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

The impact of altering the concentration of coffee constituents on their anticancer effect on oral squamous cell carcinoma cell line - in vitro study

Introduction

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies of the head and neck, which attracts much attention because of its increasing incidence and poor outcome. Coffee is one of the most popular beverages that are globally consumed. It consists of several phytochemical constituents, such as polyphenols, caffeine, and chlorogenic acid (CGA). Those constituents account for the potential effects on several diseases, including cancer. It has been reported that coffee exerts significant cytotoxicity against OSCC via inhibition of epidermal growth factor receptor tyrosine kinase (EGFR-TK) and up-regulation of apoptotic proteins, such as caspase-3 and caspase-9. The current study aims to measure the concentration of caffeine and CGA in 3 different types of coffee extracts, unroasted green coffee (GC), medium-roasted coffee (MRC), and decaffeinated coffee.

Material and methods

The cytotoxic effect against OSCC-25 cell lines was evaluated and correlated with the concentration of constituents in each extract. The mechanisms of cytotoxicity were also studied by assessing the effect of each extract on caspase-3 and caspase-9 levels, in addition to the inhibitory effect on EGFR-TK.

Results

It was found that the caffeine concentration was higher in MRC than in GC because of the roasting process. However, the concentration of caspase-3 and -9 and the inhibitory effect on EGFR-TK were much higher in GC than MRC-treated cells because of the higher concentration of CGA.

Conclusions

Decaffeinated coffee exerts lower cytotoxic effects because it was totally deprived of caffeine and CGA during the decaffeination process.

In Vitro and In Vivo Antiproliferative Actions of Solanum gilo Raddi (Solanaceae) Fruit Extract on Breast Tissues

Background

Menopause is a normal event characterized by a drop in estrogen's production, leading to numerous symptoms. To face these later, women rely on hormone replacement therapy (HRT), which alleviates numerous menopausal symptoms. Unfortunately, long-term exposure to estrogens is associated with an increase in endometrial and breast cancers. This study dealt with the evaluation of in vitro and in vivo antiproliferative effects of Solanum gilo Raddi, a plant used in folk medicine to treat tumors in Cameroon.

Materials and Methods

The in vitro antiproliferative effect of S. gilo fruit extract was investigated through the well-characterized MTT assay in one normal and three cancerous breast cells. For the in vivo study, one normal group (NOR) of rats received distilled water (vehicle), and five other groups (n = 6) were treated either with tamoxifen (3.3 mg/kg BW) as standard or with the vehicle (negative control) or S. gilo fruit hydroethanolic extract (125, 250, and 500 mg/kg BW). The treatments were administered concomitantly with the E2V to induce breast hyperplasia for 16 weeks, and the endpoints were the histopathology of the mammary glands and some biochemical parameters.

Results

The S. gilo extract significantly inhibited human (MCF-7 and MDA-MB-231) and rodent (4T1) breast carcinoma cell growth. Rats exposed only to E2V presented atypical mammary hyperplasia compared to the normal parenchyma observed in normal rats. While rats treated with S. gilo extract at the dose of 125 mg/kg BW showed a microarchitecture of mammary glands with moderate hyperplasia, the higher doses (250 and 500 mg/kg) inhibited mammary gland hyperplasia compared to the E2V group.

Conclusion

S. gilo fruit extract has antiproliferative constituents that could help to fight against estrogen-dependent breast cancer, thanks to their ability to scavenge free radicals, as exhibited in this study.

Nano-Drug Delivery Systems Entrapping Natural Bioactive Compounds for Cancer: Recent Progress and Future Challenges

Cancer is a prominent cause of mortality globally, and it becomes fatal and incurable if it is delayed in diagnosis. Chemotherapy is a type of treatment that is used to eliminate, diminish, or restrict tumor progression. Chemotherapeutic medicines are available in various formulations. Some tumors require just one type of chemotherapy medication, while others may require a combination of surgery and/or radiotherapy. Treatments might last from a few minutes to many hours to several days. Each medication has potential adverse effects associated with it. Researchers have recently become interested in the use of natural bioactive compounds in anticancer therapy. Some phytochemicals have effects on cellular processes and signaling pathways with potential antitumor properties. Beneficial anticancer effects of phytochemicals were observed in both in vivo and in vitro investigations. Encapsulating natural bioactive compounds in different drug delivery methods may improve their anticancer efficacy. Greater in vivo stability and bioavailability, as well as a reduction in undesirable effects and an enhancement in target-specific activity, will increase the effectiveness of bioactive compounds. This review work focuses on a novel drug delivery system that entraps natural bioactive substances. It also provides an idea of the bioavailability of phytochemicals, challenges and limitations of standard cancer therapy. It also encompasses recent patents on nanoparticle formulations containing a natural anti-cancer molecule.

