Pomegranate juice and specific components inhibit cell and molecular processes critical for metastasis of breast cancer

Characterization of the effect of pomegranate crude extract, and its post-harvesting preservation procedures, on redox tone, cellular growth and metabolic profile of MDA-MB-231 cell line

BACKGROUND

Pomegranate is known for its beneficial properties due to its high content in antioxidants and might constitute a natural option for preventing and treatment of different pathologies including cancer. Since mitochondria are involved in tumorigenesis through ROS production and modulation of oxidative metabolism, we investigated the biological effects of pomegranate on cellular redox state, proliferation and metabolism in the breast cancer cell line MDA-MB-231 (MDA).

METHODS

MDA were treated for 24 h with graded concentration of filtered Pomegranate juice (PJ) and tested for metabolic Flux Analysis with XFe96 Extracellular Flux Analyzer, for proliferation using the xCELLigence System Real-Time Cell Analyzer and for intracellular ROS content by Confocal Microscopy Imaging.

RESULTS

Cells-treatment with freshly prepared pomegranate juice (PJ) resulted in a significant reduction of the intracellular ROS content already at the lower concentration of PJ tested. Additionally, it enhanced mitochondria respiration, and decreased glycolysis at high concentrations, inhibiting at the same time cell proliferation. As pomegranate is a seasonal fruit, assessment of optimum storage conditions preserving its bio-active properties was investigated. Our results indicated that storage conditions under controlled atmosphere for 30 days was able to enhance mitochondrial respiration at the same extent than freshly extracted PJ. Conversely, freezing procedure, though retaining the antioxidant and cell-growth inhibitory property, elicited an opposite effect on the metabolic profile as compared with fresh extract.

CONCLUSION

Overall, the results of our study, on the one hand, confirms the preventive/therapeutic potential of PJ, as well as of its post-harvested processing, for cancer management. On the other hand, it highlights the intrinsic difficulties in attaining mechanistic insights when a multiplicity of effects is elicited by a crude mixture of bio-active compounds.

The Therapeutic Alliance between Pomegranate and Health Emphasizing on Anticancer Properties

Pomegranate is a fruit bearing-plant that is well known for its medicinal properties. Pomegranate is a good source of phenolic acids, tannins, and flavonoids. Pomegranate juice and by-products have attracted the scientific interest due to their potential health benefits. Currently, the medical community has showed great interest in exploiting pomegranate potential as a protective agent against several human diseases including cancer. This is demonstrated by the fact that there are more than 800 reports in the literature reporting pomegranate's anticancer properties. This review is an update on the research outcomes of pomegranate's potential against different types of human diseases, emphasizing on cancer. In addition, perspectives of potential applications of pomegranate, as a natural additive aiming to improve the quality of animal products, are discussed.

Pomegranate Pomace Extract with Antioxidant, Anticancer, Antimicrobial, and Antiviral Activity Enhances the Quality of Strawberry-Yogurt Smoothie

Valorizing the wastes of the food industry sector as additives in foods and beverages enhances human health and preserves the environment. In this study, pomegranate pomace (PP) was obtained from the company Schweppes and exposed to the production of polyphenols and fiber-enriched fractions, which were subsequently included in a strawberry-yogurt smoothie (SYS). The PP is rich in carbohydrates and fibers and has high water-absorption capacity (WAC) and oil-absorption capacity (OAC) values. The LC/MS phenolic profile of the PP extract indicated that punicalagin (199 g/L) was the main compound, followed by granatin B (60 g/L) and pedunculagin A (52 g/L). Because of the high phenolic content of PP extract, it (p ≤ 0.05) has high antioxidant activity with SC50 of 200 µg/mL, besides scavenging 95% of DPPH radicals compared to ascorbic acid (92%); consequently, it reduced lung cancer cell lines' viability to 86%, and increased caspase-3 activity. Additionally, it inhibited the growth of pathogenic bacteria and fungi i.e., L. monocytogenes, P. aeruginosa, K. pneumonia, A. niger, and C. glabrata, in the 45-160 µg/mL concentration range while killing the tested isolates with 80-290 µg/mL concentrations. These isolates were selected based on the microbial count of spoiled smoothie samples and were identified at the gene level by 16S rRNA gene sequence analysis. The interaction between Spike and ACE2 was inhibited by 75.6%. The PP extract at four levels (0.4, 0.8, 1.2, and 1.4 mg/mL) was added to strawberry-yogurt smoothie formulations. During 2 months storage at 4 °C, the pH values, vitamin C, and total sugars of all SYS decreased. However, the decreases were gradually mitigated in PP-SYS because of the high phenolic content in the PP extract compared to the control. The PP-SYS3 and PP-SYS4 scored higher in flavor, color, and texture than in other samples. In contrast, acidity, fat, and total soluble solids (TSS) increased at the end of the storage period. High fat and TSS content are observed in PP-SYS because of the high fiber content in PP. The PP extract (1.2 and 1.6 mg/mL) decreases the color differences and reduces harmful microbes in PP-SYS compared to the control. Using pomegranate pomace as a source of polyphenols and fiber in functional foods enhances SYS's physiochemical and sensory qualities.

Polyphenolic extract from Punica granatum peel causes cytoskeleton-related damage on Giardia lamblia trophozoites in vitro

Background

Diarrheal diseases caused by protozoa have a great impact on human health around the world. Giardia lamblia is one of the most common flagellates in the intestinal tract. Factors such as adverse effects to first-line drugs or the appearance of drug-resistant strains, make it necessary to identify new treatment alternatives. Agroindustry waste, like pomegranate peel, are a source of phenolic compounds, which possess antiparasitic activities. In vivo studies demonstrated antigiardiasic potential by reducing cyst shedding and protecting intestinal cells; however, they did not identify the compounds or elucidate any mechanism of action in the parasite. The objective of this study is to identify potential molecular targets and to test the in vitro effects of polyphenols from Punica granatum on Giardia lamblia.

