The targets of radiation pneumonia were obtained by screening the GeneCards, OMIM, TTD, DrugBank, and HERB databases, analyzing ADME parameters. In addition, compounds and Chinese herbs that can act on the targets were screened from the TCMSP database. The core target compounds for TCM were used to construct the target-compound, compound-traditional Chinese medicine, and target-compound-traditional Chinese medicine networks. These networks were further used to select the core targets, compounds, and TCM. The binding strength between the core targets and compounds was determined using AutoDock Vina. The trajectory for the molecular dynamics simulation was completed by Desmond version 2020.

Results

A total of 55 active targets in radiation pneumonia were identified. Subsequently, 137 candidate compounds and 469 Chinese herbs were matched. Frequency statistics showed that the Chinese herbs that could interfere with radiation pneumonia were mainly bitter, spicy, and sweet, with both cold and warm properties. Moreover, they mainly belonged to liver and lung channels. The core targets included TNF, IL-6, TGF-β1, and TP53. The most important components were quercetin, resveratrol, and (-)-epigallocatechin-3-gallate. Moreover, the most significant traditional Chinese herbs were Perilla pueraria, ephedra, Lonicerae japonicae, and sea buckthorn. Furthermore, analysis of 222 sets of receptor-ligand docking results suggested that the compounds had good docking activity to their core targets. By combining the docking binding energy, we determined that the chemical compounds had strong binding energy to the targets.

Conclusion

Using network pharmacology, we explored the potential mechanism of TCM in the treatment of radiation pneumonia. The general rules for application of TCM in the treatment of radiation pneumonia were summarized. This study provides baseline information for future research on the development of TCM for the management of radiation pneumonia.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial–mesenchymal transition, and migration of cancer cells).

Stiffening of Cancer Cell Membranes Is a Key Biophysical Mechanism of Primary and Tertiary Cancer Prevention with Green Tea Polyphenols

Over the past 30 years, research of green tea polyphenols, especially (-)-epigallocatechin gallate (EGCG), has revealed that consumption of green tea is a practical and effective primary cancer prevention method for the general population. More recently, we believe that green tea polyphenols are beneficial for tertiary cancer prevention using green tea alone or combined with anticancer drugs because EGCG has the potential to inhibit metastatic progression and stemness, and enhance antitumor immunity. In an effort to identify a common underlying mechanism responsible for EGCG's multifunctional effects on various molecular targets, we studied the biophysical effects of EGCG on cell stiffness using atomic force microscopy. We found that EGCG acts to stiffen the membranes of cancer cells, leading to inhibition of signaling pathways of various receptors. Stiffening of membranes with EGCG inhibited AXL receptor tyrosine kinase, a stimulator of cell softening, motility and stemness, and expression of programmed cell death-ligand 1. This review covers the following: i) primary cancer prevention using EGCG or green tea, ii) tertiary cancer prevention by combining EGCG and anticancer drugs, iii) inhibition of metastasis with EGCG by stiffening the cell membrane, iv) inhibition of AXL receptor tyrosine kinase, a stimulator of cell softening and motility, with EGCG, v) inhibition of stemness properties with EGCG, and vi) EGCG as an alternative chemical immune checkpoint inhibitor. Development of new drugs that enhance stiffening of cancer cell membranes may be an effective strategy for tertiary cancer prevention and treatment.

Diet and Nutrition in Gynecological Disorders: A Focus on Clinical Studies

A healthy lifestyle and a balanced diet play a paramount role in promoting and maintaining homeostatic functions and preventing an array of chronic and debilitating diseases. Based upon observational and epidemiological investigations, it is clear that nutritional factors and dietary habits play a significant role in gynecological disease development, including uterine leiomyoma, endometriosis, polycystic ovary syndrome, and gynecological malignancies. Diets rich in fruits and vegetables, Mediterranean diets, green tea, vitamin D, and plant-derived natural compounds may have a long-term positive impact on gynecological diseases, while fats, red meat, alcohol, and coffee may contribute to their development. Data regarding the association between dietary habits and gynecological disorders are, at times, conflicting, with potential confounding factors, including food pollutants, reduced physical activity, ethnic background, and environmental factors limiting overall conclusions. This review provides a synopsis of the current clinical data and biological basis of the association between available dietary and nutritional data, along with their impact on the biology and pathophysiology of different gynecological disorders, as well as an outlook on future directions that will guide further investigational research.

Targeting Lactate Dehydrogenase A with Catechin Resensitizes SNU620/5FU Gastric Cancer Cells to 5-Fluorouracil

Resistance to anticancer therapeutics occurs in virtually every type of cancer and becomes a major difficulty in cancer treatment. Although 5-fluorouracil (5FU) is the first-line choice of anticancer therapy for gastric cancer, its effectiveness is limited owing to drug resistance. Recently, altered cancer metabolism, including the Warburg effect, a preference for glycolysis rather than oxidative phosphorylation for energy production, has been accepted as a pivotal mechanism regulating resistance to chemotherapy. Thus, we investigated the detailed mechanism and possible usefulness of antiglycolytic agents in ameliorating 5FU resistance using established gastric cancer cell lines, SNU620 and SNU620/5FU. SNU620/5FU, a gastric cancer cell harboring resistance to 5FU, showed much higher lactate production and expression of glycolysis-related enzymes, such as lactate dehydrogenase A (LDHA), than those of the parent SNU620 cells. To limit glycolysis, we examined catechin and its derivatives, which are known anti-inflammatory and anticancer natural products because epigallocatechin gallate has been previously reported as a suppressor of LDHA expression. Catechin, the simplest compound among them, had the highest inhibitory effect on lactate production and LDHA activity. In addition, the combination of 5FU and catechin showed additional cytotoxicity and induced reactive oxygen species (ROS)-mediated apoptosis in SNU620/5FU cells. Thus, based on these results, we suggest catechin as a candidate for the development of a novel adjuvant drug that reduces chemoresistance to 5FU by restricting LDHA.

Theabrownin Induces Cell Apoptosis and Cell Cycle Arrest of Oligodendroglioma and Astrocytoma in Different Pathways

Theabrownin (TB), a natural compound present in the fresh leaves of green tea, is a potential antitumor agent. However, so far whether and how TB affects glioma is unclear. In this study, we investigated the effect of TB on astroglioma and oligodendroglioma cells. Surprisingly, TB significantly reduced the viabilities of HOG and U251 cells in a dose-dependent manner, which was accompanied by the upregulation of active-Casp-3, Bax, and PTEN; meanwhile, the antiapoptotic gene Bcl-2 was downregulated. In addition, TB treatment induced cell cycle arrest at the G1 and G2/M phases in HOG and U251 cells, respectively. TB treatment caused the downregulating of c-myc, cyclin D, CDK2, and CDK4 and upregulating of p21 and p27 in the HOG cell, while TB increased P53, p21, and p27 levels and decreased the levels of cell cycle regulator proteins such as CDK and cyclin A/B in the U251 cells. Therefore, the c-myc- and P53-related mechanisms were proposed for cell cycle arrest in these two glioma cell lines, respectively. Overall, our findings indicated that TB could be a novel candidate drug for the treatment of gliomas.