Protective Effects of Green Tea Supplementation against Lead-Induced Neurotoxicity in Mice

The use of natural products as therapeutic agents is rapidly growing recently. In the current study, we investigated the protective effects of green tea supplementation on lead-induced toxicity in mice. Forty albino mice were divided into four groups as follows: A: control group; B: green tea receiving group; C: lead-intoxicated group; and D: lead-intoxicated group supplemented with green tea. At the end of the experiment, the animals were tested for neurobehavioral and biochemical alterations. Green tea was analyzed through Gas Chromatography–Mass Spectrometry (GC/MS) analysis. We found that supplementation with green tea ameliorated the lead-associated increase in body weight and blood glucose. Green tea supplementation also changed the blood picture that was affected due to lead toxicity and ameliorated lead-induced dyslipidemia. The group of mice that were supplemented with green tea has shown positive alterations in locomotory, anxiety, memory, and learning behaviors. The GC/MS analysis revealed many active ingredients among which the two most abundant were caffeine and 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester. We concluded that green tea supplementation has several positive effects on the lead-induced neurotoxicity in mice and that these effects may be attributed to its main two active ingredients.

Cotinus coggygria Scop. induces cell cycle arrest, apoptosis, genotoxic effects, thermodynamic and epigenetic events in MCF7 breast cancer cells

Current plant-derived anticancer therapeutics aim to reach higher effectiveness, to potentiate chemosensitivity and minimize the toxic side effects compared to conventional chemotherapy. Cotinus coggygria Scop. is a herb with high pharmacological potential, widely applied in traditional phytotherapy. Our previous study revealed that leaf aqueous ethanolic extract from C. coggygria exerts in vitro anticancer activity on human breast, ovarian and cervical cancer cell lines. The objective of the present research was to investigate possible molecular mechanisms and targets of the antitumor activity of the extract in breast cancer MCF7 cells through analysis of cell cycle and apoptosis, clonogenic ability assessment, evaluation of the extract genotoxic capacity, characterization of cells thermodynamic properties, and analysis on the expression of genes involved in cellular epigenetic processes. The obtained results indicated that in MCF7 cells C. coggygria extract causes S phase cell cycle arrest and triggers apoptosis, reduces colony formation, induces DNA damage, affects cellular thermodynamic parameters, and tends to inhibit the relative expression of DNMT1, DNMT3a, MBD3, and p300. Further studies on the targeted molecules and the extract anti-breast cancer potential on animal experimental model system, need to be performed in the future.

Designing a high-performance smart drug delivery system for the synergetic co-absorption of DOX and EGCG on ZIF-8

Due to the extreme pore volume and valuable surface area, zeolitic imidazole frameworks (ZIFs) are promising vehicles that enhance the delivery of therapeutic agents to tissues. Furthermore, these nanoporous materials have high stability in the pH and temperature of the surrounding healthy cells (37 °C and pH = 7) and an exotic potential to deform in carcinogenic environment (T > 37 °C and pH ∼ 5.5), which make them perfect smart drug delivery vehicle candidates. In this work, a series of molecular dynamics (MD) and metadynamics simulations have been performed to gain molecular insight into the mechanisms involved in the process of co-loading of doxorubicin (DOX) and EpiGalloCatechin-3 Gallate (EGCG) on ZIF-8, which form a smart drug delivery system (SDDS). The obtained results revealed that DOX was adsorbed on the carrier mostly through electrostatic interactions (E coul = ∼-1200 kJ mol-1, E tot = -1700 kJ mol-1), and EGCG was stacked on ZIF-8 mainly via van der Waals interactions (E L-J = ∼-600 kJ mol-1, E tot = ∼-1200 kJ mol-1). It is worth mentioning that the drug-drug L-J interactions (E L-J = ∼500 kJ mol-1) were also important in the co-loading process. The insertion of DOX and EGCG as additive agents to the initial ZIF-8/EGCG and ZIF-8/DOX systems led to the enhancement of the drug-carrier pair interactions to about ∼-2300 kJ mol-1 and ∼-2000 kJ mol-1, respectively. This finding implied that the drug-drug interactions had a complementary role in the development of SDDS via ZIF-8. From the metadynamics simulation, it was found that the geometry of the drugs is a determining factor in an efficient co-loading SDDS.