Methods

The in vitro antigiardial potential of polyphenolic extract from pomegranate peel (Punica granatum L.) obtained using microwave-ultrasound methodology was evaluated on Giardia lamblia trophozoites. Extract phytochemical identification was performed by HPLC/MS analysis. The effect of polyphenolic extract on growth and adhesion capacity was determined by parasite kinetics; morphological damage was evaluated by SEM, alteration on α-tubulin expression and distribution were analyzed by western blot and immunofluorescence, respectively.

Results

The pomegranate peel extract showed the presence of ellagitannins (punicalin and punicalagin, galloyl-dihexahydroxydiphenoyl-hexoside), flavones (luteolin), and ellagic acid, that caused an inhibitory effect on growth and adhesion capacity, particularly on cells treated with 200 µg/mL, where growth inhibition of 74.36%, trophozoite adherence inhibition of 46.8% and IC₅₀ of 179 µg/mL at 48 h were demonstrated. The most important findings were that the extract alters α-tubulin expression and distribution in Giardia trophozoites in a concentration-independent manner. Also, an increase in α-tubulin expression at 200 µg/mL was observed in western blot and diffuse or incomplete immunolabeling pattern, especially in ventral disk. In addition, the extract caused elongation, disturbance of normal shape, irregularities in the membrane, and flagella abnormalities.

Discussion

The pomegranate peel extract affects Giardia trophozoites in vitro. The damage is related to the cytoskeleton, due to expression and distribution alterations in α-tubulin, particularly in the ventral disk, a primordial structure for adhesion and pathogenesis. Microtubule impairment could explain morphological changes, and inhibition of adhesion capacity and growth. Besides, this is the first report that suggests that ellagic acid, punicalin, punicalagin and luteolin could be interactioning with the rich-tubulin cytoskeleton of Giardia. Further investigations are needed in order to elucidate the mechanisms of action of the isolated compounds and propose a potential drug alternative for the giardiasis treatment.

Possible Beneficial Effects of Fresh Pomegranate Juice in SARS-CoV-2 Infection Conditions

Rather than the prophylactic vaccination, any effective synthetic, natural, or nutritional therapy or regimen that may cure or remedy, albeit partially, the complications of SARS-CoV-2 should be highly acknowledged. Here, we reviewed and discussed possible beneficial biological effects of pomegranate juice in such diseased condition of viral infection based on the current published evidence (direct and indirect) and owing to the robust evidence that fresh pomegranate juice is highly rich with unique bioactive compounds that are approved in various occasions to be effective in several chronic diseased conditions. All related references that serve our aim are accessed through available electronic databases, particularly PubMed and Scopus. In summary, there is accepted evidence that pomegranate juice may be beneficial in SARS-CoV-2 infection conditions, especially for patients with the clinical history of chronic diseases such as hypertension, cardiovascular disease, diabetes, and cancer. However, the interventional studies that directly probe and confirm the effectiveness of fresh pomegranate juice in the management of SARS-CoV-2 infection are mandatory.

Ellagic Acid: A Review on Its Natural Sources, Chemical Stability, and Therapeutic Potential

Ellagic acid (EA) is a bioactive polyphenolic compound naturally occurring as secondary metabolite in many plant taxa. EA content is considerable in pomegranate (Punica granatum L.) and in wood and bark of some tree species. Structurally, EA is a dilactone of hexahydroxydiphenic acid (HHDP), a dimeric gallic acid derivative, produced mainly by hydrolysis of ellagitannins, a widely distributed group of secondary metabolites. EA is attracting attention due to its antioxidant, anti-inflammatory, antimutagenic, and antiproliferative properties. EA displayed pharmacological effects in various in vitro and in vivo model systems. Furthermore, EA has also been well documented for its antiallergic, antiatherosclerotic, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties. This review reports on the health-promoting effects of EA, along with possible mechanisms of its action in maintaining the health status, by summarizing the literature related to the therapeutic potential of this polyphenolic in the treatment of several human diseases.

Ellagitannins, promising pharmacological agents for the treatment of cancer stem cells

Human tumors comprise subpopulations of cells called cancer stem cells (CSCs) that possess stemness properties. CSCs can initiate tumors and cause recurrence, metastasis and are also responsible for chemo- and radio-resistance. CSCs may use signaling pathways similar to normal stem cells, including Notch, JAK/STAT, Wnt and Hedgehog pathways. Ellagitannins (ETs) are a broad group of substances with chemopreventive and anticancer activities. The antitumor activity of ETs and their derivatives are mainly related to their antiinflammatory capacity. They are therefore able to modulate secretory growth factors and pro-inflammatory mediators such as IL-6, TGF-β, TNF-α, IL-1β and IFN-γ. Evidence suggests that ETs display their anticancer effect by targeting CSCs and disrupting stem cell signaling. However, there are still few studies in this field. Therefore, high-quality studies are needed to firmly establish the clinical efficacy of the ETs on CSCs. This paper reviews the structures, sources and pharmacokinetics of ETs. It also focuses on the function of ETs and their effects on CSCs-related cytokines and the relationship between ETs and signaling pathways in CSCs.