Therapeutic Potential of Antileukotriene Drug-Camellia sinensis Extract Co-Formulation on Histamine Induced Asthma in Guinea Pigs

BACKGROUND/OBJECTIVE

To study the therapeutic potential of Antileukotriene drug- Camellia sinensis extract co-formulation on histamine induced asthma in guinea pigs.

METHODS

SRSD of Montelukast sodium was prepared by the solvent evaporation method. Lyophilized aqueous extract of Camellia sinensis leaves and SRSD mixture was filled in capsule and the capsule shell was coated to achieve initial release lag time. In vitro and pharmacokinetic study of capsules was performed and compared with commercial tablets. A further role of green tea, as an antioxidant adjunct for asthma management, has been analyzed by lung histology, mast cell count and oxidative stress assay in the serum of control and experimental animals.

RESULTS

The drug release from the commercial tablet was immediate and rapid, but capsule has shown an initial 3.5 hr lag time followed by sustained action up to 8 hr. Pharmacokinetic results show that studied formulations are bioequivalent with respect to Cmax and AUC, while rest parameters showed asignificant difference. Mast cells count in lung tissue were increased (p<0.001) in the experimental group along with glycoprotein deposition in asthmatic bronchioles. Levels of SOD and GPX were decreased (p<0.05) while CAT was increased (p<0.04) in the asthma group in comparison to control.

CONCLUSION

In the experimental animal model, co-formulation was effective in modulating allergic inflammation and contributing to better control of the inflammatory response. Our findings suggest that Camellia sinensis leaves extract may be used as an adjunct for future improvements in asthma treatment and prevention.

Amelioration of N,N'-dimethylhydrazine induced colon toxicity by epigallocatechin gallate in Wistar rats

Colon cancer is a life-threatening disease all over the world and is linked to constant oxidative stress and inflammation. Epigallocatechin gallate (EGCG), is a naturally occurring flavone possessing health benefiting pharmacological properties including antioxidant, anti-inflammatory and free radical scavenging properties. Our study investigates the role of EGCG on N,N'-dimethylhydrazine (DMH), a toxic environmental pollutant, induced colon toxicity. To investigate the effect of EGCG, Wistar rats were given EGCG for 7 days at the two doses of 10 and 20 mg/kg body weight and DMH was injected on the seventh day in all the group rats except the control. Our results indicate that DMH administration increased the oxidative stress (MDA) and depleted the glutathione and antioxidant enzyme activities (SOD, CAT, GR, GST and GPx) which was significantly ameliorated by EGCG treatment. Additionally DMH treatment upregulated inflammatory markers expression (NF-κB, COX-2 and IL-6) and enhanced mucosal damage in the colon. EGCG treatment significantly reduced inflammation and restored the normal histoarchitecture of the colon. We can conclude from the present study findings that EGCG protects the colon from DMH toxicity through its antioxidant and anti-inflammatory potential.

Morus alba Prevented the Cyclophosphamide Induced Somatic and Germinal Cell Damage in Male Rats by Ameliorating the Antioxidant Enzyme Levels

Cytogenetic analysis is essential to determine the effect of mutagens and antimutagens on genetic material. This study was done to evaluate the protective effect of root bark extract of Morus alba (M. alba) against cyclophosphamide induced somatic and germinal cell damage in male rats. The ethanolic extract of M. alba (0.25, 0.5 and 1 g/kg, 2 weeks) was evaluated against cyclophosphamide (75 mg/kg, single dose) induced nuclear damage. The sampling was done after 48 h of the clastogen treatment. The somatic and germinal nuclear damage was studied by bone marrow micronucleus and sperm analysis, respectively. Serum superoxide and catalase levels were estimated to determine the antioxidant status in each group. The results were analyzed statistically to find the significant variation. The administration of M. alba for 2 weeks suppressed dose-dependently the changes induced by cyclophosphamide. M. alba (0.5 g/kg) decreased the frequency of micronucleated erythrocyte, sperm shape abnormality and enhanced the sperm count, sperm motility and polychromatic-normochromatic erythrocytes ratio significantly (p < 0.05) in comparison with the cyclophosphamide treated group. The highest tested dose of M. alba (1 g/kg) produced more prominent suppression (p < 0.01) in the cyclophosphamide-induced somatic and germinal cell defects. The results also showed significant (p < 0.05) improvement in the serum antioxidant enzymes levels with M. alba when compared with the challenge group. The lower dose of M. alba extract (0.25 g/kg) prevented the CP-induced changes but was found to be statistically insignificant. Therefore, antimutagenic potential of the high dose of the extract of M. alba is possibly due to its antioxidant nature. The ability of the M. alba extract to prevent the nuclear damage could play an important role in overcoming several mutational defects that are associated with anticancer chemotherapy.

Docking Characterization and in vitro Inhibitory Activity of Flavan-3-ols and Dimeric Proanthocyanidins Against the Main Protease Activity of SARS-Cov-2

We report to use the main protease (M^pro) of SARS-Cov-2 to screen plant flavan-3-ols and proanthocyanidins. Twelve compounds, (-)-afzelechin (AF), (-)-epiafzelechin (EAF), (+)-catechin (CA), (-)-epicatechin (EC), (+)-gallocatechin (GC), (-)-epigallocatechin (EGC), (+)-catechin-3-O-gallate (CAG), (-)-epicatechin-3-O-gallate (ECG), (-)-gallocatechin-3-O-gallate (GCG), (-)-epigallocatechin-3-O-gallate (EGCG), procyanidin A2 (PA2), and procyanidin B2 (PB2), were selected for docking simulation. The resulting data predicted that all 12 metabolites could bind to M^pro. The affinity scores of PA2 and PB2 were predicted to be -9.2, followed by ECG, GCG, EGCG, and CAG, -8.3 to -8.7, and then six flavan-3-ol aglycones, -7.0 to -7.7. Docking characterization predicted that these compounds bound to three or four subsites (S1, S1', S2, and S4) in the binding pocket of M^pro via different spatial ways and various formation of one to four hydrogen bonds. In vitro analysis with 10 available compounds showed that CAG, ECG, GCG, EGCG, and PB2 inhibited the M^pro activity with an IC₅₀ value, 2.98 ± 0.21, 5.21 ± 0.5, 6.38 ± 0.5, 7.51 ± 0.21, and 75.3 ± 1.29 μM, respectively, while CA, EC, EGC, GC, and PA2 did not have inhibitory activities. To further substantiate the inhibitory activities, extracts prepared from green tea (GT), two muscadine grapes (MG), cacao, and dark chocolate (DC), which are rich in CAG, ECG, GAG, EGCG, or/and PB2, were used for inhibitory assay. The resulting data showed that GT, two MG, cacao, and DC extracts inhibited the M^pro activity with an IC₅₀ value, 2.84 ± 0.25, 29.54 ± 0.41, 29.93 ± 0.83, 153.3 ± 47.3, and 256.39 ± 66.3 μg/ml, respectively. These findings indicate that on the one hand, the structural features of flavan-3-ols are closely associated with the affinity scores; on the other hand, the galloylation and oligomeric types of flavan-3-ols are critical in creating the inhibitory activity against the M^pro activity.