Abyssinone V-4' Methyl Ether, a Flavanone Isolated from Erythrina droogmansiana, Exhibits Cytotoxic Effects on Human Breast Cancer Cells by Induction of Apoptosis and Suppression of Invasion

Abyssinone V-4′ methyl ether (AVME) isolated from Erythrina droogmansiana was recently reported to exhibit anti-mammary tumor effect in mice. The present work was therefore aimed at elucidating its cellular and molecular mechanisms. To achieve our goal, the cytotoxicity of AVME against tumoral and non-tumoral cell lines was evaluated by resazurin reduction test; flow cytometry allowed us to evaluate the cell cycle and mechanisms of cell death; the mitochondrial transmembrane potential, reactive oxygen species (ROS) levels, and caspase activities as well as apoptosis-regulatory proteins (Bcl-2 and Bcl-XL) were measured in MDA-MB-231 cells. Further, the antimetastatic potential of AVME was evaluated by invasion assay. AVME exhibited cytotoxic effects in all tested tumor cell lines and induced a significant increase in the percentage of MDA-MB-231 cells at G2/M and S phases of the cell cycle in a concentration-dependent manner. AVME also induced apoptosis in MDA-MB-231 cells, which was accompanied by the activation of caspase-3 and caspase-9 and downregulation of Bcl-2 and Bcl-XL proteins. Moreover, AVME suppressed cancer cell invasion by the inhibition of the metalloproteinase-9 activity. Findings from this study suggest that AVME has anti-breast cancer activities expressed through mitochondrial proapoptotic pathway including impairment of aggressive behaviors of breast cancer cells.

Literature Review of Traditional Chinese Medicine Herbs-Induced Liver Injury From an Oncological Perspective With RUCAM

Traditional Chinese medicine (TCM) herbs are commonly regarded to be safe with minimal toxicities in Chinese communities. Cancer patients who are receiving Western oncology therapy often concurrently take TCM herbs for anticancer and symptom relief purposes. We performed a literature review for current evidence on TCM herb–induced liver injury from an oncological perspective. A literature search on PubMed was performed to identify publications regarding TCM herbs and concoctions with hepatoprotective or hepatotoxic properties. Lists of commonly used herbs and their causality levels were compiled. In view of the wide range of evidence available, cases assessed by the well-established RUCAM (Roussel Uclaf Causality Assessment Method) algorithm were categorized as the highest level of evidence. More than one case of TCM herb–induced liver injury was confirmed by RUCAM in the following herbs and concoctions: Lu Cha (Camellia sinensis), Bai Xian Pi (Dictamnus dasycarpus), Tu San Qi (Gynura segetum), Jin Bu Huan (Lycopodium serratum), He Shou Wu (Polygoni multiflora), Ge Gen (Pueraria lobata), Dan Lu Tong Du tablet, Shou Wu Pian, Xiao Chai Hu Tang, Xiao Yin pill, and Yang Xue Sheng Fa capsule. Finally, TCM with anticancer or symptom relief uses were discussed in detail with regard to their hepatotoxic or hepatoprotective properties.

Chemoprevention of Breast Cancer With Vitamins and Micronutrients: A Concise Review

Numerous dietary components and vitamins have been found to inhibit the molecular events and signalling pathways associated with various stages of breast cancer development. To identify the vitamins and dietary micronutrients that exert protective effects against breast cancer and define their mechanism of action, we performed a literature review of in vitro, animal and epidemiological studies and selected the in vitro and animal studies with robust molecular evidence and the epidemiological studies reporting statistically significant inverse associations for a breast cancer-specific protective effect. There is sufficient evidence from in vitro, animal and epidemiological human studies that certain vitamins, such as vitamin D3, folate, vitamin B6, and beta carotene as well as dietary micronutrients, such as curcumin, piperine, sulforaphane, indole-3-carbinol, quercetin, epigallocatechin gallate (EGCG) and omega-3 polyunsaturated fatty acids (PUFAs), display an antitumoral activity against breast cancer and have the potential to offer a natural strategy for breast cancer chemoprevention and reduce the risk of breast cancer recurrence. Therefore, a supplement that contains these micronutrients, using the safest form and dosage should be investigated in future breast cancer chemoprevention studies and as part of standard breast cancer therapy.