Antiproliferative effects of Turkish pomegranate (Punica granatum L.) extracts on MCF-7 human breast cancer cell lines with focus on antioxidant potential and bioactive compounds analyzed by LC-MS/MS

In this study, eight different pomegranate (Punica granatum L.) cultivars from Turkey were evaluated for their antioxidant and cytotoxic effects on the MCF-7 breast cancer cell lines and MCF-10A breast fibrocystic epithelial cell lines with a focus on their chemical compositions by LC-MS/MS. Cell lines were treated with pomegranate juice extracts in different doses at selected time intervals (24th, 48th, and 72nd hour). Afterwards, WST-1 cell proliferation assay was performed to investigate the cytotoxicity of the extracts. Accordingly, all extracts decreased the cell viability of MCF-7 breast cancer cell lines and had no cytotoxic effect on the cell viability of MCF-10A cell lines. Among eight extracts, P7 (Izmir 1513), which was rich in anthocyanins such as cyanidin chloride (69.76 ± 8.02 μg/g extract), cyanidin-3-O-glucoside (903.66 ± 101.89 μg/g extract), and punicalagin (992.09 ± 174.53 μg/g extract), was found to demonstrate the strongest cytotoxic activity on MCF-7 breast cancer cell lines by decreasing the cell viability in half at 24th hour with an IC₅₀ value of 49.08 µg/ml. PRACTICAL APPLICATIONS: Eight commercially valuable pomegranate (Punica granatum) cultivars from Turkey were examined. Pelargonidin, cyanidin, cyanidin-3-O-gl, callistephin, and delphinidin-3-O-gl were quantified. Two cultivars (P1 and P3) showed comparatively higher antioxidant effects. A cultivar (P7) showed strongest cytotoxic activity against MCF-7 breast cancer cell line. The cultivars have potential to be used as natural antioxidant and anticancer agents.

Pharmacological and Therapeutic Properties of Punica granatum Phytochemicals: Possible Roles in Breast Cancer

Background: Pomgranate (Punica granatum) represents a high source of polyphenols with great bioavailability. The role of this fruit in the prevention and treatment of various malignant pathologies has been long time cited in both scientific and non-scientific literature, making thus important to identify its involvement in the pathophysiological processes. The treatment for breast cancer had focused on the inhibition of the mechanisms that governs the estrogen activity. These mechanisms are covered either by the antagonism of the estrogen receptor (ER) or by the inhibition of the estrogen synthesis. Our interest in identifying a bioactive compound rich in polyphenols, which induces both the antagonism of the estrogen receptor, and the inhibition of the estrogen synthesis, revealed us the pomegranate fruit and its derivatives: peel and seeds. Pomegranates' chemical composition include many biological active substances such as flavonols, flavanols, anthocyanins, proanthocyanidins, ellagitannins and gallotannins. Materials and Methods: We performed a review of the scientific literature by using the following keywords: "pomegranate", "breast cancer", "Punica granatum", "pomegranate polyphenols". Our search was performed in the PubMed and Google Scholar databases, and it included only original research written in English from the last 20 years. None of the articles were excluded due to affiliation. A total number of 28 original papers, which mentioned the beneficial activity of pomegranate against breast cancer, were selected. Both clinical and preclinical studies were considered for this review. Results: Recent discoveries pointed out that polyphenols from Punica granatum possess strong anti-cancer activity, exhibited by a variety of mechanisms, such as anti-estrogenic, anti-proliferative, anti-angiogenetic, anti-inflammatory, and anti-metastatic. Pomegranate extracts induced cell cycle arrest in the G0/G1 phase, and induced cytotoxicity in a dose- and time-dependent manner. Moreover, several polyphenols extracted from pomegranate inhibited the invasion potential, migration and viability of breast cancer cells. The effects of pomegranate juice on serum estrogens and other sexual hormones levels were also investigated on two human cohorts. Conclusions: Punica granatum represents a promising area in oncology. The large availability and low cost, associated with the lack of side effects, made from this natural product a great strategy for the management of breast cancer. There are several mechanistic studies in mouse models and in breast cancer cell lines, suggesting the possible pathways through which polyphenols from pomegranate extracts act, but larger and better-controlled studies are necessary in the future. Only two small clinical trials were conducted on humans until now, but their results are contradictory and should be considered preliminary.

Pomegranate variety and pomegranate plant part, relevance from bioactive point of view: a review

Pomegranate (Punica granatum L.) belongs to the Punicaceae plant family. It is an important fruit due to its nutritional and medicinal properties. Pomegranates are widely distributed around the world and, therefore, have a broad genetic diversity, resulting in differences in their phytochemical composition. The scientific community has focused on the positive health effects of pomegranate as a whole, but the different varieties have rarely been compared according to their bioactive compounds and bioactivity. This review aims to provide a holistic overview of the current knowledge on the bioactivity of pomegranate trees, with an emphasis on differentiating both the varieties and the different plant parts. This review intends to provide a general and organized overview of the accumulated knowledge on pomegranates, the identification of the most bioactive varieties, their potential consumption pathways and seeks to provide knowledge on the present gaps to guide future research.

Evaluating Inhibitory Effects of Paclitaxel and Vitamin D3 Loaded Poly Lactic Glycolic Acid Co-Delivery Nanoparticles on the Breast Cancer Cell Line

Purpose: Paclitaxel (PTX) has transpired as a significant agent in the treatment of breast cancer. Meanwhile, polylactic glycolic acid (PLGA) nanoparticles (NPs) are able to increase the anticancer effect of the PTX in the blood.

Methods: Nano-precipitation was used to prepare the PLGA-PTX-VitD3 co-delivery NPs. Drug loading, encapsulation efficiency, in vitro release profile, cell viability, migration, apoptosis, and bcl2 expression of NPs were evaluated.

Results: The average size of co-delivery NPs was 231 ± 46 nm. Observed was a controlled release of the PTX and vitamin D3 from co-delivery NPs between 0.5 and 240 hours. MTT showed the ability of 8 μg.mL-1 of co-delivery NPs to kill 50 % of the MCF-7; likewise, the co-delivery NPs prevented MCF-7 migration. The co-delivery NPs led 46.35 % MCF-7 to enter primary apoptosis. 60.8% of MCF-7 in the control group were able to enter the G (1) phase of the cell cycle. The co-delivery NPs increased expression of bax. In addition to its higher toxicity against MCF-7 than that of PTX, co-delivery NPs were able to release drugs continuously for a long period, which indeed increased the efficiency of the drugs.