Bioactive compounds, antioxidant capacity and antitumoral activity of ethanolic extracts from fruits and seeds of Eugenia involucrata DC

Eugenia involucrata DC. (Myrtaceae) is a native tree species from Brazil that has been scarcely studied. We investigated the phenolic composition, the antioxidant capacity and the antitumoral activity of ethanolic extracts from fruits (FE) and seeds (SE) of E. involucrata. Six anthocyanins were identified by UPLC-PDA/MS/MS in FE, being four derived from cyanidin, and the other ones derived from delphinidin and pelargonidin. Using HPLC-PDA, FE presented a larger number of phenolic compounds (epicatechin, catechin, rutin, ellagic acid, myricetin and quercetin) than SE, which did not show myricetin and quercetin. However, SE showed higher total phenolic content and generally stronger in vitro antioxidant capacity than FE, except that only FE exhibited superoxide radical scavenging activity, which may be attributed to the anthocyanins present in fruits. Additionally, only SE exhibited antitumoral activity in a pancreatic cancer cell line (PANC-1). The antitumoral mechanisms involved imbalance of antioxidant status, alteration of mitochondrial membrane potential, cytoskeleton disassembly and induction of cell death by apoptosis and necrosis. Compared to the standard antitumoral drug gemcitabine, SE exhibited higher antitumoral efficacy and selectivity index. The highest concentration of total phenolics and of specific phenolic compounds bearing antitumoral properties may be related to the antitumoral activity of SE. Our results corroborate previous data of E. involucrata as an important source of bioactive compounds and provide, for the first time, evidences of in vitro antitumoral potential of its seeds on pancreatic cancer cell line.

Assessment Synergistic Effects of Integrated Therapy with Epigallocatechin-3-Gallate (EGCG) & Arsenic Trioxide and Irradiation on Breast Cancer Cell Line

Background:

Breast cancer is the most common invasive malignancy among women in the world. The current breast cancer therapies pose significant clinical challenges. Low-dose chemotherapy represents a new strategy to treat solid tumors in combination with natural products such as green tea catechins. Epigallocatechin-3-gallate (EGCG) is the major polyphenolic extract from green tea with potent anticancer and antioxidant effects. The purpose of this study was to investigate the effects of EGCG, Arsenic trioxide (ATO) and gamma radiation on MCF-7 cell line.

Methods:

The anti-proliferative effects of EGCG and ATO individually, moreover in combination with radiation on MCF-7 cells were evaluated with MTT assay. The expression of apoptotic gens (Bax, Bcl-2, Caspase-3 and Fas) was assessed by real-time PCR.

Results:

Based on the results of MTT assay, EGCG and ATO exhibited dose and time-dependent anti-proliferative effects on MCF-7 cells. The combined therapy of EGCG and ATO in presence and absence radiation could rise cell death up to 80%. Moreover, integrated therapy made Bax up-regulated and Bcl-2 down- regulated.

Conclusion:

In assessment synergistic effects of integrated therapy with EGCG and ATO and irradiation had been significant impact on low dose chemotherapy for breast cancer treatment.

Stable Isotope Tracing Metabolomics to Investigate the Metabolic Activity of Bioactive Compounds for Cancer Prevention and Treatment

A major hallmark of cancer is the metabolic reprogramming of cancer cells to fuel tumor growth and proliferation. Various plant-derived bioactive compounds efficiently target the metabolic vulnerabilities of cancer cells and exhibit potential as emerging therapeutic agents. Due to their safety and common use as dietary components, they are also ideal for cancer prevention. However, to render their use as efficient as possible, the mechanism of action of these phytochemicals needs to be well characterized. Stable isotope tracing is an essential technology to study the molecular mechanisms by which nutraceuticals modulate and target cancer metabolism. The use of positionally labeled tracers as exogenous nutrients and the monitoring of their downstream metabolites labeling patterns enable the analysis of the specific metabolic pathway activity, via the relative production and consumption of the labeled metabolites. Although stable isotope tracing metabolomics is a powerful tool to investigate the molecular activity of bioactive compounds as well as to design synergistic nutraceutical combinations, this methodology is still underutilized. This review aims to investigate the research efforts and potentials surrounding the use of stable isotope tracing metabolomics to examine the metabolic alterations mediated by bioactive compounds in cancer.

Epigallocatechin gallate inhibits dimethylhydrazine-induced colorectal cancer in rats

BACKGROUND

Epigallocatechin gallate (EGCG) is a polyhydroxy phenolic compound extracted from tea and its antitumor effect has received widespread attention. We explored the inhibitory effect of EGCG on dimethylhydrazine (DMH)-induced colorectal cancer (CRC) using a rat model, predicted the interaction between EGCG and CRC target genes using a database, and explained the EGCG associated target pathways and mechanisms in CRC.

AIM

To understand the inhibitory mechanisms of EGCG on CRC cell proliferation and identify its pharmacological targets by network pharmacology analysis.

METHODS

DMH (40 mg/kg, s.c., twice weekly for eight weeks) was used to induce CRC in rats. After model establishment, the rats were administered with EGCG (50, 100, or 200 mg/kg, p.o., once daily for eight weeks) and killed 12 and 20 wk after the start of the experiment. Formation of aberrant crypt foci and tumor was studied by histological analysis. Using network pharmacology analysis, candidate and collective targets of EGCG and CRC were identified, and Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses were used to predict the pathways altered by EGCG.