Dietary baker's yeast sensitizes Ehrlich mammary adenocarcinoma to paclitaxel in mice bearing tumor

Baker's yeast, Saccharomyces cerevisiae, has been shown to sensitize a variety of breast cancer cell (BCC) lines to paclitaxel chemotherapy in vitro. The present study evaluated the ability of S. cerevisiae to sensitize BCCs to paclitaxel in animals bearing Ehrlich ascites carcinoma (EAC). Mice bearing EAC were intratumorally injected with dead S. cerevisiae (1x107 cells/ml) in the presence or absence of low- and high-dose paclitaxel [paclitaxel-L, 2 mg/kg body weight (BW) and paclitaxel-H, 10 mg/kg BW, respectively]. At 30 days post tumor inoculation, co-treatment with yeast plus paclitaxel-L showed improvements over paclitaxel-H alone, as measured by tumor weight (-64 vs. -53%), DNA damage (+79 vs. +62%), tumor cell apoptosis (+217 vs. +177%), cell proliferation (-56 vs. -42%) and Ki-67 marker (+95 vs. +40%). Histopathology and ultra-structural examinations showed that yeast plus paclitaxel-L enhanced apoptosis in EAC more than paclitaxel-H alone and caused comparable tumor necrosis. We conclude that baker's yeast may be used with low-dose chemotherapy to achieve the same potency as high-dose chemotherapy in mice bearing EAC. This suggests that baker's yeast may be an anticancer adjuvant and may have clinical implications for the treatment of breast cancer.

The hydro-ethanolic extract of Acacia seyal (Mimosaceae) stem barks induced death in an ER-negative breast cancer cell line by the intrinsic pathway of apoptosis and inhibited cell migration

BACKGROUND

Despite the significant developments occurring in the treatment of cancer, it still remains the second deadly disease, responsible for 8.2 million deaths every year. Various natural substances have been studied for active molecules of tumor suppression in the past and the tropical flora, by its diversity, continues to provide new antitumor drugs. Acacia seyal is a plant used in Cameroonian traditional system to treat cancer. It exhibited cytotoxic effects towards human breast adenocarcinoma cells. The present work was therefore designed to elucidate the underlying mechanisms by which A. seyal extract induced its cytotoxic effect.

METHODS

The cell death mechanism (apoptosis or necrosis) and cell cycle analyses were assessed using flow cytometry. The levels of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), caspases activities as well as Bcl-2 and Bcl-xL protein contents were assessed in MDA-MB-231 cells. Afterwards, cell migration/invasion was also assessed.

RESULTS

The A. seyal extract induced apoptosis in MDA-MB-231 cells, while it failed to do so in MCF-7 cells. It induced cell cycle arrest in G2/M phase. Further it induced a decrease in ΔΨm, an increase in ROS levels and caspases activities as well as a down regulation in Bcl-2 and Bcl-xL protein contents in MDA-MB-231 cells. Moreover, A. seyal extract exhibited anti-migration, anti-invasion activities in MDA-MB-231 cells.

CONCLUSION

These results demonstrate that A. seyal extract induced its antitumor effects mainly by interference in metastasis related events, by triggering apoptosis through a ROS-mediated mitochondrial pathway.

Theabrownin triggers DNA damage to suppress human osteosarcoma U2OS cells by activating p53 signalling pathway

Osteosarcoma becomes the second leading cause of cancer death in the younger population. Current outcomes of chemotherapy on osteosarcoma were unsatisfactory to date, demanding development of effective therapies. Tea is a commonly used beverage beneficial to human health. As a major component of tea, theabrownin has been reported to possess anti‐cancer activity. To evaluate its anti‐osteosarcoma effect, we established a xenograft model of zebrafish and employed U2OS cells for in vivo and in vitro assays. The animal data showed that TB significantly inhibited the tumour growth with stronger effect than that of chemotherapy. The cellular data confirmed that TB‐triggered DNA damage and induced apoptosis of U2OS cells by regulation of Mki67, PARP, caspase 3 and H2AX, and Western blot assay showed an activation of p53 signalling pathway. When P53 was knocked down by siRNA, the subsequent downstream signalling was blocked, indicating a p53‐dependent mechanism of TB on U2OS cells (p53 wt). Using osteosarcoma cell lines with p53 mutations (HOS, SAOS‐2 and MG63), we found that TB exerted stronger inhibitory effect on U2OS cells than that on p53‐mut cell lines, but it also exerted obvious effect on SAOS‐2 cells (p53 null), suggesting an activation of p53‐independent pathway in the p53‐null cells. Interestingly, theabrownin was found to have no toxicity on normal tissue in vivo and could even increase the viability of p53‐wt normal cells. In sum, theabrownin could trigger DNA damage and induce apoptosis on U2OS cells via a p53‐dependent mechanism, being a promising candidate for osteosarcoma therapy.