Conclusion: The effect of co-delivery NPs on MCF-7 cell viability was different from that in other drugs. In fact, the co-deliver NPs were able to release drugs continuously for a long time, this could induce primary apoptosis in the MCF-7 and decrease the metastasis and toxicity of drugs.

A critical review on anti-angiogenic property of phytochemicals

Angiogenesis, a process involved in neovascularization, has been found to be associated with several metabolic diseases like cancer, retinopathy etc. Thus, currently, the focus on anti-angiogenic therapy for treatment and prevention of diseases has gained significant attention. Currently available Food and Drug Administration (FDA) approved drugs are targeting either vascular endothelial growth factor or it's receptor, but in the long term, these approaches were shown to cause several side effects and the chances of developing resistance to these drugs is also high. Therefore, identification of safe and cost-effective anti-angiogenic molecules is highly imperative. Over the past decades, dietary based natural compounds have been studied for their anti-angiogenic potential which provided avenues in improving the angiogenesis based therapy. In this review, major emphasis is given to the molecular mechanism behind anti-angiogenic effect of natural compounds from dietary sources.

Experimental Evidence of the Antitumor, Antimetastatic and Antiangiogenic Activity of Ellagic Acid

Ellagic acid (EA) is a naturally occurring polyphenolic compound endowed with strong antioxidant and anticancer properties that is present in high quantity in a variety of berries, pomegranates, and dried fruits. The antitumor activity of EA has been mostly attributed to direct antiproliferative and apoptotic effects. Moreover, EA can inhibit tumour cell migration, extra-cellular matrix invasion and angiogenesis, all processes that are crucial for tumour infiltrative behaviour and the metastatic process. In addition, EA may increase tumour sensitivity to chemotherapy and radiotherapy. The aim of this review is to summarize the in vitro and in vivo experimental evidence supporting the anticancer activity of pure EA, its metabolites, and EA-containing fruit juice or extracts in a variety of solid tumour models. The EA oral administration as supportive therapy to standard chemotherapy has been recently evaluated in small clinical studies with colorectal or prostate cancer patients. Novel formulations with improved solubility and bioavailability are expected to fully develop the therapeutic potential of EA derivatives in the near future.

Ellagic acid, sulforaphane, and ursolic acid in the prevention and therapy of breast cancer: current evidence and future perspectives

Globally, breast cancer is the most common cancer and the second leading cause of cancer-related death among women. Surgery, chemotherapy, hormonal therapy, and radiotherapy are currently available treatment options for breast cancer therapy. However, chemotherapy, hormonal therapy, and radiotherapy are often associated with side effects and multidrug resistance, recurrence, and lack of treatment in metastasis are the major problems in the treatment of breast cancer. Recently, dietary phytochemicals have emerged as advantageous agents for the prevention and therapy of cancer due to their safe nature. Ellagic acid (EA), sulforaphane (SF), and ursolic acid (UA), which are found in widely consumed fruits and vegetables, have been shown to inhibit breast cancer cell proliferation and to induce apoptosis. This review encompasses the role of EA, SF, and UA in the fight against breast cancer. Both in vitro and in vivo effects of these agents are presented.

Pomegranate extract-loaded solid lipid nanoparticles: design, optimization, and in vitro cytotoxicity study

Background

Pomegranate extract (PE) is a natural product with potent antioxidant and anticancer activity because of its polyphenols content. The main purpose of this study was to maximize the PE chemotherapeutic efficacy by loading it in an optimized solid lipid nanoparticles (SLNs) formula.

Materials and methods

The influence of independent variables, which were lipid concentration (X₁), surfactant concentration (X₂) and cosurfactant concentration (X₃), on dependent ones, which were particle size (Y₁), polydispersity index (Y₂), zeta potential (Y₃), entrapment efficiency (Y₄) and cumulative % drug release (Y₅), were studied and optimized using the Box–Behnken design. Fifteen formulations of PE-SLNs were prepared using hot homogenization followed by ultra-sonication technique. Response surface plots, Pareto charts and mathematical equations were produced to study the impact of independent variables on the dependent quality parameters. The anti-proliferative activity of the optimized formula was then evaluated in three different cancer cell lines, namely, MCF-7, PC-3 and HepG-2, in addition to one normal cell line, HFB-4.

Results

The results demonstrated that the particle sizes ranged from 407.5 to 651.9 nm and the entrapment efficiencies ranged from 56.02 to 65.23%. Interestingly, the 50% inhibitory concentration of the optimized formula had more than a 40-fold improved effect on the cell growth inhibition in comparison with its free counterpart. Furthermore, it was more selective against cancer cells than normal cells particularly in MCF-7 breast cancer cells.

Conclusion

These data proved that nanoencapsulation of PE enhanced its anticancer efficacy. Therefore, our results suggested that a PE-loaded SLNs optimized-formula could be a promising chemo therapeutic agent.

Pomegranate Extract Alters Breast Cancer Stem Cell Properties in Association with Inhibition of Epithelial-to-Mesenchymal Transition

Cancer stem cells (CSCs) have become an important target population in cancer therapy and prevention due to their ability to self-renew, initiate tumors, and resist therapy. We examined whether pomegranate extract (PE) alters characteristics of breast CSCs. Ability to grow as mammospheres is a hallmark of breast CSCs. PE inhibited mammosphere formation in two different cell lines, neoplastic mammary epithelial HMLER and breast cancer Hs578T. In addition, mammosphere-derived cells from PE treatment groups showed reduced mammosphere formation for at least two serial passages. These data indicate that PE inhibits CSC's ability to self-renew. In addition, incubation of mammospheres with PE reversed them into adherent cultures, indicating promotion of CSC differentiation. Epithelial-to-mesenchymal transition (EMT) is a key program in generating CSCs and maintaining their characteristics. Thus, we examined the effect of PE on EMT. PE reduced cell migration, a major feature of the EMT phenotype. In addition, PE downregulated genes involved in EMT, including the EMT-inducing transcription factor Twist family basic helix-loop-helix transcription factor 1 (TWIST1). This suggests that PE suppresses CSC characteristics in part due to inhibition of EMT. The ability of PE to suppress CSCs can be exploited in the prevention of breast cancer.