RESULTS

At week 12, high-dose EGCG treatment significantly reduced the tumor formation rate, total number of tumors, cancerous and non-cancerous tumors, tumor volume, ascites formation, and aberrant crypt foci count. At week 20, all three doses of EGCG were effective. Seventy-eight collective targets of EGCG and CRC were identified, of which 28 genes were dysregulated in CRC. Kyoto Encyclopedia of Genes and Genomes and GO analyses showed that the dysregulated genes were enriched in hsa05210 (CRC), hsa04115 (p53 signaling pathway), and hsa04151 (PI3K-Akt signaling pathway), GO:0043124 (negative regulation of I-kappaB kinase/NF-kappaB signaling pathway), GO:0043409 (negative regulation of mitogen-activated protein kinase cascade), and GO:2001244 (positive regulation of intrinsic apoptotic signaling pathway) respectively.

CONCLUSION

EGCG inhibits the formation of DMH-induced CRC by regulating key pathways involved in tumorigenesis.

Natural Compounds with Potential to Modulate Cancer Therapies and Self-Reactive Immune Cells

Cancer-related deaths are approaching 10 million each year. Survival statistics for some cancers, such as ovarian cancer, have remained unchanged for decades, with women diagnosed at stage III or IV having over 80% chance of a lethal cancer recurrence after standard first-line treatment (reductive surgery and chemotherapy). New treatments and adjunct therapies are needed. In ovarian cancer, as in other cancers, the immune response, particularly cytotoxic (CD8⁺) T cells are correlated with a decreased risk of recurrence. As well as completely new antigen targets resulting from DNA mutations (neo-antigens), these T cells recognize cancer-associated overexpressed, re-expressed or modified self-proteins. However, there is concern that activation of self-reactive responses may also promote off-target pathology. This review considers the complex interplay between cancer-reactive and self-reactive immune cells and discusses the potential uses for various leading immunomodulatory compounds, derived from plant-based sources, as a cancer therapy option or to modulate potential autoimmune pathology. Along with reviewing well-studied compounds such as curcumin (from turmeric), epigallocatechin gallate (EGCG, from green tea) and resveratrol (from grapes and certain berries), it is proposed that compounds from novel sources, for example, native Australian plants, will provide a useful source for the fine modulation of cancer immunity in patients.

Chemical characterization, antioxidant, enzyme inhibitory and cytotoxic properties of two geophytes: Crocus pallasii and Cyclamen cilicium

The Crocus and Cyclamen genus have been reported to possess diverse biological properties. In the present investigation, two geophytes from these genus, namely Crocus pallasi and Cyclamen cilicium have been studied. The in vitro antioxidant, enzyme inhibitory, and cytotoxic effects of the methanol extracts of Crocus pallasii and Cyclamen cilicium aerial and underground parts were investigated. Antioxidant abilities of the extracts were investigated via different antioxidant assays (metal chelating, radical quenching (ABTS and DPPH), reducing power (CUPRAC and FRAP) and phosphomolybdenum). Cholinesterases, amylase, tyrosinase, and glucosidase were used as target enzymes for detecting enzyme inhibitory abilities of the samples. Regarding the cytotoxic abilities, breast cancer cell lines (MDA-MB 231 and MCF-7) and prostate cancer cell lines (DU-145) were used. The flowers extracts of Crocus pallasii and C. cilicium possessed the highest flavonoid content. The highest phenolic content was recorded from C. cilicium root extract (47.62 mg gallic acid equivalent/g extract). Cyclamen cilicium root extract showed significantly (p < 0.05) high radical scavenging (94.28 and 139.60 mg trolox equivalent [TE]/g extract, against DPPH and ABTS radicals, respectively) and reducing potential (173.30 and 109.53 mg TE/g extract, against CUPRAC and FRAP, respectively). The best acetylcholinesterase, glucosidase and tyrosinase inhibition was observed in C. cilicium root (4.46 mg GALAE/g; 15.75 mmol ACAE/g; 136.99 mg KAE/g, respectively). Methanolic extracts of C. pallasii and C. cilicium showed toxicity against breast cancer cell lines. In light of the above findings, C. cilicium might be considered as an interesting candidate in the development of anti-cancer agent coupled with antioxidant properties.

Advances in physiological functions and mechanisms of (-)-epicatechin

(-)-Epicatechin (EC) is a flavanol easily obtained through the diet and is present in tea, cocoa, vegetables, fruits, and cereals. Recent studies have shown that EC protects human health and exhibits prominent anti-oxidant and anti-inflammatory activities, enhances muscle performance, improves symptoms of cardiovascular and cerebrovascular diseases, prevents diabetes, and protects the nervous system. With the development of modern medical and biotechnology research, the mechanisms of action associated with EC toward various chronic diseases are becoming more apparent, and the pharmacological development and utilization of EC has been increasingly clarified. Currently, there is no comprehensive systematic introduction to the effects of EC and its mechanisms of action. This review presents the latest research progress and the role of EC in the prevention and treatment of various chronic diseases and its protective health effects and provides a theoretical basis for future research on EC.

(-)-Epigallocatechin gallate inhibits stemness and tumourigenicity stimulated by AXL receptor tyrosine kinase in human lung cancer cells

Cancer stem cells (H1299-sdCSCs) were obtained from tumour spheres of H1299 human lung cancer cells. We studied low stiffness, a unique biophysical property of cancer cells, in H1299-sdCSCs and parental H1299. Atomic force microscopy revealed an average Young’s modulus value of 1.52 kPa for H1299-sdCSCs, which showed low stiffness compared with that of H1299 cells, with a Young’s modulus value of 2.24 kPa. (−)-Epigallocatechin gallate (EGCG) reversed the average Young’s modulus value of H1299-sdCSCs to that of H1299 cells. EGCG treatment inhibited tumour sphere formation and ALDH1A1 and SNAI2 (Slug) expression. AXL receptor tyrosine kinase is highly expressed in H1299-sdCSCs and AXL knockdown with siAXLs significantly reduced tumour sphere formation and ALDH1A1 and SNAI2 (Slug) expression. An AXL-high population of H1299-sdCSCs was similarly reduced by treatment with EGCG and siAXLs. Transplantation of an AXL-high clone isolated from H1299 cells into SCID/Beige mice induced faster development of bigger tumour than bulk H1299 cells, whereas transplantation of the AXL-low clone yielded no tumours. Oral administration of EGCG and green tea extract (GTE) inhibited tumour growth in mice and reduced p-AXL, ALDH1A1, and SLUG in tumours. Thus, EGCG inhibits the stemness and tumourigenicity of human lung cancer cells by inhibiting AXL.

Associations between tea and coffee beverage consumption and the risk of lung cancer in the Singaporean Chinese population

BACKGROUND

Tea and coffee are widely consumed beverages. Tea flavonoids have been shown to inhibit lung tumorigenesis using in vitro and in vivo models. Conversely, coffee contains complex mixtures of biochemically active compounds, some of which may have genotoxic and mutagenic properties. However, previous epidemiologic studies have shown inconsistent results on tea and coffee in relation to lung cancer risk.