In Vitro Cytotoxicity and In Vivo Antimammary Tumor Effects of the Hydroethanolic Extract of Acacia seyal (Mimosaceae) Stem Bark

The present study was designed to evaluate the in vitro and in vivo antitumor effects of A. seyal hydroethanolic extract on breast cancer. The cytotoxicity of A. seyal extract was evaluated using resazurin reduction assay in 9 cell lines. Further, the protective effect of the hydroethanolic extract of A. seyal stem barks was evaluated on 7,12-dimethylbenz(a)anthracene- (DMBA-) induced breast cancer rat model. Incidence, burden, volume, and histological analysis of mammary tumors were measured. The Acacia seyal extract exhibited CC50 of 100 in MCF-7 cells after 24 h. In vivo, no tumors were detected in rats from the control group, while 11 rats out of 12 (91.66%) developed mammary tumors in the DMBA-exposed group receiving only the vehicle. Acacia seyal extract significantly (p < 0.01) and in the dose-dependent manner reduced tumor incidence (3 rats out of 12 at the dose of 300 mg/kg), burden [62.1% (150 mg/kg) and 65.8% (300 mg/kg)], and mass. It protected rats against DMBA-induced breast hyperplasia, with an optimal effect at the dose of 300 mg/kg. Taken altogether, these results suggest that the hydroethanolic extract of Acacia seyal might contain phytoconstituents endowed with antitumoral properties, which could protect against the breast cancer induced in rats.

Polyphenols: dietary assessment and role in the prevention of cancers

PURPOSE OF REVIEW

Polyphenols are a large and diverse family of phytochemicals widely consumed by humans. Here we summarize the latest epidemiological evidence for associations between cancer risk and polyphenol intake, taking into account difficulties in the accurate estimation of exposure.

RECENT FINDINGS

Flavonoids are the most studied subgroup of polyphenols with regard to cancer risk. In recent epidemiological studies, total flavonoid intake has rarely been associated with a reduction in cancer risk. However, isoflavones, whose main dietary source is soy foods, plausibly reduce the risk of colorectal, breast, and prostate cancers, especially in Asian countries. Findings depend heavily upon the assessment of polyphenol intake, which is usually measured by food frequency questionnaires coupled to databases of food polyphenol composition. To a lesser extent, nutritional biomarkers have been used whenever estimating associations of polyphenol intake with cancer.

SUMMARY

Polyphenol intake may mitigate cancer risk but this depends on cancer site, the subgroup of compounds under study, and accurate assessment of dietary exposure. Further work must better characterize the effects of intake of different flavonoid subclasses and begin to investigate the role of phenolic acids and other minor polyphenol classes.

Liver toxicity mechanisms of herbs commonly used in Latin America

Mexico owns approximately 4500 medicinal plants species, a great diversity that position it at the second place after China. According to the Mexican health department, 90% of common population consumes them to treat various diseases. Additionally, herbal remedies in Latin America (LA) are considered a common practice, but the frequency of use and the liver damage related to its consumption is still unknown. Despite the high prevalence and indiscriminate herbal consumption, the exact mechanism of hepatotoxicity and adverse effects is not fully clarified and is still questioned. Some herb products associated with herb induced liver injury (HILI) are characterized by presenting a different chemical composition that may vary from batch to batch, also the biological activity of many medicinal plants and other natural products are directly related to their most active component and its concentration. There are two main biological components that are associated with liver damage, alkaloids, and flavonoids, which are frequent constituents of commonly used herbs. The interaction with the different cytochrome P-450 isoforms, inflammatory, and oxidative activities seem to be the main damage pathway involved in the liver. It is important to know the herbal adverse effects and mechanisms involved; therefore, this article is focused on the beneficial and deleterious effects as well as the possible toxicity mechanisms and interactions of the herbs that are frequently used in LA, since the herb-host interaction may not always be the expected or desired depending on the clinical context in which it is administered.