Dietary Natural Products for Prevention and Treatment of Breast Cancer

Breast cancer is the most common cancer among females worldwide. Several epidemiological studies suggested the inverse correlation between the intake of vegetables and fruits and the incidence of breast cancer. Substantial experimental studies indicated that many dietary natural products could affect the development and progression of breast cancer, such as soy, pomegranate, mangosteen, citrus fruits, apple, grape, mango, cruciferous vegetables, ginger, garlic, black cumin, edible macro-fungi, and cereals. Their anti-breast cancer effects involve various mechanisms of action, such as downregulating ER-α expression and activity, inhibiting proliferation, migration, metastasis and angiogenesis of breast tumor cells, inducing apoptosis and cell cycle arrest, and sensitizing breast tumor cells to radiotherapy and chemotherapy. This review summarizes the potential role of dietary natural products and their major bioactive components in prevention and treatment of breast cancer, and special attention was paid to the mechanisms of action.

Changes in antioxidant activities and volatile compounds of mixed berry juice through fermentation by lactic acid bacteria

The objectives of this study were to analyze antioxidant activities and identify volatile compounds in mixed berry juice after fermentation by lactic acid bacteria (LAB). Antioxidant activity of the mixed berry juice increased significantly from 209.57±2.93 to 268.30±1.75 μmol TE/g after 24 h of fermentation. After LAB fermentation, 34 volatile compounds were identified. Among them, three compounds-benzoic acid, benzaldehyde, and vitispirane-showed significant changes in their concentrations. Peak areas of benzoic acid and benzaldehyde, which are known to possess antioxidant activities, increased by 64 and 188%, respectively, after fermentation. However, the peak area of vitispirane, which is the most abundant terpene compound in berry juices, decreased by 92% after fermentation.

Anti-Inflammatory Mechanism Involved in Pomegranate-Mediated Prevention of Breast Cancer: the Role of NF-κB and Nrf2 Signaling Pathways

Pomegranate (Punica granatum L.), a nutrient-rich unique fruit, has been used for centuries for the prevention and treatment of various inflammation-driven diseases. Based on our previous study, a characterized pomegranate emulsion (PE) exhibited a striking inhibition of dimethylbenz(a)anthracene (DMBA)-initiated rat mammary tumorigenesis via antiproliferative and apoptosis-inducing mechanisms. The objective of the present work is to investigate the anti-inflammatory mechanism of action of PE during DMBA rat mammary carcinogenesis by evaluating the expression of cyclooxygenase-2 (COX-2), heat shock protein 90 (HSP90), nuclear factor-κB (NF-κB) and nuclear factor erythroid 2p45 (NF-E2)-related factor 2 (Nrf2). Mammary tumor samples were harvested from our previous chemopreventive study in which PE (0.2–5.0 g/kg) was found to reduce mammary tumorigenesis in a dose-dependent manner. The expressions of COX-2, HSP90, NF-κB, inhibitory κBα (IκBα) and Nrf2 were detected by immunohistochemical techniques. PE decreased the expression of COX-2 and HSP90, prevented the degradation of IκBα, hindered the translocation of NF-κB from cytosol to nucleus and increased the expression and nuclear translocation of Nrf2 during DMBA-induced mammary tumorigenesis. These findings, together with our previous results, indicate that PE-mediated prevention of DMBA-evoked mammary carcinogenesis may involve anti-inflammatory mechanisms through concurrent but differential regulation of two interrelated molecular pathways, namely NF-κB and Nrf2 signaling.

Pomegranate for Prevention and Treatment of Cancer: An Update

Cancer is the second leading cause of death in the United States, and those who survive cancer may experience lasting difficulties, including treatment side effects, as well as physical, cognitive, and psychosocial struggles. Naturally-occurring agents from dietary fruits and vegetables have received considerable attention for the prevention and treatment of cancers. These natural agents are safe and cost efficient in contrast to expensive chemotherapeutic agents, which may induce significant side effects. The pomegranate (Punica granatum L.) fruit has been used for the prevention and treatment of a multitude of diseases and ailments for centuries in ancient cultures. Pomegranate exhibits strong antioxidant activity and is a rich source of anthocyanins, ellagitannins, and hydrolysable tannins. Studies have shown that the pomegranate fruit as well as its juice, extract, and oil exert anti-inflammatory, anti-proliferative, and anti-tumorigenic properties by modulating multiple signaling pathways, which suggest its use as a promising chemopreventive/chemotherapeutic agent. This review summarizes preclinical and clinical studies highlighting the role of pomegranate in prevention and treatment of skin, breast, prostate, lung, and colon cancers.

Molecular evidence on the protective effect of ellagic acid on phosalone-induced senescence in rat embryonic fibroblast cells

Salient evidence testifies the link between organophosphorus (OPs) exposure and the formation of free radical oxidants; and it is well accepted that free radicals are one of the basic concerns of senescence. To show the oxidative features of phosalone (PLN) as a key member of OPs, to induce senescence in rat embryonic fibroblast (REF) cells and to demonstrate the beneficial effects of the known antioxidant ellagic acid (EA) in diminishing the PLN-induced toxic effects, the levels of cell viability, oxidative stress markers, inflammatory cytokines, telomerase activity, and the expression of the genes related to senescence were investigated. Our results lend support to the hypothesis that PLN enhances the entire premature senescence parameters of REF cells. This accounts for the mechanistic approval of the role of OPs in induction of senescence in rat fibroblasts. Moreover, incorporation of EA diminished PLN toxicity mainly through suppression of p38 and p53 at gene and protein levels, and tempered the inflammation factors (TNF-α, IL-1β, IL-6 and NF-κB), which further affected cell division. Analysis of cell cycle showed that the percentage of G0/G1 arrest, in REF cells treated by EA was elevated as compared to control and PLN treated cells.