METHODS

The Singapore Chinese Health Study is a population-based prospective cohort of 63,257 Singaporean Chinese men and women, with an average of 17.7 years of follow-up. Information on tea and coffee consumption and other lifestyle factors was collected through in-person interviews at baseline. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations with adjustment for potential confounders.

RESULTS

There were 1486 incident lung cancer cases. Compared to non-daily coffee drinkers, HRs (95% CIs) of lung cancer risk for those consuming one, two, and three or more cups of coffee per day were 1.18 (1.02-1.36), 1.21 (1.05-1.40), and 1.32 (1.08-1.62) respectively (P for trend = 0.0034). The highest category of black tea consumption (at least 2 cups per day) was inversely associated with risk of lung cancer [HR (95% CI) = 0.73 (0.53-0.99)], particularly among men [HR (95% CI) = 0.67 (0.47-0.95)], compared to less-than-weekly black tea drinkers, although the interaction by sex was not statistically significant.

CONCLUSIONS

Coffee beverage consumption was associated with higher risk of developing lung cancer. On the other hand, black tea intake was associated with lower risk of lung cancer among men in our cohort, and further studies are needed to confirm this association.

Flavonoids nanoparticles in cancer: Treatment, prevention and clinical prospects

The conventional therapies for cancer have a major concern of poor accessibility to tumor tissues. Furthermore, the requirement of higher doses and non-selective nature of therapeutic are associated with a range of adverse drug reactions (ADRs). However, flavonoids are documented to be effective against various types of cancer, but they are not evaluated for their safety profile and tumor site-specific action. Low solubility, rapid metabolism and poor absorption of dietary flavonoids in gastrointestinal tract hinder their pharmacological potential. Some studies have also suggested that flavonoids may act as pro-oxidant in some cases and may interact with other therapeutic agents, especially through biotransformation. Nanocarriers can alter pharmacokinetics and pharmacodynamic profile of incorporating drug. Moreover, nanocarriers are designed for targeted drug delivery, improving the bioavailability of poorly water-soluble drugs, delivery of macromolecules to site of action within the cell, combining therapeutic agents with imaging techniques which may visualize the site of drug delivery and co-delivery of two or more drugs. Combining two or more anti-cancer agents can reduce ADRs and nanotechnology played a pivotal role in this regard. In vitro and in vivo studies have shown the potential of flavonoids nano-formulations, especially quercetin, naringenin, apigenin, catechins and fisetin in the prevention and treatment of several types of cancer. Similarly, clinical trials have been conducted using flavonoids alone or in combination, however, the nano-formulations effect still needs to be elucidated. This review focuses on the impact of flavonoids nano-formulations on the improvement of their bioavailability, therapeutic and safety profile and will open new insights in the field of drug discovery for cancer therapeutics.

Enoxacin and Epigallocatechin Gallate (EGCG) Act Synergistically to Inhibit the Growth of Cervical Cancer Cells in Culture

Cervical cancer is a major cause of death in females worldwide. While survival rates have historically improved, there remains a continuous need to identify novel molecules that are effective against this disease. Here, we show that enoxacin, a drug most commonly used to treat a broad array of bacterial infections, is able to inhibit growth of the cervical cancer cells. Furthermore, our data show that epigallocatechin gallate (EGCG), a plant bioactive compound abundant in green tea, and known for its antioxidant effects, similarly functions as an antiproliferative agent. Most importantly, we provide evidence that EGCG functions synergistically against cancer cell proliferation in combined treatment with enoxacin. These data collectively suggest that enoxacin and EGCG may be useful treatment options for cases of cervical cancer.

(-)-Epigallocatechin Gallate (EGCG) Enhances the Sensitivity of Colorectal Cancer Cells to 5-FU by Inhibiting GRP78/NF-κB/miR-155-5p/MDR1 Pathway

Green tea accounts for approximately 20% of the world's total tea yield. (-)-Epigallocatechin gallate (EGCG) is an active catechin in green tea, which suppresses tumor growth and enhances drug sensitivity in various cancers, but the molecular mechanism is still unclear. Chemotherapy drugs, such as 5-fluorouracil (5-FU), are a common strategy for clinical treatment of cancer patients; however, the lower response rate caused by prolonged use becomes the main reason for tumor recurrence. Therefore, discovering a safe and effective chemo-sensitizer is an urgent task required to be solved. Here, we report that EGCG reinforces the sensitivity of colon cancer cells to 5-FU, and the IC₅₀ values of 5-FU is decreased from 40 ± 4.2 μM to 5 ± 0.36 μM in one human colon carcinoma cell line-HCT-116, and from 150 ± 6.4 μM to 11 ± 0.96 μM in the other human colon carcinoma cell line-DLD1 when these cells are cotreated with 50 μM EGCG. Consistently, compared to 5-FU or EGCG treatment alone, the combination of both significantly promotes cancer cell apoptosis and DNA damage. Further mechanism research reveals that treatment of colorectal cancer (CRC) with 50 μM EGCG inhibits GRP78 expression, activates the NF-κB (2.55 ± 0.05-fold for HCT-116 and 2.27 ± 0.08-fold for DLD1) pathway, and enhances miR-155-5p (2.12 ± 0.02-fold for HCT-116 and 2.01 ± 0.01-fold for DLD1) level. The elevated miR-155-5p strongly suppresses target gene MDR1 expression, which blocks the efflux of 5-FU. The accumulation of 5-FU resulted in caspase-3 and PARP activation, Bcl-2 reduction, and Bad increase, which ultimately lead to cancer cell apoptosis. Overall, our data show that EGCG may be act as a novel chemo-sensitizer, and the GRP78/NF-κB/miR-155-5p/MDR1 pathway plays a vital role in EGCG enhancing the sensitivity of colorectal cancer to 5-FU.

Polymethoxylated Flavones Target Cancer Stemness and Improve the Antiproliferative Effect of 5-Fluorouracil in a 3D Cell Model of Colorectal Cancer

Polymethoxylated flavones (PMFs) from citrus fruits are reported to present anticancer potential. However, there is a lack of information regarding their effect on cancer stem cell (CSC) populations, which has been recognized as responsible for tumor initiation, relapse, and chemoresistance. In this study, we evaluated the effect of an orange peel extract (OPE) and its main PMFs, namely, nobiletin, sinensetin, tangeretin, and scutellarein tetramethylether in targeting cell proliferation and stemness using a 3D cell model of colorectal cancer composed of HT29 cell spheroids cultured for 7 days in stirred conditions. Soft agar assay, ALDH1 activity, and relative quantitative gene expression analysis of specific biomarkers were carried out to characterize the stemness, self-renewal, and mesenchymal features of HT29 cell spheroids. Then, the impact of OPE and PMFs in reducing cell proliferation and modulating cancer stemness and self-renewal was assessed. Results showed that, when compared with monolayer cultures, HT29 cell spheroids presented higher ALDH1 activity (81.97% ± 5.27% compared to 63.55% ± 17.49% for 2D), upregulation of CD44, PROM1, SOX9, and SNAI1 genes (1.83 ± 0.34, 2.54 ± 0.51, 2.03 ± 0.15, and 6.12 ± 1.59 times) and high self-renewal capability (352 ± 55 colonies compared to 253 ± 42 for 2D). Incubation with OPE (1 mg/mL) significantly inhibited cell proliferation and modulated cancer stemness and self-renewal ability: colony formation, ALDH1 activity, and the expression of cancer stemness biomarkers PROM1 and LGR5 were significantly reduced (0.66 ± 0.15 and 0.51 ± 0.14 times, respectively). Among all PMFs, tangeretin was the most efficient in targeting the CSC population by decreasing colony formation and the expression of PROM1 and LGR5. Scutellarein tetramethylether was shown to modulate markers of mesenchymal/metastatic transition (increasing CDH1 and reducing ZEB1 and SNAI1) and nobiletin was capable of downregulating PROM1 and SNAI1 expression. Importantly, all PMFs and OPE were shown to synergistically interact with 5-fluorouracil, improving the antiproliferative response of this drug.

Green Tea Catechin Is an Alternative Immune Checkpoint Inhibitor that Inhibits PD-L1 Expression and Lung Tumor Growth

The anticancer activity of immune checkpoint inhibitors is attracting attention in various clinical sites. Since green tea catechin has cancer-preventive activity in humans, whether green tea catechin supports the role of immune checkpoint inhibitors was studied. We here report that (−)-epigallocatechin gallate (EGCG) inhibited programmed cell death ligand 1 (PD-L1) expression in non–small-cell lung cancer cells, induced by both interferon (IFN)-γ and epidermal growth factor (EGF). The mRNA and protein levels of IFN-γ–induced PD-L1 were reduced 40–80% after pretreatment with EGCG and green tea extract (GTE) in A549 cells, via inhibition of JAK2/STAT1 signaling. Similarly, EGF-induced PD-L1 expression was reduced about 37–50% in EGCG-pretreated Lu99 cells through inhibition of EGF receptor/Akt signaling. Furthermore, 0.3% GTE in drinking water reduced the average number of tumors per mouse from 4.1 ± 0.5 to 2.6 ± 0.4 and the percentage of PD-L1 positive cells from 9.6% to 2.9%, a decrease of 70%, in lung tumors of A/J mice given a single intraperitoneal injection of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In co-culture experiments using F10-OVA melanoma cells and tumor-specific CD3+ T cells, EGCG reduced PD-L1 mRNA expression about 30% in F10-OVA cells and restored interleukin-2 mRNA expression in tumor-specific CD3+ T cells. The results show that green tea catechin is an immune checkpoint inhibitor.

Anticancer Effects of Green Tea and the Underlying Molecular Mechanisms in Bladder Cancer

Green tea and green tea polyphenols (GTPs) are reported to inhibit carcinogenesis and malignant behavior in several diseases. Various in vivo and in vitro studies have shown that GTPs suppress the incidence and development of bladder cancer. However, at present, opinions concerning the anticancer effects and preventive role of green tea are conflicting. In addition, the detailed molecular mechanisms underlying the anticancer effects of green tea in bladder cancer remain unclear, as these effects are regulated by several cancer-related factors. A detailed understanding of the pathological roles and regulatory mechanisms at the molecular level is necessary for advancing treatment strategies based on green tea consumption for patients with bladder cancer. In this review, we discuss the anticancer effects of GTPs on the basis of data presented in in vitro studies in bladder cancer cell lines and in vivo studies using animal models, as well as new treatment strategies for patients with bladder cancer, based on green tea consumption. Finally, on the basis of the accumulated data and the main findings, we discuss the potential usefulness of green tea as an antibladder cancer agent and the future direction of green tea-based treatment strategies for these patients.

Nano-delivery systems for encapsulation of dietary polyphenols: An experimental approach for neurodegenerative diseases and brain tumors

Neurodegenerative diseases (NDs) and brain tumors are severe, disabling, and incurable disorders that represent a critical problem regarding human suffering and the economic burden on the healthcare system. Because of the lack of effective therapies to treat NDs and brain tumors, the challenge for physicians is to discover new drugs to improve their patients' quality of life. In addition to risk factors such as genetics and environmental influences, increased cellular oxidative stress has been reported as one of the potential common etiologies in both disorders. Given their antioxidant and anti-inflammatory potential, dietary polyphenols are considered to be one of the most bioactive natural agents in chronic disease prevention and treatment. Despite the protective activity of polyphenols, their inefficient delivery systems and poor bioavailability strongly limit their use in medicine and functional food. A potential solution lies in polymeric nanoparticle-based polyphenol delivery systems that are able to enhance their absorption across the gastrointestinal tract, improve their bioavailability, and transport them to target organs. In the present manuscript, we provide an overview of the primary polyphenols used for ND and brain tumor prevention and treatment by focusing on recent findings, the principal factors limiting their application in clinical practice, and a promising delivery strategy to improve their bioavailability.

Identification and Characterization of Phenolic Compounds in Black Walnut Kernels

Black walnuts ( Juglans nigra L.) are highly valued for producing phenolic-enriched nuts. The objectives of this study were to identify and characterize the phenolic contents of 11 different black walnut cultivars and compare the levels of these phenolics between black walnuts and English walnut ( Juglans regia L.). Totally, 16 phenolics including phenolic acids, flavonoids, and catechins were identified in the black walnut kernels, with ellagic acid predominating over the other phenolics. Significant differences were noted for the levels of quinic acid, gallic acid, 1,3,6-trigalloylglucose, catechin, and penta- O-galloyl-β-d-glucose between the studied black walnuts and English walnut. Through principal component analysis, 51.54% of the variance in the phenolic data was explained. The hierarchical cluster analysis results showed three groups to which each walnut sample belongs. Most of the phenolics identified in this study have been reported to exert potential health-promoting activities. The findings of this study will provide critical information for consumers, nutritional therapy practitioners, researchers, and producers.