Role of dietary bioactive natural products in estrogen receptor-positive breast cancer

Estrogen receptor (ER)-positive breast cancer, including luminal-A and -B, is the most common type of breast cancer. Extended exposure to estrogen is associated with an increased risk of breast cancer. Both ER-dependent and ER-independent mechanisms have been implicated in estrogen-mediated carcinogenesis. The ER-dependent pathway involves cell growth and proliferation triggered by the binding of estrogen to the ER. The ER-independent mechanisms depend on the metabolism of estrogen to generate genotoxic metabolites, free radicals and reactive oxygen species to induce breast cancer. A better understanding of the mechanisms that drive ER-positive breast cancer will help optimize targeted approaches to prevent or treat breast cancer. A growing emphasis is being placed on alternative medicine and dietary approaches toward the prevention and treatment of breast cancer. Many natural products and bioactive compounds found in foods have been shown to inhibit breast carcinogenesis via inhibition of estrogen induced oxidative stress as well as ER signaling. This review summarizes the role of bioactive natural products that are involved in the prevention and treatment of estrogen-related and ER-positive breast cancer.

Pomegranate exerts chemoprevention of experimentally induced mammary tumorigenesis by suppression of cell proliferation and induction of apoptosis

Breast cancer is the second leading cause of cancer-related death in women in the United States and discovery and development of safe chemopreventive drugs is urgently needed. The fruit pomegranate (Punica granatum) is gaining importance because of its various health benefits. This study was initiated to investigate chemopreventive potential of a pomegranate emulsion (PE) against 7,12-dimethylbenz(a)anthracene (DMBA) rat mammary carcinogenesis. The animals were orally administered with PE (0.2–5.0 g/kg), starting 2 wk before and 16 wk following DMBA treatment. PE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden, and reversed histopathological changes. PE dose-dependently suppressed cell proliferation and induced apoptosis in mammary tumors. Immunohistochemical studies showed that PE increased intratumor Bax, decreased Bcl2 and manifested a proapoptotic shift in Bax/Bcl2 ratio. In addition, our gene expression study showed PE-mediated upregulation of Bad, caspase-3, caspase-7, caspase-9, poly (ADP ribose) polymerase and cytochrome c in mammary tumors. Thus, PE exerts chemoprevention of mammary carcinogenesis by suppressing cell proliferation and inducing apoptosis mediated through upregulation of Bax and downregulation of Bcl2 in concert with caspase cascades. Pomegranate bioactive phytoconstituents could be developed as a chemopreventive drug to reduce the risk of breast cancer.

Mechanism of Breast Cancer Preventive Action of Pomegranate: Disruption of Estrogen Receptor and Wnt/β-Catenin Signaling Pathways

A pomegranate emulsion (PE), containing various bioactive phytochemicals, has recently been found to exert substantial chemopreventive effect against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumorigenesis in rats via antiproliferative and proapoptotic actions. Nevertheless, the underlying mechanisms of action are not completely understood. The present study was designed to investigate the effects of PE treatment on intratumor expression of estrogen receptor (ER)-α, ER-β,β-catenin and cyclin D1 during DMBA rat mammary carcinogenesis. Mammary tumor sections were harvested from a chemopreventive study in which PE (0.2, 1.0 and 5.0 g/kg) exhibited inhibition of mammary tumorigenesis in a dose-response manner. The expressions of ER-α, ER-β, β-catenin and cyclin D1 were analyzed by immunohistochemical techniques. PE downregulated the expression of intratumor ER-α and ER-β and lowered ER-α:ER-β ratio. PE also decreased the expression, cytoplasmic accumulation, and nuclear translocation of β-catenin, an essential transcriptional cofactor for Wnt signaling. Moreover, PE suppressed the expression of cell growth regulatory protein cyclin D1, which is a downstream target for both ER and Wnt signaling. Our current results in conjunction with our previous findings indicate that concurrent disruption of ER and Wnt/β-catenin signaling pathways possibly contributes to antiproliferative and proapoptotic effects involved in PE-mediated chemoprevention of DMBA-inflicted rat mammary tumorigenesis.

Therapeutic Potential of Dietary Phenolic Acids

Although modern lifestyle has eased the quality of human life, this lifestyle's related patterns have imparted negative effects on health to acquire multiple diseases. Many synthetic drugs are invented during the last millennium but most if not all of them possess several side effects and proved to be costly. Convincing evidences have established the premise that the phytotherapeutic potential of natural compounds and need of search for novel drugs from natural sources are of high priority. Phenolic acids (PAs) are a class of secondary metabolites spread throughout the plant kingdom and generally involved in plethora of cellular processes involved in plant growth and reproduction and also produced as defense mechanism to sustain various environmental stresses. Extensive research on PAs strongly suggests that consumption of these compounds hold promise to offer protection against various ailments in humans. This paper focuses on the naturally derived PAs and summarizes the action mechanisms of these compounds during disease conditions. Based on the available information in the literature, it is suggested that use of PAs as drugs is very promising; however more research and clinical trials are necessary before these bioactive molecules can be made for treatment. Finally this review provides greater awareness of the promise that natural PAs hold for use in the disease prevention and therapy.