Role of EGCG in Containing the Progression of Lung Tumorigenesis - A Multistage Targeting Approach

Lung cancer is a prominent form among various types of cancers, irrespective of the sex worldwide. Treatment of lung cancer involves the intensive phase of chemotherapy/radiotherapy which is associated with high rate of adverse events. There is a need of safe and reliable treatment/adjunctive therapy to apprehend the cancer by reducing the undesirable outcome of primary therapy. Epigallocatechin-3-gallate (EGCG), which is a potent antioxidant and anticancer compound extracted from the plant camellia sinensis has proved to be a novel agent to control or reduce lung tumorigenesis by affecting the signaling molecules of cell cycle regulation and apoptotic pathways. In vitro studies have revealed that EGCG can contain carcinogenesis by altering the molecules involved in multiple signal transduction pathways like ERK, VEGF, COX2, NEAT, Ras-GTPase, and kinases. The animal studies have also demonstrated effectiveness of EGCG by inhibiting various molecular pathways which include AKT, NFkB, MAPK, Bcl/Bax, DNMT1, and HIF-1α. Various attempts have been made to see the adjunctive role of EGCG in human lung cancer. Phase I/II clinical studies have recommended that EGCG is quite safe and effective in providing protection against cancer. In this review, we will discuss the role of EGCG and its molecular mechanisms in lung carcinogenesis.

Cancer Prevention with Green Tea and Its Principal Constituent, EGCG: from Early Investigations to Current Focus on Human Cancer Stem Cells

Cancer preventive activities of green tea and its main constituent, (-)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes ground-breaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young's moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.

ROS-responsive capsules engineered from green tea polyphenol–metal networks for anticancer drug delivery

Reactive oxygen species (ROS)-responsive nanocapsules for cancer drug delivery were engineered from green tea polyphenol–metal networks.

The synergistic potential of various teas, herbs and therapeutic drugs in health improvement: a review

Tea is one of the most widely consumed non-alcoholic beverages in the world next to water. It is classified as Camellia sinensis and non-Camellia sinensis (herbal teas). The common bioactive compounds found mainly in green teas are flavan-3-ols (catechins) (also called flavanols), proanthocyanidins (tannins) and flavonols. Black tea contains theaflavins and thearubigins and white tea contains l-theanine and gamma-aminobutyric acid (GABA), while herbal teas contain diverse polyphenols. Phytochemicals in tea exhibit antimicrobial, anti-diabetic and anti-cancer activities that are perceived to be helpful in managing chronic diseases linked to lifestyle. Many of these phytochemicals are reported to be biologically active when combined. Knowledge of the synergistic interactions of tea with other teas or herbs in terms of biological activities will be of benefit for therapeutic enhancement. There is evidence that various types of teas act synergistically in exhibiting health benefits to humans, improving consumer acceptance and economic value. Similar observations have been made when teas and herbs or medicinal drugs were combined. The aim of this review is to highlight potential beneficial synergies between combinations of different types of teas, tea and herbs, and tea and medicinal drugs. © 2017 Society of Chemical Industry.

Combination curcumin and (-)-epigallocatechin-3-gallate inhibits colorectal carcinoma microenvironment-induced angiogenesis by JAK/STAT3/IL-8 pathway

Tumor microenvironment has a crucial role in cancer development and progression, whereas the mechanism of how it regulates angiogenesis is unclear. In this study, we simulated the colorectal carcinoma microenvironment by conditioned medium (CM) of colorectal carcinoma cell lines (SW620, HT-29, HCT116) supernatant or colorectal carcinoma tissue homogenate supernatant to induce normal endothelial cells (NECs). We found that colorectal carcinoma CM promoted tumor angiogenesis by coercing NECs toward tumor endothelial cells (TECs) with the activation of the JAK/STAT3 signaling pathway. Antibody array analysis showed HT-29 supernatant contained numerous angiogenesis-related proteins, especially IL-8. Interestingly, the production of IL-8 in NECs induced by HT-29 CM was also increased. We also verified the crucial role of IL-8 in promoting the CM-induced angiogenesis, as IL-8 repression by neutralizing antibody abolished the transition of NECs toward TECs. Curcumin and (-)-epigallocatechin-3-gallate (EGCG) are broadly investigated in cancer chemoprevention. However, poor bioavailability hurdles their application alone, and the mechanism of their anti-angiogenesis still need to be illuminated. Here, we found that curcumin combination with EGCG attenuated the tumor CM-induced transition of NECs toward TECs by inhibiting JAK/STAT3 signaling pathway. Furthermore, the combination of curcumin and EGCG markedly reduced tumor growth and angiogenesis in the colorectal carcinoma PDX mouse model, and the combined anti-angiogenic effect was better than that of curcumin or EGCG alone. Taken together, our findings provide a new mechanism of tumor angiogenesis, and the combination of curcumin and EGCG represents a potential anti-angiogenic therapeutic method for colorectal carcinoma.

Human cancer stem cells are a target for cancer prevention using (-)-epigallocatechin gallate

Purpose

Our previous experiments show that the main constituent of green-tea catechins, (−)-epigallocatechin gallate (EGCG), completely prevents tumor promotion on mouse skin initiated with 7,12-dimethylbenz(a)anthracene followed by okadaic acid and that EGCG and green tea extract prevent cancer development in a wide range of target organs in rodents. Therefore, we focused our attention on human cancer stem cells (CSCs) as targets of cancer prevention and treatment with EGCG.

Methods

The numerous reports concerning anticancer activity of EGCG against human CSCs enriched from cancer cell lines were gathered from a search of PubMed, and we hope our review of the literatures will provide a broad selection for the effects of EGCG on various human CSCs.

Results

Based on our theoretical study, we discuss the findings as follows: (1) Compared with the parental cells, human CSCs express increased levels of the stemness markers Nanog, Oct4, Sox2, CD44, CD133, as well as the EMT markers, Twist, Snail, vimentin, and also aldehyde dehydrogenase. They showed decreased levels of E-cadherin and cyclin D1. (2) EGCG inhibits the transcription and translation of genes encoding stemness markers, indicating that EGCG generally inhibits the self-renewal of CSCs. (3) EGCG inhibits the expression of the epithelial-mesenchymal transition phenotypes of human CSCs. (4) The inhibition of EGCG of the stemness of CSCs was weaker compared with parental cells. (5) The weak inhibitory activity of EGCG increased synergistically in combination with anticancer drugs.

Conclusions

Green tea prevents human cancer, and the combination of EGCG and anticancer drugs confers cancer treatment with tissue-agnostic efficacy.