Potential Effects of Pomegranate Polyphenols in Cancer Prevention and Therapy

Cancer is the second leading cause of death and is becoming the leading one in old age. Vegetable and fruit consumption is inversely associated with cancer incidence and mortality. Currently, interest in a number of fruits high in polyphenols has been raised due to their reported chemopreventive and/or chemotherapeutic potential. Pomegranate has been shown to exert anticancer activity, which is generally attributed to its high content of polyphenols. This review provides a comprehensive analysis of known targets and mechanisms along with a critical evaluation of pomegranate polyphenols as future anticancer agents. Pomegranate evokes antiproliferative, anti-invasive, and antimetastatic effects, induces apoptosis through the modulation of Bcl-2 proteins, upregulates p21 and p27, and downregulates cyclin-cdk network. Furthermore, pomegranate blocks the activation of inflammatory pathways including, but not limited to, the NF-κB pathway. The strongest evidence for its anticancer activity comes from studies on prostate cancer. Accordingly, some exploratory clinical studies investigating pomegranate found a trend of efficacy in increasing prostate-specific antigen doubling time in patients with prostate cancer. However, the genotoxicity reported for pomegranate raised certain concerns over its safety and an accurate assessment of the risk/benefit should be performed before suggesting the use of pomegranate or its polyphenols for cancer-related therapeutic purposes.

Punica granatum and its therapeutic implications on breast carcinogenesis: A review

Punica granatum has a recorded history of pharmacological properties which can be attributed to its rich reservoir of phytochemicals. Investigations in recent years have established its tremendous potential as an antitumorogenic agent against various cancers including breast cancer, which is the second leading cause of cancer-related deaths in women. The plausible role of Punica as a therapeutic agent, as an adjuvant in chemotherapy, and its dietary implications as chemopreventive agent in breast cancer have been explored. Mechanistic studies have revealed that Punica extracts and its components, individually or in combination, can modulate and target key proteins and genes involved in breast cancer. Our earlier finding also demonstrated the role of methanolic extract of pomegranate pericarp in reducing proliferation in breast cancer by binding to estrogen receptor at the same time not affecting uterine weight unlike estradiol or tamoxifen. This review analyses other plausible mechanisms of Punica in preventing the progression of breast cancer and how it can possibly be a therapeutic agent by acting at various steps of carcinogenesis including proliferation, invasion, migration, metastasis, angiogenesis, and inflammation via various molecular mechanisms.

Pomegranate and its components as alternative treatment for prostate cancer

Prostate cancer is the second leading cause of cancer deaths in men in the United States. There is a major need for less toxic but yet effective therapies to treat prostate cancer. Pomegranate fruit from the tree Punica granatum has been used for centuries for medicinal purposes and is described as “nature’s power fruit”. Recent research has shown that pomegranate juice (PJ) and/or pomegranate extracts (PE) significantly inhibit the growth of prostate cancer cells in culture. In preclinical murine models, PJ and/or PE inhibit growth and angiogenesis of prostate tumors. More recently, we have shown that three components of PJ, luteolin, ellagic acid and punicic acid together, have similar inhibitory effects on prostate cancer growth, angiogenesis and metastasis. Results from clinical trials are also promising. PJ and/or PE significantly prolonged the prostate specific antigen (PSA) doubling time in patients with prostate cancer. In this review we discuss data on the effects of PJ and PE on prostate cancer. We also discuss the effects of specific components of the pomegranate fruit and how they have been used to study the mechanisms involved in prostate cancer progression and their potential to be used in deterring prostate cancer metastasis.

Luteolin, ellagic acid and punicic acid are natural products that inhibit prostate cancer metastasis

Prostate cancer (PCa) is the second cause of cancer deaths in men in the USA. When the cancer recurs, early stages can be controlled with hormone ablation therapy to delay the rate of cancer progression but, over time, the cancer overcomes its hormone dependence, becomes highly aggressive and metastasizes. Clinical trials have shown that pomegranate juice (PJ) inhibits PCa progression. We have previously shown that the PJ components luteolin (L), ellagic acid (E) and punicic acid (P) together inhibit growth of hormone-dependent and -independent PCa cells and inhibit their migration and chemotaxis towards CXCL12, a chemokine that is important in PCa metastasis. On the basis of these findings, we hypothesized that L+E+P inhibit PCa metastasis in vivo. To test this possibility, we used a severe combined immunodeficiency mouse model in which luciferase-expressing human PCa cells were injected subcutaneously near the prostate. Tumor progression was monitored with bioluminescence imaging weekly. We found that L+E+P inhibits PC-3M-luc primary tumor growth, inhibits the CXCL12/CXCR4 axis for metastasis and none of the tumors metastasized. In addition, L+E+P significantly inhibits growth and metastasis of highly invasive Pten (-/-) ;K-ras (G12D) prostate tumors. Furthermore, L+E+P inhibits angiogenesis in vivo, prevents human endothelial cell (EC) tube formation in culture and disrupts preformed EC tubes, indicating inhibition of EC adhesion to each other. L+E+P also inhibits the angiogenic factors interleukin-8 and vascular endothelial growth factor as well as their induced signaling pathways in ECs. In conclusion, these results show that L+E+P inhibits PCa progression and metastasis.

Research progress on the anticarcinogenic actions and mechanisms of ellagic acid

Cancer is a leading cause of death worldwide. Cancer treatments by chemotherapeutic agents, surgery, and radiation have not been highly effective in reducing the incidence of cancers and increasing the survival rate of cancer patients. In recent years, plant-derived compounds have attracted considerable attention as alternative cancer remedies for enhancing cancer prevention and treatment because of their low toxicities, low costs, and low side effects. Ellagic acid (EA) is a natural phenolic constituent. Recent in vitro and in vivo experiments have revealed that EA elicits anticarcinogenic effects by inhibiting tumor cell proliferation, inducing apoptosis, breaking DNA binding to carcinogens, blocking virus infection, and disturbing inflammation, angiogenesis, and drug-resistance processes required for tumor growth and metastasis. This review enumerates the anticarcinogenic actions and mechanisms of EA. It also discusses future directions on the applications of EA.

Influence on longevity of blueberry, cinnamon, green and black tea, pomegranate, sesame, curcumin, morin, pycnogenol, quercetin, and taxifolin fed iso-calorically to long-lived, F1 hybrid mice

Phytonutrients reportedly extend the life span of Caenorhabditis elegans, Drosophila, and mice. We tested extracts of blueberry, pomegranate, green and black tea, cinnamon, sesame, and French maritime pine bark (Pycnogenol and taxifolin), as well as curcumin, morin, and quercetin for their effects on the life span of mice. While many of these phytonutrients reportedly extend the life span of model organisms, we found no significant effect on the life span of male F1 hybrid mice, even though the dosages used reportedly produce defined therapeutic end points in mice. The compounds were fed beginning at 12 months of age. The control and treatment groups were iso-caloric with respect to one another. A 40% calorically restricted and other groups not reported here did experience life span extension. Body weights were un-changed relative to controls for all but two supplemented groups, indicating most supplements did not change energy absorption or utilization. Tea extracts with morin decreased weight, whereas quercetin, taxifolin, and Pycnogenol together increased weight. These changes may be due to altered locomotion or fatty acid biosynthesis. Published reports of murine life span extension using curcumin or tea components may have resulted from induced caloric restriction. Together, our results do not support the idea that isolated phytonutrient anti-oxidants and anti-inflammatories are potential longevity therapeutics, even though consumption of whole fruits and vegetables is associated with enhanced health span and life span.

Single-nucleotide polymorphism markers from de-novo assembly of the pomegranate transcriptome reveal germplasm genetic diversity

Pomegranate is a valuable crop that is grown commercially in many parts of the world. Wild species have been reported from India, Turkmenistan and Socotra. Pomegranate fruit has a variety of health-beneficial qualities. However, despite this crop's importance, only moderate effort has been invested in studying its biochemical or physiological properties or in establishing genomic and genetic infrastructures. In this study, we reconstructed a transcriptome from two phenotypically different accessions using 454-GS-FLX Titanium technology. These data were used to explore the functional annotation of 45,187 fully annotated contigs. We further compiled a genetic-variation resource of 7,155 simple-sequence repeats (SSRs) and 6,500 single-nucleotide polymorphisms (SNPs). A subset of 480 SNPs was sampled to investigate the genetic structure of the broad pomegranate germplasm collection at the Agricultural Research Organization (ARO), which includes accessions from different geographical areas worldwide. This subset of SNPs was found to be polymorphic, with 10.7% loci with minor allele frequencies of (MAF<0.05). These SNPs were successfully used to classify the ARO pomegranate collection into two major groups of accessions: one from India, China and Iran, composed of mainly unknown country origin and which was more of an admixture than the other major group, composed of accessions mainly from the Mediterranean basin, Central Asia and California. This study establishes a high-throughput transcriptome and genetic-marker infrastructure. Moreover, it sheds new light on the genetic interrelations between pomegranate species worldwide and more accurately defines their genetic nature.

A comparative study for the evaluation of two doses of ellagic acid on hepatic drug metabolizing and antioxidant enzymes in the rat

The present study was designed to evaluate different doses of ellagic acid (EA) in vivo in rats for its potential to modulate hepatic phases I, II, and antioxidant enzymes. EA (10 or 30 mg/kg/day, intragastrically) was administered for 14 consecutive days, and activity, protein, and mRNA levels were determined. Although the cytochrome P450 (CYP) 2B and CYP2E enzyme activities were decreased significantly, the activities of all other enzymes were unchanged with the 10 mg/kg/day EA. In addition, western-blot and qRT-PCR results clearly corroborated the above enzyme expressions. On the other hand, while the NAD(P)H:quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPX), and glutathione S-transferase (GST) activities were increased significantly, CYP1A, 2B, 2C, 2E, and 19 enzyme activities were reduced significantly with 30 mg/kg/day EA. In addition, CYP2B, 2C6, 2E1, and 19 protein and mRNA levels were substantially decreased by the 30 mg/kg/day dose of EA, but the CYP1A protein, and mRNA levels were not changed. CYP3A enzyme activity, protein and mRNA levels were not altered by neither 10 nor 30 mg/kg/day ellagic acid. These results indicate that EA exerts a dose-dependent impact on the metabolism of chemical carcinogens and drugs by affecting the enzymes involved in xenobiotics activation/detoxification and antioxidant pathways.

Pomegranate Juice Metabolites, Ellagic Acid and Urolithin A, Synergistically Inhibit Androgen-Independent Prostate Cancer Cell Growth via Distinct Effects on Cell Cycle Control and Apoptosis

Ellagitannins (ETs) from pomegranate juice (PJ) are bioactive polyphenols with chemopreventive potential against prostate cancer (PCa). ETs are not absorbed intact but are partially hydrolyzed in the gut to ellagic acid (EA). Colonic microflora can convert EA to urolithin A (UA), and EA and UA enter the circulation after PJ consumption. Here, we studied the effects of EA and UA on cell proliferation, cell cycle, and apoptosis in DU-145 and PC-3 androgen-independent PCa cells and whether combinations of EA and UA affected cell proliferation. EA demonstrated greater dose-dependent antiproliferative effects in both cell lines compared to UA. EA induced cell cycle arrest in S phase associated with decreased cyclin B1 and cyclin D1 levels. UA induced a G2/M arrest and increased cyclin B1 and cdc2 phosphorylation at tyrosine-15, suggesting inactivation of the cyclin B1/cdc2 kinase complex. EA induced apoptosis in both cell lines, while UA had a less pronounced proapoptotic effect only in DU-145. Cotreatment with low concentrations of EA and UA dramatically decreased cell proliferation, exhibiting synergism in PC-3 cells evaluated by isobolographic analysis and combination index. These data provide information on pomegranate metabolites for the prevention of PCa recurrence, supporting the role of gut flora-derived metabolites for cancer prevention.