Catechin ameliorates doxorubicin-induced neuronal cytotoxicity in in vitro and episodic memory deficit in in vivo in Wistar rats

Cognitive dysfunction by chemotherapy compromises the quality of life in cancer patients. Tea polyphenols are known chemopreventive agents. The present study was designed to evaluate the neuroprotective potential of (+) catechin hydrate (catechin), a tea polyphenol, in IMR-32 neuroblastoma cells in vitro and alleviation of episodic memory deficit in Wistar rats in vivo against a widely used chemotherapeutic agent, Doxorubicin (DOX). In vitro, neuroprotective studies were assessed in undifferentiated IMR-32 cells using percentage viability and in differentiated cells by neurite length. These studies showed catechin increased percentage viability of undifferentiated IMR-32 cells. Catechin pretreatment also showed an increase in neurite length of differentiated cells. In vivo neuroprotection of catechin was evaluated using novel object recognition task in time-induced memory deficit model at 50, 100 and 200 mg/kg dose and DOX-induced memory deficit models at 100 mg/kg dose. The latter model was developed by injection of DOX (2.5 mg/kg, i.p.) in 10 cycles over 50 days in Wistar rats. Catechin showed a significant reversal of time-induced memory deficit in a dose-dependent manner and prevention of DOX-induced memory deficit at 100 mg/kg. In addition, catechin treatment showed a significant decrease in oxidative stress, acetylcholine esterase and neuroinflammation in the hippocampus and cerebral cortex in DOX-induced toxicity model. Hence, catechin may be a potential adjuvant therapy for the amelioration of DOX-induced cognitive impairment which may improve the quality of life of cancer survivors. This improvement might be due to the elevation of antioxidant defense, prevention of neuroinflammation and inhibition of acetylcholine esterase enzyme.

Theabrownin Inhibits Cell Cycle Progression and Tumor Growth of Lung Carcinoma through c-myc-Related Mechanism

Green tea, the fresh leaves of Camellia sinensis, is not only a health-promoting beverage but also a traditional Chinese medicine used for prevention or treatment of cancer, such as lung cancer. Theabrownin (TB) is the main fraction responsible for the medicinal effects of green tea, but whether it possesses anti-cancer effect is unknown yet. This study aimed to determine the in vitro and in vivo anti-lung cancer effect of TB and explore the underlying molecular mechanism, by using A549 cell line and Lewis lung carcinoma-bearing mice. In cellular experiment, MTT assay was performed to evaluate the inhibitory effect and IC50 values of TB, and flow cytometry was conducted to analyze the cell cycle progression affected by TB. In animal experiment, mice body mass, tumor incidence, tumor size and tumor weight were measured, and histopathological analysis on tumor was performed with Transferase dUTP nick-end labeling staining. Real time PCR and western blot assays were adopted to detect the expression of C-MYC associated genes and proteins for mechanism clarification. TB was found to inhibit A549 cell viability in a dose- and time-dependent manner and block A549 cell cycle at G0/G1 phase. Down-regulation of c-myc, cyclin A, cyclin D, cdk2, cdk4, proliferation of cell nuclear antigen and up-regulation of p21, p27, and phosphate and tension homolog in both gene and protein levels were observed with TB treatment. A c-myc-related mechanism was thereby proposed, since c-myc could transcriptionally regulate all other genes in its downstream region for G1/S transitions of cell cycle and proliferation of cancer cells. This is the first report regarding the anti-NSCLC effect and the underlying mechanism of TB on cell cycle progression and proliferation of A549 cells. The in vivo data verified the in vitro result that TB could significantly inhibit the lung cancer growth in mice and induce apoptosis on tumors in a dose-dependent manner. It provides a promising candidate of natural products for lung cancer therapy and new development of anti-cancer agent.

Down-regulation of histone deacetylase 4, -5 and -6 as a mechanism of synergistic enhancement of apoptosis in human lung cancer cells treated with the combination of a synthetic retinoid, Am80 and green tea catechin

(-)-Epigallocatechin gallate (EGCG), a green tea catechin, acts as a synergist with various anticancer drugs, including retinoids. Am80 is a synthetic retinoid with a different structure from all-trans-retinoic acid: Am80 is now clinically utilized as a new drug for relapsed and intractable acute promyelocytic leukemia patients. Our experiments showed that the combination of EGCG and Am80 synergistically induced both apoptosis in human lung cancer cell line PC-9 and up-regulated expressions of growth arrest and DNA damage-inducible gene 153 (GADD153), death receptor 5, and p21^waf1 genes in the cells. To understand the mechanisms of synergistic anticancer activity of the combination, we gave special attention to the lysine acetylation of proteins. Proteomic analysis using nanoLC-ESI-MS/MS revealed that PC-9 cells treated with the combination contained 331 acetylated proteins, while nontreated cells contained 553 acetylated proteins, and 59 acetylated proteins were found in both groups. Among them, the combination increased acetylated-p53 and acetylated-α-tubulin through reduction of histone deacetylase (HDAC) activity in cytosol fraction, although the levels of acetylation in histones H3 or H4 did not change, and the combination reduced protein levels of HDAC4, -5 and -6 by 20% to 80%. Moreover, we found that a specific inhibitor of HDAC4 and -5 strongly induced p21^waf1 gene expression, and that of HDAC6 induced both GADD153 and p21^waf1 gene expression, which resulted in apoptosis. All results demonstrate that EGCG in combination with Am80 changes levels of acetylation in nonhistone proteins via down-regulation of HDAC4, -5 and -6 and stimulates apoptotic induction.

Healthy properties of green and white teas: an update

Green tea has been consumed for centuries in Japan, China and Morocco.

Effect of Tea Polyphenol Compounds on Anticancer Drugs in Terms of Anti-Tumor Activity, Toxicology, and Pharmacokinetics

Multidrug resistance and various adverse side effects have long been major problems in cancer chemotherapy. Recently, chemotherapy has gradually transitioned from mono-substance therapy to multidrug therapy. As a result, the drug cocktail strategy has gained more recognition and wider use. It is believed that properly-formulated drug combinations have greater therapeutic efficacy than single drugs. Tea is a popular beverage consumed by cancer patients and the general public for its perceived health benefits. The major bioactive molecules in green tea are catechins, a class of flavanols. The combination of green tea extract or green tea catechins and anticancer compounds has been paid more attention in cancer treatment. Previous studies demonstrated that the combination of chemotherapeutic drugs and green tea extract or tea polyphenols could synergistically enhance treatment efficacy and reduce the adverse side effects of anticancer drugs in cancer patients. In this review, we summarize the experimental evidence regarding the effects of green tea-derived polyphenols in conjunction with chemotherapeutic drugs on anti-tumor activity, toxicology, and pharmacokinetics. We believe that the combination of multidrug cancer treatment with green tea catechins may improve treatment efficacy and diminish negative side effects.